JP2003173765A - Sealed battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealed battery which can improve power-collecting efficiency by surely bonding a collector part and a metal foil and reduce battery performance loss. <P>SOLUTION: The sealed battery 10 is provided with a power-generating element 14 equipped with a metal foil 12 to become a cathode and an anode with a separator interposed, and collector plates 15, 20 of positive and negative electrodes connected to an end edge in the plane direction of the metal foil 12. Nearly cross section V-shaped collector parts 16, 17 of positive and negative electrodes each laminating and storing a plurality of metal foils 12 are fitted to collector plates 15, 20 more than one, and at the same time, each collector part of the positive and the negative electrodes are arrayed in parallel with each other. With the sealed battery 10, the positive electrode collector part 16 is arrayed in parallel with the adjacent positive collector part 17 so as not to interfere with each other. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sealed battery,
In particular, it has a power generation element in which a negative electrode and a positive electrode are wound or laminated via a separator, and a negative electrode current collector plate is connected to one side surface of this power generation element and a positive electrode current collector plate is connected to the other side surface. Regarding batteries.

[0002]

2. Description of the Related Art In a sealed battery 70 shown in FIG. 11, a negative electrode and a positive electrode are stacked with a separator interposed therebetween, and a winding type power generating element 72 is flattened into a substantially elliptical shape and an axial direction of the power generating element 72. Positive electrode portion 74 and negative electrode portion provided at both ends
76, a positive electrode current collector plate 75 and a negative electrode current collector plate 77 connected to the positive electrode part 74 and the negative electrode part 76, respectively, and a power generating element connected to the positive electrode current collector plate 75 and the negative electrode current collector plate 77, respectively.
Power is generated so that a positive electrode terminal 78 and a negative electrode terminal 79 that extend from the positive electrode portion 74 side of 72 to be substantially parallel to the axis of the power generation element 72, and an end portion 78A of the positive electrode terminal 78 and an end portion 79A of the negative electrode terminal 79 are exposed to the outside. It has a substantially box-shaped sealed battery package 80 containing elements 72.

A strip-shaped copper foil is used as a metal foil for the negative electrode of the power-generating element 72, and a carbon-based organic polymer is applied as an active material on both surfaces of the negative electrode so that copper is exposed at a predetermined width from both ends in the width direction. Has been done. On the other hand, the positive electrode of the power-generating element 72 uses a strip-shaped aluminum foil as the metal foil, and oxides of cobalt, nickel, manganese, or the like are formed on both surfaces of the active material so that the aluminum is exposed from both ends in the width direction with a predetermined width. Is applied as. Here, in the negative electrode and the positive electrode,
A portion where copper or aluminum is exposed is referred to as a “metal foil active material non-coated portion”.

By the way, various improvements have been made in order to increase the efficiency of current collection in response to high rate discharge. For example, in FIG.
2, the positive electrode terminal 78 and the negative electrode terminal 79 are arranged so as to extend in a direction substantially perpendicular to the axis of the power generating element 72, and are formed on the positive electrode current collector plate 75 and the negative electrode current collector plate 77. Press the plate into a bellows shape, or make a cut in the plate and fold each of the divided rectangular parts into a V shape,
A method of sandwiching the active material non-coated portions of several metal foils laminated on each bent portion and joining them by laser welding can be considered. According to this method, since the positive electrode part 74 and the negative electrode part 76 are not covered with the positive electrode terminal 78 and the negative electrode terminal 79, the degree of freedom in arranging the positive electrode current collector plate and the negative electrode current collector plate is improved, and a higher rate is achieved. The battery can be dischargeable. FIG. 13 is an enlarged view of a main part of the battery shown in FIG.
Only a part of the positive electrode current collector plate 75 and the negative electrode current collector plate 77 is shown.

[0005]

However, in the above configuration, the plates corresponding to the positive electrode current collector plate and the negative electrode current collector plate, which sandwich the active material non-coated portion of the metal foil, are densely arranged in parallel. Therefore, the plates interfere with each other. In order to prevent the interference of each plate and arrange each plate appropriately, the width of each plate arranged in parallel becomes wide and the width of the power generation element becomes wide. Therefore, there is a problem that the current collection efficiency of the sealed battery is deteriorated.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to reliably join a current collector and a metal foil to improve current collection efficiency and reduce battery performance loss. It is to provide a sealed battery that can be used.

[0007]

In order to achieve the above-mentioned object, according to the present invention, as described in claim 1, a power generating element comprising a metal foil serving as a negative electrode and a positive electrode via a separator, and A current collector plate connected to the edge of the metal foil in the plane direction by electric resistance welding, and a plurality of current collectors each having a substantially V-shaped cross section for accommodating and stacking a plurality of the metal foils are provided on the current collector plate. A sealed battery in which the current collecting portions are arranged in parallel with each other, and the current collecting portions are connected to each other via terminal supporting portions provided at longitudinal ends thereof. , The terminal supporting portions have different longitudinal dimensions from the other terminal supporting portions adjacent to each other so that the current collecting portions do not interfere with other adjacent current collecting portions. I am trying.

In the sealed battery thus constructed, each terminal supporting portion has a different longitudinal dimension from the other terminal supporting portions adjacent to each other, so that each current collecting portion is adjacent to the other current collecting portion. You can prevent it from interfering with. Accordingly, the width of the entire current collector can be suppressed to be small in a state where the current collectors are arranged, and thus the width of the power generation element can be narrowed.

Further, in the present invention, as described in claim 2, each current collecting portion is crimped in a direction in which the cross-sectional shape is closed around the ridgeline of each current collecting portion. It has a feature. By crimping each current collector,
The metal foil can be stacked and housed in a stable state in each current collector, and the adhesion between each current collector and the metal foil is improved.

Further, according to the present invention, as described in claim 3, a notch is provided so as to cross the ridgeline of each current collector. By providing a cutout on the ridge of each current collector, it is possible to confirm whether or not the metal foil has been inserted into each current collector. In addition, by providing a notch on the ridgeline of each current collector, each current collector can be easily bent at the ridge, and the tightness between each current collector and the metal foil can be improved. It is possible to prevent problems during resistance welding.

Further, in the present invention, as described in claim 4, each of the current collecting portions is formed by subjecting a plate material punched into a predetermined shape to sheet metal working. . After punching the plate material into a predetermined shape,
Each current collector is formed by subjecting this plate material to sheet metal processing. Accordingly, by integrally forming the current collecting portion and the current collecting plate by punching, it is not necessary to join the current collecting portion and the current collecting plate, and thus the current collecting resistance is not increased.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. In each embodiment described below, the members already described with reference to FIG. 1 are denoted by the same reference numerals or corresponding reference numerals in the drawing to simplify or omit the description.

As shown in FIG. 1, a sealed battery 10 according to a first embodiment of the present invention has a metal foil 12 (a metal foil 12 of a positive electrode 12) serving as a positive electrode and a negative electrode via a separator (not shown).
(Only shown in the figure) are provided, the positive electrode current collector plate 15 connected to the edge of the metal foil 12 serving as the positive electrode in the surface direction by electric resistance welding, and the surface direction of the metal foil serving as the negative electrode. The negative electrode current collector plate 20 connected to the edge by electric resistance welding, the positive electrode current collector plate 15 and the positive electrode terminal 25 and the negative electrode terminal 26 respectively connected to the negative electrode current collector plate 20, and the end of the positive electrode terminal 25. 25 A
And a substantially box-shaped sealed battery package 29 accommodating the power generation element 14 such that the end 26A of the negative electrode terminal 26 is exposed to the outside.

In this sealed battery 10, a positive electrode current collector plate 15 and a negative electrode current collector plate 20 which are bent in a substantially L shape are arranged symmetrically to each other so that a positive electrode terminal 25 and a negative electrode terminal 26 stand upright in parallel. The winding axis of the power generation element 14 is arranged substantially horizontally. Therefore, the sealed battery 10 has a larger end surface of the power generating element 14, which is a portion for extracting energy, as compared with a normal sealed battery in which the winding axis of the power generating element and the positive electrode terminal and the negative electrode terminal are arranged in parallel. Can be secured.

As shown in FIG. 2, the positive electrode current collector plate 15 is provided with positive electrode current collectors 16 and 17 each having a substantially V-shaped cross section for accommodating a plurality of metal foils 12 serving as positive electrodes at longitudinal ends thereof. A plurality of positive electrode terminal support portions 15D and 15E are provided. While each positive electrode current collector 16 is arranged in parallel with each other,
The positive electrode current collectors 17 are arranged in parallel with each other. Specifically, the positive electrode current collectors 16 and 17 are connected via the positive electrode terminal support portions 15D and 15E having different lengths, so that
17 is arranged below the positive electrode terminal 16. Further, the positive electrode terminals 16 and the positive electrode terminals 17 are arranged alternately. As a result, the positive electrode current collectors 16 are arranged in parallel so as not to interfere with other adjacent positive electrode current collectors 17.

By the way, the positive electrode current collectors 16 and 17 are integrally formed with the positive electrode current collector plate 15 via the positive electrode terminal support portions 15D and 15E, respectively. That is, by pressing one flat plate 19 shown in FIG. 3 to bend the positive electrode current collector plate 15 into a substantially L shape at the center 15A, a lower piece 15B and an upper piece 15C are formed. The electric parts 16 and 17 are the central parts 16A and 17 respectively.
It is bent into a substantially V shape at A, resulting in the state shown in FIG.

Here, as shown in FIG. 2, each positive electrode current collector 1
Since 6 and 17 are arranged over both sides 14A and 14B of the winding type power generation element 14 which is flattened into an approximately elliptical shape, current can be collected from both sides 14A and 14B of the power generation element 14, so that the power collection efficiency is improved. Can be increased. In particular, since the sealed battery 10 can secure a large end surface of the power generation element 14, the current collection efficiency can be further improved. Further, since the plurality of positive electrode current collectors 16 and 17 are integrally formed with the positive electrode current collector plate 15, there is no joint resistance due to welding or the like, and the current collection efficiency can be improved.

Further, since the plurality of positive electrode current collectors 16 and 17 are provided for one positive electrode current collector plate 15, the plurality of positive electrode current collectors 16 and 17 are provided independently of each other. ing. Therefore, it is possible to collect current from the positive electrode current collectors 16 and 17 to the positive electrode current collector plate 15 in a parallel manner, so that a specific place (that is, one of the plurality of positive electrode current collectors 16 and 17) is damaged. Even in this case, the current can be collected from the other positive electrode current collectors 16 and 17. Therefore, current collection efficiency can be improved.

This positive electrode current collector plate 15 is bent at the center 15A so as to have a substantially L shape, and each lower electrode 15B has each positive electrode current collector 16,
17 is provided, and the upper piece 15C is the upper side 14C of the power generating element 14 (see FIG.
The upper electrode 15C is provided with a positive electrode 25 standing upright. Therefore, the positive electrode 25 is a power generation element.
It is provided on the upper 14C side of 14.

The negative electrode current collector plate 20 shown in FIG.
Similarly, a plurality of negative electrode current collectors (not shown) having a substantially V-shaped cross section for stacking and accommodating a plurality of negative electrode metal foils are provided, and the negative electrode current collectors are arranged in parallel with each other.
The negative electrode current collectors are connected to each other via a negative electrode terminal support 21 provided at a longitudinal end (not shown). Therefore, the same effect as the positive electrode current collector plate can be obtained. Since the negative electrode current collector plate 20 has the same configuration as the positive electrode current collector plate 15, the positive electrode current collector plate 15 will be described below and the description of the negative electrode current collector plate 20 will be omitted.

Since the positive electrode current collector plate 15 shown in FIG. 2 is formed integrally with the positive electrode current collectors 16 and 17, as described above,
It is possible to reduce the component cost and the manufacturing cost. Also,
Each of the positive electrode current collectors 16 and 17 is formed by pressing into a substantially V-shaped cross section. By pressing the positive electrode current collectors 16 and 17, it is possible to form the positive electrode current collectors 16 and 17 at a lower cost than when cutting the positive electrode current collectors 16 and 17.

As shown in FIG. 4, the metal foil 12 fitted in the positive electrode current collector 16 and serving as a positive electrode has an electrical resistance in the vicinity of the ridge 16A of the positive electrode current collector 16 along the thickness direction of the metal foil 12. The positive electrode current collector 16 and the metal foil 12 are joined by welding. As with the positive electrode current collector 16, the positive electrode current collector 17 and the metal foil 12 are joined together.

At this time, since the positive electrode current collectors 16 and 17 are alternately arranged, in other words, since a constant gap is provided between the positive electrode current collectors 16 adjacent to each other, the metal foil is formed. When electric resistance welding is performed on the positive electrode current collector 16 and the metal foil 12 along the thickness direction of the electrode 12, the welding terminal does not interfere with another adjacent positive electrode current collector 16. That is, in the past,
When joining the positive electrode current collector and the metal foil 12, since the adjacent positive electrode current collectors interfere with each other, welding along the thickness direction of the metal foil 12 cannot be performed, and thus the surface of the metal foil 12 is prevented. There was no choice but to perform laser welding along the direction. Therefore, conventionally, there is a possibility that the laser light that melts the positive electrode current collector may excessively melt the metal foil 12 along the surface direction.

On the other hand, in the first embodiment, since electric resistance welding can be adopted for joining the positive electrode current collectors 16 and 17 and the metal foil 12, unlike the case where they are joined by laser light, for example, The above-mentioned problem that the metal foil 12 is excessively melted along the surface direction can be avoided, the cost such as equipment cost can be suppressed, the working time can be shortened, and the productivity can be improved. In addition, since it is not necessary to strictly adjust the angle of the laser light 28, it is possible to prevent a welding error. Therefore, the quality of the sealed battery 10 can be improved.

Further, the positive electrode current collector 16 is formed by crimping both pieces 16B, 16C bent in a substantially V shape from both sides as shown by an arrow. In this way, both pieces 16B, 16 of the positive electrode current collector 16 are
By crimping C, the positive electrode collector 16 is provided with a plurality of metal foils 12
Can be reliably maintained in the inserted state, and sparks during electric resistance welding can be reliably prevented. For this reason,
The quality of the sealed battery 10 can be improved. The positive electrode current collector 17 has the same shape as the positive electrode current collector 16 and
The same effect as 16 can be obtained.

Next, a second embodiment will be described with reference to FIGS. The positive electrode current collector plate 30 of the second embodiment shown in FIG.
Has notches 31A and 32A formed at the ridges of the positive electrode current collectors 31 and 32. Therefore, as shown in FIG. 6, it can be confirmed whether or not the metal foil 12 serving as the positive electrode is inserted deep into the positive electrode current collectors 31 and 32. In addition, a notch 31 is formed in the ridge of the positive electrode current collector 31, 32
By providing A and 32A, the expanded positive electrode current collector 31 shown in FIG. 7 can be easily bent at the ridge 31B as shown by the arrow. Therefore, the quality of the sealed battery 1O can be improved. In addition, by providing the cut 31A,
When crimping both pieces of the positive electrode current collectors 31 and 32 bent into a V shape, it is possible to crimp with a light crimping force.
The positive electrode current collectors 31 and 32 can surely hold 12. For this reason,
The quality of the sealed battery 1O can be further improved.

Next, a third embodiment will be described with reference to FIGS. The positive electrode current collector plate 40 of the third embodiment shown in FIG.
Is a plurality of through holes 41A, 42A at the ridges of the positive electrode current collectors 41, 42.
Are formed at predetermined intervals. Therefore, as shown in FIG. 9, it can be confirmed whether or not the metal foil 12 serving as the positive electrode has been inserted all the way into the positive electrode current collectors 41 and 42. In addition, the positive electrode current collector
By providing the through holes 41A and 42A at the ridges of the ridges 41 and 42, the positive electrode current collectors 41 and 42 in the expanded state can be easily bent at the ridges. Therefore, the quality of the sealed battery 1O can be improved. Further, by providing the through holes 41A and 42A, when the both pieces of the positive electrode current collectors 41 and 42 bent into the V shape can be swaged, they can be swaged with a light swaging force. The current collectors 41, 42 can be surely gripped. Therefore, the quality of the sealed battery 1O can be further improved.

The sealed battery 50 of the fourth embodiment shown in FIG.
With the positive electrode current collector plate 51 and the negative electrode current collector plate 55 not being bent in an L shape, the positive electrode terminal 54 and the negative electrode terminal 58 are provided at both ends 14D and 14E of the power generation element 14. Therefore, the positions of the positive and negative electrode terminals can be appropriately changed according to the application of the sealed battery. The positive electrode current collector plate 51 and the negative electrode current collector plate 55
The positive electrode terminal support portions 52, 53, 56, 57 are integrally formed with each of them.

The sealed battery of the present invention is not limited to the above-mentioned embodiments, but can be appropriately modified and improved. In addition, materials, shapes, dimensions, forms, numbers, and arrangements of the negative electrode, the positive electrode, the power generation element, the positive and negative electrode current collectors, the positive and negative electrode current collectors, the positive and negative electrode terminal support parts, and the like illustrated in each of the above-described embodiments. The location, thickness and the like are arbitrary and not limited as long as the present invention can be achieved.

[0030]

As described above, according to the present invention, as described in claim 1, each terminal supporting portion has a different longitudinal dimension from the other terminal supporting portions adjacent to each other. It is possible to prevent each current collector from interfering with another adjacent current collector. Accordingly, the width of the entire current collector can be suppressed to be small in a state where the current collectors are arranged, and thus the width of the power generation element can be narrowed. For this reason, the width of the sealed battery can be set narrower to make it compact, so that the efficiency of current collection can be improved.

Further, in the present invention, as described in claim 2, by crimping each current collecting portion, the metal foil can be stacked and accommodated in each current collecting portion in a stable state,
The adhesion between each current collector and the metal foil is improved. Therefore, the quality of the sealed battery can be improved.

Further, in the present invention, as described in claim 3, it is confirmed whether or not the metal foil is inserted into the depth of each current collecting portion by providing the notch on the ridge of each current collecting portion. it can. In addition, by providing a notch on the ridge of each current collector, each current collector can be easily bent at the ridge, and the tightness between each current collector and the metal foil can be improved.
It is possible to prevent problems during electric resistance welding. Therefore, the quality of the sealed battery can be improved.

Further, in the present invention, as described in claim 4, after the plate material is punched into a predetermined shape, the plate material is subjected to sheet metal working to form each current collector. Thus, by integrally forming the current collector and the current collector plate by punching, it is not necessary to join the current collector and the current collector plate, so that the current collecting resistance is not increased and the work is performed. Time and production costs can be reduced. Furthermore, the quality of the sealed battery can be improved.

Further, as described above, the active material non-coated portion of the metal foil provided for connection with the current collector plate can be set narrower than the conventional one. Therefore, since the active material can be applied over a wider area, it is possible to provide a sealed battery having a higher energy density than the conventional one.

[Brief description of drawings]

FIG. 1 is a perspective view showing a sealed battery according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the sealed battery according to the first embodiment of the present invention.

FIG. 3 is a development view showing a main part of the sealed battery according to the first embodiment of the invention.

FIG. 4 is a cross-sectional view showing a positive electrode current collector of the sealed battery according to the first embodiment of the present invention.

FIG. 5 is a perspective view showing a positive electrode current collector plate of a sealed battery according to a second embodiment of the present invention.

FIG. 6 is a side view showing a positive electrode current collector of a sealed battery according to a second embodiment of the present invention.

FIG. 7 is a development view showing a positive electrode current collector plate of a sealed battery according to a second embodiment of the present invention.

FIG. 8 is a perspective view showing a positive electrode current collector plate of a sealed battery according to a third embodiment of the present invention.

FIG. 9 is a side view showing a positive electrode current collector of a sealed battery according to a third embodiment of the present invention.

FIG. 10 is a perspective view showing a sealed battery according to a fourth embodiment of the present invention.

FIG. 11 is a perspective view showing a conventional sealed battery.

FIG. 12 is a perspective view showing a conventional sealed battery.

FIG. 13 is an enlarged view of a main part of a conventional sealed battery.

[Explanation of symbols]

10, 30, 40, 50 Sealed battery 12 Metal foil 14 Power generating element 15, 51 Current collector (positive electrode current collector) 16, 17, 31, 32, 41, 42, 52, 53 Current collector (positive electrode current collector) Part) 15D, 15E Terminal support part (positive electrode terminal support part) 20, 55 Current collector plate (negative electrode current collector plate)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tetsuo Ono             2-32 Kosobe-cho, Takatsuki City, Osaka Prefecture Stock             Ceremony company Yuasa Corporation F-term (reference) 5H022 AA02 BB03 BB16 CC12

Claims (4)

[Claims] 1. A metal foil, comprising: a power generation element including a metal foil serving as a negative electrode and a positive electrode via a separator; and a current collector plate connected to an edge of a plane direction of the metal foil by electric resistance welding. A plurality of current collectors each having a substantially V-shaped cross-section, each of which is stacked and housed, are provided on the current collector plate, and the current collectors are arranged in parallel with each other. The current collectors are connected to each other through terminal support portions provided at the ends in the longitudinal direction, and the terminal supports are provided so that the current collectors do not interfere with other adjacent current collectors. A sealed battery, wherein the portion has a longitudinal dimension different from that of the other terminal support portions adjacent to each other. 2. The sealed battery according to claim 1, wherein each current collecting portion is crimped in a direction in which the cross-sectional shape is closed around the ridgeline of each current collecting portion. 3. The sealed battery according to claim 1, wherein a cutout is provided so as to cross a ridgeline of each current collector. 4. The sealed battery according to claim 1, wherein each of the current collecting portions is formed by subjecting a plate material punched into a predetermined shape to sheet metal working.