JP3475782B2 - Rechargeable battery - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode group in which a positive electrode and a negative electrode are wound with a separator interposed therebetween, a cylindrical container in which the electrode group is accommodated together with an electrolytic solution, and an output terminal led out from the end face of the cylindrical container. And a structure suitable for a secondary battery for an electric vehicle, in particular.

[0002]

2. Description of the Related Art Conventionally, a secondary electrode has an electrode group in which a positive electrode and a negative electrode are wound via a separator, a cylindrical container in which the electrode group is accommodated together with an electrolytic solution, and an output terminal led out from an end surface of the cylindrical container. In batteries, especially in secondary batteries for electric vehicles,
In order to reduce the internal resistance and improve the current collecting characteristics, as described in JP-A-9-92338, a large number of current collecting tabs are derived from the positive electrode or the negative electrode on the end face of the electrode group,
It has been proposed to weld the current collecting tab to the outer peripheral portion of the disk-shaped portion provided on the pole of the output terminal.

[0003]

However, if a disc-shaped portion for welding a large number of current collecting tabs is provided on the outer peripheral portion as described above, the disc-shaped portion becomes thick and the weight of the secondary battery is increased. Becomes heavy. On the other hand, in order to reduce the weight of the electrode group, when a thin piece of aluminum or aluminum alloy is used for the current collecting tab derived from the positive electrode and a thin piece of copper or copper alloy is used for the current collecting tab derived from the negative electrode, the resistance welding method is used. In the laser welding method, the current collecting tab is too melted and easily broken,
Even if a gentle ultrasonic welding method is adopted, the anvil must be arranged facing the ultrasonic wave transmitting horn at the outer peripheral portion of the disc-shaped portion and separated by the diameter of the disc-shaped portion. Easy to be incomplete. An object of the present invention is to provide a structure of a lightweight secondary battery having good current collecting property from a current collecting tab.

[0004]

A secondary battery of the present invention is made to solve the above problems. A first invention is an electrode group in which a positive electrode and a negative electrode are wound with a separator interposed therebetween, A secondary battery having a cylindrical container in which the electrode group is housed together with an electrolytic solution, and an output terminal led out from an end face of the cylindrical container, wherein the end face of the electrode group has a large number derived from the positive electrode or the negative electrode. The current collecting tab comprises a ring-shaped current collector welded to a metal ring periphery, and the ring-shaped current collector is electrically connected to the output terminal. The ring-shaped current collector can be made lightweight, and the ultrasonic transmitter horn is placed outside the ring-shaped collector, and the anvil is placed inside to enable ultrasonic welding with a close distance between the ultrasonic transmitter horn and the anvil. Multiple collector tabs and rings to enable Welding the current collecting portion is ensured, thus improving the current collection from the collector tab. The second invention is
In the first invention, a lead plate is connected between the ring-shaped current collector and the output terminal, and the lead plate comprises:
The length is longer than the distance between connections, and the surplus length portion is folded inside the peripheral edge of the ring-shaped current collector, so that a longer lead plate is used to The connection work between the current collector and the output terminal is facilitated, and the ring-shaped current collector can accommodate the extra length of the lead plate inside the peripheral edge thereof, thus improving space efficiency.

In a third aspect based on the first or second aspect, a lead plate is connected between the ring-shaped current collecting portion and the output terminal, and the lead plate is connected to the current collecting tab. By being characterized by being composed of a laminated body in which a plurality of the same materials are stacked, it is possible to reduce the weight while improving the material yield and the current collecting property. 4th invention has the resin-made support member which positions the said electrode group in the said cylindrical container in the end surface of the said electrode group in any one invention of 1st-3rd invention, Comprising: This resin Since the ring-shaped current collecting portion is fixed to a support member made of resin, the support member made of resin absorbs an impact to improve the earthquake resistance and reduce the weight. In a fifth aspect based on the fourth aspect, the ring-shaped current collecting portion has a through hole at a peripheral edge thereof and is fixed to the resin supporting member by a resin rivet inserted into the through hole. By being characterized in that, the resin rivet achieves easy and reliable fixing and weight reduction. A sixth invention is the invention of any one of the first to fifth inventions, wherein the positive electrode contains a substance capable of releasing lithium ions during charging, and the negative electrode contains a substance capable of absorbing lithium ions, and is derived from the positive electrode. The current collecting tab is a thin piece of aluminum or an aluminum alloy, and the current collecting tab led out from the negative electrode is a thin piece of copper or a copper alloy, thereby reducing the size and weight and improving the energy density.

[0006]

1 to 3 show an example of an embodiment of a secondary battery according to the present invention. FIG. 1 shows an assembly structure of a secondary battery of the present invention, which includes an electrode group 1 in which a positive electrode and a negative electrode are wound with a separator interposed therebetween, a cylindrical container 2 in which the electrode group 1 is housed together with an electrolytic solution, and a cylindrical body. A secondary battery having an output terminal 3 led out from an end face of a container 2, wherein a large number of collector tabs 4 led out from the positive electrode or the negative electrode are provided on a metal ring periphery at an end face of the electrode group 1. A welded ring-shaped current collector 5 is provided, and the ring-shaped current collector 5 is electrically connected to the output terminal 3. The ring-shaped current collector 5
The lead plate 6 is connected between the output terminal 3 and the output terminal 3, and the length of the lead plate 6 is longer than the distance between the connections. As shown in FIG. It is folded inside the peripheral edge of the ring-shaped current collector 5. Further, the lead plate 6 is made of a laminated body in which a plurality of the same materials as the current collecting tab 4 are stacked.

On the end face of the electrode group 1, there is provided a resin support member 7 for positioning the electrode group 1 in the cylindrical container 2, and the resin support member 7 has the ring-shaped current collecting portion. 5 is fixed. As shown in FIG. 3, the ring-shaped current collector 5 has a through hole at the periphery thereof, and the resin support member 7 is formed by a resin rivet 8 inserted into the through hole.
It is fixed to. The positive electrode contains a substance capable of releasing lithium ions during charging, the negative electrode contains a substance capable of absorbing lithium ions, and the current collecting tab 4 derived from the positive electrode is a thin piece of aluminum or aluminum alloy, derived from the negative electrode. The current collecting tab 4 is a thin piece of copper or a copper alloy. In FIG. 1, 9 is a resin spacer fitted to the resin supporting member 7, and 10 is a lid of the cylindrical container.

[0008]

As described above, according to the present invention, it is possible to provide a lightweight secondary battery having good current collecting property from the current collecting tab, and as a result, high energy density (Wh / kg, Wh / l) and output. Density (W / k
It can be used as a practical secondary battery for electric vehicles that requires g, W / l).

[Brief description of drawings]

FIG. 1 is a perspective view showing an assembly structure according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a lead plate connection structure according to an embodiment of the present invention.

FIG. 3 is an explanatory view showing a fixing structure of a ring-shaped current collector shown in FIG. 1 and a resin support member.

[Explanation of symbols]

1 is an electrode group, 2 is a cylindrical container, 3 is an output terminal, 4 is a current collecting tab, 5 is a ring-shaped current collecting portion, 6 is a lead plate, 7 is a resin support member, 8 is a resin rivet, 9 is a resin spacer, 10 is a lid of the cylindrical container

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kensuke Goto 2-8-7 Nihonbashi Honcho, Chuo-ku, Tokyo Shin-Kobe Electric Machinery Co., Ltd. (56) References JP-A-10-83805 (JP, A) JP-A 9-92338 (JP, A) JP-A-9-92258 (JP, A) JP-A-10-79243 (JP, A) JP-A-10-83833 (JP, A) JP-A-8-315834 (JP, A) A) Jikkou 57-1402 (JP, Y1) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01M 2/20-2/34 H01M 10/04 H01M 10/40

Claims (6)

(57) [Claims] 1. A secondary battery having an electrode group in which a positive electrode and a negative electrode are wound with a separator interposed therebetween, a cylindrical container in which the electrode group is accommodated together with an electrolytic solution, and an output terminal led out from an end surface of the cylindrical container. And, a plurality of current collecting tabs led out from the positive electrode or the negative electrode is provided on the end surface of the electrode group with a ring-shaped current collecting portion welded to a metal ring periphery, and the ring-shaped current collecting portion is provided. Is a secondary battery electrically connected to the output terminal. 2. A lead plate is connected between the ring-shaped current collector and the output terminal, and the lead plate has a length longer than a distance between connections and a portion having an excess length. The secondary battery according to claim 1, wherein the secondary battery is folded inside the periphery of the ring-shaped current collector. 3. The ring-shaped current collector and the output terminal are connected by a lead plate, and the lead plate is composed of a laminated body in which a plurality of the same materials as the current collector tab are stacked. The secondary battery according to claim 1 or 2, which is characterized in that. 4. A resin support member for positioning the electrode group in the cylindrical container is provided on an end surface of the electrode group, and the ring-shaped current collector is fixed to the resin support member. The secondary battery according to any one of claims 1 to 3, wherein 5. The ring-shaped current collector has a through hole in its periphery and is fixed to the resin support member by a resin rivet inserted in the through hole. The secondary battery according to claim 4. 6. The negative electrode contains a substance capable of releasing lithium ions during charging, the negative electrode contains a substance capable of absorbing lithium ions, and a current collecting tab led out from the positive electrode is a thin piece of aluminum or an aluminum alloy. The secondary battery according to any one of claims 1 to 5, wherein the current collecting tab derived from (1) is a thin piece of copper or a copper alloy.