KR100619282B1 - Capacitor and manufacturing method thereof - Google Patents

Abstract

In order to provide a large capacity capacitor and a method of manufacturing the same to maximize the number of leads to improve the output density, the present invention, the plate-shaped positive electrode and negative electrode electrode formed by coating an active material on a metal current collector, a plurality of laminated through the separation film And a plurality of leads drawn from the stacked anode electrode and the cathode electrode, the stacked leads of the anode and the cathode stacked together from the leads drawn from the electrodes of the same polarity, the stacked anode electrode, the cathode electrode, the anode and the cathode And a case in which the laminated lead of the present invention is housed, and an anode and a cathode external terminal provided in the case and electrically connected to the laminated lead of the positive electrode and the negative electrode, respectively, wherein the laminated lead and the external terminal are joined by electric resistance welding. Provide a capacitor.

Large capacity, capacitor, electric resistance welding

Description

Capacitor and Method of Manufacturing the Same {CAPACITOR AND METHOD FOR MANUFACTURING THE SAME}

1 is a view showing an electrode, a separator and a lead of a large capacity capacitor according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing an electrode group in which the electrodes and leads shown in FIG. 1 are stacked.

3 is a side cross-sectional view showing a lead bonding method of a large capacity capacitor according to Embodiment 1 of the present invention.

4 is a side cross-sectional view of a large capacity capacitor according to Embodiment 1 of the present invention.

FIG. 5 is a diagram illustrating electrodes, separators, and leads of a large capacity capacitor according to a second exemplary embodiment of the present invention.

FIG. 6 is a view showing an electrode group in which electrodes and leads shown in FIG. 5 are stacked.

7 is a side cross-sectional view showing a lead bonding method of a large capacity capacitor according to a second embodiment of the present invention.

8 is a side cross-sectional view of a large capacity capacitor according to Embodiment 2 of the present invention.

9 is a view showing electrodes, separators, and leads of a large capacity capacitor according to Embodiment 3 of the present invention.

FIG. 10 is a view showing an electrode group in which electrodes and leads shown in FIG. 9 are stacked.

11 is a side sectional view showing a lead bonding method of a large capacity capacitor according to a third embodiment of the present invention.

12 is a diagram showing an electrode group of a large capacity capacitor according to a fourth embodiment of the present invention.

13A, 13B and 13C show examples of the insulating plate according to the fourth embodiment of the present invention.

It is a figure which shows the form in which the insulating plate and electrode group of this invention were combined.

15 is a plan view of a case cap of a large capacity capacitor according to Embodiment 4 of the present invention.

16 is a side cross-sectional view of a large capacity capacitor according to Embodiment 4 of the present invention.

17A and 17B are a front view and a bottom view of an external terminal according to a fifth embodiment of the present invention.

18 is a front sectional view of a large capacity capacitor according to Embodiment 5 of the present invention.

19 is a view showing an electrode group of a wound capacitor according to the prior art.

20 is a view showing an electrode group of a wound capacitor according to another conventional technique.

It is a figure which shows the electrode group of the capacitor wound by plate according to another conventional technique.

22 is a plan view of the electrode group of FIG. 21.

<Description of main parts of drawing>

1, 1 ': electrode 2: separator

3a-3f: Lead 4, 4b, 4c: External terminal

5a, 5b: lower welding rod 6: upper welding rod

7a: External terminal junction 7b: Lead junction

8: case 9: insulation material

10: case cap 11: insulation plate

12a, 12b: electrolyte injection hole 13: lead bent groove

14: welding groove 15: pressing pin

The present invention relates to a large-capacity capacitor, and in particular, by applying an electric resistance welding method using resistance heat generated by high current flow to a plurality of stacked lead junctions included in a capacitor, a large-capacity of which the output density is improved by maximizing the number of leads. Relates to a capacitor.

As an electric energy storage device for a system that requires a power supply such as various portable electronic devices, an electric vehicle, or a system for regulating or supplying an overload occurring momentarily, a battery, an electrolytic capacitor, an electric double layer capacitor, a water capacitor, etc. In particular, the electric double layer capacitor is a capacitor using an electrostatic charge phenomenon generated in an electric double layer formed at the interface of different phases, and has a faster charge and discharge rate than a battery whose energy storage mechanism depends on the redox process. Its discharging efficiency is higher than that of batteries and its cycle characteristics are superior, so it is widely used in backup power supply.

Such an electric double layer capacitor is installed between the electrodes of the positive electrode and the negative electrode composed of the current collector and the active material layer, the positive electrode and the negative electrode to enable only ion conduction, and a separator of porous material for insulation and short circuit prevention, and a metal case and a case for packaging them. It consists of a charged electrolyte solution.

The active material layer is a part for storing electrical energy, and different active materials are used according to the type, and the current collector emits electrical energy stored in the active material layer to the outside or delivers electrical energy applied from the outside to the active material. And metals such as Cu are used. The separator is installed between the anode and the cathode to enable ion conduction only and to prevent insulation and short circuit. Porous polypropylene or paper is commonly used. The electrolyte is a form in which salts are dissolved in a solvent having a high dielectric constant so as to store electrical energy, and a combination of a solvent and a salt may be used differently according to the type of active material.

Electric energy storage devices such as electric double layer capacitors have an amount of electrical energy storage per weight / volume depending on the type and amount of active material, so the amount of active material layer should be increased to increase the capacity per unit volume. Maximization of lead area is required.

The present invention has been devised to increase the capacity of such an electric double layer capacitor, but can be generally applied to increase the capacity of other capacitors as well.

19 is a view showing an electrode group of a wound capacitor according to the prior art. The wound capacitor shown in this figure is a method of riveting the lead 103a and 103a 'to the metal current collector and withdrawing the lead capacitor, and is a capacitor suitable for being applied to a wound capacitor having a medium capacity or less.

However, in a large capacity capacitor that requires a large current discharge, the structure of maximizing the energy density by maximizing the electrode area per volume and having as many leads as possible is ideal. In this aspect, in the wound capacitor according to the related art shown in FIG. 19, it is very difficult in the process to draw out and join a plurality of leads 103a and 103a '. There are obvious limitations to improvement.

20 is a view showing an electrode group of a wound capacitor according to another conventional technique. In the winding capacitor shown in the drawing, the leads 103b and 103b 'are drawn out at predetermined intervals of the metal current collectors constituting the electrodes 101 and 101', and the separator 102 and the electrodes 101 and 101 'are sequentially As a method of winding by arranging the wires, the output characteristics can be improved to some extent by increasing the number of leads 103b and 103b ', but the plurality of leads 103b and 103b' due to the structural characteristics having a circular shape by winding. ), It is difficult to bend the lead and take up a lot of empty space, which is undesirable.

FIG. 21 is a view illustrating a capacitor electrode group wound in a plate shape according to another conventional technique. Similar to the capacitor electrode group of FIG. 20, FIG. 21 illustrates a lead (eg, a portion of a metal current collector constituting electrodes 101 and 101 ′). 103c and 103c ') can be taken out, further wound up into a plate shape to form one electrode group, and a plurality of electrode groups thus constructed can be stacked to form a capacitor electrode group. FIG. 21 shows an electrode group in the case where two electrode groups are stacked, and FIG. 22 is a plan view of the electrode group of FIG.

The capacitor electrode group wound in a plate shape as described above has the advantage of being easily laminated with another electrode group by winding in a plate shape and easily forming lead wires by laminating the electrode group wound in a plate shape. Since the bent portions of the electrodes 101 and 101 'are formed, damage of the electrodes 101 and 101' may be accompanied, resulting in a loss of capacity of the bent portions.

On the other hand, in order to manufacture a large capacity capacitor with excellent electrical characteristics, when a plurality of leads are drawn out by drawing leads for each electrode, minimizing contact resistance between leads becomes a key. For example, when a plurality of leads having a thickness of 20 μm are laminated to form a laminated lead, a welding method is used for joining leads. In the conventional welding method, a thin film of about 10 to 70 μm is laminated. Ultrasonic welding has been widely used as a method of bonding at one time.

However, due to the characteristics of ultrasonic welding, lead damage occurs frequently due to vibration, which leads to a high defect rate, and there is a problem in that it is applied to construct a high output large capacity capacitor by increasing the lead drawing length as the bonding limit of the stacked leads is about 50 sheets. .

The present invention has been made to solve the above problems, by adopting an efficient bonding method when configuring a capacitor to be able to join hundreds of leads, thereby increasing the number of stacking electrode and electrode loss due to bending It is aimed to provide a high output high capacity capacitor which eliminates and improves the bonding characteristics of the leads.

In order to achieve the above object, the capacitor of the present invention is a capacitor formed by stacking a plurality of plate-shaped positive electrode and negative electrode formed by coating an active material on a metal current collector through a separator, and the laminated positive electrode and negative electrode A plurality of leads drawn out from the electrodes having the same polarity, the leads of which are laminated between the positive and negative electrodes stacked together, the case where the laminated positive and negative electrodes, the negative electrode and the positive and negative electrode laminated leads are housed; A positive electrode and a negative electrode external terminal are electrically connected to the laminated leads of the positive electrode and the negative electrode, respectively, and the laminated lead and the external terminal are joined by electric resistance welding.

According to the present invention, by joining the stacked leads by electrical resistance welding, up to 200 leads can be laminated and welded without bending, based on a lead thickness of 20 µm, and a high output large capacity capacitor can be constituted. Compared with the conventional ultrasonic welding, the lead damage and the failure rate due to vibration are greatly reduced, and the productivity is greatly improved.

In addition, the capacitor of the present invention is a capacitor configured by stacking a plurality of plate-shaped positive electrode and negative electrode formed by coating an active material on a metal current collector through an isolation film, and a plurality of lead-out electrodes drawn from the stacked positive electrode and negative electrode. A lead in which a lead is stacked between leads drawn from electrodes having the same polarity, and a stacked lead of a positive electrode and a negative electrode, a laminated positive electrode, a negative electrode, and a laminated lead of a positive electrode and a negative electrode are housed; A positive electrode and a negative electrode external terminal electrically connected to each of the laminated leads of the first electrode, and a first junction is formed between the laminated leads drawn from the electrode having the same polarity, and a second junction is formed between the laminated lead and the external terminal. .

According to the present invention, by performing the first bonding between the leads and the second bonding between the laminated leads and the external terminals, the number of stacked leads can be improved, and the bonding between the leads can be further strengthened by the first bonding. Can be.

In addition, the capacitor of the present invention is a capacitor configured by stacking a plurality of plate-shaped positive electrode and negative electrode formed by coating an active material on a metal current collector through an isolation film, and a plurality of lead-out electrodes drawn from the stacked positive electrode and negative electrode. A lead in which a lead is stacked between leads drawn from electrodes having the same polarity, and a stacked lead of a positive electrode and a negative electrode, a laminated positive electrode, a negative electrode, and a laminated lead of a positive electrode and a negative electrode are housed; A plurality of leads stacked on the laminated lead, each of which has a positive electrode and a negative electrode external terminal electrically connected to the laminated lead of each of the two or more leads, and among the laminated leads drawn from the electrodes of the same polarity, relatively laminated. The large number of parts is the first junction between leads, and the relatively small number of parts is the second contact between the laminated lead and the external terminal. It is sum.

According to the present invention, by varying the length of the stacked leads, a relatively large number of stacked parts performs the first bonding between the leads, and a relatively small number of stacked parts performs the second bonding between the laminated leads and the external terminals. By doing this, the number of stacked layers of leads can be improved up to twice.

In addition, the capacitor of the present invention is a capacitor configured by stacking a plurality of plate-shaped positive electrode and negative electrode formed by coating an active material on a metal current collector through an isolation film, and a plurality of lead-out electrodes drawn from the stacked positive electrode and negative electrode. A lead in which a lead is stacked between leads drawn from electrodes having the same polarity, and a stacked lead of a positive electrode and a negative electrode, a laminated positive electrode, a negative electrode, and a laminated lead of a positive electrode and a negative electrode are housed; A plurality of laminated leads drawn from the electrodes having the positive electrode and the negative electrode external terminals electrically connected to the laminated leads of the electrode, and having one or more leads drawn out from one electrode and having the same polarity. The portion where the first junction is formed and the relatively small number of stacks is formed is the second junction between the laminated lead and the external terminal.

According to the present invention, the number of leads drawn out from each electrode is increased to increase the number of stacked leads so that a relatively large number of stacked parts performs first bonding between leads, and a relatively small number of stacked parts is used for the laminated leads and the external terminals. By carrying out the second bonding in between, the number of stacked layers of leads can be improved up to twice.

In the above capacitor according to the present invention, the first junction is preferably joined by electric resistance welding.

According to the present invention, it is possible to firmly bond even if the number of leads to be laminated is increased by joining a portion of the laminated leads with a large number of stacked layers by electric resistance welding.

In the above capacitor according to the present invention, it is preferable that the second bonding is made by laser welding, and the outer terminal is further provided with a welding groove having a protrusion for pressing the laminated lead.

According to the present invention, it is possible to perform the second bonding for joining the laminated lead and the external terminal by laser welding capable of joining in one direction, which simplifies the process, and at this time, has a protrusion for pressing the laminated lead in the welding groove. By this, welding efficiency can be improved.

Further, in the above capacitor according to the present invention, it is also preferable that the second junction is made by crimping, and the external terminal has one or more crimp protrusions on the joining surface of the laminated lead.

According to the present invention, it is possible to perform the second bonding for joining the laminated lead and the external terminal by pressing, thereby simplifying the process.

In the above capacitor according to the present invention, it is preferable to further include an insulating plate having a bent groove arranged between the stacked anode and cathode electrodes and the external terminal and supporting the lead.

According to the present invention, since the insulating plate having the bent groove is disposed between the electrode and the external terminal, the stacked leads can be easily bent to minimize the empty space, and also serve as a support during laser welding or pressing. .

In the capacitor according to the present invention, it is also preferable that the second junction is made by riveting. Bonding between leads is made firm by the first joining, and in the second joining between the external terminal and the lead, a simple and physically firm joining is possible by riveting.

And, in order to achieve the above object, the capacitor manufacturing method of the present invention, the electrode stacking step of laminating a plurality of plate-shaped positive electrode and negative electrode formed by coating an active material on a metal current collector, through an isolation membrane, A lead stacking step of extracting leads from the positive electrode and the negative electrode and stacking leads drawn from the electrodes having the same polarity; and electric resistance welding between at least one of the stacked leads and external terminals or between the stacked leads. A bonding step is included. In addition, in the capacitor manufacturing method according to the present invention, in the bonding step, the electric resistance welding is performed using two welding rods, electric resistance welding by using one electrode as a welding rod having a larger area than the contact surface with the external terminal. It is preferable to carry out. In addition, in the capacitor manufacturing method according to the present invention, in the bonding step, it is preferable that the electric resistance welding uses resistance heat generated by current supply of 2 kA to 80 kA.

According to the present invention, high-capacity large-capacity capacitors can be realized by joining stacked leads by resistance welding, and by using a large electrode, a large area can be firmly bonded at one point of contact without damaging external terminals even though a large current is applied. All.

Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention.

Example 1

FIG. 1 is a view showing electrodes 1, 1 ', separator 2 and leads 3a, 3a' of a large capacity capacitor according to Embodiment 1 of the present invention. The anode electrode 1 and the cathode electrode 1 'are sequentially stacked with the separator 2 interposed therebetween, and the leads 3a and 3a' are drawn out from all the electrodes 1 and 1 '. The number of stacked layers of the leads 3a and 3a 'is significantly increased as compared with the prior art.

As described above, the large-capacity capacitor configured by stacking the plate-shaped electrodes 1 and 1 'has no bent portions of the electrodes 1 and 1' as compared with the conventional capacitors shown in FIGS. 21 and 22. 1 ') loss and leakage current are reduced, and the number of leads 3a and 3a' is greatly increased so that the leads 3a and 3a 'form a large area, thereby exhibiting excellent electrical characteristics during high current discharge. do. In the present specification, in order to distinguish between the positive electrode, the lead and the negative electrode, and the lead, the negative electrode and the lead are attached with the same reference numeral (') as the positive electrode and the lead. In the part which is not necessary, the additional code is omitted and collectively described.

The electrode group of the large-capacity capacitor according to the first embodiment of the present invention shown in FIG. 1 first coats an active material on a metal current collector to form a positive electrode 1 and a negative electrode 1 ′, and each electrode 1 ), Leads 3a of approximately the same length are drawn out. Although it is also possible to take out a lead by joining another lead with a metal current collector, Preferably, the shape of the metal current collector itself is extended, and it is good that a lead is formed integrally with a metal current collector. The leads 3a drawn out from the anode electrode 1 and the leads 3a 'drawn out from the cathode electrode 1' are arranged in a position not overlapping with each other and are drawn out, and the leads drawn from electrodes having the same polarity overlap each other. It is arrange | positioned at the position to be taken out, and is taken out. The anode electrode 1, the separator 2, the cathode electrode 1 'and the separator 2 thus formed are sequentially and repeatedly stacked.

FIG. 2 shows a perspective view of an electrode group in which the electrodes and leads shown in FIG. 1 are stacked. As the electrode 1 and the separator 2 are stacked, the current collectors of the respective electrodes 1 are all drawn out with the leads 3a having the same length, and the leads drawn from the same electrodes are stacked with each other. In FIG. 1 and FIG. 2, although the length of the lead 3a was shortened than actual for the sake of simplicity, it is clear that the length of the lead can be extended to suit the configuration of the capacitor. In addition, the capacitor according to the present invention implements a large-capacity capacitor, but the actual number of stacking electrodes may be hundreds or more, but only a case where several tens of sheets are stacked for clarity. This manner of illustration is the same in the following description.

3 is a side sectional view showing a lead bonding method of a large capacity capacitor according to the first embodiment. As shown in Fig. 3, a suitable point of the laminated leads 3a and the external terminals 4 are joined according to the present invention. The external terminal 4 shown is the external terminal of the positive electrode which is joined to the laminated lead 3a of the positive electrode drawn out of the positive electrode, and although not shown, the laminated lead 3a 'of the negative electrode drawn from the negative electrode and the external terminal of the negative electrode are also shown. In the same way.

In the present invention, an electric resistance welding method using resistance heating is used for joining a plurality of leads stacked. By using the electric resistance welding method in joining the leads drawn from each electrode of the capacitor in which the electrodes are stacked, it has much improved bonding characteristics compared to the prior art, and it is possible to simplify up to hundreds of leads, for example, up to 400 sheets. It can be joined easily. As a result, a large capacity multilayer capacitor can be realized. The conduction current used for the electrical resistance welding according to the present invention is preferably 2kA to 80kA.

In joining the lead 3a and the external terminal 4 by electric resistance welding according to the present invention, since the external terminal 4 is interposed between the laminated lead 3a and the lower electrode 5a, the external terminal In order to prevent the damage of (4) and to facilitate the energization to minimize the damage of the external terminal (4), it is preferable to use the lower electrode 5a is deformed to form a flat and wider area than the contact surface with the external terminal. Do. When welding the laminated lead 3a and the external terminal 4 at the same time, even if a large current of 2kA to 80kA is applied by using the lower electrode 5a having a large area, there is no damage to the external terminal, and the laminated lead 3a and The external terminal joining point 7a, which is the joining point of the external terminal 4, is firmly joined at one point of contact. In FIG. 3, only the lead 3a drawn out of the anode electrode 1 has been described. However, as described above, the lead 3b drawn out of the cathode electrode 2 is joined in the same manner. Also in the following description, the lead drawn from the anode electrode 1 will be described mainly, and the overlapping description of the lead drawn from the cathode electrode 1 'will be omitted.

When welding the laminated leads 3a and the external terminals 4 by the electric resistance welding using the resistance heating according to the present invention as described above, up to 200 sheets can be laminated and welded on the basis of the 20 μm thickness of each lead. When the conventional ultrasonic welding is used, it is possible to realize a significantly increased number of laminations, compared to the case where welding is possible up to about 50 sheets. In addition, in the case of using conventional ultrasonic welding, lead damage and failure rate due to vibration are greatly reduced, and productivity is greatly improved.

4 is a side cross-sectional view of the large capacity capacitor in which the electrode group according to the first embodiment is accommodated in the case 8. The electrode group in which the electrodes 1, 1 'and the isolation film 2 are stacked is accommodated in the case 8, and the external terminal 4 joined to the lead 3a according to the present invention is interposed with the insulating material 9. To the case cap (10). Since the lead 3a is pulled out from all the anode electrodes and hardly bent at a large angle so that the step between the electrode 1 and the separator 2 is stacked at a small angle, the lead 3a is hard. It is possible to minimize the empty space by bending the external terminal 4 bonded to and without difficulty, it is possible to increase the electrode area per volume.

In FIG. 4, which shows the large-capacity capacitor of the present embodiment, the lead portion is bent in a 'd' shape, but may be bent in various shapes including a 'c' shape. If bent in the 'c' shape, the welded portion with the external terminal 4 is formed closer to the electrode portion in the lead 3a, and the area occupied by the lead portion can be reduced to reduce the volume of the capacitor. Can be reduced. This also applies to the following examples.

Example 2

Embodiment 2 of the present invention is to make it possible to implement a larger capacity capacitor compared to the first embodiment.

FIG. 5 is a view showing electrodes 1, 1 ', separator 2, and leads 3b, 3b', 3c, 3c 'of a large capacity capacitor according to Embodiment 2 of the present invention. Unlike the first embodiment, in the second embodiment, since the anode electrode 1, the separator 2, the cathode electrode 1 ', and the separator 2 are sequentially stacked, the anode electrode 1 and the cathode that are first stacked are first stacked. The lengths of the leads 3b and 3b 'drawn out from the electrode 1' and the leads 3c and 3c 'drawn out from the anode electrode 1 and the cathode electrode 1' stacked next are different. . After that, the pattern is repeated.

FIG. 6 shows an electrode group of a large capacity capacitor according to the second embodiment, which is laminated as described above. As can be seen from the shapes of the leads 3b and 3c in Fig. 5, when the lead leads are stacked, the leads 3b and 3c are stacked at the same time, and the lead 3c with a relatively large number of stacked leads and the leads 3c. Only lamination can be classified into a laminated lead portion having a relatively small number of laminations.

7 is a side sectional view showing a lead bonding method of a large capacity capacitor according to the second embodiment. In the second embodiment, as shown in FIG. 7, electrical resistance welding is performed on the lead parts having a large number of stacks and the lead parts having relatively few stacks.

At this time, in the laminated lead portion having a relatively large number of laminations, bonding is performed at the lead bonding point 7b between the leads 3b and 3c. In this case, even if it is bonded to the lower electrode 5b of the same shape as the upper electrode 6 does not damage the lead, when using a current collector having a thickness of 20㎛ can be welded by stacking up to 400 sheets. In the laminated lead portion having a relatively small number of stacks, the bonding between the stacked leads 3e and the external terminals 4 is performed in the same manner as in Example 1, and 200 sheets are provided as long as they do not damage the external terminals 4. The leads stacked up to now become weldable. As a result, the large-capacity capacitor according to the second embodiment can stack up to 400 electrodes of the same polarity, which can further increase the capacity as compared with the first embodiment.

8 is a side sectional view of a large capacity capacitor in which an electrode group according to the second embodiment is housed in a case 8. As in the first embodiment, empty spaces can be minimized by bending the leads 3b and 3c without difficulty. According to the second embodiment, by configuring the leads 3b and 3c by the above-described method, the number of stacked layers can be doubled compared to the first embodiment, so that a large capacity capacitor having a capacity twice as large as that of the lead part is minimized. You can do it.

In the present embodiment, the case where the leads 3b and 3c have only two types of lengths and the welding part has two parts has been described, but the present invention is not limited thereto. That is, the leads 3b and 3c may have more various types of lengths, and the welding sites may be two or more parts. The lead 3b having a relatively short length and the lead 3c having a relatively long length are described, but the present invention is not limited thereto. For example, it is apparent to those skilled in the art that various modifications are possible, such as a configuration of repeating an arrangement in which two relatively short leads 3b are laminated on a relatively long lead 3c.

Example 3

Embodiment 3 of the present invention is to enable the implementation of a larger capacity capacitor than in Embodiment 1 as in Embodiment 2.

FIG. 9 is a view showing electrodes 1, 1 ', separator 2 and leads 3d, 3d', 3e, 3e 'of a large capacity capacitor according to Embodiment 3 of the present invention. Unlike Embodiment 1, the third embodiment has the following characteristics in that the anode electrode 1, the separator 2, the cathode electrode 1 'and the separator 2 are sequentially stacked.

Referring to the anode electrode 1 as a reference, first, the lead electrode 1 to be laminated is formed with a relatively long lead 3d and a relatively short lead 3e, and then the anode electrode ( In 1), only the lead 3e having a relatively short length is formed at the same position. Similarly, in the case of the negative electrode 1, a lead 3d 'having a relatively long length and a lead 3e having a relatively short length are formed. The patterns of the two positive electrode 1 and the negative electrode 1 'as described above are alternately repeated to be stacked.

FIG. 10 shows the electrode group of the large-capacity capacitor according to the third embodiment constructed by stacking as described above. As can be seen from the shapes of the leads 3d and 3e in Fig. 9, when the lead leads are stacked, the leads 3d are stacked so that the laminated lead portions having a relatively small number of stacks and the leads 3e are stacked. Therefore, it can be divided into lead parts having a relatively large number of stacks.

11 is a side sectional view showing a lead bonding method of a large capacity capacitor according to the third embodiment. As shown in Fig. 11, electric resistance welding is performed on the lead portion 3e having a large number of stacks and the lead portion 3d having a relatively small number of stacks, respectively. Therefore, the large capacity capacitor according to the third embodiment can stack up to 400 electrodes of the same polarity as in the case of the second embodiment.

In the present embodiment, the leads 3d are relatively long and are repeated for each of two electrodes of the same polarity, and the leads 3e are described as having relatively short lengths and included in every electrode. It is not limited. That is, the leads 3d and 3e may have more various types of lengths, the types of leads may increase, and there is no limitation in the number of repetitions or the like. As such, it will be apparent to those skilled in the art that various modifications may be made without departing from the spirit of the present invention.

Example 4

Example 4 is to increase the number of stacking of leads by performing the bonding between the leads by the resistance welding by the resistance heating, and the bonding of the stacked leads and the external terminals by using laser welding.

12 is a perspective view showing an electrode group of a large capacity capacitor according to a fourth embodiment of the present invention. In this figure, the electrode group similar to the electrode group of FIG. 6 concerning Example 2 is shown. That is, due to the difference in the lead length drawn from each electrode, it is divided into a relatively large number of lead stacks and a relatively small number of lead stacks. And in the part where a relatively large number of lamination | stacking is carried out, the electric resistance welding which concerns on this invention, respectively, is firmly joined by the lead junction 7b between leads. Further, the lead 3f drawn out from the positive electrode 1 and the lead 3f 'drawn out from the negative electrode 1' constitute a portion where the number of lead stacks is relatively small. Therefore, also in the fourth embodiment, as in the second embodiment, the number of lead stacks can be increased as compared with the prior art.

On the other hand, in the fourth embodiment is described as being applied to the case of the second embodiment, if the number of the laminated stack of the lead and the small number of stacked stack can be divided into the part according to the invention of the fourth embodiment Can be. That is, the same applies to the third embodiment.

In addition, the present embodiment 4 can be applied to the case where the number of the stacked stacks of leads and the number of the stacked stacks of leads is not divided, that is, in the case of the first embodiment. When the electrode group of the large-capacity capacitor according to the fourth embodiment shown in FIG. 12 is the same as that of the electrode group of FIG. 2 according to the first embodiment, the leads drawn from each electrode are separated from each other by the electrical resistance welding according to the present invention. Is firmly bonded at the lead bonding point 7b.

Therefore, the number of lead stacks can be increased, and the bonding strength between leads can be strengthened. In this case, the joint between the lead and the external terminal can use any of the methods described herein. However, since the number of lead stacks by joining the leads and the number of lead stacks by joining the leads and the external terminals are the same, when the number of lead stacks reaches several hundred by electrical resistance welding, the riveting method is used for joining the leads and the external terminals. It is preferable to use.

13A, 13B and 13C show an example of the insulating plate 11 according to the present embodiment. The insulating plate 11 according to the present embodiment includes a lead bent groove 13 and an electrolyte injection hole 12a. The lead bending groove 13 makes it possible to easily bend the stacked leads 3f. Since the insulating plate 11 should serve as a support to enable secondary bonding between the stacked leads 3f and the external terminals 4, the insulating plate 11 should be made of a material having excellent physical properties. In addition, as shown in FIGS. 13A, 13B, and 13C, the position of the bending groove 13 may be changed according to the bending position of the lead 3f. In particular, as shown in FIG. 13C, the bending groove 13 of the insulating plate 11 may be changed. In the inside of the insulating plate 11, the short with the case 8 can be easily prevented.

14 is a view showing a form in which the insulating plate 11 and the electrode group of the present invention are combined. This figure shows a state in which the insulating plate 11 and the electrode group shown in FIG. 13B are combined. By the insulating plate 11, the laminated leads 3f are easily bent through the bending grooves 13, so that the laminated leads 3f and the external terminals can be easily joined. In addition, the plurality of leads can be effectively and uniformly bent by the insulating plate 11 to minimize the empty space.

15 is a plan view of the case cap 10 of the large-capacity capacitor according to the fourth embodiment of the present invention, wherein the external terminal 4b according to the present invention is welded to allow the lead 3f to be joined by laser welding. 14) is installed.

FIG. 16 is a side cross-sectional view of the large capacity capacitor according to the fourth embodiment, in which the stacked leads 3f are bent by the insulating plate 11, and the laminated leads (3) interposed between the insulating plate 11 and the case cap 10 (FIG. 3f) is laser-welded with the external terminal 4b through the welding groove 14. If the case 8 steps are provided at both ends of the insulating plate 11, the insulating plate 11 is fixed on the step to support the force applied in the direction of the electrode group, so that joining by laser welding is easy. It is possible to more reliably serve as a support to make. In addition, it is preferable that the welding groove 14 formed in the external terminal 4b according to the present invention is protruded in the direction of the stack lead 3f so as to facilitate laser welding to compress the stack lead 3f.

As described above, according to the fourth embodiment, the plurality of stacked leads 3f can be easily bent in a constant state by the insulating plate 11, and serve as a solid support during laser welding with the external terminals 4b. By doing so, the welding efficiency can be increased. In addition, the welding groove 14 formed in the external terminal 4b according to the fourth embodiment has a shape protruding in the direction of the stacked leads 3f, thereby compressing the laminated leads 3f during welding to improve welding efficiency. It can increase.

In this way, the laminated leads 3f are first bonded using electrical resistance welding, and the laminated leads 3f are bent through the bending grooves 13 and supported by the insulating plate 11 while the external terminals 4b are supported. By joining with laser welding, a large capacity capacitor can be realized. In the above embodiment, the bonding of the laminated leads 3f and the external terminals 4b is described as being performed by laser welding. However, the present invention is not limited thereto, and any welding method that can be bonded from one side may be used. It is available. In addition, it is of course possible to perform the bonding of the stacked leads 3f and the external terminals 4b by the riveting method as described above.

Example 5

In Example 5, the lead-to-lead bonding is performed using resistance welding by resistance heating in the same manner as in Example 4, but unlike the fourth embodiment, the laminated lead and the external terminal are bonded to each other by a plurality of pressing pins ( It is carried out by crimping a large area by the external terminal 4c having 15).

17A and 17B show a front view and a bottom view of the external terminal 4c according to the fifth embodiment of the present invention. The lower pressing pin 15 configured in the outer terminal 4c according to the present invention is configured to be crimped with a large area when pressed, and in terms of the size and number of the pressing pins 15 below the outer terminal 4c. Various configurations are possible as long as the laminated leads 3f can be pressed in a large area to bond the laminated leads 3f and the external terminals 4c.

Fig. 18 is a front sectional view of the large capacity capacitor according to the fifth embodiment, in which the laminated leads are firmly joined up to 400 sheets by electric resistance welding using electric heat generation, and the laminated leads 3f joined by electric resistance welding are shown in FIG. Constantly bent by the insulating plate 11 according to the invention and disposed between the insulating plate 11 and the external terminal 4c, the pressing pin 15 formed on the external terminal 4c according to the fifth embodiment is crimped. The laminated lead 3f and the external terminal 4c are firmly bonded in a large area.

Also in the present embodiment, similarly to the fourth embodiment, since the insulating plate 11 is fixed on the end portion provided on the side of the case 8, the force applied in the direction of the electrode portion can be supported. It serves as a support for supporting the pressing by.

[Comparative Example]

Experiments were performed to compare the capacitors according to the invention with the capacitors of the prior art. As a comparative example for this comparison, a capacitor wound in a plate shape according to the prior art shown in Figs. 21 and 22 was used. The conditions for comparing the electrical characteristics of the capacitor of the comparative example and the capacitor according to Example 1 are shown in Table 1 below.

In the case of the comparative example, as shown in FIG. 22, it wound up in plate shape, formed the electrode group, was laminated | stacked, and 52 lead was taken out from the electrode, and these leads were joined by ultrasonic welding. On the other hand, in Example 1, after stacking plate-shaped electrodes as shown in Figs. 1 to 4, 104 leads were taken out of the electrodes and these leads were joined by resistance welding. And the carbon amount of a comparative example and Example 1 is the same.

In the comparative example, 52 leads, which is the maximum number of bonds that can be joined by ultrasonic welding, were drawn out. In Example 1, the lead was drawn up to 200 sheets because of joining by resistance welding. It was.

Lamination Method Lead withdrawals Lead bonding method Comparative example Lamination after winding 52 Ultrasonic welding Example 1 Lamination 104 Resistance welding

With respect to the capacitors of Comparative Examples and Example 1 described above, the capacitance when the discharge current of 100A, 200A, 300A was generated was measured, and the DC resistance when the discharge current was 100A was also measured. The result data thus obtained is shown in Table 2 below.

Condition Comparative example Example 1 Capacity by discharge current [F] 100 A 2931 3043 200 A 2835 3025 300 A 2721 3000 DC resistance [mΩ] 100 A 0.5 0.2 Capacity reduction rate 100-300 A 7.16% 1.41%

First, when the discharge current was 100 A, the capacitor of the comparative example showed a capacity of 2931 (F), and the capacitor of Example 1 showed a capacity of 3043 (F). Ideally, since the amount of carbon is the same, it should ideally exhibit the same capacity, but the capacitance difference occurs due to the influence of IR drop or the like caused by the internal resistance, and the capacitor capacity value of the comparative example with the larger internal resistance value was measured to be smaller. In other words, in Table 2, when the discharge current is 100 A, the DC resistance value of the comparative example is 0.5 (mΩ) and the capacitor of Example 1 is 0.2 (mΩ), and the capacitor DC resistance value of Example 1 is the capacitor of the comparative example. You can see that it is smaller than the DC resistance value.

In addition, when the discharge current is 200A, the capacitors of the comparative example and Example 1 are 2835 (F) and 3025 (F), and when the discharge current is 300A, the capacitors of the comparative example and Example 1 are 2721. (F) and 3000 (F). That is, as the discharge current increases, the capacitance of each capacitor decreases under the influence of IR drop and the like, and the DC resistance value of the comparative example is more than doubled compared to the internal resistance of Example 1, whereby the comparative example and the example It can be seen that the capacitance difference between the capacitors of 1 becomes wider. When the discharge current is changed from 100A to 300A with respect to the above result, the reduction rate of the capacity value is 7.16% in the comparative example, but only 1.41% in the case of the first example.

Referring to the comparison result, it can be seen that the electrical characteristics of the capacitor of Example 1 of the present invention is superior to the capacitor of Comparative Example 1. In the conventional capacitor of Comparative Example 1, the bent portion of the electrode is formed at the time of winding in the form of a plate, resulting in loss of the electrode, and also due to the use of ultrasonic welding, lead damage due to vibration occurs, and the junction limit of the lead is increased. Since it is only about 50 sheets, it is difficult to reduce the resistance value by reducing the lead loss, and there are many problems to implement a high output large capacity capacitor, and the present invention solves this problem.

It is to be understood that the present invention is not limited to the above-described exemplary preferred embodiments but may be embodied in various ways without departing from the spirit and scope of the present invention. If you grow up, you can easily understand. If the implementation by such improvement, change, replacement or addition falls within the scope of the appended claims, the technical idea should also be regarded as belonging to the present invention.

The present invention relates to a large-capacity capacitor, by applying an electric resistance welding method using the resistance heat generated by the current flow of a large current range of 2kA to 80kA for the bonding of a plurality of stacked leads included in the large capacity capacitor, Compared with the capacitor lead junction performance, it shows superior junction performance, and the number of lead junctions, which is one of the key processes in the manufacture of large capacity capacitors, is dramatically increased compared to the existing method, thereby minimizing terminal loss and widening the application range of high output large capacity capacitors. It became possible.

Claims (13)

delete delete delete In the capacitor configured by laminating a plurality of plate-shaped positive electrode and negative electrode electrode formed by coating an active material on a metal current collector through an isolation film, Stacking leads of a positive electrode and a negative electrode in which a plurality of leads drawn from the stacked positive electrode and the negative electrode are laminated; A case accommodating the stacked anode and cathode electrodes and the stack lead; External terminals of a positive electrode and a negative electrode electrically connected to the laminated leads of the positive and negative electrodes, respectively, through the case; And An insulating plate disposed between the laminated lead and the external terminal with a bent groove that can be bent while supporting the laminated lead; The metal current collector on which the positive electrode is formed includes a first metal current collector from which one lead is drawn from the positive electrode and a second metal current collector from which two leads having different lengths are drawn from the positive electrode; The metal current collector on which the electrode is formed includes a third metal current collector from which one lead is drawn from the negative electrode and a fourth metal current collector from which two leads having different lengths are drawn from the negative electrode; Among the stacked leads drawn out from the electrodes of the same polarity, a portion having a relatively large number of stacks is the first junction between leads, and a portion having a relatively small number of stacks is a second junction between the stack lead and the external terminal. Characterized by a capacitor. The method of claim 4, wherein And the first junction is an electrical resistance welding. The method of claim 4, wherein And the second junction is laser welding. delete delete The method of claim 4, wherein And the second junction is made by riveting. delete A plurality of plate-shaped positive electrode and negative electrode electrodes formed by coating an active material on a metal current collector are laminated through a separator to accommodate a plurality of metal current collectors in which a lead is drawn from the positive electrode. The first metal current collector and the second metal current collector having two leads different from each other in length from the positive electrode are formed, and the metal current collector on which the negative electrode is formed is a third metal with one lead drawn from the negative electrode. A first process of forming a fourth metal current collector from which a current collector and two leads having different lengths from each other are drawn; A second process of stacking leads drawn from the electrodes having the same polarity; A third step of disposing an insulating plate having a bending groove that can be bent while supporting the stacked leads between the stacked leads and an external terminal; And Among the stacked leads drawn out from the electrodes of the same polarity, a portion having a relatively large number of stacked portions performs first bonding between leads, and a portion having a relatively small number of stacked portions performs second bonding between the stacked leads and the external terminals. Capacitor manufacturing method comprising a four process. The method of claim 11, The first welding is carried out by electric resistance welding, the second welding is carried out by laser welding, the electric resistance welding is performed by using two welding rods, and in contact with the external terminal during the electric resistance welding. And a welding rod having a larger area than the contact surface with the external terminal. The method of claim 12, The electrical resistance welding method for producing a capacitor, characterized in that using the resistance heat generated by the current flow of 2kA ~ 80kA.

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