JPH1125951A - Battery - Google Patents

Abstract

(57) [Summary] [Problem] To easily and easily connect an electrode tab and a current collecting comb.
In addition, they are securely connected without difficulty. The electrode tabs are connected with a mechanically strong structure, and the electrode tabs and the poles are connected with a small electric resistance. SOLUTION: The battery includes an electrode group 7 formed by laminating a plurality of electrode plates via a separator, and an electrode plate of the electrode group 7;
A pole 4 is provided which is electrically connected to the electrode tab 2 via the current collecting comb 1. The current collecting comb 1 has a plurality of rows of slits 3 arranged in parallel with each other. The plurality of slits 3 are opened on one side of the current collecting comb 1, and the electrode tabs 2 are inserted into the slits 3 for electrical connection. The pole 4 has a plurality of rows of ridges 8 connected to the upper surface of the current collecting comb 1 at the lower end, and the ridges 8 are electrically connected to the current collecting comb 1.

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 current collecting structure suitable for charging and discharging a large current.

[0002]

2. Description of the Related Art A battery used for a mobile body, such as a battery mounted on an electric vehicle or the like, requires a large capacity and an extremely large charging / discharging current. For large-sized batteries for such applications, electrode tabs electrically connected to the electrode plates
Welding by attaching to the current collecting comb, and then welding the pole to the current collecting comb to take out electricity, or spot welding electrode tab directly to the pole, or connecting using screws or rivets A known structure is known. Further, there is also known a structure in which an electrode tab is attached and welded to a unit in which a current collecting comb and a pole are integrated.

The current collecting structure in which the electrode tab is directly connected to the pole by spot welding has a disadvantage that the mechanical strength of the connection between the electrode tab and the pole cannot be increased. In addition, the current collection structure that is connected to the pole with screws and rivets makes it difficult to reduce the electrical resistance at the connection between the electrode tab and the pole, causing a large voltage drop when a large current flows. I have a problem. The current collecting structure that electrically connects the electrode tabs to the current collecting comb and connects the poles to the current collecting comb does not have such disadvantages, and also allows efficient and reliable connection between the electrode tabs and the current collecting comb. There is.

FIG. 1 shows a current collecting structure for connecting a pole to an electrode tab via a current collecting comb. In the current collecting structure of this figure, slits 3 are provided in a plurality of rows on both sides of a current collecting comb 1 for mounting electrode tabs 2, and a pole 4 is arranged at the center. In this current collecting structure, one electrode tab 2 is inserted into the narrow slits 3 provided on both sides of the current collecting comb 1, so that this work is extremely troublesome and has a drawback that efficient production is not possible. In particular, the electrode tab 2 is an extremely thin metal plate, and the slit 3 is provided with a narrow gap to reduce the gap with the electrode tab 2, so that the electrode tab 2 can be smoothly inserted into the slit 3. Extremely difficult.

[0005]

The present inventors have developed a current collecting structure shown in FIG. 2 in order to smoothly insert an electrode tab into a slit of a current collecting comb. In this current collecting structure, a slit 3 is provided to be opened on one side of the current collecting comb 1. In the current-collecting comb 1 having this structure, the electrode tab 2 can be inserted from the side into the slit 3 of the current-collecting comb 1 as shown by an arrow, so that the electrode tab 2 can be smoothly inserted into the slit 3. However, this structure has a problem that the welding area between the current collecting comb 1 and the electrode tab 2 cannot be increased, and when a large current flows, the voltage drop at the current collecting portion increases.

[0006] The present invention has been developed with the object of solving such disadvantages. An important object of the present invention is to make it possible to easily and easily connect the electrode tab and the current collecting comb with ease and reliability, and to connect the electrode tab with a mechanically strong structure. It is an object of the present invention to provide a battery having a current collecting structure capable of connecting the batteries in a state of low electric resistance.

[0007]

The battery of the present invention has the following unique current collecting structure to achieve the above-mentioned object.
The battery has an electrode group 7 formed by laminating a plurality of electrode plates via a separator, and an electrode group formed by electrically connecting the electrode plates of the electrode group 7 via an electrode tab 2 and a current collecting comb 1. And a pillar 4. The current collecting comb 1 has a plurality of rows of slits 3 arranged in parallel with each other. The plurality of slits 3 are opened on one side of the current collecting comb 1, and the electrode tabs 2 are inserted into the slits 3 for electrical connection. The pole 4 has, at its lower end, a plurality of rows of ridges 8 connected to the upper surface of the current collecting comb 1, and connects the ridges 8 to the current collecting comb 1.

The battery having this structure has a structure in which the electrode tab 2 and the current collecting comb 1 are easily connected to each other, and has a large contact area between the electrode tab 2 and the current collecting comb 1 to reduce the electric resistance of the current collecting portion. Can be smaller. This is because a plurality of rows of ridges 8 are provided at the lower end of the pole 4, and the ridges 8 are connected to the current collecting comb 1. The current collecting comb 1 for connecting the ridges 8 of the pole 4 does not require a space for connecting the pole poles 4,
A long slit 3 can be provided open to one side.
For this reason, the electrode tab 2 can be easily inserted into the current collecting comb 1 from the side, and the connection area between the electrode tab 2 and the current collecting comb 1 can be increased. To the current collecting comb 1 having no space for connecting the columnar poles 4, the ridges 8 parallel to the slits 3 are electrically connected to connect the pole 4 to the current collecting comb 1. The current collecting comb 1 and the pole 4 are electrically connected to each other over a wide area via the ridges 8. The ridge 8 has an elongated and wide connecting surface. Since the pole 4 connects this wide surface to the current collecting comb 1, the pole 4 and the current collecting comb 1 can be connected with a wide area and connected with a small electric resistance.

According to a second aspect of the present invention, there is provided a battery
The opening end of the slit 3 opened on one side is widened in an insertion tapered shape so that the electrode tab 2 can be more smoothly inserted.

In the battery according to the third aspect of the present invention, the ridges 8 provided at the lower end of the pole 4 are arranged in two separate rows electrically connected to both sides of the current collecting comb 1. Or, it is arranged in a U-shape connected to both sides and one end of the current collecting comb 1.

In the battery according to a fourth aspect of the present invention, the electrode tab 2 and the current collecting comb 1 are electrically connected to each other by laser welding. The ridges 8 of the pole columns 4 are electrically connected by laser welding.

Further, in the battery according to claim 6 of the present invention, the current collecting comb 1 and the pole 4 are fixed by vibration welding.

[0013]

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

Further, in this specification, in order to make it easier to understand the claims, the numbers corresponding to the members shown in the embodiments will be referred to as “claims” and “ In the column of “means”.
However, the members described in the claims are not limited to the members of the embodiments.

The battery shown in FIG. 3 is a prismatic battery. In this battery, a battery case 5 is closed with a lid 6, an electrode group 7 is built therein, and an electrolyte is filled. The electrode group 7 is formed by laminating an electrode plate composed of a positive electrode plate and a negative electrode plate with a separator interposed therebetween and insulated. The battery is a secondary battery such as a nickel-cadmium battery, a nickel-hydrogen battery, and a lithium ion secondary battery.

In the electrode group 7, the positive electrode plate and the negative electrode plate are separately separated and electrically connected to the positive and negative poles 4 via the electrode tabs 2 and the current collecting combs 1. The electrode tab 2 is a thin metal plate, and is formed in a shape that protrudes the core of the electrode plate. The electrode tab 2 composed of a core is not coated with an active material for forming a positive electrode plate or a negative electrode plate, and the metal plate of the core is exposed. The electrode plate that constitutes the electrode tab 2 by extending the core of the electrode plate has a feature that the electrode tab 2 can be electrically connected to the electrode plate with the smallest electric resistance. However, the electrode tab may be formed as a metal plate different from the core, and this may be connected to the core of the electrode plate by a method such as welding. Further, an electrode tab, which is another metal plate, may be electrically connected to the surface of the electrode plate.

As shown in the perspective view of FIG. 4, the current collecting comb is provided with a plurality of rows of slits 3 in a metal plate. The plurality of rows of slits 3 are arranged in parallel with each other. Slit 3
The electrode tab 2 is inserted from the side as shown by the arrow in FIG. (In the drawings, one tab is inserted into one slit for simplicity, but usually several tabs are inserted into one slit.) Therefore, the slit 3 is a collection The electric comb 1 is provided on one side with an opening. The current collecting comb 1 shown in FIG.
And the current collecting comb 1 is connected to the left side of the slit 3. The opening 3A of the slit 3 is tapered so that the electrode tab 2 can be inserted more smoothly.

The ridge 8 of the pole 4 is electrically connected to the upper surface of the current collecting comb 1. The lower end of the pole 4 is formed by forming a metal plate into a groove shape, and is provided with ridges 8 on both sides. The ridges 8 are welded to the upper surface of the current collecting comb 1 to be electrically connected. Ridge 8
Are arranged outside the slit 3 in parallel with the slit 3 and are connected to the current collecting comb 1 by welding.

A pole 4 having a plurality of rows of ridges 8 at its lower end.
Can be manufactured by injecting molten metal into a mold. Also,
It can also be manufactured by cutting metal. Furthermore, the columnar portion and the plate-shaped portion provided with the protruding ridge at the lower end can be separately manufactured, and both can be manufactured by electric welding.

As shown in FIG. 3, the pole 4 having the ridges 8 at its lower end penetrates the lid 6 in an airtight manner, and becomes a + -electrode terminal.

The battery having the above structure is assembled in the following steps. A positive electrode plate and a negative electrode plate are laminated with a separator interposed therebetween to produce an electrode group 7. A plurality of electrode tabs 2 connected to the positive and negative plates
Is inserted into the slit 3 of the + -collecting comb 1. The positive electrode plate and the negative electrode plate are separated from each other by a current collecting comb 1, that is, a positive pole 4.
And the current-collecting comb 1 connecting the negative pole 4 to the slit 3 of the current-collecting comb 1. The electrode tab 2 and the current collecting comb 1 are electrically connected by, for example, a method such as laser welding.

The ridge 8 at the lower end of the pole 4 is connected to and fixed to the upper surface of the current collecting comb 1. Polar pole 4 and current collecting comb 1
Are connected by, for example, a method such as laser welding or vibration welding.

The current collecting comb 1 and the pole 4 are connected to the positive electrode plate and the negative electrode plate, and an electrode group 7 capable of collecting current is placed in the battery case 5. After that, the electrolytic solution is injected into the battery case 5,
The lid 6 is connected to the opening of the battery case 5 and hermetically closed.
The cover 6 is provided with a through hole 6A of the pole 4 and the pole 4 is inserted into the through hole 6A, a filler is injected into the gap, and the lid 6 is hermetically sealed.

In the above assembling process, after the electrode group 7 in which the pole 4 is connected to the electrode tab 2 is put in the battery case 5, the pole 4 is attached to the lid 6.
Airtight connection. However, after connecting the electrode group, the pole, and the lid, the electrode group can be put in the battery case.

The battery of the present invention has a unique current collecting structure for connecting the electrode plate to the pole. Hereinafter, how the current collecting structure of the battery of the present invention exhibits excellent characteristics will be described based on specific examples.

However, the following embodiment is a prototype manufactured to measure only the electric resistance and the voltage drop of the current collecting portion, and only the electrode tab, the current collecting comb, the negative electrode plate and the pole are actually used. It is connected by the same structure as the battery. In the following examples, the performance of the current collecting structure was not measured in the state of a battery provided with a positive electrode plate, a negative electrode plate, an electrolytic solution, and the like. However, in the current collecting structure of the following embodiment, equivalent performance is guaranteed in a state where the current collecting structure is incorporated in an actual battery.

[0027]

【Example】

[Example 1] Electrode tabs having the following dimensions were electrically connected to a current collecting comb having the following dimensions by laser welding. The current collecting comb has the shape shown in FIG. 5 and is obtained by plating a steel material with Ni. The electrode tab has the shape shown in FIG.
i. Dimensions of current collecting comb Length L1 = 35 mm, width W1 = 27 mm, thickness t1 = 2 m
m, number of slits 5 slit length L2 = 26 mm, slit width W2 = 0.4 mm dimensions of electrode tab width W3 = 26 mm, W4 = 35 mm, length L3 = 50 m
m, thickness t2 = 0.08 mm

The electrode tabs 2 are inserted into five rows of slits 3 provided in the current collecting comb 1. Four electrode tabs 2 are inserted into one row of slits, and a total of 20 electrode tabs are inserted. Thereafter, as shown in FIG. 7, the upper surface of the current collecting comb 1 is seam-welded by a laser welding machine to be electrically connected. A YAG laser with a maximum rated output of 400 W is used for the laser welding machine. The welding conditions were as follows: charging voltage 600 V, pulse width 7 msec, repetition rate 3 pps, welding speed 0.8 mm / sec.
Perform seam welding in N ₂ atmosphere.

Next, the ridges 8 of the poles 4 are seam-welded to the upper surface of the current collecting comb 1 using a laser welding machine. As shown in FIG. 4, the ridges 8 of the pole 4 are located on both sides of the current collecting comb 1 and outside the slit 3 and are welded to the current collecting comb 1. The pole 4 has a dimension of a contact surface of the ridge 8 connected to the current collecting comb 1 with a length L4 = 35 mm and a width W5 = 2.
7 mm and width W6 = 2 mm. The pole 4 is made of Ni-plated steel.

The pole 4 and the current-collecting comb 1 are formed by the ridges 8 of the pole 4.
Is placed on the current collecting comb 1, as shown in FIG. 8, the boundary between the ridge 8 and the current collecting comb 1 is irradiated with laser from the side and connected by seam welding. A YAG laser with a maximum rated output of 400 W is used for the laser welding machine. The welding conditions were a charging voltage of 600 V and a pulse width of 6 ms.
c, repetition rate 2pps, welding speed 0.7mm / sec
Seam welding is performed in an N ₂ atmosphere.

When the cross section of each part after welding was measured, the penetration margin between the electrode tab 2 and the current collecting comb 1 was 0.4 mm.
And the welding area was 104 mm ² . In addition, between the current collecting comb 1 and the ridges 8 of the pole 4, the penetration was 0.9 mm, and the welding area was 63 mm ² .

The current-collecting structure prototyped as described above has 1
A current of 00 A was applied to measure the voltage drop of the current collecting structure. As shown in FIG.
The lead wire 11 was attached to the electrode with bolts 9 and nuts 10, and a voltage drop between the pole 4 and the electrode tab 2 when 100 A was supplied was measured. As a result of the measurement, the pole 4 and the electrode tab 2
Was about 22 mV.

Embodiment 2 The shape of the lower end of the pole 4 is shown in FIG.
As shown in FIG. 3, the electrode tab 2 and the current collecting comb 1 are formed in the same manner as in Example 1 except that the convex ridges 8 are provided in a U-shape so as to connect the convex ridges 8 in two rows on both sides. And a pole collection 4 were connected to each other to produce a current collecting structure. However, the lower end of the pole 4 is the same as the current collecting comb 1, the length L5 = 35 mm and the width W7 =
The width W8 and W9 of the ridges 8 provided in a U-shape along the periphery of the plate were set to 2 mm. The ridges 8 were welded and fixed to the outside of the slit 3 and to the smooth surface on the left edge of the current collecting comb 1 where the slit 3 was not opened.

When the cross section of each part after welding was measured, the penetration margin between the electrode tab 2 and the current collecting comb 1 was 0.4 mm.
And the welding area was 104 mm ² . In addition, between the current collecting comb 1 and the ridges 8 of the pole 4, the penetration was 0.9 mm, and the welding area was 87 mm ² .
A current of 100 A was applied to the current collector prepared as described above, and the voltage drop of the current collecting structure was measured in the same manner as in Example 1. As a result, the voltage drop between the pole 4 and the electrode tab 2 was about 16 mV.

[Embodiment 3] As shown in FIG. 11, a long current collector comb 1 is used, and a wide electrode tab 2 is used. 2
And a current collecting structure in which the current collecting comb 1 and the pole 4 were connected. However, the length of the current collecting comb 1 was 45 mm, and the width of the electrode tab 2 and the length of the slit 3 were 35 mm.

When the cross section of each part after welding was measured, the penetration margin between the electrode tab 2 and the current collecting comb 1 was 0.4 mm.
And the welding area was 144 mm ² . In addition, between the current collecting comb 1 and the ridges 8 of the pole 4, the penetration was 0.9 mm, and the welding area was 87 mm ² .
The electrode tab 2 and the current collecting comb 1 prototyped as described above.
When a current of 100 A was applied to the current collecting structure and the voltage drop was measured in the same manner as in Examples 1 and 2, the voltage drop was about 12 mV.

COMPARATIVE EXAMPLE For comparison, a conventional current collecting structure using a columnar pole having no ridges was prototyped, and the voltage drop was measured. For the current collecting comb and the electrode tab, the same material and the same thickness of metal as in the example were used.

As the current collecting structure, the current collecting comb 1 shown in FIG. 12 was used, and its dimensions were as follows. Length L6 of current collecting comb 1 = 35 mm, width W10 = 27 mm, thickness t3 = 2 mm, number of slits 10, slit length L7 = 12
mm, slit width W11 = 0.4 mm.

The electrode tab 2 had the shape shown in FIG. 13 and had the following dimensions. Width Wl2 = 35mm, W13 = 1
2mm, length L8 = 50mm, thickness t4 = 0.08mm

The electrode tab 2 and the current collecting comb 1 were laser-welded in the same manner as in the embodiment. Further, the pole 4 was abutted on the upper surface of the current collecting comb 1 and the lower end thereof was connected by seam welding with a laser welding machine. The pole 4 was a cylinder having a diameter of 8 mm and a base having a size of 10 mm × 10 mm × 2 mm fixed to the lower end. When the cross section of each part after welding was measured, the penetration margin between the electrode tab 2 and the current collecting comb 1 was 0.4 mm, and the welding area was 96 mm ² . Also, between the current collecting comb 1 and the pole 4, the penetration was 0.5 mm, and the welding area was 19 mm ² .

The electrode tabs 2 connected as described above
A current of 100 A was applied to the current-collecting comb 1 and the pole 4 to measure a voltage drop in the same manner as in Examples 1 to 3. As a result, the voltage drop between the pole 4 and the electrode tab 2 was about 34 mV.

Examples 1 to 5 produced as described above
3 and the results of the current collecting structure of Comparative Example 1 are summarized as follows.

The welding area between the electrode tab and the current collecting comb Example 1 ········ 104 mm ² Example 2 ····· 104 mm ² Example 3 ······· 144 mm ² Comparative example 1 ····· 96 mm ²

Welding area between current-collecting comb and polar pole Example 1 63 mm ² Example 87 mm ² Example 3 87 mm ² Comparative example 1 19mm ²

The voltage drop between the pole and the electrode tab [1
[00A] [Electricity is applied] Example 1 ... 22 mV Example 2 ... 16 mV Example 3 ... 12 mV Comparative Example 1 ... 34 mV

[0046]

According to the battery of the present invention, it is possible to reduce the voltage drop of the current collecting portion, and to easily and easily form the electrode tab and the current collecting comb without causing adverse effects such as deformation of the thin electrode tab. The feature is that it can be connected to poles efficiently. That is, the battery of the present invention is provided with a plurality of slits which are opened on one side of the current collecting comb, and the electrode tabs are inserted and connected to the slits, and provided on the current collecting comb at the lower end of the pole. This is because it has a unique current collecting structure that connects multiple rows of ridges.

In the current collecting structure of the conventional battery shown in FIG. 1, the two separated electrode tabs are inserted from below, so that it is extremely difficult to insert the electrode tabs into the narrow slits. In the current collecting structure shown in FIG. 2, the electrode tab can be easily inserted into the slit of the current collecting comb. However, since the pole is provided, the contact area between the electrode tab and the current collecting comb is reduced, so that a large current can be obtained. The voltage drop increases. Further, in this structure, since the width of the electrode tab is reduced, the connection strength between the electrode tab and the current collecting comb is also reduced.

The battery of the present invention has a unique structure in which a plurality of rows of ridges are provided at the lower end of the pole, and the ridges are connected to the current collecting comb, thereby eliminating the drawbacks of the current collecting structure shown in FIGS. I do. That is, the battery of the present invention has a unique structure in which a plurality of rows of ridges provided at the lower end of the pole are connected to the current collecting comb, thereby increasing the total length of the slit opened on one side and increasing the width of the electrode tab. it can. This is because the ridge provided at the lower end of the pole can be connected to the outside of the slit over a wide area. For this reason,
In the battery of the present invention, the connection area between the electrode tab and the current collecting comb can be increased, and the two can be connected with a mechanically tough structure in an electrically low-resistance state.

Further, the battery according to the second aspect of the present invention has a feature that the electrode tabs can be inserted very smoothly and without difficulty because the opening end of the slit provided in the current collecting comb is widened in a tapered shape.

In the battery according to the third aspect of the present invention, the ridges provided on the poles are arranged in two rows or in a U-shape. It has the feature that it can be connected to a part with no resistance and connected with low resistance.

In the battery according to the fourth aspect of the present invention, the electrode tab and the current collecting comb are connected by laser welding, and the battery according to the fifth aspect of the present invention is formed by laser welding the ridge of the pole and the current collecting comb. Link. The current collecting structure connected in this state has a feature that the electrode tab, the current collecting comb, and the ridge of the pole can be efficiently and reliably welded and connected.

Further, the battery according to claim 6 of the present invention is
Since the current collecting comb and the ridge of the pole are connected by vibration welding, there is a feature that the current collecting comb and the pole can be connected in a wider area.

[Brief description of the drawings]

FIG. 1 is an enlarged perspective view showing a current collecting structure of a conventional battery.

FIG. 2 is an enlarged perspective view showing a current collecting structure of a battery previously developed by the present inventors.

FIG. 3 is a sectional view of a battery according to an embodiment of the present invention.

FIG. 4 is an enlarged perspective view showing a current collecting structure of the battery according to the embodiment of the present invention.

FIG. 5 is a perspective view of a current collecting comb of the battery according to the embodiment of the present invention.

FIG. 6 is a perspective view of an electrode tab of the battery according to the embodiment of the present invention.

FIG. 7 is a front view showing a state in which the electrode tab and the current collecting comb are connected by welding.

FIG. 8 is a front view showing a state where the pole and the current collecting comb are connected by welding.

9 is a front view showing a state in which a current is applied to the electrode tab and the pole shown in FIG. 8;

FIG. 10 is a perspective view of the pole of the battery according to Example 2 of the present invention as viewed from below.

FIG. 11 is a front view showing a current collecting structure of a battery according to a third embodiment of the present invention.

FIG. 12 is a perspective view of a current collecting comb of the battery of the comparative example.

FIG. 13 is a perspective view of a current collecting tab of the battery of the comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Current collection comb 2 ... Electrode tab 3 ... Slit 3A ... Opening 4 ... Polar pole 5 ... Battery case 6 ... Lid 6A ... Through hole 7 ... Electrode group 8 ... Protrusion 9 ... Bolt 10 ... Nut 11 ... Lead wire

 ──────────────────────────────────────────────────の Continuation of the front page (72) Inventor Michinori Ikezoe 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (6)

[Claims] An electrode group (7) formed by laminating a plurality of electrode plates via a separator, and an electrode plate of the electrode group (7) are connected to an electrode tab (2) and a current collecting comb (1). In the battery provided with the pole (4) electrically connected through the current collector comb (1) has a plurality of rows of slits (3) arranged parallel to each other, a plurality of slits ( 3) is opened on one side of the current collecting comb (1), and is electrically connected by inserting an electrode tab (2) into the slit (3). A battery comprising: a plurality of rows of ridges (8) connected to an upper surface of a comb (1); and the ridges (8) are electrically connected to a current collecting comb (1). 2. The battery according to claim 1, wherein the opening (3A) of the slit (3) opened on one side of the current collecting comb (1) is widened in a tapered shape. The ridges (8) provided on the pole (4) are arranged in two rows separated from each other and electrically connected to both sides of the current collecting comb (1). 2. The battery according to claim 1, wherein the battery is arranged in a U-shape connected to both sides and one end of (1). 4. The battery according to claim 1, wherein the electrode tab (2) and the current collecting comb (1) are laser-welded. 5. The battery according to claim 1, wherein the current collecting comb (1) and the ridge (8) of the pole (4) are laser-welded. 6. The battery according to claim 1, wherein the current collecting comb (1) and the pole (4) are vibration-welded.