JPH0636756A - Cylindrical battery - Google Patents

Abstract

PURPOSE:To reduce the IR loss and satisfactorily perform a high-duty discharge by arranging a metal spring inside a through hole provided on an insulator, and bringing the metal spring into contact with a seal cover and a current collection section to form an electric conducting passage. CONSTITUTION:An insulator 7 is provided with a bend section covering a current collection section 4 and a circular projection extended in the direction of a seal cover 3, and the current collection section 4 is prevented from being kept in contact with a battery can 1. A through hole is provided inside the circular projection, and a metal spring 6 is arranged inside it. The metal spring 6 is pressed into strong contact with the metal portion of the seal cover 3 and the current collection section 4 when the seal cover 3 is caulked to the battery can 1. The conducting passage of the seal cover 3 and the current collection section 4 can be branched. Pressure is applied to the current collection section 4 via the metal spring 6, a spiral electrode 2 is satisfactorily pressed, and the dropping of an electrode active material due to vibration can be prevented. The metal portion of the seal cover 3 and the current collection section 4 are connected by the metal spring 6 to form a current branch path, thus the IR loss is reduced, and a high-duty discharge can be satisfactorily performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a cylindrical battery, particularly to a current collector.

[0002]

2. Description of the Related Art Conventionally, in a cylindrical battery in which an electrode plate group is formed by spirally winding an anode plate and a cathode plate with a separator interposed therebetween, one end of a strip-shaped collector terminal is The other end of the electrode plate was connected to the sealing lid to conduct electricity. In this case, since all the current concentrates on the connection between the collector terminal and the electrode plate, there is a problem that IR loss is large and high rate discharge cannot be performed. 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 and the electrode plate.

[0003]

However, the conventional collector terminal is composed of a collector part connected to the electrode plate at multiple points and a lead part connected to the sealing lid. The connection had to be made before the sealing lid was sealed, and the lead part had a certain length or more. Therefore, in the case of high rate discharge of 6 fraction (10 C) or more, there is a problem that the IR loss of the lead portion becomes large. An object of the present invention is to provide a cylindrical battery that reduces the above IR loss and is excellent in high rate discharge.

[0004]

According to the present invention, a spirally wound electrode is provided in which a positive electrode plate and a negative electrode plate are spirally wound via a separator in a battery can closed by a sealing lid. Multiple points of plate-shaped current collectors are connected to the exposed core material exposed on the lid side of the spiral electrode, and the tip ends of the strip-shaped lead parts extending from one side of the current collector are connected to the lid. In a cylindrical battery in which an insulator is arranged so as to prevent the collector from coming into contact with the battery can, the insulator has a through hole, a metal spring is arranged inside the through hole, and the metal spring is It is characterized in that an electric conduction path is formed by contacting the sealing lid and the current collector.

[0005]

Since the present invention has the above-described structure, after the battery can is sealed with the sealing lid, the sealing lid and the current collecting portion of the current collector are connected or contact via the metal spring, so that the current can be branched. It is possible to reduce IR loss during high rate discharge and improve discharge characteristics. In the second aspect, since the cross section is flat, the contact between the wire rods is good, and the effect of lowering the resistance is great.

Further, in the third aspect, since the truncated cone-shaped portion produces elasticity in compression, it has an effect of pressing the electrode group.

[0007]

Embodiments of the present invention will be described in more detail with reference to the drawings. Example 1 FIGS. 1, 2 and 3 are sectional views of essential parts of a sealed Ni—Cd battery accommodating a metal spring according to the present invention. 4, 5 and 6 are perspective views of the metal springs used in FIGS. Figure 4
Is a flat spring, FIG. 5 is a compression coil spring having a polygonal cross section, and FIG. 6 is a compression coil spring having a polygonal cross section and a truncated cone shape in the compression direction of the spring. Fig. 7 shows the conventional closed type N
The principal part longitudinal cross-sectional view of an i-Cd battery is shown. 1, 2, and 3
In the battery shown in FIG. 7, the spiral electrode 2 is housed in the cylindrical battery can 1, and the sealing lid 3 is caulked at the opening of the battery can 1 to keep airtightness. The current collector is a plate-shaped current collector 4 and a sealing lid 3 for connecting or contacting one end of a spiral electrode 2 wound so that the long side end of one electrode plate is exposed from the separator. Has a strip-shaped lead portion 5 extending from one side of the current collector 4 for connecting to or contacting
The spiral electrode 2 is connected to the current collector 4 in advance to the end face of the electrode plate exposed by resistance welding, and the lead 5 and the sealing lid 3 are similarly connected by resistance welding. The insulator 7 has a bent portion that covers the current collector 4 and an annular protrusion that extends in the direction of the sealing lid 3, and prevents the current collector 4 from contacting the battery can 1. Further, a through hole is provided inside the annular convex portion, and the metal spring 6 is arranged in that portion except the battery shown in FIG. The metal spring 6 is pressed against the metal portion of the lid 3 and the current collector 4 when the lid 3 is caulked to the battery can 1, and is in strong contact with them. Therefore, the conduction path between the sealing lid 3 and the current collector 4 can be branched. Further, pressure is applied to the current collector 4 via the metal spring 6, so that the spiral electrode 2 is satisfactorily pressed and the electrode active material is prevented from falling off due to vibration or the like. Types of the metal spring 6 include a flat spring, a compression coil spring having a polygonal cross section, and a compression coil spring having a polygonal cross section and a truncated cone shape in the compression direction of the spring. A sintered nickel positive electrode and a sintered cadmium negative electrode were prepared according to a conventional method, spirally wound through a separator to form an electrode plate group, and then an SC battery having a nominal capacity of 1200 mAh was assembled. The battery having the structure of FIG. 1 was designated as A, the battery having the structure of FIG. 2 was designated as B, and the battery having the structure of FIG. 3 was designated as C. A battery having the conventional structure shown in FIG. 7 was also manufactured.
Table 1 shows the internal resistance of these batteries after charging.

[0008]

[Table 1]

As can be seen from Table 1, the battery A of the present invention,
The internal resistance of B and C is smaller than that of the conventional battery by 0.5 mΩ or more. FIG. 8 shows discharge curves when the battery A of the present invention and the conventional battery were charged at 1.2 A for 90 minutes at room temperature and then discharged at 20 A. As is clear from FIG. 8, the battery A of the present invention has excellent voltage characteristics at a high rate discharge of 3 fractions.

[0010]

As described above, according to the present invention, the metal portion of the sealing lid and the current collecting portion are connected by the metal spring, and the current branching path can be formed. As a result, IR loss is reduced and high rate discharge can be achieved. It can be done well. Further, by disposing the metal spring, it is possible to prevent the electrode active material from falling off due to vibration or the like.

[Brief description of drawings]

FIG. 1 is a sealed Ni housing accommodating a flat spring according to the present invention.
It is a principal part sectional drawing of a -Cd battery.

FIG. 2 is a cross-sectional view of essential parts of a sealed Ni—Cd battery accommodating a compression coil spring having a polygonal cross section according to the present invention.

FIG. 3 is a cross-sectional view of a main part of a hermetically sealed Ni—Cd battery accommodating a compression coil spring having a polygonal cross section according to the present invention and having a truncated cone shape in the compression direction of the spring.

FIG. 4 is a sectional view of a flat spring according to the present invention.

FIG. 5 is a sectional view of a compression coil spring having a polygonal sectional shape according to the present invention.

FIG. 6 is a cross-sectional view of a compression coil spring according to the present invention, which has a polygonal cross section and is frustoconical in the compression direction of the spring.

FIG. 7 is a vertical sectional view of a main part of a conventional sealed battery.

FIG. 8 is a relationship diagram showing the battery voltage during high rate discharge of the battery of the present invention and the conventional battery.

[Explanation of symbols]

1 is a battery can, 2 is a spiral electrode, 3 is a sealing lid, 4 is a current collecting part, 5 is a lead part, 6 is a metal spring, and 7 is an insulator.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsunori Oda 2-1-1, Nishishinjuku, Shinjuku-ku, Tokyo Shin-Kindo Electric Co., Ltd.

Claims (3)

[Claims] 1. A spirally wound electrode formed by spirally winding an anode plate and a cathode plate with a separator interposed in a battery can closed by a sealing lid, the spiraling electrode side of the spirally wound electrode. A plate-shaped current collector is connected to the exposed core material at multiple points, the tip of a strip-shaped lead extending from one side of the current collector is connected to the lid, and the current collector is a battery. In a cylindrical battery having an insulator arranged to prevent contact with a can, the insulator has a through hole, and a metal spring is arranged inside the through hole, and the metal spring is the sealing member. A cylindrical battery, wherein the cover and the current collector are in contact with each other to form an electric conduction path. 2. The cylindrical battery according to claim 1, wherein the metal spring is a compression coil spring, the wire rod has a polygonal cross-sectional shape, and the contact surfaces of the wire rods are flat. 3. The cylindrical battery according to claim 1, wherein a part or all of the metal spring has a truncated cone shape in the compression direction of the spring.