JP2002246007A - Batteries with stacked electrode groups - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reliably join a negative electrode current collecting terminal and a positive electrode current collecting terminal to a negative electrode plate and a positive electrode plate, and to improve the current collecting efficiency of the negative electrode current collecting terminal and the positive electrode current collecting terminal. Provided is a battery including a stacked electrode group that is improved in strength. SOLUTION: A sheet-like negative electrode plate with a separator 12 interposed therebetween
A stacked electrode group 18 including a positive electrode plate 14 and a positive electrode plate 16, and a pair of electrodes that are welded to one end of the negative electrode plate and one end of the positive electrode plate, respectively, in a direction along the direction in which the negative electrode plate 14 and the positive electrode plate 16 are stacked And a current collecting terminal. The negative electrode plate 14 and the positive electrode plate 16 have communication holes or cutouts communicating with each other in the stacking direction in a state where both electrodes are stacked.
A plurality of 1a are formed, and a conductive pin is made to penetrate the communication hole or notch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery having a laminated electrode group, and more particularly to a laminated electrode group in which a negative electrode plate and a positive electrode plate are laminated via a separator. The present invention relates to a battery including a stacked electrode group in which current collecting terminals are joined to a group.

[0002]

2. Description of the Related Art As shown in FIG. 7, a nickel-metal hydride battery or a lithium-ion battery,
Reference numeral 60 denotes a stacked electrode plate group 68 in which a negative electrode plate 64 and a positive electrode plate 66 are stacked via a separator 62, and a plate-shaped negative electrode plate bonded to one end of the negative electrode plate 64 and one end of the positive electrode plate 66, respectively. And a positive electrode current collecting terminal 72. The negative electrode current collecting terminal 70 and the positive electrode current collecting terminal 72 are arranged in the direction along the laminating direction of the negative electrode plate 64 and the positive electrode plate 66, and each surface 70 of the negative electrode current collecting terminal 70 and the positive electrode current collecting terminal 72.
A, 72A (see FIG. 8 for 72A) is joined to the negative electrode plate 64 and the positive electrode plate 66 by laser welding, electron beam welding or resistance welding in which a laser beam or an electron beam 75 is irradiated. It is housed in a battery package 78. Hereinafter, an example in which the positive electrode current collecting terminal 72 is joined to the positive electrode 66 will be described with reference to FIG.

As shown in FIG. 8, a positive current collecting terminal 72 is mounted on a positive electrode plate 66 constituting a laminated electrode group 68, and the positive current collecting terminal 72 is provided.
By irradiating the laser beam 75 from above, the irradiation energy of the laser beam 75 welds the right side 66A of the positive electrode plate 66 and the positive electrode current collecting terminal 72. Thereby, the positive electrode current collecting terminal 72 can be joined to the right side 66A of the positive electrode plate 66 by the welded portion 73.
In the case of the negative electrode plate 64, similarly to the positive electrode plate 66, the left side of the negative electrode plate 64 is laser-welded to the negative electrode current collecting terminal 70.

[0004]

SUMMARY OF THE INVENTION By the way, nickel
In order to maintain the quality of the hydrogen battery and the lithium ion battery 60, the negative electrode current collector terminals
It is important that the 70 and the positive electrode current collecting terminal 72 are securely joined. For this reason, it is desired that the bonding property between the negative electrode plate 64 and the negative electrode current collecting terminal 70 be higher and the bonding property between the positive electrode plate 66 and the positive electrode current collecting terminal 72 be higher.

In addition, in order to increase the productivity of the nickel-metal hydride battery or the lithium ion battery 60, the negative electrode current collector terminal 70 and the positive electrode current collector terminal
It is important that 72 can be easily joined. This is because, when the positive electrode plate 66 and the negative electrode plate 64 are arranged side by side and welded, as described above, each of the surfaces 70 of the negative electrode current collecting terminal 70 and the positive electrode current collecting terminal 72 is formed.
A and 72A are joined to the negative electrode plate 64 and the positive electrode plate 66 by welding with irradiation of an electron beam 75 or the like.
Maintaining and fixing the laminated state when welding the positive electrode plate 66 and the positive electrode plate 66 is relatively troublesome, and workability is particularly poor in a small battery. For this reason, it is desired that the joining operation between the negative electrode plate 64 and the negative electrode current collecting terminal 70 and between the positive electrode plate 66 and the positive electrode current collecting terminal 72 be made simpler and more secure.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to make it possible to more reliably join a negative electrode current collector terminal and a positive electrode current collector terminal to a negative electrode plate and a positive electrode plate, and to provide a negative electrode current collector. It is an object of the present invention to provide a battery provided with a stacked electrode group capable of improving the current collecting performance of a terminal and a positive electrode current collecting terminal and having high mechanical strength.

[0007]

In order to achieve the above-mentioned object, the present invention provides an electrode plate group comprising a plurality of stacked positive electrode plates, separators and negative electrode plates. There is a core of the positive electrode plate and a core of the negative electrode plate constituting the electrode plate group are exposed at one end of the electrode plate,
An end of the exposed core of the positive electrode plate and an end of the core of the negative electrode plate protrude from two opposing surfaces of the electrode plate group, and the exposed core of the positive electrode plate and the negative electrode plate is exposed. A plurality of communication holes or notches communicating with each other in the laminating direction are provided at the end of the body, and a conductive pin is penetrated through the communication holes or the notches.

In the battery provided with the stacked electrode group configured as described above, a communication hole or notch is formed so as to communicate with the positive electrode plate and the negative electrode plate in the stacking direction when the two electrode plates are stacked. Is provided, when stacking the positive electrode plate and the negative electrode plate in a stacked state, the positive electrode plate and the negative electrode plate can be relatively positioned and held by penetrating the conductive pin through the communication hole or the cutout portion. And, even if the cross-sectional area of the positive electrode plate and the negative electrode plate is partially reduced by the communication hole or the cutout portion, it is possible to avoid a decrease in current collection efficiency by penetrating the conductive pin into the communication hole or the cutout portion. Can be.

In a battery provided with such a stacked electrode group, a plurality of communication holes or cutouts may be formed along one side of the positive electrode plate and the negative electrode plate and biased toward the one side. For example, the positive electrode plate and the negative electrode plate can be securely held and fixed by the conductive pins separately penetrating. In addition,
The hole is more preferable than the cutout portion in terms of the good positioning of the electrode plate and the reliability of welding the core and the pin.

Further, in the present invention, as described in claim 2, the end of the core of the electrode plate and the communication hole or the cutout provided at the end of the core are penetrated. If the conductive pin is welded, good conductivity can be obtained because the end of the core and the conductive pin can be securely joined.
That is, in the present invention, since the inner peripheral surface of the communication hole or the notch and the outer peripheral surface of the conductive pin are kept in a conductive state, the conductive pin is collected at the end of the core as in the related art. As compared with the case where the power terminals are joined, the state of conduction through a large contact area is maintained, and thereby better current collection efficiency can be obtained.

On the other hand, a battery provided with a laminated electrode group according to the present invention is an electrode group formed by laminating a plurality of positive plates, separators and negative plates, as described in claim 3. The core of the positive electrode plate and the core of the negative electrode plate constituting the electrode plate group are exposed at one end of the electrode plate, and the exposed end of the core of the positive electrode plate and the core of the negative electrode plate are exposed. End portion of the core is provided at the end of the core body at the facing portion where the current collector terminal is in contact with the core body. A facing communicating hole or a facing notch communicating with the communicating hole or the notch is provided at the communicating hole or the notch and the current collecting terminal provided at an end of the core body. The conductive pin is penetrated through the facing portion communication hole or the facing portion cutout portion.

[0012] In the battery provided with this stacked electrode group, the conductive pins are passed through communication holes or cutouts provided at the end of the core when stacking the positive electrode plate and the negative electrode plate in a stacked state. At the same time, in order to penetrate through the facing communication hole or the facing notch of the current collecting terminal, the positive electrode plate and the negative electrode plate can be relatively positioned and held similarly to the above-described invention of claim 1, and the current collection efficiency can be improved. Can be improved.

[0013] In the battery provided with the stacked electrode group having the above-described configuration, a conductive hole or a cutout in the facing portion provided in the facing portion of the current collecting terminal having a U-shaped cross section is provided. The current collector terminal and the positive electrode plate or the negative electrode plate can be fixed by the conductive pin as well, so that the current collector terminal and the positive electrode plate or the negative electrode plate are not only easily positioned but also stacked. The strength of the electrode plate group can be improved. Furthermore, the current collecting terminal has a facing portion whose one end side is bent and faces a flat portion of the positive electrode plate or the negative electrode plate,
Since the facing portion is provided with the facing portion communication hole or the facing notch portion corresponding to the communication hole or the notch portion, the facing portion can be laminated and positioned simultaneously with the positive electrode plate or the negative electrode plate.

Further, in the battery provided with the stacked electrode group of the present invention, at least one of the end of the core body and the facing portion of the current collecting terminal may be provided. Since the conductive pins are welded, the strength of the stacked electrode group can be improved.

[0015] In the battery provided with the stacked electrode group of the present invention, as described in claim 5, the current collecting terminal and the conductive pin are welded to each other at an engaging portion of the both. , The contact area between the collecting terminal and the negative electrode and the positive electrode can be increased, and not only the bonding strength between the negative electrode and the positive electrode and the collecting terminal can be increased, but also the occurrence of poor connection between the negative electrode and the positive electrode and the collecting terminal can be prevented. it can.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment. The shape, material, and the like of the component according to the present invention are not limited to the examples shown below. Figure 1
1 is a partially exploded perspective view showing the structure of a stacked electrode group according to the present invention. FIG. 2 is a cross-sectional view of a main part of the stacked electrode group taken along line AA ′ in FIG. FIG. 3 is a perspective view showing the structure of a monoblock battery composed of a plurality of unit cells according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, a sealed battery such as a nickel-metal hydride battery or a lithium-ion battery as a battery provided with a stacked electrode group according to a first embodiment of the present invention.
Reference numeral 10 denotes a laminated electrode group 18 in which a negative electrode plate 14 and a positive electrode plate 16 are laminated via a separator 12 (see also FIG. 2);
And a positive electrode current collector terminal 20 and a positive electrode current collector terminal 22 which are respectively joined to the ends of the positive electrode plate 16 (hereinafter, simply referred to as “electrode plate” when collectively referring to the negative electrode plate and the positive electrode plate). The negative current collecting terminal 20 and the positive current collecting terminal 22
Along with the negative electrode plate 14 and the positive electrode plate 16 being oriented along the laminating direction, the negative current collecting terminal 20 and the positive current collecting terminal
Laser light 25 is applied to each surface 20A, 22A of 22 (see FIG. 2 for 22A).
The negative electrode plate 14 and the positive electrode plate 16 are joined to each other by laser welding or electron beam welding or resistance welding for irradiating a bundle of electrons. Stacked electrode group configured in this way
18 is a substantially box-shaped sealed battery case 28 (see FIGS. 1 and 3).
Is a case in which a plurality of storage sections are provided).

The negative electrode plate 14 has, for example, a thickness of 0.06 mm and an exposed portion of about 0.06 mm.
It is a 0.4mm thick 30mm wide x 80mm high simplest hydrogen storage alloy negative electrode plate with a 2.5mm core material. The positive electrode plate 16 is, for example, a 0.1mm thick core material with an exposed portion of about 2.5mm. With thickness 0.6mm
It is a sintered nickel positive electrode plate with a width of 30 mm and a height of 80 mm. The laminated electrode group 18 has a separator having a thickness of 150 μm so that the exposed portion of the end of the core material on the negative electrode plate 14 and the exposed portion of the end of the core material on the positive electrode plate 16 are arranged on both sides. 12 electrode plates enclosing the positive electrode plate 16 and the negative electrode plate 14
It is formed by laminating 13 sheets, thickness about 16mm, width 30mm, height 80mm
It is manufactured in.

In the sealed battery 10 of the present embodiment, a plurality of communication holes 1a are formed in the exposed portion of the end of the core material in the negative electrode plate 14 and the exposed portion of the end of the core material in the positive electrode plate 16. I have. As shown in FIGS. 1 and 2, a plurality of these communication holes 1a are formed so as to be arranged at positions communicating with each other in the stacking direction when the negative electrode plate 14 and the positive electrode plate 16 are stacked. The diameter of these communication holes 1a is desirably 1.6 mm to 2.1 mm, and the distance between adjacent communication holes 1a is 25 mm to 60 m.
m is preferred

In the present embodiment, the negative electrode current collecting terminal 20 and the positive electrode current collecting terminal 22
And facing portions 20a, 20a, 22 facing the surface of the positive electrode plate 16.
a, 22a, and both facing portions 20a, 20a, 22a, 22a
In addition, a facing communicating hole 2 corresponding to the communicating hole 1a is provided.

As shown in FIG. 2, the laminated electrode plate group 18 has a left side 14A of the negative electrode plate 14 protruding leftward from a left side 16A of the positive electrode 16, and a right side 16B of the positive electrode plate 16 They are stacked so as to protrude rightward from the right side 14B of 14. Further, the positive electrode current collecting terminal 22 is penetrated by the conductive pin 9 (FIG. 2).
The positive electrode plate 16 is also welded to the right side 16B of the positive electrode plate 16 while being penetrated by the conductive pins 9. Thereby, it is attached to the right side of the stacked electrode group 18. Reference numeral 33 indicates a welded portion. The diameter of the conductive pin 9 is set to 1.5 to 2.0 mm so that the diameter is slightly smaller than the diameter of the communication hole.

The negative electrode current collecting terminal 20 is applied to the left side 14A of the negative electrode 14 as shown by an arrow, and then penetrates through the communication hole 1a and the facing communication hole 2 with the conductive pin 9; To the left side 14A. Thus, the negative electrode current collecting terminal 20 is attached to the left side of the stacked electrode group 18. In this way, by penetrating the communication hole 1a and the facing portion communication hole 2 with the conductive pin 9, the current collecting terminals 20, 22 and the negative electrode plate 14 and the positive electrode plate 16 can be positioned at accurate positions. Can be.

In the present embodiment, a plurality of (three) communication holes 1a for the negative electrode plate 14 and the positive electrode plate 16 are formed along one side of the negative electrode plate 14 and the positive electrode plate 16 and biased toward the one side. The negative electrode plate 14 is a conductive pin 9 on the negative electrode plate 14 side, and is connected to the positive electrode plate 16.
Are separately penetrated and held by the conductive pins 9 on the positive electrode plate 16 side.

In the present embodiment, the negative electrode current collecting terminal 20 and the positive electrode current collecting terminal 22, and the negative electrode plate 14 and the positive electrode plate 16 are also welded at a portion 19 (see FIG. 2) where the conductive pin 9 is engaged. It can be configured. In this case, the joint area between the current collecting terminals 20, 22 and the electrode plates 14, 16 can be increased, and the joint strength between the electrode plates 14, 16 and the current collecting terminals 20, 22 can be increased. As well as the stacked electrode group 18
Can be improved in strength. Furthermore, the negative electrode plate 14
In addition, it has an effect of preventing a joint failure between the positive electrode plate 16 and the current collecting terminals 20 and 22.

The sealed battery case shown in FIGS. 1 and 3
The upper end 28 has a plurality of openings 29 for accommodating the stacked electrode plate group 18 to which the negative electrode current collecting terminal 20 and the positive electrode current collecting terminal 22 are attached. Then, the stacked electrode group 18 to which both the current collecting terminals 20 and 22 are attached is housed so as to be connected in series to the sealed battery case 28 from each opening 29, and the adjacent cells are connected to each other.
The battery is connected via a connection terminal 30c, the positive electrode terminal 30a and the negative electrode terminal 30b at both ends of the sealed battery case 28 are taken out, and the opening 29 is closed with a lid provided with a gas discharge valve.
10 are manufactured.

The conductive pin 9 on the side of the negative electrode current collecting terminal 20 can be made of the same material as the negative electrode current collecting terminal 20 or an alloy whose main component is the material of the current collecting terminal. The conductive pins 9 are preferably made of nickel or a nickel alloy in a nickel-metal hydride battery, and are preferably made of copper or a copper alloy, nickel, a nickel alloy, or nickel-plated iron in a lithium ion battery.

The conductive pins 9 on the side of the positive current collecting terminal 22 are made of the same material as the positive current collecting terminal 22 or an alloy mainly composed of the material of the current collecting terminal. In addition, the conductive pin 9 on the side of the positive electrode current collecting terminal 22 is made of nickel,
Nickel alloy or nickel-plated iron or aluminum or aluminum alloy in lithium ion batteries. Among them, A3003 is preferable as an aluminum alloy material because it has high strength and hardly corrodes.

As shown in FIG. 4, the current collecting terminal 40 may be formed to have a substantially U-shaped cross section including a surface 40A of the current collecting terminal and facing portions 40a provided at both ends thereof. it can. The facing portion communication hole 2 is provided in the facing portion 40a. With such a configuration, the current collecting terminal 40
Can be penetrated by the conductive pins together with the electrodes and held at the same time, for example, during stacking of the electrodes during manufacturing.

As shown in FIG. 5, the current collecting terminal 50 is
Both ends of the surface 50A are bent to have a facing portion 50a facing the flat portion of the electrode, and the facing portion 50a is provided with a facing notch 55 corresponding to the communication hole 1a. According to such a configuration, the current collecting terminal 50 allows the conductive pin 9 and the facing notch 55 to correspond to the electrode positioned and laminated via the conductive pin 9, Since the contact can be made with the electrode, welding can be performed in a state where the current collecting terminal 50 is brought into contact with the conductive pin 9 so as to correspond thereto.

The sealed battery of the present invention is not limited to the above embodiments, but can be appropriately modified and improved. For example, the present invention has been described by taking a nickel-metal hydride battery and a lithium-ion battery as examples of sealed batteries, but the present invention is not limited to these and can be applied to other sealed batteries.

In addition, the materials, shapes, dimensions, forms, numbers, locations, etc. of the negative electrode plate, the positive electrode plate, the laminated electrode group, the current collecting terminals, the conductive pins, the welding members, etc. exemplified in the above-described embodiments. Is arbitrary as long as the present invention can be achieved,
Not limited.

Next, a battery provided with a laminated electrode group was manufactured based on the present invention, and a battery having a conventional structure was compared as a comparative example. The results will be described.

(Example 1) A sintered nickel positive electrode plate having a thickness of 30 mm and a height of 80 mm having a thickness of 0.6 mm and a core material having a thickness of 0.1 mm and an exposed portion of about 2.5 mm, and a 0.06 mm thick, exposed portion A positive type hydrogen storage alloy negative electrode plate with a thickness of 0.4 mm and a width of 30 mm x a height of 80 mm with a core material of about 2.5 mm, and a positive electrode with a separator of 150 μm thickness so that each exposed part is arranged on both sides Twelve plates and thirteen negative plates were laminated to form a laminated electrode group having a thickness of about 16 mm, a width of 30 mm, and a height of 80 mm.

On the exposed portion of the positive electrode plate of the electrode plate group, a current collector made of nickel and having a U-shaped cross section having a length of 100 mm × width of 16.2 mm and a thickness of 0.6 mm was placed. Sandwiched between
A conductive pin made of nickel and also having a diameter of 1.9 mm serving as a positioning member was inserted from both sides of the current collector having a U-shaped cross section, and then laser-welded. Similarly to the positive electrode, the negative electrode plate also uses a current collector, sandwiches the negative electrode plates on both sides, inserts conductive pins that also serve as positioning into the communication holes from both sides, performs laser welding, and collects the current collectors into the positive and negative electrodes. Were fabricated by welding. The current collecting terminals of these electrode plates were welded so as to form a 6-cell series. Next, a prescribed amount of an alkaline electrolyte containing potassium hydroxide as a main component was injected into six places, and a lid provided with a gas discharge valve and a battery case were sealed. Battery A having a battery capacity of 6.5 Ah and an average voltage of 7.2 V was used. Obtained.

(Example 2) A battery was produced in the same manner as in Example 1 except that the welding pin of the example was inserted from one side and laser welding was performed. The present invention had a battery capacity of 6.5 Ah and an average voltage of 7.2 V. Battery B was obtained.

(Comparative Example 1) For comparison with Example 1, the same as Example 1 except that a pin made of non-conductive ceramic was used instead of the conductive pin serving also for positioning. Then, a battery C of Comparative Example having a battery capacity of 6.5 Ah and an average voltage of 7.2 V was obtained.

(Comparative Example 2) For comparison with Example 1, the above-described positive and negative plates without communication holes were laminated, and a conventional current collector having a U-shaped cross section was used. A battery was prepared in the same manner as in Example 1, and the battery capacity was 6.5 Ah and the average voltage was
A 7.2 V comparative battery D was obtained.

Each of these batteries was subjected to a 0.2 I
The charge / discharge cycle is repeated 5 times with a current of t (A) (Note 1 It (A) = C5 (Ah) / 1h), and after activating the battery, the current of 1.OIt (A) is used. Then, charge and discharge were repeated 500 cycles from DOD 20% to DOD 80%, and a decrease in capacity was investigated. Also,
After the same activation was performed using another battery, the same battery was used to investigate the discharge characteristics at each discharge rate. The current value was 1.OIt (A) to 30It (A), and the battery capacity when discharged to a final voltage of 4.8V was examined. The result is shown in FIG.
In the case of the battery of this example, discharge was possible up to 30 It (A), but in Comparative Examples 1 and 2, discharge was impossible at 25 It (A) and 20 It (A), respectively.

From these results, by using the current collector and the conductive pin of the present invention, the battery capacity at the time of high-rate discharge was improved. It is considered that the reason for this is due to the difference in resistance between the welds between the electrode group and the current collector, as is apparent from the results in FIG. For those using conductive pins, conductive pins with large cross-sectional area are strongly welded to each electrode plate,
Compared to those without conductive pins, the resistance of the electrode plate weld is smaller, so the IR drop during large current discharge is smaller,
It is considered that discharge was possible even with a large current of 30 It (A). Also, if an electrode group is formed using an electrode plate having no plurality of communicating holes, the electrode plate is likely to be displaced in the process of stacking the electrode plates, and the flat surface of the protruding portion does not appear. It is probable that the current collector terminals could not be reliably welded.

[0040]

As described above, according to the present invention, as described in claim 1, the positive electrode plate and the negative electrode plate are connected so as to communicate with each other in the laminating direction in a state where the two electrode plates are laminated. Since the communication holes or notches are provided, when stacking the positive electrode plate and the negative electrode plate in a stacked state, the conductive pins are passed through the communication holes or the notches so that the positive electrode plate and the negative electrode plate can be relatively positioned. And the current collection efficiency is improved.

Further, according to the present invention, as described in claim 2, an end of the core of the electrode plate and a conductive hole penetrating through a communication hole or notch provided in the end of the core. If the pins are welded, the end of the core and the conductive pin can be securely joined to each other, so that good conductivity can be obtained. In comparison, a state of conduction through a large contact area is maintained, thereby obtaining better current collection efficiency.

On the other hand, according to the present invention, when stacking the positive electrode plate and the negative electrode plate in a stacked state, the conductive pin is provided at the end of the core body with a communication hole or notch. In addition to the above, the positive electrode plate and the negative electrode plate can be relatively positioned and held in the same manner as in the first aspect of the present invention, as described above, in order to allow the positive electrode plate and the negative electrode plate to penetrate into the facing communication hole or the facing notch of the current collecting terminal. In order to improve the current collection efficiency, and to allow the conductive pin to penetrate the facing part communication hole or the facing part cutout provided in the facing part of the current collector terminal having a U-shaped cross section, the current collector terminal and the positive electrode plate Alternatively, fixation to the negative electrode plate can be performed by a conductive pin, so that not only the positioning of the current collecting terminal and the positive electrode plate or the negative electrode plate can be easily performed, but also the strength of the stacked electrode group can be improved.
Further, the current collecting terminal has a facing portion whose both ends are bent to face the flat portion of the positive electrode plate or the negative electrode plate, and the facing portion has a communicating hole corresponding to the communication hole or the cutout portion or the facing portion. By having a notch,
It can be laminated together with the positive electrode plate or the negative electrode plate and positioned simultaneously.

According to the present invention, since the conductive pin is welded to at least one of the end portion of the core and the facing portion of the current collecting terminal, a stacked type is provided. The strength of the electrode plate group can be improved.

According to the present invention, as described in claim 5, the current collecting terminal and the conductive pin are welded at the engaging portion of the both, so that the current collecting terminal and the negative electrode and the positive electrode contact each other. The area can be increased, and not only the bonding strength between the negative electrode and the positive electrode and the current collecting terminal can be increased, but also the occurrence of poor bonding between the negative electrode and the positive electrode and the current collecting terminal can be prevented.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a structure of an electrode group of a battery according to the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a schematic perspective view showing the entire structure of the battery according to the present invention.

FIG. 4 is a schematic perspective view showing a modification of the current collecting terminal of the battery according to the present invention.

FIG. 5 is a schematic perspective view showing another modified example of the current collecting terminal of the battery according to the present invention.

FIG. 6 is a graph showing discharge characteristics of an example battery and a comparative example battery.

FIG. 7 is an exploded perspective view showing a structure of an electrode group of a conventional battery.

FIG. 8 is a sectional view taken along line BB in FIG. 7;

[Explanation of symbols]

 1a Communication hole 2 Facing hole 9 Conductive pin 12 Separator 14 Negative plate 16 Positive plate 18 Stacked electrode plate group 20 Negative current collecting terminals 20a, 22a Facing portion 22 Positive current collecting terminal 55 Notch

 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference) 5H022 AA04 AA09 BB11 CC12 CC16 CC22 5H028 AA05 CC05 CC11

Claims (5)

[Claims] 1. An electrode group formed by laminating a plurality of positive plates, separators and negative plates, wherein the core of the positive plate and the core of the negative plate constituting the group of electrodes are The end of the exposed core of the positive electrode plate and the end of the core of the negative electrode plate are exposed at one end, and project from two opposing surfaces of the electrode plate group. A plurality of communication holes or notches communicating in the laminating direction are provided at the ends of the exposed core of the plate and the negative electrode plate, and a conductive pin is penetrated through the communication holes or the notches. A battery provided with a stacked electrode group. 2. The method according to claim 1, wherein an end of the core of the electrode plate is welded to the conductive pin that penetrates the communication hole or the cutout provided at the end of the core. A battery comprising the group of stacked electrode plates according to claim 1. 3. An electrode plate group formed by laminating a plurality of positive electrode plates, separators and negative electrode plates, wherein a core of the positive electrode plate and a core of the negative electrode plate constituting the electrode plate group are formed of an electrode plate. An end of the exposed core of the positive electrode plate and an end of the exposed core of the negative electrode plate are exposed at one end, and have a U-shaped cross section having a facing surface with the core. The current collector terminal is provided with an end face of the core body at the facing part where the current collecting terminal is in contact with the core body. The conductive pin is passed through the communication hole or the notch provided at the end of the core body and the facing communication hole or the facing notch provided in the current collecting terminal. A battery provided with a stacked electrode group. 4. The laminated electrode plate according to claim 3, wherein the conductive pin is welded to at least one of an end portion of the core body and the facing portion of the current collecting terminal. Battery with group. 5. The battery according to claim 4, wherein the current collecting terminal and the conductive pin are welded to each other at an engaging portion between the current collecting terminal and the conductive pin.