JPH0545898U - Cylindrical battery - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a cylindrical battery with reduced IR loss in the lead portion and excellent high rate discharge. [Structure] A spiral electrode 1 is arranged in a battery can 1 which is closed by a sealing lid 3, and a current collecting part 5 of a current collector 7 is connected to a multipoint connection to an exposed end of a core material of the spiral electrode 2. The tip portion of the lead portion 6 of the current collector 7 is connected to the terminal portion 3 a of the sealing lid 3,
In a cylindrical battery in which the insulator 8 is arranged so as not to contact the battery can 1, the metal foam 10 is arranged inside the through hole 9 of the insulator 8. The lead portion 6 is passed through the through hole 11 of the foam 10. The foam cover 10 is used to seal the lid 3 and the current collector 5.
A current branching path that connects and with the shortest length is formed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical battery, and more particularly to improvement of a current collecting portion thereof.

[0002]

[Prior Art]

 FIG. 3 shows a sealed Ni-Cd battery, which is a conventional cylindrical battery. The battery has a cylindrical battery can 1, and a spiral electrode 2 is housed inside the battery can 1. The spiral electrode 2 is configured by spirally winding with a separator interposed between an anode plate and a cathode plate. A sealing lid 3 is arranged inside the opening of the battery can 1, an insulating sealing material 4 is arranged on the outer periphery of the sealing lid 3, and the outer periphery of the sealing lid 3 is tightened via the insulating sealing material 4. By caulking 1, the opening of the battery can 1 is hermetically sealed.

At the exposed end portion of the core member exposed on the side of the sealing lid 3 of the spiral electrode 2, there is provided a plate-shaped current collector 5 and a strip-shaped lead 6 extending from one side of the current collector 5. The electric body 7 is arranged. The current collector 5 is connected at multiple points to the exposed end of the core material of the spiral electrode 2. The tip portion of the lead portion 6 is connected to the lower surface of the terminal portion 3 a provided on the sealing lid 3 by resistance welding. An insulator 8 is arranged to prevent the collector 7 from coming into contact with the battery can 1. The insulator 8 is provided with a through hole 9 through which the lead portion 6 is inserted.

In such a cylindrical battery, the current is wholly concentrated in the connection portion between the current collecting terminal 7 and the spiral electrode 2, so that there is a problem that the IR loss in the lead portion is large and high rate discharge cannot be performed. It was

Therefore, as disclosed in Japanese Patent Laid-Open No. 60-72160, a proposal has been made to increase the number of connection points between the collector terminal 7 and the spiral electrode 2.

[0006]

In this case, the connection between the sealing lid 3 and the lead portion 6 needs to be made before the sealing lid 3 is sealed, and the lead portion 6 has a certain length or more. I had. Therefore, there is a problem that the IR loss of the lead portion 6 becomes large in the case of high rate discharge of 6 fractions (10 C) or more.

An object of the present invention is to provide a cylindrical battery that reduces IR loss in the lead portion and is excellent in high rate discharge.

[0008]

[Means for Solving the Problems]

 The structure of the present invention which achieves the above object will be described. The present invention is a spirally wound electrode in which an anode plate and a cathode plate are spirally wound via a separator in a battery can closed by a sealing lid. And a current collector composed of a plate-shaped current collector and a lead extending from one side of the current collector is disposed at an exposed end of the core member exposed on the side of the sealing lid of the spiral electrode. The current collector is connected at multiple points to the exposed end of the core material, and the tip of the lead is connected to the terminal provided on the sealing lid to prevent the current collector from contacting the battery can. In a cylindrical battery in which an insulator is arranged in the insulator, and a through hole through which the lead portion is inserted is provided in the insulator, a metal foam is arranged inside the through hole of the insulator, and the foam is formed. Has a through hole through which the lead portion is inserted, and the foam is the sealing member. Abuts on the current collector is characterized by forming a current branch path with.

[0009]

[Action]

 According to this structure, after the sealing lid is sealed, the sealing lid and the current collecting portion of the current collector are branched and connected with the metal foam at the shortest length. It is possible to reduce the IR loss of the discharge part and improve the discharge characteristics.

[0010]

【Example】

 1 and 2 show an example of a sealed Ni-Cd battery as a cylindrical battery to which the present invention is applied. The parts corresponding to those in FIG. 3 described above are designated by the same reference numerals.

In this sealed Ni—Cd battery, the metal foam 10 is arranged inside the through hole 9 of the insulator 8. The metal foam 10 has a through hole 11 into which the lead portion 6 is inserted. The metal foam 10 is pressed by the sealing lid 3 and the current collector 5 when the sealing lid 3 is caulked with the battery can 1, and is in strong contact with them. Therefore, the metal foam 10 forms a current branching path for branching and connecting the sealing lid 3 and the current collector 5 with the shortest length. Further, since pressure is applied to the current collector 4 via the metal foam 10, the spirally-wound electrode 2 is satisfactorily pressed to prevent the electrode active material from falling off due to vibration or the like. Further, since the metal foam 10 absorbs the electrolytic solution liberated from the spiral electrode 2 into its pores, leakage of the free electrolytic solution from the sealing lid 3 is prevented.

[0012]

[Table 1] Table 1 shows a battery 1 without the metal foam 10 and a battery 2 with the metal foam 10 and the porosity changed to 98%, 90%, 76%, 48%, 32%. The relationship between the internal resistances of Battery 4, Battery 5, and Battery 6 and the number of leaked liquids after charging and discharging is shown. As is clear from the figure, in this experiment, when the porosity of the metal foam 10 was 48%, the number of leaked liquids after charge and discharge was the smallest.

A sintered nickel positive electrode and a sintered cadmium negative electrode were prepared according to a conventional method and spirally wound through a separator to form a spiral electrode (electrode plate group). An SC battery was assembled. The embodiment of the present invention is a battery A, and the conventional example is a battery B. Fig. 4 shows the discharge curves when each battery was charged at 1.2 A for 90 minutes at room temperature and then discharged at 20 A. As is clear from FIG. 4, the battery A of the present invention has excellent voltage characteristics at a high rate discharge of 3 minutes.

[0014]

[Effect of the device]

 As described above, in the cylindrical battery according to the present invention, the metal foam forms the current branching path by connecting the sealing lid and the current collecting portion of the current collector with the shortest length. The IR loss of the lead part is reduced, and high rate discharge can be favorably performed. Further, according to the present invention, the spiral foam electrode housed in the battery can is pressed by disposing the metal foam, so that the active material can be prevented from falling off due to vibration or the like. Further, since the metal foam absorbs the free electrolytic solution, it is possible to prevent the electrolytic solution from leaking from the sealing lid.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of a cylindrical battery according to the present invention.

2 is a perspective view of the metal foam used in FIG. 1. FIG.

FIG. 3 is a vertical cross-sectional view of a conventional cylindrical battery.

FIG. 4 is a comparison diagram showing changes in battery voltage during high rate discharge of the cylindrical battery according to the present invention and the conventional cylindrical battery.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Battery can, 2 ... Spiral electrode, 3 ... Sealing lid, 3a ... Terminal part, 4 ... Insulating sealing material, 5 ... Current collecting part, 6 ... Lead part, 7
... current collector, 8 ... insulator, 9 ... through hole, 10 ... metal foam, 11 ... through hole.

Claims (1)

[Scope of utility model registration request] 1. A spirally wound electrode, which is formed by spirally winding an anode plate and a cathode plate through a separator, is arranged in a battery can closed by a sealing lid, and the spirally wound electrode side of the spirally wound electrode. A current collector including a plate-shaped current collector and a lead extending from one side of the current collector is disposed at the exposed end of the core, and the current collector is provided at multiple points at the exposed end of the core. The tip of the lead portion is connected to a terminal portion provided on the sealing lid, and an insulator is arranged to prevent the current collector from coming into contact with a battery can. In a cylindrical battery having a through hole through which a lead portion is inserted, a metal foam is disposed inside the through hole of the insulator, and the foam has a through hole through which the lead portion is inserted. And the foam is in contact with the sealing lid and the current collector to form a current branching path. Cylindrical battery, characterized in that there.