JPH066460Y2 - Cylindrical battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a cylindrical battery having a spiral electrode body.

(B) Conventional technology As an example of this type of battery, as disclosed in Japanese Patent Publication No. 53-32851, one side made of a metal plate and one strip-shaped electrode plate in which an active material is held by an electrode plate core. There is a spiral electrode body in which another strip-shaped electrode plate obtained by crimping a lead piece is wound around a separator via a separator.

Here, the strip-shaped electrode plate in which the active material is held in the electrode plate core is prepared and then cut to a predetermined size for use.
When mechanically cutting with a slitter or the like, burr of the core occurs at the cut surface of the end face of the electrode plate.

(C) Problems to be solved by the invention As described above, when the burr of the core body is present on the end face of the electrode plate, the lead piece of the other electrode plate is close to the burr direction of the core body. However, there is a problem that the core and the lead piece come into contact with each other at the time of assembling or dropping the battery to cause an internal short circuit.

The present invention has been made in view of the above point, and an object thereof is to provide a battery structure in which an internal short circuit is unlikely to occur.

(D) Means for Solving the Problems There are various configurations of the cylindrical battery. That is, there are cases where the outer can is used as a positive electrode terminal or a negative electrode terminal, and where the outer can is used as a negative electrode terminal and the negative electrode lead piece is fixed to the negative electrode plate located at the outermost periphery of the electrode body.

The present invention provides a battery structure in which an internal short circuit is unlikely to occur according to these various forms, and the gist of the present invention is to provide a positive electrode plate having an active material held in an electrode plate core and a metal plate. And a negative electrode plate formed by fixing one end of a negative electrode lead piece to one surface and having a spirally wound electrode body wound via a separator, and an outer can that stores the electrode body also serves as a positive electrode terminal. The lead piece is fixed to the outer surface of the negative electrode plate, and the free end thereof is bent toward the center of the battery, and the end portion is fixed to the inner bottom surface of the negative electrode terminal member that closes the opening of the outer can. And the burr direction of the electrode plate core on the upper end surface of the positive electrode plate is in the battery inner / outer peripheral direction.

Also, a spirally wound electrode body is formed by winding a positive electrode plate having an electrode plate core body holding an active material and a negative electrode plate made of a metal plate and having one end of a negative electrode lead piece fixedly attached to one surface through a separator. The outer can for accommodating the electrode body also serves as a negative electrode terminal, the negative electrode lead piece is fixed to the inner surface of the negative electrode plate, and its free end is bent toward the center of the battery to form an end part. Is fixed to the inner bottom surface of the outer can, and the burr direction of the electrode plate core body on the lower end surface of the positive electrode plate is toward the inner center of the battery.

Further, a spirally wound electrode body is formed by winding a positive electrode plate in which an active material is held in a core plate of an electrode plate, and a negative electrode plate made of a metal plate and having one end of a negative electrode lead piece fixed to one surface via a separator. The outer can for accommodating the electrode body also serves as a negative electrode terminal, the negative electrode lead piece is fixed to the outer surface of the negative electrode plate located at the outermost periphery of the electrode body, and the free end of the negative electrode lead piece is in the center of the battery. A cylinder characterized in that the bent end is fixed to the inner bottom surface of the outer can, and the burr direction of the electrode plate core body at the lower end surface of the positive electrode plate is in the battery inner center direction. Type batteries.

(E) Action According to the battery structure of the present invention, the burr portion of the core body on the end face of one electrode plate and the lead piece of the other electrode plate are the most difficult to contact when the battery is assembled or dropped. Therefore, it is possible to suppress an internal short circuit caused by the contact between the core body and the lead piece.

(F) Example Example 1 A case where the outer can also serves as the positive electrode terminal will be described in detail with reference to FIGS. 1 to 3.

FIG. 1 is a vertical cross-sectional view of the battery immediately after assembly, FIG. 2 is a vertical cross-sectional view of the battery after a drop test, and FIG. 3 is an enlarged cross-sectional view of the main part of the upper right side of FIG.

In these figures, (1) is a positive electrode plate, and a mixture mainly composed of manganese dioxide is applied to both surfaces of a core body (2) consisting of a stainless lath net with a width of 100 mm, a thickness of 0.1 mm and a porosity of 50%. The original plate, which is put on and dried, is 25m wide by a slitter.
It was cut into m, length 90 mm, and thickness 0.5 mm, and at the time of this cutting, the burr (2 ') of the core body on the cut surface of the positive electrode plate (1)
Is occurring. In addition, (3) is a positive electrode lead piece in which a part of the active material of the positive electrode plate is removed and one end is fixed to the exposed core body.

(4) is a negative electrode plate made of a metallic lithium plate, and the negative electrode lead piece (5) is pressure-bonded to a part of the outer surface side thereof.

Then, when assembling the battery, the positive and negative electrode plates (1) and (4) are wound around the separator (6) to form a spiral electrode body. Here, the burr (2 ') of the core body (2) on the upper end surface of the positive electrode plate (1) faces the inner and outer peripheral portions of the battery. An insulating washer (7) is placed on the lower surface of this spiral electrode body, and the positive electrode is placed with the other end of the positive electrode lead piece (3) positioned on the outer surface of the washer (7) through the notch hole of the washer (7). The other end of the positive electrode lead piece (3) is housed in an outer can (8) that also serves as a terminal and a welding electrode (not shown) is inserted through the center hole (9) of the washer (7) to attach the other end of the outer can (8). Stick to the inner bottom surface.

Next, a ring-shaped inward projection (10) is formed on the upper portion of the outer can (8), and after injecting a predetermined amount of electrolytic solution, the negative electrode lead piece (5).
Bend the free end of the battery toward the center of the battery and fix the end to the inner bottom surface of the sealing lid (11) that also serves as the negative electrode terminal, and seal the sealing lid (11) through the insulating packing (12). After mounting in the opening of 8), bend the opening end of the outer can (8) inward to complete the battery. Let this battery be (A ₁ ).

In this embodiment, the positive and negative curved lead pieces (3) and (5) are not protected by an insulating tape, but each lead piece is partially covered with an insulating tape to improve safety. The present invention also includes the case where an insulating tape is used.

When such a battery is dropped with the sealing lid facing downward, the electrode body moves upward as shown in FIG. 2 and the portion of the free end of the negative electrode lead piece (5) close to the upper portion of the electrode body. Will move toward the inside and outside of the battery.

4, 5, and 6 are comparative batteries (B ₁ ), (B ₂ ), and (B ₃ ), which differ from the battery of the present invention in the crimping surface of the negative electrode lead piece to the negative electrode plate or the burr direction of the core body. The enlarged cross-sectional views of the essential parts of the above are respectively shown.

Table 1 shows a comparison of the occurrence rates of internal short circuits when 50 batteries were prepared for each of these batteries, and the batteries were assembled and after the drop test.

The drop test conditions were dropped from the sealing lid from a position 1 m above the ground, the number of drops was 10, and the short circuit occurrence rate after 10 drop tests was calculated.

Example 2 The case where the outer can also serves as the negative electrode terminal will be described in detail with reference to FIGS. 7 to 9.

FIG. 7 is a vertical cross-sectional view of the battery immediately after assembly, FIG. 8 is a vertical cross-sectional view of the battery after the drop test, and FIG. 9 is an enlarged cross-sectional view of the main part of the lower left portion of FIG.

Example 2 is different from Example 1 in that the outer can (8) also serves as a negative electrode terminal, the negative electrode lead piece (5) is fixed to the inner surface of the negative electrode plate (4) and the lead piece (5) is The free end is fixed to the inner bottom surface of the outer can (8), and the burr (2 ') on the lower end surface of the positive electrode plate (1) faces the center of the battery. Let this battery be (A ₂ ).

FIGS. 10, 11 and 12 show comparative batteries (B ₄ ), (B ₅ ), and (B ₆ ), which differ from the battery of the present invention in the crimping surface of the negative electrode lead piece to the negative electrode plate or the burr direction of the core body. The enlarged cross-sectional views of the essential parts of the above are respectively shown.

Table 2 compares the internal short circuit occurrence rates of these batteries, and the test conditions are the same as those in Table 1.

Example 3 The case where the outer can also serves as the negative electrode terminal and the negative electrode lead piece is attached to the negative electrode plate located at the outermost periphery of the electrode body will be described in detail with reference to FIGS. 13 to 15.

FIG. 13 is a vertical cross-sectional view of the battery immediately after assembly, FIG. 14 is a vertical cross-sectional view of the battery after the drop test, and FIG. 15 is an enlarged cross-sectional view of the main part of the lower left portion of FIG.

The third embodiment differs from the first embodiment in that the outer can (8) also serves as the negative electrode terminal, and the negative electrode plate positioned at the outermost periphery of the electrode body.
The negative electrode lead piece (5) is fixed to the outer surface of (4), and the burr portion (2 ') on the lower end surface of the positive electrode plate (1) faces the center of the battery. Let this battery be (A ₃ ).

FIGS. 16, 17 and 18 show comparative batteries (B ₇ ), (B ₈ ), and (B ₉ ), which differ from the battery of the present invention in the direction in which the negative electrode lead piece is pressed against the negative electrode plate or the burr direction of the core The enlarged cross-sectional views of the essential parts of the above are respectively shown.

Table 3 compares the internal short circuit occurrence rates of these batteries, and the test conditions are the same as those in Table 1.

(G) Effect of the Invention As is clear from Tables 1 to 3, according to the battery structure of the present invention in various types of cylindrical batteries, at the time of battery assembly and battery drop, the end surface of one electrode plate is Since the burr portion of the core body and the lead piece of the other electrode plate are the most difficult to contact, it is possible to suppress an internal short circuit due to the contact between the core body and the lead piece, and a highly safe cylinder Type battery can be provided, and its practical value is extremely large.

[Brief description of drawings]

1 to 3 relate to a first embodiment of the present invention.
FIG. 3 is a vertical cross-sectional view of the battery immediately after assembly, FIG. 2 is a vertical cross-sectional view of the battery after a drop test, and FIG. 3 is an enlarged cross-sectional view of the main part of the upper right side of FIG. 4 to 6 are enlarged cross-sectional views of a main part of the comparative battery corresponding to FIG. 7 to 9 relate to the embodiment of FIG. 2 of the present invention, FIG. 7 is a vertical sectional view of the battery immediately after assembly, FIG. 8 is a vertical sectional view of the battery after the drop test, and FIG. FIG. 8 is an enlarged sectional view of a main part of a lower left portion of FIG. 7. 10 to 12 are enlarged cross-sectional views of the main part of the comparative battery corresponding to FIG. 13 to 15 relate to a third embodiment of the present invention,
FIG. 13 is a vertical cross-sectional view of the battery immediately after assembly, FIG. 14 is a vertical cross-sectional view of the battery after a drop test, and FIG. 15 is an enlarged cross-sectional view of the essential part of the lower left side of FIG. 16 to 18 are enlarged cross-sectional views of a main part of the comparative battery corresponding to FIG. (1) …… Positive plate, (2) …… Core body, (2 ′) …… Burr,
(3) …… Positive electrode lead piece, (4) …… Negative electrode plate, (5) …… Negative electrode lead piece, (6) …… Separator, (7) …… Washer, (8)
…… Exterior can, (9) …… Central hole, (10) …… Inward projection, (11)
...... Sealing lid, (12) …… Insulating packing.

Claims (3)

[Scope of utility model registration request] 1. A positive electrode plate having an active material held on an electrode plate core,
A negative electrode plate made of a metal plate and having one end of a negative electrode lead piece fixed to one side thereof and a spirally wound electrode body wound via a separator, and an outer can that stores the electrode body also serves as a positive electrode terminal. The negative electrode lead piece is fixed to the outer surface of the negative electrode plate, and the free end of the negative electrode lead piece is bent toward the center of the battery, and the end of the negative electrode lead piece is attached to the inner bottom surface of the negative electrode terminal member that closes the opening of the outer can. A cylindrical battery, which is fixed and in which the burr direction of the electrode plate core body at the upper end surface of the positive electrode plate is the inner and outer peripheral direction of the battery. 2. A positive electrode plate having an active material held on an electrode plate core,
A negative electrode plate made of a metal plate and having one end of the negative electrode lead piece fixed to one surface thereof and a spirally wound electrode body wound via a separator, and an outer can that stores the electrode body also serves as a negative electrode terminal. The negative electrode lead piece is fixed to the inner surface of the negative electrode plate, and its free end is bent toward the center of the battery, and the end is fixed to the inner bottom surface of the outer can. A cylindrical battery, wherein a burr direction of the electrode plate core on the lower end face is a central portion direction inside the battery. 3. A positive electrode plate having an active material held on an electrode plate core,
A negative electrode plate made of a metal plate and having one end of the negative electrode lead piece fixed to one surface thereof and a spirally wound electrode body wound via a separator, and an outer can that stores the electrode body also serves as a negative electrode terminal. The negative electrode lead piece is fixed to the outer surface of the negative electrode plate located at the outermost periphery of the electrode body, and its free end is bent toward the center of the battery, and the end is fixed to the inner bottom surface of the outer can. The cylindrical battery is characterized in that the burr direction of the electrode plate core body on the lower end surface of the positive electrode plate is the central portion direction in the battery.