JPH0822816A - Square sealed battery - Google Patents

Abstract

PURPOSE:To raise the operation voltage at discharge of a large current by lessening the inner resistance of a battery with simple structure. CONSTITUTION:For a square-shaped sealed battery, an electrode 4 is accommodated in an armor can 6. A group of electrode boards of either positive or negative polarity constituting the electrode body 4 are equipped with at least three sets of coupling electrode boards 7 U shaped in cross section and electrode boards 8 for current collection having lead parts 8A at the ends of the electrode boards. For two sets of coupling boards 7, each electrode board on one side is positioned on the most outside of the electrode body 4 so as to be in contact with the inner side face of the armor can 6. The lead 8A of the electrode board 8 for current collection is caught between the electrode body 4 and the armor can 6, whereby currents are collected in the armor can 6, and also the lead is welded to the coupling part 7A of the coupling electrode board 7 positioned inside the electrode body 4, and this coupling electrode board 7 is electrically connected to the armor can 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a prismatic sealed battery, and more particularly to a prismatic sealed battery having a unique structure in a portion for electrically connecting an electrode plate to an outer can.

[0002]

2. Description of the Related Art A prismatic sealed battery incorporates a prismatic electrode body in which electrode plates are laminated. The electrode body is formed by laminating a positive electrode plate and a negative electrode plate with a separator interposed therebetween. The positive electrode plate and the negative electrode plate of the electrode body are connected to the positive electrode terminal and the outer can.

FIG. 7 shows the internal structure of a conventional prismatic sealed battery. In the prismatic sealed battery shown in this figure, a positive electrode current collecting tab 5 and a negative electrode current collecting tab 5A are connected to a positive electrode plate 2 and a negative electrode plate 1, respectively. The positive electrode current collecting tab 5 is welded and the electrode plate is connected to the positive electrode terminal. In addition, in the prismatic closed battery having this structure in which the negative electrode current collecting tab 5A is welded, the outermost negative electrode plate 1 is pressed against the inner surface of the outer can 6 for electrical connection. The negative electrode plate 1 disposed on the inner side is connected to the outer negative electrode plate 1 via the negative electrode current collecting tab 5A and is connected to the outer can 6 via the outer negative electrode plate 1.
Since the negative electrode current collecting tab 5A is not pressed and is electrically connected by welding, each electrode plate can be reliably electrically connected to the positive electrode terminal and the negative electrode current collecting tab 5A even if the number of electrode plates is large. There is.

However, the prismatic sealed battery having this structure has a complicated structure for connecting the negative electrode current collecting tabs 5A,
It has the drawback of poor productivity. It is necessary to have a structure in which all the negative electrode plates 1 are connected to the negative electrode current collecting tabs 5A, and moreover, the negative electrode current collecting tabs 5A of the negative electrode plate 1 are insulated from the positive electrode current collecting tabs 5 of the positive electrode plate 2 in the battery. This is because it is welded to the upper part. Further, in the prismatic sealed battery having this structure, it is difficult to widen the width of the positive electrode current collecting tab 5, so that the electric resistance of the negative electrode current collecting tab 5A is increased and it is difficult to reduce the internal resistance of the battery, and thus the large current discharge is performed. There is a drawback that the operating voltage drops when the

In order to improve the productivity of the battery having this structure, a prismatic sealed battery having the structure shown in FIG. 8 has been developed.
In the prismatic sealed battery shown in this figure, the positive electrode plate 2 is sandwiched between the connecting electrode plates 7 having a U-shaped cross section in which the two negative electrode plates 1 are connected by the connecting portion 7A which is the exposed portion of the core body. Connecting part 7 of electrode plate 7
A is pressed against and brought into contact with the inner bottom surface of the outer can 6, and the connecting portion 7
A and the outer can 6 are electrically connected, and at the same time, one negative electrode plate 1 forming the connecting electrode plate 7 located on the outermost side of the electrode body 4 is pressed against the inner surface of the outer can 6 to make contact with the outer can. Electric current is collected by making electrical contact with the can 6.

In the prismatic sealed battery having this structure, when the number of the negative electrode plates 1 increases, it becomes difficult to reliably electrically connect the connecting electrode plate 7 not located on the outermost side of the electrode body 4 to the outer can 6. The negative electrode plate 1 located on the outermost side is directly pressed by the outer can 6 and thus is reliably electrically connected to the outer can 6. Further, the negative electrode plate 1 connected to the outermost negative electrode plate 1 via the connecting portion 7A is also electrically connected to the outer can 6 via the outermost negative electrode plate 1. Therefore, the electrodes 4 arranged outside the electrode body 4
The sheet of negative electrode plate 1 is electrically connected to the outer can 6 via the connecting portion 7A without being electrically connected to the bottom surface of the outer can 6. However, as shown in FIG. 8, the electrode body 4 in which the six negative electrode plates 1 are laminated electrically connects the negative electrode plate 1 located at the center to the outer can 6 via the connecting portion 7A. Therefore, if the connecting portion 7A is separated from the outer can 6, it becomes impossible to collect current. When the battery is dropped, the electrode body 4 may be displaced upward in the outer can 6, and when collecting the electric power with the inner bottom surface of the outer can 6, it is surely electrically connected to the outer can with a low resistance. Difficult to do.

In order to solve this drawback, a prismatic sealed battery having the structure shown in FIG. 9 has been developed. In the prismatic sealed battery shown in this figure, the negative electrode plate 1 which is not located on the outermost side of the electrode body 4 is not formed as the U-shaped connecting electrode plate 7, but the core body exposed portion is extended from the end portion of the electrode plate and is led out. The lead portion 8A extends from the lower side of the electrode body 4 to the outer surface of the electrode body 4 and is sandwiched between the electrode body 4 and the inner side surface of the outer can 6 to electrically connect to the outer can 6. It is configured to connect.

In the prismatic sealed battery having this structure, when the number of negative electrode plates 1 increases, the number of lead-out portions 8A of the negative electrode plate 1 to be sandwiched between the inner surface of the outer can 6 and the electrode body 4 increases. However, a useless portion is increased between the inner surface of the outer can 6 and the electrode body 4. Further, there is an unfavorable drawback because the current collecting portion due to contact increases.

This drawback is as shown in FIG.
This can be solved by disposing the current collector 3 below the electrode and welding the lower end of the negative electrode plate 1 to this current collector. In the prismatic sealed battery having this structure, the outermost negative electrode plate 1 can be pressed against the inner surface of the outer can 6 for electrical connection. The negative electrode plate 1 disposed inside is connected to the outer negative electrode plate 1 via the current collector 3, and can be connected to the outer can 6 via the outer negative electrode plate 1.

In the prismatic sealed battery of this structure, in order to insert the electrode body 4 into the outer can 6, the size of the electrode body 4 must be smaller than the inner size of the outer can 6. However, as shown in FIG. 10, when the negative electrode plate 1 is welded to one current collector 3 on the bottom surface of the electrode body 4, the negative electrode plate 1
Is fixed to the current collector 3, the electrode body 4 cannot spread in the stacking direction of the electrode plates after the electrode body 4 is inserted into the outer can 6, and the outermost negative electrode of the electrode body 4 is not enough. The contact cannot be made with the contact pressure, and it becomes difficult to electrically connect the negative electrode plate 1 and the outer can 6 with low resistance.

The present invention was developed for the purpose of solving these drawbacks, and an important object of the present invention is to reduce the internal resistance of a battery with a simple structure and operate it at the time of discharging a large current. It is to provide a prismatic sealed battery capable of increasing the voltage.

[0012]

The prismatic closed battery of the present invention has the following constitution in order to achieve the above-mentioned object.
The prismatic sealed battery includes an electrode body 4 in which a plurality of positive electrode plates 2 and a negative electrode plate 1 are stacked with a separator interposed therebetween, and a metal outer can 6 that houses the electrode body 4.

The positive or negative polarity electrode plate group includes at least three connecting electrode plates 7 and a current collecting electrode plate 8.
The connecting electrode plate 7 connects the two electrode plates via the conductive connecting portion 7A, and is bent at the connecting portion 7A to have a cross section U.
It has a letter shape. The current collecting electrode plate 8 has a conductive lead portion 8A extending from the end of the electrode plate.

Two sets of the connecting electrode plates 7 of the connecting electrode plates 7 are arranged such that one electrode plate forming each of the connecting electrode plates 7 is located on the outermost side of the electrode body 4 and is in contact with the inner surface of the outer can 6. It collects electricity by doing. The lead-out portion 8A extending from the current collector electrode plate 8 is led out from the lower portion of the electrode body 4 to the outermost side of the electrode body 4, and is pressed and fixed between the electrode body 4 and the outer can 6 to be exteriorized. The lead portion 8A extending from the collecting electrode plate 8 is welded to the connecting portion 7A of the connecting electrode plate 7 located inside the electrode body 4 while being brought into contact with the can 6 to collect current.

[0015]

In the prismatic sealed battery of the present invention, as shown in FIG. 1 showing a preferred embodiment thereof, the lead-out portion 8A extending from the current collecting electrode plate 8 is provided from the lower part of the electrode body 4 to the uppermost part of the electrode body 4. It is introduced to the outside and pressed between the electrode body 4 and the outer can 6 to fix it to the outer can 6.
The connecting portion 7A of the connecting electrode plate 7 located inside the electrode body 4 is welded to the lead-out portion 8A of the collecting electrode plate 8 while being electrically connected to Connecting electrode plate 7
Is electrically connected to the outer can 6. The prismatic sealed battery having this structure can be electrically connected to the outer can 6 with a low resistance even if the number of electrode plates is large. This is because the connecting electrode plate 7 located inside the electrode body 4 is reliably electrically connected to the outer can 6 via the lead-out portion 8A of the collecting electrode plate 8. The prismatic closed battery that collects current with this structure is similar to the conventional prismatic closed battery shown in FIG. 9 even if the number of electrode plates is large.
It is not necessary to sandwich a plurality of lead-out portions 8A between the outer case 6 and the outer can 6 for electrical connection. Even if the number of laminated electrode plates increases, one lead-out portion 8A is sandwiched between the current collector 3 and the outer can 6 to electrically connect the inner electrode plate to the outer can 6. it can.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. However, the examples described below exemplify a prismatic sealed battery for embodying the technical idea of the present invention, and the present invention does not specify the prismatic sealed battery to the following.

Further, in this specification, in order to make it easy to understand the claims, the numbers corresponding to the members shown in the embodiments will be referred to as “claims”, “action”, and “action”. In the column of "Means for solving the problem". However, the members shown in the claims are
It is by no means specific to the members of the examples.

The prismatic sealed battery of the present invention can be applied to an alkaline storage battery which can be used as a battery such as a nickel-hydrogen battery or a nickel-cadmium battery. Hereinafter, the nickel-hydrogen battery will be described.

A prismatic sealed battery according to Example A of the present invention is manufactured by the following steps. (1) As shown in FIG. 2, three sets of connecting electrode plates 7 that connect two negative electrode plates 1 to each other, and as shown in FIG. Prepare one electrode plate 8. The connecting electrode plate 7 has a structure in which two negative electrode plates 1 are connected by a connecting portion 7A. This negative electrode plate 1 is obtained by coating both surfaces of a punching metal, which is a core, with a negative electrode active material containing a hydrogen storage alloy. The central portion of the core body is the connecting portion 7A without being coated with the negative electrode active material. For the negative electrode plate, foamed nickel filled with an active material can also be used. In this negative electrode plate, a portion which is not filled with the active material can be used as a connecting portion. The current collecting electrode plate 8 of FIG. 3 has a lead-out portion 8A provided at one end of the core body. The lead-out portion 8A is a portion to which the active material is not applied or filled in the core, similarly to the connecting portion 7A of the connecting electrode plate. Lead-out part 8A of the collector plate 8
Is designed to have a length such that the end can be sandwiched between the side surface of the electrode body 4 and the outer can 6.

A hydrogen storage alloy is used as the negative electrode active material coated on the core. The hydrogen storage alloy of the negative electrode plate 1 has the following composition formula. MmNi _3.4 Co _0.8 Al _0.2 Mn _0.6, however, Mm is the misch shows a metal (a mixture of rare earth metals).

(2) Positive electrode plate 2 made of non-sintered nickel
Is coated with a separator to manufacture six positive electrode plates 2. (3) A positive electrode plate 2 and a negative electrode plate 1 coated with a separator are laminated to form a prismatic electrode body 4. Since the electrode body 4 is formed by laminating the six positive electrode plates 2 and the seven negative electrode plates 1, the negative electrode plates 1 are located on the outermost sides on both sides as shown in FIG. FIG.
In, in order to make the negative electrode plate 1 easy to understand, the signs of are attached in order from left to right. The outermost negative electrode plate is connected to the negative electrode plate disposed inside the negative electrode plate via the connecting portion 7A. 3 arranged in the middle
The negative electrode plates, and the negative electrode plate are used as the connecting electrode plate 7, and the negative electrode plate 1 is used as the current collecting electrode plate 8.

(4) The connecting portion 7A for connecting with the negative electrode plate which is the connecting electrode plate 7 located inside the electrode body 4 is welded to the lead-out portion 8A of the negative electrode plate 1 which is the current collecting electrode plate 8. ing. The lead-out portion 8A connected to the negative electrode plate 1 is bent from the bottom surface of the electrode body 4 along the side surface of the electrode body 4,
It is sandwiched between the electrode body 4 and the outer can 6 to electrically connect the lead portion 8A to the outer can 6.

(5) The electrode body 4 is inserted into the outer can 6, the electrolytic solution is poured into the outer can 6, and then the positive electrode plate 2 is welded to the positive terminal of the sealing member (not shown). The electrolyte to be injected is an aqueous potassium hydroxide solution having a specific gravity of 1.3. After that, the sealing body is welded to the upper edge of the outer can 6 to close the opening of the outer can 6.

As described above, the theoretical capacity is 1000 m.
A rectangular sealed battery of Example A designated Ah was manufactured. In order to clarify how the prismatic sealed batteries of the examples of the present invention exhibit excellent characteristics as compared with conventional ones, the following comparative example B,
C and D prismatic sealed batteries were prototyped. These comparative examples B,
The rectangular sealed batteries C and D have the same structure as in Example A, except that the positive electrode plate, the negative electrode plate, the electrolytic solution, and the theoretical capacity are the same, and the electrode body is connected to the outer can as shown in FIGS. 7, 9, and 10. Are doing

A prismatic sealed battery of Comparative Example B having the structure shown in FIG. 7 is manufactured as follows. (1) Using the same positive electrode plate 2 and negative electrode plate 1 as in Example A,
The positive electrode plate 2 and the negative electrode plate 1 to be laminated are connected to the positive electrode current collecting tab 5 and the negative electrode current collecting tab 5A, respectively, to manufacture the electrode body 4. (2) Insert the electrode body 4 into the outer can 6 and inject the electrolytic solution. (3) After that, an insulating spacer (not shown) is arranged so that the current collecting tab 5 of the negative electrode plate 1 does not contact the positive electrode plate 2 and the sealing body (not shown). After welding 5 to the positive electrode terminal of the sealing body, the sealing body is welded to the outer can 6 to close the outer can 6 to obtain a prismatic sealed battery of Comparative Example B.

A prismatic sealed battery of Comparative Example C having the structure shown in FIG. 9 is manufactured as follows. (1) Two sets of the negative electrode plates 1 (four negative electrode plates 1) of the connecting electrode plate 7 having the structure shown in FIG. 2 and three negative electrode plates 1 which are the collecting electrode plates 8 having the structure shown in FIG. Make one. The negative electrode plate 1 of FIG.
Has a structure in which two negative electrode plates 1 are connected by a connecting portion 7A. This negative electrode plate 1 is obtained by coating both surfaces of a core with a negative electrode active material containing a hydrogen storage alloy. The central portion of the core body is not coated with the negative electrode active material, and the connecting portion 7A is provided.
And The negative electrode plate 1 of FIG. 3 has a lead-out portion 8 at one end of the core body.
A is provided.

(2) The positive electrode plate 2 and the negative electrode plate 1 which are covered with the separator are laminated to form an electrode body 4. In the electrode body 4, the U-bent connection electrode plate 7 is located outside the electrode body 4, and the current collecting electrode plate 8 is located in the central portion of the electrode body 4. The lead-out portion 8A of the current collecting electrode plate 8 is bent to have a shape extending from the bottom surface to the side surface of the electrode body 4.

(3) Insert the electrode body 4 into the outer can 6, inject the electrolytic solution, connect the positive electrode plate 2 to the positive terminal of the sealing body, and weld the sealing body (not shown) to the outer can 6. A rectangular sealed battery of Comparative Example C is obtained.

A rectangular sealed battery of Comparative Example D having the structure shown in FIG. 10 was manufactured in the same manner as in Example A except for the current collecting portion of the negative electrode plate. In this prismatic sealed battery, the lower end of the negative electrode plate 1 is welded to the current collector 3, the negative electrode plate 1 disposed inside is connected to the outer negative electrode through the current collector 3, and the outer negative electrode plate 1 is Exterior can 6
To be electrically connected to the outer can 6.

When the operating voltage of the prismatic sealed battery manufactured as described above was measured, the one of Example A of the present invention showed extremely excellent characteristics as compared with those of Comparative Examples B, C and D. . The operating voltage was measured under the following conditions. (1) Charge the battery for 16 hours at a charging current of 100 mA. (2) Stop charging and leave for 1 hour. (3) Discharge with a discharge current of 4000 mA. Discharge is stopped when the voltage of the prismatic sealed battery reaches 1.0V. (4) Measure the voltage at the center of the time from the start of discharge to the end of discharge as the operating voltage.

The operating voltage of the prismatic closed battery charged and discharged as described above is shown in Table 1 and FIG.

[0032]

[Table 1]

In the prismatic sealed battery of the present invention, when the electrode body 4 is inserted into the outer can 6, the electrode body 4 is pressed and compressed in the laminating direction of the electrode plates and the thickness in the laminating direction is set to the thickness of the outer can 6. Insert smaller than the inner size. For this reason, after the electrode body 4 is inserted into the outer can 6, a force that spreads in the stacking direction acts on the electrode body 4, and the electrode body 4 comes into pressure contact with the inner surface of the outer can 6. In the prismatic battery of the present invention, the negative electrode plate,
Is in a state in which the lead-out portion 8A of the negative electrode plate is slightly deformable, although the lead-out portion 8A led out of the negative electrode plate which is the current collecting electrode plate 8 is in contact with the outer can 6. Further, the negative electrode plate 1, which is the connecting electrode plate 7 positioned outside the electrode body 4, is not fixed and is in a free state. Therefore, after the electrode body 4 is housed in the outer can 6, the electrode body 4 spreads in the stacking direction, and the electrode body 4 and the inner surface of the outer can 6 contact with each other with a contact pressure sufficient to collect current. It becomes possible.

As described above, the prismatic closed battery of the present invention capable of electrically connecting the negative electrode plate 1 to the outer can 6 is as shown in the table and FIG. The operating voltage can be made higher than that of In the prismatic sealed battery of the present invention, even if the number of negative electrode plates 1 inside the electrode body 4 that cannot be connected to the outermost negative electrode plate 1 via the connecting portion 7A increases,
Unlike the prismatic sealed battery shown in FIG. 9, it is not necessary to stack a large number of current collectors 3 and sandwich them between the electrode body 4 and the outer can 6. In the prismatic sealed battery of the present invention shown in FIG. 1, one current collector 3 is sandwiched between the side surface of the electrode body 4 and the inner surface of the outer can 6 and disposed inside the electrode body 4. Three negative electrode plates 1 are connected to an outer can 6. This structure is characterized in that the current collector 3 disposed between the side surface of the electrode body 4 and the outer can 6 is brought into close contact with the inner surface of the outer can 6 in an ideal state to reduce the contact resistance.

On the other hand, in the prismatic sealed battery of Comparative Example B shown in FIG. 7, the negative electrode current collecting tab 5 for connecting the electrode plate to the outer can 6 is used.
Since there is no choice but to narrow the width of A, the internal resistance increases and the operating voltage decreases. Further, in the prismatic sealed battery having this structure, it is necessary to weld the negative electrode current collecting tabs 5A to all the negative electrode plates 1, and further, the current collecting tabs 5 of the positive electrode plate 2 and the negative electrode plate 1 are insulated. Since it is necessary, the structure becomes complicated.

The prismatic sealed battery of Comparative Example C shown in FIG. 9 does not require welding, but the lead-out portion 8 is provided between the electrode body 4 and the outer can 6.
Since A is stacked in multiple layers, there are many portions that are electrically connected by contact, it is difficult to electrically connect to the outer can 6 in an ideal state, the contact resistance increases, and the operating voltage decreases.

Further, in the prismatic sealed battery of Example D shown in FIG. 10, since all of the negative electrode plate 1 is fixed to the flat plate-shaped current collector 3 by welding, the lower part of the electrode body 4 is Even after inserting 4 into the outer can 6, it cannot spread in the stacking direction of the electrode body 4, and the negative electrode plate 1 located on the outermost side of the electrode body 4 and the inner surface of the outer can 6 collect electricity. Cannot be contacted with a sufficient contact pressure. Therefore, the outermost negative electrode plate 1 cannot be electrically connected to the outer can 6 in a low resistance state,
The resistance of this portion increases and the operating voltage of the battery decreases.

The prismatic sealed battery according to the above-described embodiment has the outer can 6
The negative electrode plate 1 is connected to. However, the prismatic sealed battery of the present invention is not necessarily specified as a battery in which the negative electrode plate is connected to the outer can. Although not shown, the positive electrode plate may be connected to the outer can and the negative electrode plate may be connected to the negative electrode terminal via the current collecting tab.

Furthermore, in the prismatic sealed battery of the above embodiment, the electrode body is composed of the six positive electrode plates and the seven negative electrode plates. In the present invention, the structure of the prismatic sealed battery is changed to this structure. Not specified. For example, as shown in FIG. 5, two current collecting electrode plates 8 and two sets of connecting electrode plates 7 are disposed inside the electrode body 4, and one lead portion 8A of the current collecting electrode plate 8 is provided. Connecting part 7 of connecting plate 7
The lead-out portions 8A may be arranged on both sides of the electrode body 4 by welding to A. Further, as shown in FIG. 6, it is also possible to dispose two current collecting electrode plates 8 inside the electrode body 4 and connect the lead-out portions 8A of the respective current collecting electrode plates 8 by welding. . Furthermore, the present invention is not limited to a nickel-hydrogen battery for a prismatic sealed battery, but can be used for all batteries in which a positive electrode plate and a negative electrode plate are laminated via a separator and inserted into a rectangular outer can.

[0040]

The prismatic sealed battery of the present invention is characterized in that the structure for connecting the electrode plate to the outer can is simplified and the internal resistance of the battery can be reduced to increase the operating voltage during large current discharge. . In the prismatic sealed battery of the present invention, the connecting portion of the connecting electrode plate disposed inside the electrode body is welded to the lead-out portion of the collecting electrode plate sandwiched between the electrode body and the outer can. Then, the current collecting electrode plate and the connecting electrode plate inside the electrode body are electrically connected to the outer can. In the prismatic sealed battery having this structure, even if the number of collecting electrode plates and connecting electrode plates arranged inside the electrode body increases, one lead-out portion is sandwiched between the electrode body and the outer can. The feature is that you can wear it and connect it to the outer can securely. 1
A rectangular sealed battery in which the lead-out part of the sheet is sandwiched between the electrode body and the outer can and the electrode group inside the electrode body is electrically connected to the outer can has a low resistance for all electrode groups. It can be electrically connected to the outer can in any state. This is because one lead portion can be surely electrically connected to the outer can, and the electrode plate disposed on the outermost side of the electrode body can be brought into close contact with the inner surface of the outer can in an extremely large area.

As shown in FIG. 9, in a conventional prismatic sealed battery in which a plurality of lead-out portions are sandwiched in a laminated state between an electrode body and an outer can to collect current, all lead-out portions have a large area. The lead-out portion cannot be electrically connected to the outer can while contacting the inner surface of the outer can with low resistance. In addition, since a plurality of lead-out portions are laminated and sandwiched between the electrode body and the outer can, the gap between the electrode body and the outer can becomes wide, and the entire outermost electrode plate becomes the inner surface of the outer can. You will not be able to adhere to each other. Therefore, it is difficult to electrically connect the lead-out portion and the outermost electrode plate to the outer can with low resistance.

On the other hand, the prismatic sealed battery of the present invention is
By sandwiching one lead-out portion between the electrode body and the outer can, the current collecting electrode plate and the connecting electrode plate disposed inside the electrode body can be securely electrically connected to the outer can in a low resistance state. Connecting. Furthermore, since one lead-out portion, which is a thin metal plate, is sandwiched between the electrode body and the outer can, this does not widen the gap between the electrode body and the outer can. With a very large area, almost the entire surface is in close contact with the inner surface of the outer can and is electrically connected to the outer can with a low resistance.

Therefore, the prismatic sealed battery of the present invention has an excellent feature that all the electrode plate groups can be electrically connected to the outer can in a low resistance state and the operating voltage at the time of large current discharge can be increased. .

[Brief description of drawings]

FIG. 1 is a sectional view of a prismatic sealed battery according to an embodiment of the present invention.

FIG. 2 is a plan view showing a negative electrode plate of a connecting electrode plate used for a prismatic sealed battery.

FIG. 3 is a plan view showing a negative electrode plate of a current collecting electrode plate used for a prismatic sealed battery.

FIG. 4 is a graph showing high rate discharge characteristics of a prismatic sealed battery according to an embodiment of the present invention and a conventional prismatic sealed battery.

FIG. 5 is a sectional view of a prismatic sealed battery according to another embodiment of the present invention.

FIG. 6 is a sectional view of a prismatic sealed battery according to another embodiment of the present invention.

FIG. 7 is a cross-sectional view showing the internal structure of a conventional prismatic sealed battery.

FIG. 8 is a cross-sectional view showing the internal structure of a conventional prismatic sealed battery.

FIG. 9 is a cross-sectional view showing the internal structure of a conventional prismatic sealed battery.

FIG. 10 is a cross-sectional view showing the internal structure of a conventional prismatic sealed battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Negative electrode plate 2 ... Positive electrode plate 3 ... Current collector 4 ... Electrode body 5 ... Positive electrode current collection tab 5A ... Negative electrode current collection tab 6 ... Outer can 7 ... Connection electrode plate 7A ... Connection part 8 ... Current collection electrode plate 8A … Derivation part

Claims (1)

[Claims] 1. An electrode body (4) in which a plurality of positive electrode plates (2) and negative electrode plates (1) are laminated with a separator interposed therebetween, and the electrode body (4).
In a prismatic sealed battery provided with a metal outer can (6) for housing a positive or negative polarity electrode plate group, two electrode plates are connected via a conductive connecting portion (7A). And the connection part (7A)
From at least three sets of connecting electrode plates (7) having a U-shaped cross section and a current collecting electrode plate (8) in which a conductive lead portion (8A) extends from the end of the electrode plate. Two sets of the connecting electrode plates (7) of the connecting electrode plates (7) are arranged such that one electrode plate forming each of the connecting electrode plates (7) is located on the outermost side of the electrode body (4). Electric current is collected by contacting the inner surface of the outer can (6), and the lead-out portion (8A) extending from the current collecting electrode plate (8) extends from the lower part of the electrode body (4) to the electrode body (4). ) Is brought out to the outermost side and is pressed and fixed between the electrode body (4) and the outer can (6) to come into contact with the outer can (6) to collect current, and the current collecting electrode plate
The lead-out portion (8A) extending from (8) is welded to the connecting portion (7A) of the connecting electrode plate (7) located inside the electrode body (4), which is a sealed prismatic battery.