JPH09213299A - Current collecting structure of storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the breaking of electrode plates without reducing the capacity of a storage battery, by providing more than three of connecting surfaces with the electrode plates, to the side surface of a collector terminal, and reducing the distance with the connecting surfaces. SOLUTION: To the collecter terminal 1 of a storage battery, plural welding surfaces 11 to 14 in order to connect the leads of plural electrode plates 2a to 2h are provided. To each welding surface, two sheets of electrode plates are connected respectively. The welding surfaces 11 to 14 are provided at the different positions each other in the laminating direction of the electrodes (X- direction). And in the direction (Y-direction) orthogonal to the electrode plates laminating direction, the welding surfaces 11 and 12, and the welding surfaces 13 and 14, are provided at the different positions each other. The elctrode plates are welded to the welding surfaces by bundling the projections of the leads of two sheets of electrode plates. The electrode plates 2a to 2h can be connected either one of the welding surfaces 11 to 14 at the positions close to the electrode plates, and the distance in the X-direction between each electrode plate and the welding surface corresponding to the electrode plate can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current collecting structure for a storage battery, and more particularly to a structure for connecting a plurality of electrode plates to a current collecting terminal in the storage battery.

[0002]

2. Description of the Related Art Storage batteries (secondary batteries) that can be repeatedly used by charging are widely used in various fields. Recently, not only small storage batteries used for mobile terminals and audio equipment, but also large storage batteries such as batteries for electric vehicles are increasing in demand.

As a general large-sized storage battery, a plurality of positive electrode plates and a plurality of negative electrode plates are alternately superposed and connected in parallel, and these electrode plates are immersed in an electrolytic solution. It has been known.

FIG. 6 is a diagram showing the internal structure of a general large-sized storage battery. Each positive electrode plate includes a reaction section 101 and a lead section 102. Similarly, each negative electrode plate is composed of a reaction section 103 and a lead section 104. The reaction part 101 and the lead part 102 and the reaction part 103 and the lead part 104 are electrically connected by welding. The battery case 105 is a container of a storage battery, and the electrolytic solution is contained therein.

The electrode plate for the positive electrode and the electrode plate for the negative electrode are assembled so that the reaction parts 101 and 103 are alternately overlapped with each other. Although omitted in FIG. 6, a separator is actually provided between the reaction unit 101 and the reaction unit 103 so that they are not in electrical contact with each other. The electrode plate for the positive electrode and the electrode plate for the negative electrode are arranged in the battery case 105 in a state of being combined so as to overlap with each other, and the reaction section 101 and the reaction section 103 are immersed in the electrolytic solution.

Electrons generated by the reaction of the reaction part 103 with the electrolytic solution are conducted to the negative electrode current collecting terminal through the lead part 104 and then supplied to the outside. Electrons flowing from the outside are conducted to the reaction section 101 via the positive electrode current collector terminal and the lead section 102, where they react with the electrolytic solution and are absorbed. The current collecting terminal is a battery terminal for taking out electric power from this storage battery.

FIG. 7 is a diagram showing an example of a connection structure between the electrode plate and the collector terminal. Although the positive electrode is shown in FIG. 7, the configuration on the negative electrode side is also the same. In the configuration shown in FIG. 7, the collector terminal 106 has a slit for accommodating the lead portion 102 of each electrode plate. When assembling the storage battery, the tip portion (protrusion) of the lead portion 102 of each electrode plate is fitted into the slit of the current collector terminal 106, and in that state, the lead portion 102 of each electrode plate and the current collector terminal 106 are welded. And connect them electrically.

In the above work, in order to securely connect the lead portion 102 to the inside of the slit, it is necessary to weld with a large amount of input energy. Because welding is essentially
The objects to be welded are melted by applying heat energy in a state where they are surely brought into contact with each other. However, if the tips of the lead portions 102 are simply fitted into the slits shown in FIG. ) Is not obtained enough contact, because it requires a lot of thermal energy to forcefully melt in this state. However, since the heat at the time of welding is conducted to the reaction part 101 via the lead part 102, if the temperature of the welding part is made too high, the characteristics of the reaction part 101 are adversely affected, or the reaction part 1
01 and the reaction part 103 may damage the separator. In order to prevent the reaction part 101 from becoming hot during welding, a method of spot welding each lead part 102 to the inside of the slit can be considered.

However, the electric connection may not be sufficient in spot welding. As a result, the bonding area between the lead portion 102 and the current collecting terminal 106 is different for each electrode plate, and a resistance difference is generated, resulting in large variations in characteristics, which may result in unstable performance as a storage battery. If the resistance varies with the electrode plate, a large amount of charge flows to the electrode plate having a low resistance during charging, etc., and the frequency of use of the electrode plate increases, so that the deterioration of a specific electrode plate is accelerated.

As described above, in the structure shown in FIG. 7, it is difficult to reliably connect the electrode plate and the collector terminal. FIG. 8 is a diagram showing an example of a configuration that solves the above problem. In the configuration shown in FIG. 8, a welding surface is provided on a side portion of the collector terminal in order to facilitate welding, and the lead portion of the electrode plate is connected to the welding surface. That is, the electrode plates 107a and 10
The lead portion 7b is welded to the welding surface 109 of the collector terminal 108, and the lead portions of the electrode plates 107c and 107d are welded to the welding surface provided on the opposite side of the connection surface 109.

With such a structure, the electrode plate 107a
Since the fixing (positioning) of ~ 107d and the current collecting terminal 108 is simple and welding can be performed with a relatively small input energy, they can be reliably connected without raising the temperature so much.

[0012]

FIG. 9 is a cross-sectional view of the storage battery having the configuration shown in FIG. 8 as seen from the top, side, and front, in which only the battery case is cut.

The storage battery shown in FIG. 9 has a structure in which eight positive electrode plates and eight negative electrode plates are provided. The side sectional view shown on the right side of the figure shows the electrode plate for the positive electrode and the current collecting terminal. The configuration of the positive electrode side of the storage battery will be described below, but the configuration of the negative electrode side is also the same.

The two welding surfaces 109 provided on the side surfaces of the collector terminal 108 are respectively provided on the lead portions 102 of the four electrode plates.
Are bundled and welded. At this time, attach each electrode plate to the battery case 1
In order to connect the tip of the lead portion 102 to the welding surface 109 while arranging it at a predetermined position in 05, the lead portion 102 needs to be bent appropriately with respect to the reaction portion 101. In other words, while the respective electrode plates are arranged at the predetermined positions in the battery case 105, the leading end of the lead portion 102 is welded to the welding surface 10.
The lead portion 102 is appropriately bent with respect to the reaction portion 101 so as to be connected to the connector 9.

However, the welding surface 109 of the collector terminal 108
In the electrode plate located at a position away from in the X direction, the bending angle of the lead portion 102 with respect to the reaction portion 101 becomes large. That is, as shown in FIG. 10, the electrode plate arranged in the vicinity of the battery case 105 has the lead portion 10 with respect to the reaction portion 101.
The bending angle θ of 2 becomes considerably large. In particular, in the case of high capacity type batteries that meet the needs of electric vehicles and the like, the number of electrode plates to be laminated increases and the bending angle becomes even larger.

When a nickel-hydrogen battery is assumed as the storage battery, as the battery is charged and discharged, atomization of the active material adhering to the reaction part 101 of each electrode plate progresses and the reaction part 101 becomes Expands. Reaction part 1 of each electrode plate
When 01 expands, a force acts in a direction in which the distance between the electrode plates expands, so that the electrode plate near the battery case 105 further increases the distance in the X direction from the welding surface 109, and the bending angle accordingly. As θ further increases, tension is applied to the lead portion 102.

As described above, when the bending angle θ increases and the tension is applied to the lead portion 102, a crack is generated in the joint portion between the reaction portion 101 and the lead portion 102.
In order to prevent the above-mentioned damage of the joint portion, the height of the lead portion 102 of each electrode plate may be increased. That is,
If the height of the lead portion 102 is increased, the lead portion 102
Since the bending angle of the lead portion 102 when connecting the lead portion 102 to the welding surface 109 becomes gentle, the reaction portion 101 and the lead portion 1
The load applied to the joint portion with 02 becomes small, and damage to that portion can be prevented.

However, since the shape of the storage battery is usually defined as a standard, if the height of the lead portion 102 is increased, the height of the reaction portion 101 is correspondingly reduced. If the reaction section 101 becomes smaller, the area in which a chemical reaction occurs during charging / discharging inevitably becomes smaller, and the capacity of the storage battery becomes smaller.

X from the welding surface 109 to each electrode plate
Since the distance in the direction differs for each electrode plate, it is necessary to lengthen the lead portion 102 as the distance in the X direction from the welding surface 109 increases. Therefore, the lead portion 1 is previously prepared for each electrode plate.
It was necessary to change the length of 02 before processing. Alternatively, when the lead portions 102 of each electrode plate have the same shape as each other, if they are connected to the welding surface 109, the tips of the lead portions of the electrode plate near the welding surface 109 will have the welding surface 1
09, since it projects from the tip of the lead part of the electrode plate far away from 09, a step of cutting the tip of the lead part after welding is required.

As described above, the conventional storage battery has a problem that the capacity of the storage battery becomes small in order to prevent the electrode plate from being damaged. An object of the present invention is to prevent damage to the electrode plate without reducing the capacity of the storage battery.

[0021]

The storage battery of the present invention is premised on a structure in which each lead portion of a plurality of electrode plates is connected to a collector terminal.

At least three connecting surfaces for connecting the lead portions of the electrode plate are provided on the side surfaces of the collector terminal. Then, the lead portion of at least one electrode plate is connected to each of the connection surfaces.

In another aspect, the plurality of electrode plates are divided into at least three groups. Then, the lead portions of the electrode plates are bundled for each group, and the bundled lead portions are respectively connected to the side portions of the current collecting terminal.

In any of the above configurations, there are three or more connecting points between the plurality of electrode plates and the current collecting terminals. Therefore, when a large number of electrode plates are respectively provided at predetermined positions in the container of the storage battery, each electrode plate can be connected to the collector terminal at a position close to the electrode plate. Therefore, it is not necessary to forcibly bend the lead portion in order to connect the lead portion of each electrode plate to the collector terminal, and the electrode plate is not damaged.

Since the lead portion of each electrode plate is connected to the side surface of the current collecting terminal, the connecting process is easy and each electrode plate and the current collecting terminal can be reliably connected. The at least three connecting surfaces may be provided at different positions in the direction in which the plurality of electrode plates are stacked. With such a configuration, since the connection surface of the collector terminal is located near each electrode plate, it is not necessary to forcibly bend the lead portion of each electrode plate when connecting the lead portion to the collector terminal.

The at least three connecting surfaces may be provided at least at two or more locations in the direction orthogonal to the direction in which the plurality of electrode plates are laminated. With such a configuration, since a large number of connecting surfaces can be provided on the current collecting terminal, even in a storage battery having a large number of electrode plates, it is possible to position the connecting surfaces near each electrode plate. .

[0027]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing the internal structure of the storage battery of the present invention, and is a cross-sectional view of the storage battery as seen from the top, side, and front. Also, FIG.
Similar to the configuration shown in FIG. 9, the storage battery shown in FIG. 8 has a configuration in which eight positive electrode plates and eight negative electrode plates are provided. Further, the side sectional view shown on the right side of the figure shows the electrode plate for the positive electrode and the current collecting terminal. The configuration of the positive electrode side of the storage battery will be described below, but the configuration of the negative electrode side is also the same.

The collector terminal 1 of this embodiment has four welding surfaces for welding the lead portions of the electrode plate 2. That is, the current collector terminal 1 has welding surfaces 11 to 14 (corresponding to the connection surfaces described in claims 1 to 5) on its side surface. Then, two electrode plates 2 are connected to each welding surface.

The welding surfaces 11 to 14 are provided at positions different from each other in the direction in which the electrode plates 2 are laminated (X direction). Further, in the direction (Y direction) orthogonal to the direction in which the electrode plates 2 are stacked, the welding surfaces 11 and 12 and the welding surface 13
And 14 are provided at different positions.

FIG. 2 is an oblique view for explaining the structure of the connecting portion between the collector terminal 1 and the electrode plate 2. The current collecting terminal 1 has a configuration in which eight electrode plates are connected, but here, only four electrode plates 2a to 2d are shown to make the drawing easy to see.

As shown in FIG. 2, the welding surface 11 is connected to the electrode plates 2a and 2b, and the welding surface 13 is connected to the electrode plates 2c and 2d. When connecting the electrode plates 2a and 2b to the collector terminal 1, the electrode plates 2a and 2b
The protrusions of the lead portion are bundled and welded to the welding surface 11. The same applies to the electrode plates 2c and 2d.

FIG. 3 is an enlarged view of the side sectional view shown on the right side of FIG. As shown in the figure, eight electrode plates 2a to
Two pieces of 2h are connected to the welding surfaces 11 to 14.
As described above, since the four welding surfaces 11 to 14 are provided on the collector terminal 1, each electrode plate 2a to 2h can be connected to any of the welding surfaces 11 to 14 at a position close to the electrode plate. . This reduces the distance in the X direction between each electrode plate and the welding surface corresponding to the electrode plate.

As described above, the current collecting terminal 1 of this embodiment is
Welding surfaces 11 to 14 in the X direction (direction in which electrode plates are stacked)
Since the electrodes are provided at different positions in
The connection surface of the collector terminal is located in the vicinity of ~ 2h. Therefore, when connecting the lead portion 102 of each of the electrode plates 2a to 2h to the current collecting terminal, it is not necessary to forcibly bend the lead portion 102 with respect to the reaction portion 101.

Next, the configuration of this embodiment will be compared with the conventional configuration shown in FIG. In the conventional configuration, as shown in FIG. 10, for example, the distance in the X direction from the electrode plate arranged near the battery case 105 to the welding surface 109 was large.
Therefore, when connecting the lead portion of the electrode plate to the collector terminal 108, the bending angle θ of the lead portion with respect to the reaction portion 101 is set to a certain angle in order to prevent damage to the joint portion between the reaction portion 101 and the lead portion 102. If the condition is set to be smaller than that, the height of the lead portion 102 must be increased.

On the other hand, in the configuration of this embodiment shown in FIGS. 1 to 3, the distance in the X direction between each electrode plate and the welding surface corresponding to the electrode plate is small. Therefore, even if the height of the lead portion 102 of each electrode plate is reduced, the bending angle θ of the lead portion 102 with respect to the reaction portion 101 of each electrode plate is increased.
Can be smaller than the angle at which a load that damages the joint between the reaction portion 101 and the lead portion 102 is generated. That is, even if the height of the lead portion 102 of each electrode plate is reduced, an excessive load is not applied to the joint portion between the reaction portion 101 and the lead portion 102, and the joint portion is not damaged. Further, since the shape of the storage battery is usually defined as a standard, if the height of the lead portion 102 can be reduced,
The height of the reaction part 101 is correspondingly increased. As a result, the area in which a chemical reaction occurs during charging / discharging becomes large, and the capacity of the storage battery becomes large.

The superiority of this embodiment in the above comparison is
The same applies when a nickel-hydrogen battery is assumed as the storage battery. That is, in the case of a nickel-hydrogen storage battery, by repeating charge and discharge (especially at the time of charging), the reaction part 101 of each electrode plate expands, and the electrode plate (for example, the electrode plate 2d) arranged outside is Further, although it moves so as to approach the battery case 105, even if such a movement is made, the distance in the X direction between the electrode plate 2d and the welding surface 13 does not become so large. Therefore, the bending angle θ of the lead portion 102 with respect to the reaction portion 101 does not become so large, and
Since the tension applied to the lead portion 102 is not large, a load that damages the joint between the reaction portion 101 and the lead portion 102 does not occur.

Further, in this embodiment, since the welding surface can be provided in the vicinity of each electrode plate by increasing the number of welding surfaces with respect to the number of electrode plates, the welding corresponding to each electrode plate is performed. The variation in the distance to the surface in the X direction is small. Therefore, even if the lead portions of each electrode plate have the same length, the tips of the lead portions of a particular electrode plate do not project when they are welded to the welding surface. Therefore, unlike the prior art, the step of previously changing the length of the lead portion for each electrode plate or cutting the tip of the lead portion after welding is unnecessary. This effect becomes more remarkable as the number of electrode plates to be stacked increases.

Both the configuration of the present embodiment shown in FIGS. 1 to 3 and the conventional configuration shown in FIGS. 9 and 10 are configurations in which eight positive electrode plates and eight negative electrode plates are provided. In the conventional configuration, the lead portions of four electrode plates are welded for each welding surface, whereas in the configuration of the present embodiment, the lead portions of two electrode plates are welded for each welding surface. . As described above, in the present embodiment, since the number of electrode plates to be welded on one welding surface is small, the input energy required for welding at one place can be small. For example, in the case of laser welding the electrode plate and the current collector terminal, the configuration of the present embodiment enables good welding with a small laser emission power.

In the above embodiment, the current collecting terminal has the structure having four welding surfaces 11 to 14, but the present invention is not limited to this structure, and the welding has three or more current collecting terminals. Applies to configurations with faces. FIG. 4 is a diagram showing a configuration in which the current collecting terminal has six welding surfaces. In FIG.
Welding surface (corresponding to the connection surface described in claims 1 to 5) 2
1 to 23 are drawn, welding surfaces 24 to 26 are provided at positions symmetrical to the welding surfaces 21 to 23. This current collecting terminal is, for example, one positive electrode plate and one negative electrode plate.
If it is applied to a storage battery that has two batteries, each welding surface 2
Two electrode plates are welded to each of the plates 1 to 26.

The number of electrode plates to be welded to each welding surface does not have to be the same. For example, three electrodes may be provided for one welding surface and two electrodes may be provided for another welding surface. Further, the number of electrode plates is not limited to that in the embodiment, and the number of electrode plates is 3
Other numbers may be used as long as the number is one or more.

Further, the shape of the current collecting terminal is not limited to that of the embodiment, and may be another shape. For example, Figure 5 (a)
Also, the shape shown in FIG. Further, in the above embodiment, the configuration in which each electrode plate and the current collecting terminal are welded has been shown, but the present invention is not limited to this configuration, and each electrode plate and the current collecting terminal are electrically connected. The configuration can be applied to other forms. For example, in FIG. 3, the lead portions of the two electrode plates may be collectively bundled and screwed to the current collecting terminal.

[0042]

In the storage battery of the present invention, since the side surface of the collector terminal is provided with three or more connection surfaces with each electrode plate, the distance between each electrode plate and the connection surface corresponding to the electrode plate is reduced. Is small. Therefore, even if the height of the lead portion of each electrode plate is reduced, the bending angle of the lead portion with respect to the reaction portion of each electrode plate is small, and an excessive load is not applied to the joint portion between the reaction portion and the lead portion. Since it does not exist, the part will not be damaged. Further, if the height of the lead portion can be reduced, the height of the reaction portion is correspondingly increased, which increases the area in which a chemical reaction occurs during charge and discharge, thereby increasing the capacity of the storage battery.

[Brief description of drawings]

FIG. 1 is a diagram showing an internal structure of a storage battery of the present embodiment, and is a cross-sectional view seen from a top surface, a side surface, and a front surface.

FIG. 2 is an oblique view for explaining a configuration of a connecting portion between a current collecting terminal and an electrode plate.

FIG. 3 is an enlarged view of a side sectional view of FIG.

FIG. 4 is a diagram showing a configuration of a current collector terminal having six welding surfaces.

FIG. 5 is a diagram showing an example of another shape of a current collecting terminal.

FIG. 6 is a diagram showing an internal configuration of a general large-sized storage battery.

FIG. 7 is a diagram showing an example of a connection structure between an electrode plate and a collector terminal.

8 is a diagram showing a configuration example for solving the problem of the configuration of FIG.

9 is a cross-sectional view of the storage battery having the configuration shown in FIG. 8 as seen from the top, side, and front.

FIG. 10 is an enlarged view of the side sectional view of FIG. 9.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Current collector terminal 2 (2a-2h) Electrode plate 11-14 Welding surface 21-26 Welding surface 105 Battery case 101, 103 Reaction part 102, 104 Lead part

Claims (5)

[Claims] 1. A storage battery having a structure in which each lead portion of a plurality of electrode plates is connected to a current collecting terminal, wherein the current collecting terminal has at least three connecting surfaces on its side surface for connecting the lead portions of the electrode plate. A storage battery current collecting structure characterized in that at least one lead portion of the electrode plate is connected to each of the connection surfaces. 2. The current collecting structure for a storage battery according to claim 1, wherein the at least three connection surfaces are provided at different positions in a direction in which the plurality of electrode plates are stacked. 3. The at least three connecting surfaces are provided at least at two or more locations in a direction orthogonal to a direction in which the plurality of electrode plates are stacked.
The storage structure of the storage battery described in. 4. The lead parts of the plurality of electrode plates are connected to one of the at least three connection faces which is closest to the electrode plate.
3. The current collecting structure for the storage battery according to any one of 3. 5. A storage battery having a configuration in which each lead portion of a plurality of electrode plates is connected to a collector terminal, wherein the plurality of electrode plates are divided into at least three groups,
A current collecting structure for a storage battery, characterized in that the lead portions of the electrode plates are bundled for each group and connected to the side portions of the current collecting terminals.