JPH11317214A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase current capacity in a current collecting part and prevent the shape change of a power generating element by arranging the current collecting part in the straight part on both sides of the boundary between long cylindrical winding axis parts, repeatedly crooking a metal plate in a bellows shape, and narrowing the groove width of a recessed part facing a power generating element to form a slit-like gap. SOLUTION: A negative electrode current collector 2 and a positive electrode current collector 3 are connected to a power generating element 1, and a current collecting part 2a is arranged on the straight part on the top ends of long cylindrical winding axis parts. The current collecting part 2a is constituted by repeatedly crooking a copper plate of the negative current collector 2 in a bellows shape, and narrowing the groove width of each recess in six portions facing downward, to form a slit-like gap. The slit-like gaps in the six portions in the current collecting part 2a are arranged three by three on the straight part on both sides of the boundary between the long cylindrical winding axis parts of the power generating element 1. Positive and negative electrodes 1a, 1b of the power generating element 1 are supported with the straight parts on both sides.

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 winding type power generating element in which a band-like positive and negative electrode is wound into a long cylindrical shape via a band-like separator.

[0002]

2. Description of the Related Art FIG. 5 shows an example of the configuration of a non-aqueous electrolyte secondary battery provided with a winding type power generating element 1 having a long cylindrical shape. This power generating element 1 is configured by winding a strip-shaped negative electrode 1a and a positive electrode 1b into a long cylindrical shape via a strip-shaped separator 1c.
By winding the negative electrode 1a and the positive electrode 1b slightly up and down, respectively, the negative electrode 1a
, And only the lower edge of the positive electrode 1b protrudes from the lower end. At this time, the active material is not applied to the upper edge of the negative electrode 1a, and the active material is not applied to the lower edge of the positive electrode 1b. The metal foil of the positive electrode 1b is exposed. Further, the separator 1c surely covers the portion where the negative electrode 1a and the positive electrode 1b overlap,
The upper and lower edges are wound so as not to cover.

In the above-mentioned non-aqueous electrolyte secondary battery, a negative electrode current collector 2 as shown in FIG. 6 has been conventionally arranged at the upper end of the power generating element 1 to collect the current of the negative electrode 1a. That is, this negative electrode current collector 2
Has a shape that covers the upper part of the long cylindrical straight part (the part where the negative electrode 1a or the positive electrode 1b becomes linear between the semicircular parts on both sides in the long cylindrical form) and the semicircular part on one side of the power generating element 1. It consists of a copper plate. Then, the current collector 2a is disposed above a straight portion on one side of the power generating element 1 that is bounded by the long cylindrical winding axis. The current collecting portion 2a is a portion in which a slit-shaped gap is formed by repeatedly bending a copper plate in a bellows shape to further narrow the groove width of each of the three concave portions facing downward. Also, the terminal connection portion 2 disposed above the semicircular portion
b, a through hole is formed at the center to connect and fix the negative electrode terminal 4. In addition, the lead-out part 2c arrange | positioned above the straight part on the opposite side to the side which formed the current collection part 2a is a flat plate-shaped part for connecting between this current collection part 2a and the terminal connection part 2b. is there.

[0004] As shown in FIG.
The edge of the negative electrode 1a protruding from the upper end of the power generating element 1 is sandwiched by a plurality of sheets at a time in the slit-shaped gap of the current collector 2a and caulked and connected and fixed by ultrasonic welding. In the drawings, for simplicity, the negative electrode 1a and the positive electrode 1b of the power generating element 1 are coarsely wound with a small number of windings, but are actually extremely densely wound with a large number of windings.
A large number of edge portions of the negative electrode 1a are sandwiched and fixedly connected to the slit-shaped gaps. Power generation element 1
A positive electrode current collector (not shown) using an aluminum plate having the same structure as that of the negative electrode current collector 2 is also arranged at the lower end of the power generation element 1, and the edge of the positive electrode 1 b protruding from the lower end of the power generating element 1 is connected and fixed. It has become.

[0005]

However, when the long cylindrical non-aqueous electrolyte secondary battery is used in an electric vehicle, a hybrid car, or the like, it is necessary to discharge or charge with a very large current in a short time. However, in the conventional negative electrode current collector 2, since the current collecting portion 2a is disposed only above the linear portion on one side of the power generating element 1, the connection area with the negative electrode 1a is reduced, so that the power generating element 1 itself is not provided. However, there is a problem that even if the power supply unit has a sufficient current supply capability, the amount of current that can be collected by the current collection unit 2a is limited, and a large current cannot be supplied. The same applies to the positive electrode current collector.

Conventionally, these negative electrode current collectors 2 and positive electrode current collectors connect and fix the upper and lower edges of the negative electrode 1a and the positive electrode 1b to the current collector 2a only by the linear portion on one side of the power generating element 1. Because it was in a cantilevered state, if it was subjected to severe vibration for a long time by using it in an electric car or hybrid car,
Negative electrode 1a on the straight part on the side where current collector 2a was not connected and fixed
Also, there has been a problem that the positive electrode 1b is gradually displaced and the shape of the winding is lost.

The present invention has been made in order to cope with such a situation. By arranging the current collectors on the straight portions on both sides of the long cylinder, the current capacity of the current collectors can be increased. It is another object of the present invention to provide a battery current collector that does not cause the power generating element to lose its shape.

[0008]

According to the first aspect of the present invention, there is provided a winding type power generating element in which strip-shaped positive and negative electrodes are respectively shifted in a winding axis direction and wound into a long cylindrical shape via a strip-shaped separator. A current collector, which is disposed at both ends of a winding shaft of the power generating element, and fixes the connection by inserting and sandwiching the edges of positive and negative electrodes projecting at both ends of the power generating element into slit-shaped gaps, respectively. And a current collector configured to be disposed on straight portions on both sides bounded by an elongated cylindrical winding shaft portion.

According to the first aspect of the present invention, since the current collecting portions are arranged on the straight portions on both sides of the long cylindrical shape, the connection area is reduced as compared with the case where the current collecting portions are arranged on only one straight portion. The current capacity can be greatly increased. Moreover,
Since the positive and negative electrodes of the power generation element can be supported by the linear portions on both sides by the current collecting portion, there is no possibility that the windings will be deformed due to vibration or the like as in the case where the linear portions on one side are in a cantilevered state.

According to a second aspect of the present invention, the current collector has a slit-like gap formed by repeatedly bending a metal plate in a bellows shape and further narrowing a groove width of a concave portion facing the power generation element side. It is characterized by.

According to the second aspect of the present invention, since the current collector can be formed only by pressing the metal plate, the current collector can be manufactured at low cost.

According to a third aspect of the present invention, a connection piece is projected from the current collector, and the connection piece of the current collector is fixedly connected to a connection portion of a terminal connecting plate having terminals. .

[0013] Usually, the current collector is connected to the power generating element by clamping the edges of the positive and negative electrodes on the side facing the power generating element and then fixing the connection by tooling or ultrasonic welding from the opposite side. However, the opposite side cannot be closed by the lead portion or the terminal. However, according to the third aspect of the present invention, the terminal connection plate can be connected and fixed after the operation of connecting and fixing the edge portions of the positive and negative electrodes, so that the space on the opposite side of the current collector can be effectively used. The size of the current collector can be reduced by utilizing the present invention.

[0014]

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

FIGS. 1 and 2 show a first embodiment of the present invention. FIG. 1 is a perspective view showing a negative electrode current collector and a positive electrode current collector fixedly connected to a power generating element, and FIG. It is a perspective view showing composition of a current collector and a positive electrode current collector. Components having the same functions as those of the conventional example shown in FIGS. 5 to 7 are denoted by the same reference numerals.

In this embodiment, a non-aqueous electrolyte secondary battery provided with a power generating element 1 wound in a long cylindrical shape and used for an electric vehicle or the like will be described. As shown in FIG. 5, the power generating element 1 of this non-aqueous electrolyte secondary battery is configured such that the negative electrode 1a and the positive electrode 1b are wound while being slightly shifted in the vertical direction (axial direction), respectively. Only the upper edge of the negative electrode 1a protrudes from the upper end, and only the lower edge of the positive electrode 1b protrudes from the lower end. The negative electrode 1a is obtained by applying a negative electrode active material such as graphite to the surface of a strip-shaped copper foil, and the positive electrode 1b is obtained by applying a positive electrode active material such as a lithium-cobalt composite oxide to the surface of a strip-shaped aluminum foil. is there. However, the negative electrode 1a is coated with the negative electrode active material only on the portion excluding the upper edge portion, and the positive electrode 1b is coated with the positive electrode active material only on the portion except the lower edge portion, thereby generating power. The copper foil and the aluminum foil are exposed and protruded from the upper and lower ends of the element 1. The separator 1c uses a strip-shaped microporous resin film, and the portion where the negative electrode 1a and the positive electrode 1b overlap with each other is surely covered.
The upper and lower edges are wound so as not to cover.

The power generating element 1 is connected to a negative electrode current collector 2 and a positive electrode current collector 3 as shown in FIG. Negative electrode current collector 2
Is formed by pressing a long and narrow rectangular copper plate, and a current collector 2 a is arranged on a long cylindrical straight portion at the upper end of the power generating element 1. The current collector 2a is a portion where slit-shaped gaps are formed by repeatedly bending the copper plate of the negative electrode current collector 2 in a bellows shape to further narrow the groove widths of the six concave portions facing downward. is there. The six slit-shaped gaps of the current collecting portion 2a are respectively arranged on the straight portions on both sides bounded by the long cylindrical winding shaft portion of the power generating element 1 at three locations. This current collector 2a
One end is bent and drawn downward to form a drawn portion 2c along the outer peripheral side surface of the elongated cylindrical linear portion, and the lower end is further bent horizontally to form a terminal connection portion 2b. By inserting the upper end of the negative electrode terminal 4 into the central through hole in the terminal connection portion 2b, the negative terminal 4 projects downward and is fixedly connected thereto. The positive electrode current collector 3
It is made by pressing an elongated aluminum plate.
The shape and configuration are the same as those of the negative electrode current collector 2. A current collector 3 a is disposed below the long cylindrical linear portion at the lower end of the power generation element 1, and a drawer 3 is formed by pulling one end of the current collector 3 a upward.
c, and a terminal connecting portion 3b for connecting and fixing the positive electrode terminal 5 by bending the upper end portion horizontally.

As shown in FIG. 1, the negative electrode current collector 2
A portion where the copper foil at the edge of the negative electrode 1a projecting from the upper end of the power generating element 1 is exposed is collectively sandwiched into a plurality of slits in the slit-shaped gap of the current collector 2a and caulked and connected and fixed by ultrasonic welding. Here, the edge of the negative electrode 1a protruding at one linear portion bounded by the long cylindrical winding shaft portion of the power generating element 1 is distributed and connected to three slit-shaped gaps on the back side in the drawing. The edge of the negative electrode 1a protruding from the other linear portion is divided and connected to three slit-shaped gaps on the near side in the drawing to be fixed. In the drawing, for simplicity,
Although the negative electrode 1a and the positive electrode 1b of the power generating element 1 are coarsely wound with a small number of windings, actually, the windings are extremely densely wound with a large number of windings. A large number of edges of 1a are respectively sandwiched and fixedly connected. Similarly to the negative electrode current collector 2, the positive electrode current collector 3 also has a portion where the aluminum foil is exposed at the edge of the positive electrode 1b protruding from the lower end of the power generating element 1 is formed in a slit-shaped gap of the current collector 3a. A plurality of sheets are collectively sandwiched and swaged, and connected and fixed by ultrasonic welding. At this time, the terminal connecting portion 2b of the negative electrode current collector 2 is arranged with a small gap below the current collecting portion 3a of the positive electrode current collector 3, and the terminal connecting portion 3b of the positive electrode current collector 3 is The current collector 2 is arranged with a gap slightly above the current collector 2a. An insulating plate is later inserted into these gaps to prevent a short circuit.

The current collector 2a of the negative electrode current collector 2
After sandwiching the edge portion of a in the slit-shaped gap, the attachment of the caulking tool is inserted from above, and caulking is performed by applying force so as to crush the convex portion. The ultrasonic welder also performs ultrasonic welding by inserting an attachment from above and applying ultrasonic vibration across the projection. However, if, for example, the current collector 2a of the negative electrode current collector 2 is first connected and fixed to the power generating element 1, the current collector 3 of the positive electrode current collector 3
If the terminal a is to be connected and fixed, the terminal connecting portion 2b of the negative electrode current collector 2 becomes an obstacle. For this reason, at the time of actual caulking or ultrasonic welding work, the lead-out portions 2 c and 3 c are slightly bent outward to move the terminal connection portions 2 b and 3 b to positions off the end face of the power generation element 1. Alternatively, these terminal connecting portions 2b, 3b may be formed at slightly shifted positions so as not to overlap with the current collecting portions 3a, 2a.

The power generating element 1 in which the negative electrode current collector 2 and the positive electrode current collector 3 are connected and fixed is housed in a long cylindrical battery case (not shown), filled with a non-aqueous electrolyte, and hermetically sealed. Construct an electrolyte secondary battery. Further, the negative electrode terminal 4 and the positive electrode terminal 5 are insulated and sealed from each other and protrude from the upper and lower parts of the battery.

According to the above configuration, the negative electrode 1a of the power generating element 1
And the positive electrode 1b are connected and fixed to the current collectors 2a and 3a of the negative electrode current collector 2 and the positive electrode current collector 3 at the straight portions on both sides of the long cylindrical shape. The connection area can be doubled as compared with that of the first embodiment, and the current capacity can be greatly increased. In addition, since the negative electrode 1a and the positive electrode 1b of the power generating element 1 are supported by the current collectors 2a and 3a at the straight portions on both sides as described above, even if the device is mounted on an electric vehicle or the like and is subjected to severe vibration for a long time, These negative electrodes 1a
Also, there is no fear that the winding of the positive electrode 1b is gradually displaced to cause shape collapse.

FIGS. 3 and 4 show a second embodiment of the present invention. FIG. 3 is a perspective view showing the structure of a negative electrode current collector 2 and a positive electrode current collector 3, and FIG. It is a perspective view which shows the negative electrode current collector and the positive electrode current collector 3 which were connected and fixed. In addition, FIG.
Components having the same functions as those of the first embodiment shown in FIG. 2 are denoted by the same reference numerals, and description thereof is omitted.

In the first embodiment, the negative electrode current collector 2 is provided with a current collector 2a and a terminal connection 2 arranged on both sides of a long cylindrical linear portion.
b is difficult to arrange at the upper end of the same power generating element 1, so that the terminal connecting portion 2 to which the negative electrode terminal 4 is connected and fixed is connected.
b was arranged at the lower end of the power generation element 1 via the drawer 2c. The same applies to the case of the positive electrode current collector 3. But,
In this embodiment, as shown in FIG. 3, the negative electrode terminal 4 is combined with the terminal connection plate 6 as a separate component to form the negative electrode terminal 4 into the same power generation element 1 as the current collector 2a. It is arranged at the upper end of. That is, the negative electrode current collector 2 is formed by repeatedly bending the copper plate in a bellows shape, and further narrowing the groove width of each of the six concave portions facing the lower side, so that the negative electrode current collector 2 is formed only from the current collector 2 a in which a slit-shaped gap is formed. Become. However, in two of the six concave portions at both ends, the folded portion of the copper plate is lengthened so that a connecting piece 2d formed of a folded portion having no gap protrudes above the slit-shaped gap. The terminal connection plate 6 is formed by pressing the same copper plate as the negative electrode current collector 2, and is connected by bending both ends of the copper plate covering the upper part of the negative electrode current collector 2 to form downward concave portions. It is a part 6a. In the terminal connection plate 6, a copper plate between the connection portions 6a is pulled out to one side to form a terminal connection portion 6b, and the negative electrode terminal 4 is connected and fixed thereto.

As in the case of the first embodiment, the current collector 2a of the negative electrode current collector 2 has a power generation element 1 as shown in FIG.
After the edge of the negative electrode 1a is sandwiched in the slit-like gap, it is swaged and fixed by ultrasonic welding. At this time, there is nothing on the upper part of the power collection unit 2a that would interfere with the work. And the terminal connection plate 6
The connection pieces 2d are inserted into the gaps of the connection portions 6a and fitted onto the negative electrode current collector 2, and these connection portions 6a are crushed from both sides and caulked to fix the connection. Further, the positive electrode current collector 3 (not shown) has the same configuration as the negative electrode current collector 2, and a terminal connection plate is connected and fixed to the lower side, and the positive electrode terminal 5 is attached.

According to the above-structured non-aqueous electrolyte secondary battery,
In addition to the effect of the first embodiment in which the current capacity is increased to prevent the shape of the winding from being lost, a drawer along the outer peripheral side surface of the power generating element 1 is not required, and the negative electrode current collector 2, the positive electrode current collector 3, and the negative electrode Terminal 4
And the effect of shortening the connection distance with the positive electrode terminal 5 can be obtained.

The present invention is not limited to the connection method between the current collectors 2 and 3 and the terminals 4 and 5 shown in the first and second embodiments. Connection is possible. Further, in the above-described embodiment, the case where the negative electrode current collector 2 and the positive electrode current collector 3 are formed by pressing a metal plate is described. However, the present invention is not limited to this. It is also possible to use a combination of metal parts and the like.

Further, in the above embodiment, the non-aqueous electrolyte secondary battery has been described. However, the present invention can be generally applied to other batteries.

[0028]

As is apparent from the above description, according to the current collector of the battery of the present invention, the current collecting portion is arranged on the straight portions on both sides of the long cylindrical shape in the power generating element, so that the current capacity is reduced. It can be greatly increased. In addition, since the positive and negative electrodes of the power generating element can be supported by the linear portions on both sides by the current collecting portion, there is no possibility that the winding will be deformed due to vibration or the like.

[Brief description of the drawings]

FIG. 1, showing a first embodiment of the present invention, is a perspective view showing a negative electrode current collector and a positive electrode current collector connected and fixed to a power generation element.

FIG. 2, showing the first embodiment of the present invention, is a perspective view illustrating a configuration of a negative electrode current collector and a positive electrode current collector.

FIG. 3 illustrates a second embodiment of the present invention, and is a perspective view illustrating a configuration of a negative electrode current collector and a terminal connection plate.

FIG. 4 is a perspective view showing a second embodiment of the present invention and showing a negative electrode current collector connected to and fixed to a power generation element and a terminal connection plate.

FIG. 5 is a perspective view showing a configuration of a power generating element of the nonaqueous electrolyte secondary battery.

FIG. 6 is a perspective view showing a conventional example and showing a configuration of a negative electrode current collector connected and fixed to a power generating element.

FIG. 7 is a perspective view showing a conventional example and showing a negative electrode current collector connected and fixed to a power generation element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power generation element 1a Negative electrode 1b Positive electrode 1c Separator 2 Negative electrode current collector 2a Current collection part 2d Connection piece 3 Positive electrode current collector 3a Current collection part 6 Terminal connection plate 6a Connection part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Zenzo Hagiwara 1 inosinobabacho, Kichijoin, Minami-ku, Kyoto-shi Inside Nippon Battery Co., Ltd. Nobaba-cho No. 1 Inside Nihon Battery Co., Ltd.

Claims (3)

[Claims] 1. A winding type power generating element in which strip-shaped positive and negative electrodes are respectively shifted in a winding axis direction and wound into a long cylindrical shape via a strip-shaped separator, and disposed at both ends of a winding shaft of the power generating element. It is a current collector that fixes and connects the edges of the positive and negative electrodes protruding at both ends of the power generation element in slit-shaped gaps, wherein the current collector is bounded by an elongated cylindrical winding shaft. And a current collector configured to be disposed on the linear portions on both sides of the battery. 2. The power collector according to claim 1, wherein the current collector is formed by repeatedly bending a metal plate in a bellows shape, and further narrowing a groove width of a concave portion facing the power generating element side to form a slit-shaped gap. Item 7. The battery according to Item 1. 3. A connecting piece protruding from the current collector,
The connection piece of the current collector is fixedly connected to a connection portion of a terminal connection plate having terminals.
The battery according to 1.