JP2532434Y2 - Cylindrical lithium battery - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spiral-shaped cylindrical lithium battery having a characteristic shape of a negative electrode current collector.

[0002]

2. Description of the Related Art FIG. 5 is a front view showing an example of a conventional negative electrode current collector used for a spiral cylindrical lithium battery. FIG. 6 is a conventional negative electrode current collector used for a spiral cylindrical lithium battery. 7 is an enlarged sectional view showing an example of the surface shape of the negative electrode current collector shown in FIG. 5 or FIG. 6, and FIG. 8 is a surface of the negative electrode current collector shown in FIG. 5 or FIG. It is an expanded sectional view showing another example of a shape.

Conventionally, the overall shape of this type of negative electrode current collector 9 is generally L-shaped as shown in FIG. 5 or rod-shaped as shown in FIG. As the surface shape of the negative electrode contact portion 15 that comes into contact, a surface in which a plurality of biting projections 15f are formed as shown in FIG. 7 and a surface in which irregularities 15g are formed as shown in FIG. Had been.

[0004]

[Problem to be solved by the invention] However, in this case, L
Regardless of the character shape or the rod shape, since the welded portion 16 to be welded to the negative electrode can is elongated and narrow, a sufficient welding area is not ensured, and there is a risk of poor welding.

On the other hand, when the negative electrode contact portion 15 is formed with a plurality of biting projections 15f (see FIG. 7), when the lithium negative electrode 6 is consumed by discharging, these biting projections 15f are exposed, There was a risk that the separator would break and penetrate. On the other hand, in the case where the concave and convex portions 15g are formed on the negative electrode contact portion 15 (see FIG. 8), the adhesion to the lithium negative electrode 6 is insufficient as compared with the bite projection 15f, and the negative electrode contact portion 15 is missing during the manufacturing process or a predetermined pressure There was a risk of movement (deviation) from the surface.

[0006] In view of the above circumstances, the present invention has no welding failure with the negative electrode can, prevents penetration of the separator due to exposure of biting projections accompanying consumption of the lithium negative electrode, and ensures close contact with the lithium negative electrode. It is an object to provide a cylindrical lithium battery having a negative electrode current collector.

[0007]

According to the present invention, a negative electrode current collector (9) comprising a substantially rectangular negative electrode contact portion (15) and a welded portion (16) is replaced with a sheet-like lithium negative electrode (6). ) Through the negative electrode abutting portion, and a separator (5) and a positive electrode (3) are superposed thereon and spirally wound to form an electrode group (7). The electrode group is placed in the negative electrode can (2). And a perforation (15d) is formed in the negative electrode contact portion of the cylindrical lithium battery (1) formed by welding the bottom portion (2b) of the negative electrode can and the welded portion of the negative electrode current collector. Recess (15
c) are arranged in the length direction of the negative electrode contact portion, and bent portions (1) are provided at both ends in the width direction of the negative electrode contact portion.
5a, 15b) is formed using a negative electrode current collector formed by bending the negative electrode current collector in the negative electrode pressing direction.

[0008] Further, the welding portion (16) has a substantially circular shape,
The diameter (D1) is larger than the width (W1) of the negative electrode contact portion (15) and is equal to or less than the outer diameter of the electrode group (7). A burr (15e) is formed around the perforation (15d).
Are formed in the direction opposite to the negative electrode crimping direction.

Further, the bent portions (15a, 15b) are configured such that the bending depth is smaller than the depth of the concave portion (15c).

It is to be noted that the numbers in parentheses are for convenience showing corresponding elements in the drawings, and therefore, the present invention is not limited to the description on the drawings. The same applies to the fields of “claims for registering utility model” and “action”.

[0011]

According to the present invention, when the negative electrode current collector (9) is pressure-bonded to the lithium negative electrode (6), the lithium negative electrode enters the perforations (15d) of each recess (15c) and is securely adhered. Then, the bent portions (15a, 15b) bite into the lithium anode to prevent the movement of the anode current collector. Further, when welding the negative electrode current collector to the bottom portion (2b) of the negative electrode can, the welding position does not come to the end of the current collector, and the accuracy may be roughened.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front sectional view showing an embodiment of a cylindrical lithium battery according to the present invention. FIG. 2 is a view of a negative electrode current collector constituting the cylindrical lithium battery shown in FIG. FIG. 3B is an enlarged sectional view taken along line AA of FIG. 3A, FIG. 3 is a front view showing a state where a negative electrode current collector is attached to a lithium negative electrode, and FIG. 4 is a perspective view showing an electrode group. is there.

As shown in FIG. 1, the cylindrical lithium battery 1 according to the present invention has a cylindrical negative electrode can 2 having a bottom.
In the negative electrode can 2, an electrode group 7 in which a sheet-shaped positive electrode 3 mainly composed of manganese dioxide, a separator 5 and a sheet-shaped lithium negative electrode 6 are stacked and spirally wound is accommodated. A positive electrode terminal plate 12 is attached to the opening 2 a of the negative electrode can 2 via a sealing gasket 10.
The positive electrode terminal plate 12 is connected to the positive electrode 3 of the electrode group 7 via a positive electrode lead plate 13. Further, a negative electrode current collector 9 is attached to the lithium negative electrode 6 of the electrode group 7, and the tip of the negative electrode current collector 9 is fixed to the bottom 2 b of the negative electrode can 2 by spot welding.

By the way, this negative electrode current collector 9 is shown in FIG.
As shown in (a), a substantially rectangular negative electrode contact portion 15,
The negative electrode contact portion 15 and a substantially circular welded portion 16 integrally formed. Bent portions 15a and 15b are provided at both ends in the width direction (left and right direction in FIG. 2A) of the negative electrode contact portion 15 at a predetermined angle (for example, 45 degrees) in the negative electrode crimping direction (FIG. 2B downward). °), and a plurality of dish-shaped recesses 15 c are arranged in a staggered manner in two rows at the center in the width direction of the negative electrode contact portion 15. A circular hole 15d is formed in the center of each recess 15c, and a burr 15e is formed around the hole 15d in a direction opposite to the negative electrode crimping direction.

Since the cylindrical lithium battery 1 according to the present invention has the above-described structure, the manufacturing of the cylindrical lithium battery 1 is performed as follows. That is, first,
As shown in FIG. 3, the negative electrode current collector 9 is pressure-bonded to a predetermined position on the sheet-shaped lithium negative electrode 6 via the negative electrode contact portion 15, and an insulating tape 17 is attached to the back side. Next, the positive electrode 3 is laminated on the lithium negative electrode 6 with the separator 5 interposed therebetween, and this is spirally wound to form a cylindrical electrode group 7. Next, as shown in FIG. 4, an insulating plate 19 is disposed on the bottom of the electrode group 7, and the negative electrode current collector 9 is bent so that the welded portion 16 is located at the center of the bottom of the electrode group 7. . In this state, this is inserted into the negative electrode can 2, and the negative electrode can 2
And the welded portion 16 of the negative electrode current collector 9 is spot-welded. At this time, the diameter D1 of the welded portion 16 of the negative electrode current collector 9
Is larger than the width W1 of the negative electrode contact portion 15,
Since the area of the electrode 6 becomes large, the hole at the center of the electrode group 7 can be reliably closed, thereby preventing poor welding with the negative electrode can 2.

Next, as shown in FIG. 1, a predetermined amount of the electrolytic solution 20 is injected into the negative electrode can 2, and then the opening 2 of the negative electrode can 2 is opened.
The positive electrode terminal plate 12 is mounted on the battery pack a through the sealing gasket 10, and in this state, the opening 2a is caulked and curled, and the production of the cylindrical lithium battery 1 is completed.

[0018]

[Effects of the Invention] As described above, according to the present invention,
A negative electrode current collector 9 composed of a substantially rectangular negative electrode contact portion 15 and a welded portion 16 is pressure-bonded to a sheet-shaped lithium negative electrode 6 via the negative electrode contact portion 15, and a separator 5 and a positive electrode 3 are stacked thereon. The negative electrode can 2 was inserted into the negative electrode can 2, and the bottom 2b of the negative electrode can 2 and the welded portion 16 of the negative electrode current collector 9 were welded. In the cylindrical lithium battery 1, the perforated 1
A plurality of concave portions 15c in which 5d are formed are provided in the length direction of the negative electrode contact portion 15, and bent portions 15a and 15b are respectively provided at both ends in the width direction of the negative electrode contact portion 15 in the negative electrode crimping direction. The negative electrode current collector 9 formed in a bent shape was used. Therefore, when the negative electrode current collector 9 is pressed against the lithium negative electrode 6, the lithium negative electrode 6 enters the perforations 15 d of each of the recesses 15 c and securely adheres to the bent portion 15 a,
15b bites into the lithium negative electrode 6 to prevent the negative electrode current collector 9 from moving. Accordingly, it is possible to prevent the separator 5 from penetrating due to the consumption of the lithium negative electrode 6 due to the discharge as seen in the biting protrusion and to ensure the close contact with the lithium negative electrode 6.

If the welded portion 16 is formed to be substantially circular and the diameter D1 is larger than the width W1 of the negative electrode contact portion 15 and equal to or less than the outer diameter of the electrode group 7, the welded portion 16 of the negative electrode current collector 9 is formed. Is large, the welded portion 16 reliably closes the center hole of the electrode group 7. From this, when the negative electrode current collector 9 is welded to the bottom 2b of the negative electrode can 2, the welding position does not come to the end of the current collector and the accuracy can be roughened. Defects can be prevented.

A burr 15e is formed around the perforation 15d.
Is formed so as to face in the direction opposite to the negative electrode pressing direction, the burr direction of the perforation 15d of the concave portion 15c is opposite to the negative electrode pressing surface, so that the negative electrode current collector 9 generated by the consumption of the lithium negative electrode 6 due to the discharge. It is possible to prevent occurrence of a situation in which the negative electrode current collector 9 and the separator 5 penetrate through the exposure.

Further, when the bent portions 15a and 15b are formed so that the bent depth is smaller than the depth of the concave portion 15c,
Since the bent portions 15a and 15b of the negative electrode contact portion 15 are shallower than the concave portions 15c, the bent portions 15a and 15b are separated by the exposure of the negative electrode current collector 9 due to consumption of the lithium negative electrode 6.
Never contact.

[Brief description of the drawings]

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

2 is a diagram of a negative electrode current collector constituting the cylindrical lithium battery shown in FIG. 1, (a) is a front view, and (b) is an enlarged cross-sectional view taken along line AA of (a).

FIG. 3 is a front view showing a state where a negative electrode current collector is attached to a lithium negative electrode.

FIG. 4 is a perspective view showing an electrode group.

FIG. 5 is a front view showing an example of a conventional negative electrode current collector used for a cylindrical lithium battery having a spiral structure.

FIG. 6 is a front view showing another example of a conventional negative electrode current collector used for a cylindrical lithium battery having a spiral structure.

FIG. 7 is an enlarged sectional view showing an example of the surface shape of the negative electrode current collector shown in FIG. 5 or FIG.

FIG. 8 is an enlarged sectional view showing another example of the surface shape of the negative electrode current collector shown in FIG. 5 or FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cylindrical lithium battery 2 ... Negative electrode can 2b ... Bottom part 3 ... Positive electrode 5 ... Separator 6 ... Lithium negative electrode 7 ... Electrode group 9 ... Negative electrode current collector 15 ... Negative electrode contact part 15a 15b Folded portion 15c Concave portion 15d Drilled hole 15e Burr 16 Welded portion D1 Diameter of welded portion W1 Width of negative electrode contact portion

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaaki Suzuki 5-36-11 Shimbashi, Minato-ku, Tokyo Inside Fuji Electric Chemical Co., Ltd. (56) References JP-A-63-13258 (JP, A) JP-A Hei 4-292857 (JP, A) Real opening Hei 4-47264 (JP, U) Real opening Sho-59-4171 (JP, U)

Claims (4)

(57) [Scope of request for utility model registration] 1. A negative electrode current collector (9) comprising a substantially rectangular negative electrode contact portion (15) and a welded portion (16) is attached to a sheet-like lithium negative electrode (6) via the negative electrode contact portion. Crimping, a separator (5) and a positive electrode (3) are overlapped and wound spirally to form an electrode group (7), and the electrode group is inserted into the negative electrode can (2), and the bottom of the negative electrode can (2) 2b) and a welded portion of the negative electrode current collector, wherein the cylindrical lithium battery (1) is formed by welding a concave portion (15) in which a perforation (15d) is formed in the negative electrode contact portion.
c) are arranged in the length direction of the negative electrode contact portion, and bent portions (1) are provided at both ends in the width direction of the negative electrode contact portion.
A cylindrical lithium battery using a negative electrode current collector formed by bending 5a, 15b) in the negative electrode pressing direction. 2. The welding part (16) is substantially circular, and its diameter (D1) is larger than the width (W1) of the negative electrode contact part (15) and is equal to or less than the outer diameter of the electrode group (7). The cylindrical lithium battery according to claim 1, wherein: 3. A burr (15e) around the perforation (15d).
The cylindrical lithium battery according to claim 1, wherein the battery is formed in a direction opposite to a direction in which the negative electrode is crimped. 4. The cylindrical lithium battery according to claim 1, wherein the bending depth of the bent portions (15a, 15b) is smaller than the depth of the concave portion (15c).