JP2002042773A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery capable of eliminating a dead space in a battery container by drawing a drawing part of a collecting connector to the upper end surface via the central part of a winding. SOLUTION: A drawing part 6c of a collecting connector 6 connected to a negative electrode 1b at the lower end surface of a generating element 1 is drawn to the upper end surface via an axial center hole 7a of a core material 7 arranged in the central part of a winding of the generating element 1, and then it is connected to a negative electrode terminal 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery provided with a power generating element in which a belt-like positive electrode and a negative electrode are wound in a long cylindrical shape with a separator interposed therebetween.

[0002]

2. Description of the Related Art If a battery having a winding type power generating element is a small one, it is possible to collect electrodes from the upper end of the power generating element via tab leads and connect them to the positive and negative terminals. However, a large battery requires a large number of tab leads because a large charge / discharge current flows, and it is difficult to collect these from the same end face of the power generation element by distinguishing between the positive and negative electrodes. The power is collected separately from the upper and lower end faces of the power supply. However, in the case of a battery used as an assembled battery, if the terminals of the positive and negative electrodes are arranged separately on the upper and lower end faces, wiring between these batteries becomes difficult. Is preferred.

FIG. 5 shows an example of the structure of a conventional long-cylindrical lithium-ion secondary battery in which the positive and negative terminals are arranged side by side on the upper end face. This lithium ion secondary battery houses a long cylindrical power generating element 1 in a battery container 2 comprising a battery can 2a in a long cylindrical shape (not shown) and a lid plate 2b closing an upper end opening of the battery can 2a. It was done. A positive electrode terminal 3 and a negative electrode terminal 4 are attached to the cover plate 2b.
The power supply element 1 is connected to a positive electrode 1a and a negative electrode 1b not shown in FIG.

As shown in FIG. 6, a power generating element 1 is formed by winding a strip-shaped positive electrode 1a and a negative electrode 1b up and down via a separator 1c and winding them into a long cylindrical shape. , The side end of the aluminum foil as the current collector of the positive electrode 1a protrudes, and the side end of the copper foil as the current collector of the negative electrode 1b protrudes from the lower end. As shown in FIG. 5, the current collector 5 on the positive electrode side is connected by ultrasonic welding on the upper end surface of the power generating element 1 with the aluminum foil of the positive electrode 1a interposed between the U-shaped portions 5a having a corrugated plate shape. To collect electricity. Also, as shown in FIG. 7, the current collector 6 on the negative electrode side also has a plurality of copper foils of the negative electrode 1b sandwiched between the corrugated U-shaped portions 6a on the lower end surface of the power generating element 1. Current collection is performed by connecting with ultrasonic welding. The current collector 6 is drawn out to the upper end face via a drawer 6 c extending along the outer peripheral side surface of the power generating element 1. In addition,
In the drawings, the number of windings of the positive electrode 1a and the negative electrode 1b is reduced for the sake of simplicity. U
A large number of positive electrodes 1a and negative electrodes 1b are also sandwiched and connected between the character portions 5a and 6a.

As shown in FIG. 5, the battery can 2a is a long cylindrical metal container with a bottom made of stainless steel, aluminum, or the like. The lid plate 2b is an elliptical plate made of the same stainless steel plate, aluminum plate, or the like as the battery can 2a, and is fitted into the upper end opening of the battery can 2a in the shape of a long cylindrical container, and has an upwardly curved end around it. Battery container 2 that covers the exterior of the lithium ion secondary battery by welding the edges
Is composed. A positive electrode terminal 3 and a negative electrode terminal 4 penetrate the upper and lower surfaces of the cover plate 2b, and are insulatively sealed and fixed. These terminals 3 and 4 projecting from the lower surface side of the lid plate 2b.
Is caulked with the upper ends of the current collectors 5 and 6 via a washer (not shown) to be connected and fixed.

[0006] In this way, the current collecting connectors 5, 5 are attached to the lid plate 2b.
When the power generation element 1 is mounted via the battery case 6, first, the battery can 2a
After the power generating element 1 is inserted into the battery case 2a, the lid plate 2b is fitted into the upper end opening of the battery can 2a and welded, and then the electrolyte is injected into the battery container 2 from a liquid inlet (not shown) and sealed. The assembly of the lithium ion secondary battery is completed.

[0007]

However, in the above-mentioned lithium ion secondary battery, with respect to the current collector 5 on the positive electrode side, current is collected from the positive electrode 1a at the upper end face of the power generating element 1 and disposed above the current collector. Although connected to the positive electrode terminal 3, the current collecting connector 6 on the negative electrode side collects the current of the negative electrode 1 b at the lower end surface of the power generating element 1. Is a drawer 6 along the outside of the peripheral side surface of the power generating element 1.
It is necessary to connect via c. For this reason, conventionally,
Since the draw-out portion 6c of the current collecting connector 6 protrudes outside the peripheral side surface of the long cylindrical power generating element 1, the battery container 2
However, there is a problem that an extra space is required inside and the volume efficiency is deteriorated.

[0008] This problem is not limited to lithium ion secondary batteries, but is generally common to batteries having a winding type power generating element wound in a long cylindrical shape.

The present invention has been made in order to cope with such a situation. The current collector is pulled out to the upper end face through the center of the winding of the power generating element to increase the space efficiency and increase the capacity. It is intended to provide a battery that can be used.

[0010]

According to a first aspect of the present invention, a positive electrode terminal and a negative electrode terminal are arranged side by side above a power generating element in which a strip-shaped positive electrode and a strip-shaped negative electrode are wound into a long cylindrical shape via a strip-shaped separator. In the battery, a first current collector connected to a side end of the first electrode at an upper end surface of the power generation element is connected to a first terminal disposed above the power generation element,
A second current collector connected to the lower end face of the power generating element and connected to the side end of the second electrode protrudes from the upper end face through the center of the winding of the power generating element, and extends above the power generating element. Is connected to the second terminal arranged in the first position.

According to the first aspect of the present invention, the first current collector connects the first electrode from the upper end face of the power generating element, while the second current collector connects below the power generating element. The second electrode is collected from the end face and is drawn out to the upper end face through the center of the winding of the power generating element, so that the first and second terminals are arranged on the positive terminal and the negative terminal arranged side by side above the power generating element. 2 current collectors can be connected. Moreover, since the second current collecting connector is not disposed outside the peripheral side surface of the power generating element, there is no waste of battery space.

According to a second aspect of the present invention, the first and second current collectors are plate-shaped, and the second current collector is drawn to the upper end surface through the center of the winding of the power generating element. The connection part of the body to the second terminal is arranged substantially on the same plane as the connection part of the first current collector connection part to the first terminal.

According to the second aspect of the present invention, utilizing the fact that the power generating element is wound in a long cylindrical shape, the plate-shaped second collector having good current collection efficiency is provided at the center of the winding. And the connecting portion of the second current collecting connector is arranged substantially on the same plane as the connecting portion of the first current collecting connector. Can be performed in the same step. In addition, in order to facilitate the connection work between the current collecting connector and the terminal, it is most preferable that the connecting portions of the current collecting connector are arranged on a completely same plane. Even if it is off,
Actually, there is almost no trouble. The configuration in which the connecting portions of the current collector are arranged side by side substantially on the same plane as described above,
This is particularly preferable in the case where a connection is made by bending these current collecting connectors.

According to a third aspect of the present invention, a core is disposed at the center of the winding of the power generating element, and the second current collecting connector is pulled out from the lower end surface to the upper end surface through the through hole of the core material. It is characterized by having. It is preferable that the core material has a long cylindrical shape.

According to the third aspect of the present invention, since the core member is disposed at the center of the winding of the power generating element, the second current collector can be pulled out through the through hole provided in the core member. . In addition, since such a core material is arranged at the center of the winding of the power generation element, it is made of an insulating resin or the like, or is made of an insulated metal material or the like.
It is not necessary to insulate the current collecting connector again. Furthermore, if such a core material is arranged at the center of the winding of the wound power generating element, particularly in the case of a power generating element wound in a long cylindrical shape, the electrode is located at the center of the winding. It does not occur that the gap between the electrodes becomes uneven due to bending into the space and the battery performance deteriorates.

According to a fourth aspect of the present invention, the core member disposed at the center of the winding of the power generating element is formed with two through holes arranged in the longitudinal direction between both end surfaces of the long cylindrical shape. The second current collecting connector is characterized in that it is pulled out from the lower end surface to the upper end surface through one through hole of the core material.

According to the fourth aspect of the present invention, the long cylindrical core is disposed at the center of the winding of the power generating element wound in the long cylindrical shape. Is 2 of this core material
By passing one of the through holes, the rib can be used as a gap between the other through hole to prevent the through hole from being depressed, and the electrode presses the core material to depress the through hole and bend. There is no waste.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 show an embodiment of the present invention. FIG. 1 is a perspective view showing an arrangement of a current collector connected to electrodes of a power generating element, and FIG. 2 is a lithium ion secondary battery. FIG. 3 is an exploded perspective view showing the structure of the battery, FIG. 3 is a longitudinal sectional perspective view showing a core material arranged at the center of the winding of the power generating element, and FIG. 4 is a perspective view of an insulating plate. Components having the same functions as those of the conventional example shown in FIGS. 5 to 7 are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, a long cylindrical lithium ion secondary battery will be described. As shown in FIG. 2, the lithium ion secondary battery includes a battery including a long cylindrical power generating element 1 and a battery can 2a in a long cylindrical container shape and a lid plate 2b closing an upper end opening of the battery can 2a. It is stored in the container 2. A positive electrode terminal 3 and a negative electrode terminal 4 are attached to the cover plate 2b, and are connected to the positive electrode 1a of the power generation element 1 and the negative electrode 1b not shown in FIG. It is connected.

As shown in FIG. 6, the power generating element 1 has a strip-shaped positive electrode 1a and a negative electrode 1b which are vertically shifted and wound into a long cylindrical shape via a separator 1c. In addition,
In this embodiment, the strip-shaped positive electrode 1a and the negative electrode 1b
Are wound in the direction of the winding axis so that the side ends of the positive electrode 1a and the negative electrode 1b protrude from both end surfaces of the power generating element 1, thereby facilitating the connection between the current collecting connectors 5 and 6. However, in order to connect these current collectors 5 and 6 to the positive electrode 1a and the negative electrode 1b, it is not always necessary to wind them while being shifted in the winding axis direction. As shown in FIG. 3, an elongated cylindrical core member 7 is disposed at the center of the winding of the power generating element 1. The core 7 has a plate shape made of PP (polypropylene), and has a semi-cylindrical surface with curved both side surfaces, so that the entire peripheral side surface is formed in a thin long cylindrical shape. The core member 7 is formed with two shaft core holes 7a penetrating between both end surfaces along the winding axis direction of the power generating element 1 (vertical direction in FIG. 3). These two shaft core holes 7a are elongated holes formed side by side along the longitudinal direction of the long cylindrical shape of the core material 7, and these elongated holes penetrate between both end surfaces of the core material 7. Also,
Between them, there is a rib 7b which separates two shaft core holes 7a penetrating between both end surfaces of the core material 7. Such a core material 7 can be manufactured by integrally molding, or can be manufactured by bonding two resin-made plate materials with an adhesive or the like. When two plate members are bonded to each other, two wide grooves are formed in a bonding surface of these plate members to form two shaft holes 7a.

When the power generating element 1 is manufactured, the core 7 is set on a winding machine (not shown). The core material 7 is set by inserting a fork-shaped bifurcated winding core into each of two shaft core holes 7a. Then, the separator 1c is wound around the core material 7, and the negative electrode 1b is placed between the separators 1c while rotating the winding core of the winding machine.
The positive electrode 1a and the negative electrode 1b are supplied and wound so that the positive electrode 1a and the negative electrode 1b are separated from each other as shown in FIG.
c to form a long cylindrical shape.

As shown in FIGS. 1 and 2, the current collector 5 on the positive electrode side has a corrugated U-shaped portion 5 on the upper end surface of the power generating element 1.
The current is collected by connecting the aluminum foil of the positive electrode 1a between the electrodes a by ultrasonic welding. Further, in the current collecting connector 5, the plate material at the inner end of the U-shaped portion 5a is drawn upward to form a connecting portion 5b with the positive electrode terminal 3. The current collector 6 on the negative electrode side is connected to the lower end surface of the power generating element 1 by ultrasonic welding with a large number of copper foils of the negative electrode 1b sandwiched between corrugated U-shaped portions 6a. Perform electricity. However,
The current collector 6 on the negative electrode side has a U-shaped portion 6a as in the prior art.
The inner plate material, not the outer plate material, is drawn upward to form a drawn portion 6c, and the drawn portion 6c is fitted into one shaft core hole 7a of the core material 7. And this current collector 6
Has a lead portion 6c penetrating through the shaft core hole 7a and projecting from the upper end surface of the power generation element 1, and this upper end portion is used as a connection portion 6b with the negative electrode terminal 4. At this time, the connecting portion 6b of the current collector 6
Is protruded straight above one shaft core hole 7a of the core material 7, and the connecting portion 5b of the current collector 5 is drawn upward just above the other shaft core hole 7a of the core material 7. The connecting portions 6b and the connecting portions 5b are arranged such that their plate surfaces are arranged on the same plane.

Since the connecting portion 6b of the current collector connector 6 on the negative electrode side projects from the upper end surface of the power generating element 1 on which the aluminum foil of the positive electrode 1a overlaps, insulation is provided so as not to come into contact with these aluminum foils. There is a need to do. Therefore,
On the upper end surface of the power generating element 1, an insulating plate 8 as shown in FIG. The insulating plate 8 is a long cylindrical PP (polypropylene) resin plate having electrolytic solution resistance and insulating properties, and is connected to the current collecting connector 5 and the current collecting connector 5 in two elongated holes 8a arranged in the longitudinal direction. The connection portions 5b, 6b of the body 6 are made to pass therethrough. Further, a sleeve 8b extending downward is formed in the hole 8a through which the connection portion 6b of the current collector connector 6 on the negative electrode side passes, and the current collector connector 6 projecting upward from the shaft core hole 7a of the core member 7 is formed. The sleeve 8b covers the periphery of the connection portion 6b. Therefore, the current collector connector 6 on the negative electrode side is reliably insulated from the aluminum foil of the positive electrode 1 a overlapping on the upper end surface of the power generation element 1 by the insulating plate 8. As described above, in the battery of the present invention, the current collecting connector 5 and the current collecting connector 6
It is preferable to provide an insulating plate 8 provided with a hole 8a through which the connecting portions 5b, 6b pass through. In this case, the connection of the current collecting connector 6 on the negative electrode side passing through the center of the winding of the power generating element 1 It is particularly preferred to provide a downwardly extending sleeve 8b in the hole 8a through which the part 6b passes. Examples of the resin material of the insulating plate 8 include PE (polyethylene) and P
PS (polyphenylene sulfide) or the like can also be used.

The configurations of the battery can 2a and the cover plate 2b shown in FIG. 2 are the same as those of the conventional example. The lower portions of the terminals 3 and 4 protruding from the lower surface of the cover plate 2b are connected to the connecting portions 5b and 5b of the current collecting connectors 5 and 6 via washers (not shown).
6b and caulked and fixed. At this time, since the connecting portions 5b and 6b of the current collecting connectors 5 and 6 are arranged on the same plane, they can be simultaneously clamped and swaged with the washer of the positive terminal 3 and the negative terminal 4. Further, in this state, the gap between the upper end surface of the power generation element 1 and the cover plate 2b is too large, so that the connection portions 5b,
6b and the washer are bent to narrow the gap. At this time, the connection portions 5b and 6b and the washer can be bent at the same time.

In this way, the current collectors 5 and 5 are attached to the lid plate 2b.
When the power generation element 1 is mounted via the battery case 6, first, the battery can 2a
After the power generating element 1 is inserted into the battery case 2a, the lid plate 2b is fitted into the upper end opening of the battery can 2a and welded, and then the electrolyte is injected into the battery container 2 from a liquid inlet (not shown) and sealed. The assembly of the lithium ion secondary battery is completed.

In the lithium ion secondary battery configured as described above, the lead-out portion 6c of the current-collecting connector 6 on the negative electrode side has the shaft core hole of the core member 7 arranged at the center of the winding of the power generating element 1. Since the lead-out portion 6c is pulled out through the upper portion 7a, unlike the case where the lead-out portion 6c is arranged outside the peripheral side surface of the power generating element 1, no space is wasted inside the battery container 2.

The connecting portions 5b and 6b of the current collecting connector 5 and the current collecting connector 6 project side by side from the upper end surface of the power generating element 1 on the same plane. Since processing for connection can be performed at the same time and parts such as washers can be shared, productivity can be improved.

Further, since the core 7 is disposed at the center of the winding of the long cylindrical power generating element 1, the positive electrode 1a and the negative electrode 1b of the power generating element 1 bend inward due to expansion and contraction when the battery is used. It is also possible to prevent the distance between the poles from becoming uneven. Moreover, since the ribs 7b are formed between the two core holes 7a, the core material 7 does not dent even when the positive electrode 1a or the negative electrode 1b is strongly pressed.
a and the bending of the negative electrode 1b can be reliably prevented.

In the above-described embodiment, the case where the current collecting connector 6 passing through the center of the winding is plate-shaped in order to improve current collecting efficiency has been described. Is not particularly limited, and may be, for example, one or a plurality of rods. Further, instead of the current collector 6 on the negative electrode side passing through the center of the winding, the current collector 5 on the positive electrode side may be passed.

In the above embodiment, the core 7 made of PP is used.
Although the description has been given of the case where is used, any material may be used as long as it is resistant to the electrolytic solution and has sufficient rigidity. However, if the core material 7 is made of resin, the molding process is easy, light weight and insulating, so that the battery weight of the lithium ion secondary battery is significantly larger than when the metal core material 7 is used. The metal core 7 does not need to be insulated by a resin coat or the like. It is preferable to use a polyolefin-based resin as the resin material of the core material 7, and in addition to PP used in the present embodiment, PE (polyethylene) or P
PS (polyphenylene sulfide) is also suitable.

In the above embodiment, the core 7 is disposed at the center of the winding of the power generating element 1, and the lead 6
Although the case where c is passed through the shaft core hole 7a of the core member 7 has been described, if the lead portion 6c of the current collecting connector 6 can be reliably insulated by covering it with the separator 1c or an insulating sheet, such a core member 7 is It is not always necessary to arrange them.

In the above embodiment, the lithium ion secondary battery has been described. However, the type of the battery is not particularly limited, and the present invention can be generally applied to a battery including the wound power generating element 1.

[0034]

As is apparent from the above description, according to the battery of the present invention, despite the fact that power is collected from the upper and lower end faces of the power generating element, the current collector is connected to the peripheral surface of the power generating element. Since the battery can be connected to the positive electrode terminal and the negative electrode terminal disposed above the power generating element without being disposed outside, no wasteful space is generated in the battery.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention and showing an arrangement of a current collector connected to an electrode of a power generating element.

FIG. 2, showing one embodiment of the present invention, is an exploded perspective view showing a structure of a lithium ion secondary battery.

FIG. 3, showing an embodiment of the present invention, is a longitudinal cross-sectional perspective view showing a core material arranged at the center of the winding of the power generating element.

FIG. 4 shows one embodiment of the present invention, and is a perspective view of an insulating plate.

FIG. 5, which shows a conventional example, is an exploded perspective view showing a structure of a lithium ion secondary battery.

FIG. 6 is an exploded perspective view showing a conventional example and showing a structure of a power generating element.

FIG. 7 is a perspective view showing a conventional example and showing an arrangement of a current collecting connector connected to electrodes of a power generating element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power generation element 1a Positive electrode 1b Negative electrode 1c Separator 3 Positive electrode terminal 4 Negative terminal 5 Current collecting connector 5b Connection 6 Current collecting connector 6b Connection 6c Leader 7 Core material 7a Shaft core hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Taketo Matsubara No. 1 Nishinosho Inonoba Babacho, Kichijoin, Minami-ku, Kyoto, Kyoto Inside Nippon Battery Co., Ltd. No. 1 Nishinosho Inomabacho F-term (reference) in Nihon Battery Co., Ltd. 5H022 AA09 AA18 CC12 CC16 CC22

Claims (4)

[Claims] 1. A battery in which a positive electrode terminal and a negative electrode terminal are arranged side by side above a power generating element in which a band-shaped positive electrode and a negative electrode are wound in a long cylindrical shape with a band-shaped separator interposed therebetween. A first current collector connected to a side end of the electrode is connected to a first terminal disposed above the power generating element, and a second electrode is connected to a second electrode at a lower end surface of the power generating element. A second current collecting connector connected to the side end protrudes from the upper end surface through the center of the winding of the power generating element and is connected to a second terminal disposed above the power generating element. A battery comprising: 2. The second current-collecting connector of a second current-collecting connector, which is plate-shaped, and is drawn to the upper end surface through a center of the winding of the power generating element. The connection to the terminal is the first
2. The battery according to claim 1, wherein the battery is arranged substantially on the same plane as a connecting portion of the current collecting connector to the first terminal. 3. 3. A core material is disposed at a central portion of the winding of the power generating element, and the second current collector is drawn from a lower end surface to an upper end surface through a through hole of the core material. The battery according to claim 1. 4. A core material disposed at the center of the winding of the power generating element is formed by forming two through holes arranged in the longitudinal direction between both end surfaces of a long cylinder, and 4. The battery according to claim 3, wherein the current collector is drawn out from the lower end face to the upper end face through one through hole of the core material. 5.