JP5630859B2 - Cylindrical storage battery - Google Patents

Description

  The present invention relates to a cylindrical storage battery, and more particularly to a structure of a cylindrical storage battery.

For example, a cylindrical storage battery such as a nickel metal hydride secondary battery is configured by winding a positive electrode plate and a negative electrode plate in a spiral shape with a separator sandwiched in a cylindrical sealed container.
In such a cylindrical storage battery, a positive electrode current collector plate of a positive electrode plate is provided on one end side, and a negative electrode current collector plate of a negative electrode plate is provided on the other end side, and these positive electrode current collector plate and negative electrode current collector plate are batteries. Are respectively electrically connected to the positive electrode and the negative electrode.
The positive electrode plate includes a substrate made of a metal porous body, and this substrate is filled with an active material. A connecting portion made of a metal porous body integrally protrudes from the end portion on the one end side of the substrate, and a metal thin plate is welded or the like extending along the end portion on one surface of the connecting portion.

By the way, in the cylindrical storage battery, the material is different between the metal porous body and the metal thin plate. Generally, the metal porous body is soft and easy to bend while the metal thin plate is hard and difficult to bend. At the end portion on the side, that is, at the beginning of winding of the positive electrode plate, there is a problem that the metal porous body is easily cut at the connection portion between the metal thin plate and the metal porous body connection portion. If the metal porous body is cut in this way, the tip of the thin metal plate protruding away from the metal porous body breaks the separator and may come into contact with the adjacent negative electrode plate, resulting in an internal short circuit.
Therefore, for example, a technique for preventing an internal short circuit by covering a connecting portion between a thin metal plate and a connecting portion of a metal porous body with an insulating coating such as an adhesive tape is known (see Patent Document 1).

JP-A-11-307089

However, as disclosed in Patent Document 1, it is not easy to appropriately apply a relatively small adhesive tape to the connecting portion between the metal thin plate and the connecting portion of the metal porous body. There's a problem.
The present invention has been made based on the above-described circumstances, and an object of the present invention is to provide a cylindrical storage battery that can suppress the occurrence of an internal short circuit with a simple configuration.

In order to achieve the above object, a cylindrical storage battery according to claim 1 is a cylinder in which an electrode group formed by spirally winding a positive electrode plate and a negative electrode plate via a separator is housed in a cylindrical outer can. A positive electrode current collector plate is interposed between the positive electrode plate and the positive electrode terminal of the outer can so as to be energized, and the positive electrode plate is made of a metal porous body filled with a positive electrode active material. A conductive positive electrode substrate; and a strip-shaped metal thin plate that is protruded and joined to the positive electrode current collector plate side at an end of the positive electrode substrate on the positive electrode current collector plate side, the metal thin plate being the positive electrode current collector plate The negative electrode plate is separated from the positive electrode current collector plate, and the thin metal plate is disposed at an end corresponding to the start of winding of the positive electrode plate and the positive electrode substrate. Are connected to the corners on the positive electrode current collector plate side so as to be displaced inward of the positive electrode substrate. Yo, characterized in that by forming a cut-out notch obliquely.

  The cylindrical storage battery according to claim 2 is the cylindrical storage battery according to claim 1, wherein the notch is formed on the side of the notch of the metal thin plate and the side of the positive electrode current collector plate of the positive electrode substrate when the metal thin plate is joined to the positive electrode substrate. It is characterized by being cut out obliquely toward the positive electrode substrate with a corner portion on the positive electrode current collector plate side as a base point so that an angle formed with a side is in a range of 60 ° to 85 °.

The cylindrical storage battery according to claim 3 is characterized in that, in claim 1 or 2, the upper end of the negative electrode plate is positioned below the lower end of the thin metal plate.
The cylindrical storage battery according to claim 4 is characterized in that, in any one of claims 1 to 3, the upper end of the separator is located between the upper end of the negative electrode plate and the positive electrode current collector plate.

  According to the cylindrical storage battery of claim 1 of the present invention, in the cylindrical storage battery in which the electrode group formed by spirally winding the positive electrode plate and the negative electrode plate through the separator is housed in the cylindrical outer can. The negative electrode plate is separated from the positive electrode current collector plate, and at the end corresponding to the beginning of winding of the positive electrode plate of the thin metal plate joined to the positive electrode substrate, the connecting portion between the thin metal plate and the positive electrode substrate is the positive electrode current collector plate A cutout portion is formed so as to be positioned so as to be displaced inward of the positive electrode substrate with respect to the corner portion on the side.

Therefore, at the end corresponding to the beginning of winding of the positive electrode plate, the positive electrode substrate was cut at the connecting portion between the metal thin plate and the positive electrode substrate, and the tip of the metal thin plate on the positive electrode current collector plate side broke the separator and reached the area of the negative electrode plate. However, since the negative electrode plate is separated from the positive electrode current collector plate, the tip of the metal thin plate does not come into contact with the negative electrode plate, and the portion corresponding to the connecting portion of the metal thin plate and the positive electrode substrate in the metal thin plate Since it is not sharp compared to the tip, breaking the separator to reach the area of the negative electrode plate is preferably suppressed.
Thereby, it is possible to prevent the metal thin plate and the negative electrode plate of the positive electrode plate from being inadvertently short-circuited, and to prevent an internal short-circuit of the cylindrical storage battery with a simple configuration. Therefore, the production efficiency (yield) of the cylindrical storage battery can be improved, and the safety of the cylindrical storage battery can be improved.

  Further, according to the cylindrical storage battery of claim 2, the cutout portion is formed so that an angle formed between the cut-out side of the thin metal plate and the side of the positive electrode substrate on the side of the positive electrode current collector plate is in a range of 60 ° to 85 °. Since the corner on the side of the positive electrode current collector plate is cut away obliquely toward the positive electrode substrate, if the angle is less than 60 °, the positive electrode substrate is likely to be cut at the connecting portion between the thin metal plate and the positive electrode substrate. If the angle exceeds 85 °, the entire tip of the thin metal plate may penetrate the separator and reach the area of the negative electrode plate. However, such inconvenience can be avoided and an internal short circuit can be surely prevented.

  According to the cylindrical storage battery of claim 3, since the upper end of the negative electrode plate is located below the lower end of the thin metal plate, the protruding portion of the thin metal plate from the positive electrode substrate penetrates the separator and reaches the region of the negative electrode plate. Even if it does, since there is no negative electrode plate in this range, it can avoid reliably that the front-end | tip of a metal thin plate contacts a negative electrode plate, and can prevent an internal short circuit.

  According to the cylindrical storage battery of claim 4, since the upper end of the separator is located between the upper end of the negative electrode plate and the positive electrode current collector plate, the positive electrode substrate is a metal thin plate and a positive electrode substrate at the end corresponding to the start of winding of the positive electrode plate. Even if it cuts at the connecting part, the side of the notch part of the metal thin plate hits the separator, and the part corresponding to the connecting part of the metal thin plate and the positive electrode substrate breaks the separator and the region of the negative electrode plate It is preferably prevented from reaching.

It is the longitudinal cross-sectional view which expanded and showed a part about the nickel hydride secondary battery which concerns on one Embodiment of the cylindrical storage battery of this invention. It is sectional drawing which shows the connection part of the positive electrode plate, positive electrode current collector plate, negative electrode plate, and negative electrode current collector plate in the nickel hydride secondary battery of FIG. It is a front view which shows the positive electrode plate of the nickel hydride secondary battery of FIG. It is a cross-sectional view in the AA line of FIG. 1, Comprising: It is a figure explaining the effect of the nickel-hydrogen secondary battery which concerns on this invention. FIG. 3 is a diagram in which the contents related to the operational effects of the nickel hydride secondary battery according to the present invention are added to FIG. 2.

FIG. 1 is a longitudinal sectional view showing a part of a cylindrical nickel-hydrogen secondary battery according to an embodiment of the cylindrical storage battery of the present invention.
The nickel metal hydride secondary battery (cylindrical storage battery) includes a cylindrical outer can 2 having one end opened, and the outer can 2 has conductivity. In the outer can 2, a substantially cylindrical electrode group 4 is accommodated together with an alkaline electrolyte (not shown). The electrode group 4 is spirally wound with a strip-like positive electrode plate 6 and a negative electrode plate 8 sandwiching a separator 10. It is formed by winding in a shape.

The opening of the outer can 2 is closed by a lid body 14, and the lid body 14 includes a substantially circular lid plate 16 having a valve hole 16a in the center. The outer peripheral portion of the cover plate 16 is fixed by caulking an opening edge to the outer can 2 via an insulating gasket 18. Further, on the outer surface of the cover plate 16, a valve body 20 in which rubber and a metal plate are laminated so as to close the valve hole 16 a is disposed, and a cylindrical positive electrode terminal 22 with a flange so as to cover the valve body 20. Is fixed. A compression coil spring 24 that energizes the valve body 20 is accommodated in the positive electrode terminal 22.
One end of the bent positive electrode lead 26 is welded to the inner surface of the lid plate 16, and the other end of the positive electrode lead 26 is connected to a circular positive electrode current collector plate 28. On one end side of the electrode group 4, the positive electrode current collector plate 28 and the positive electrode plate 6 are electrically connected, whereby the positive electrode plate 6 and the positive electrode terminal 22 are electrically connected.

The positive electrode plate 6 is a non-sintered electrode, for example, and has a conductive positive electrode substrate 7 having a strip shape. The positive electrode substrate 7 is a porous metal body having a porous structure, and includes innumerable holes formed by a skeleton having a three-dimensional network structure. In the holes of the positive electrode substrate 7, nickel hydroxide is used as a positive electrode active material. The particles are filled.
As shown in a cross-sectional view of the connection between the positive electrode plate and the positive electrode current collector plate and the negative electrode plate and the negative electrode current collector plate in FIG. 2, the end of the positive electrode substrate 7 on the positive electrode current collector plate 28 side is made of a porous metal body. A connecting portion 30 is formed extending. And the strip | belt-shaped metal thin plate 32 which consists of nickel ribbon etc., for example is joined and fixed to the inner surface of the connection part 30 by welding or a conductive adhesive.
The metal thin plate 32 protrudes from the connecting portion 30 toward the positive electrode current collector plate 28 as viewed in the axial direction of the nickel metal hydride secondary battery, and the radial inner surfaces of the metal thin plate 32 and the positive electrode substrate 7 are substantially flush with each other. .

Thus, the metal thin plate 32 is joined to the end portion of the positive electrode substrate 7, so that the positive electrode current collector plate 28 and the positive electrode plate 6 are in contact with each other through the metal thin plate 32 and are reliably electrically connected.
FIG. 3 is a front view showing the positive electrode plate of the nickel hydride secondary battery shown in FIG. 1, and the details of the configuration of the positive electrode plate 6 according to the present invention will be described below.
As described above, the positive electrode plate 6 is configured by fixing the metal thin plate 32 to the connecting portion 30 by welding or a conductive adhesive. Of the metal thin plate 32, the electrode group 4 is used as a nickel metal hydride secondary battery. The end located on the center side of the nickel-metal hydride secondary battery when housed, that is, the end corresponding to the start of winding of the positive electrode plate 6 with a reduced winding diameter is based on the corner on the positive current collector plate 28 side as the positive electrode substrate. 7 is formed in an oblique cutout 7 to form a cutout portion 33.

  Here, as to the amount by which the metal thin plate 32 is notched in the notch 33, the notched side of the metal thin plate 32 and the positive electrode of the positive electrode substrate 7 when the metal thin plate 32 is fixed to the connecting portion 30, as shown in FIG. The angle formed by the side on the current collecting plate 28 side (the included angle) is set to be in the range of 60 ° to 85 °. That is, at the end corresponding to the start of winding of the positive electrode plate 6, the metal thin plate 32 is connected to the corner on the positive electrode current collecting plate 28 side at the connecting portion between the thin metal plate 32 and the positive electrode substrate 7. It is comprised so that it may be biased and located inward.

On the other hand, the negative electrode plate 8 is made of a hydrogen storage alloy and has a conductive negative electrode substrate 9 having a strip shape. The negative electrode substrate 9 is configured by filling the surface of an electrode plate core with a paste-like hydrogen storage alloy as a negative electrode active material.
The upper end of the negative electrode plate 8 is configured to be positioned below the lower end of the thin metal plate 32, and the upper end of the separator 10 is positioned between the upper end of the negative electrode plate 8 and the positive electrode current collector plate 28. It is configured.
Hereinafter, the function and effect of the electrode group 4 configured as described above will be described.
4 is a cross-sectional view taken along line AA in FIG. 1, that is, a view showing a wound state of the electrode group 4 housed in the outer can 2.

In FIG. 4, the metal thin plate 32 when the metal thin plate 32 of the positive electrode plate 6 is appropriately wound together with the positive electrode substrate 7 is indicated by a solid line, and at the end corresponding to the start of winding of the positive electrode plate 6, the positive electrode substrate 7. Is shown by a broken line when the metal thin plate 32 is cut at the connecting portion between the thin metal plate 32 and the positive electrode substrate 7.
As shown in the figure, when the positive electrode substrate 7 is cut at the connection portion between the thin metal plate 32 and the positive electrode substrate 7 at the end corresponding to the start of winding of the positive electrode plate 6, the thin metal plate 32 is attached to the positive electrode substrate 7. It follows away from the positive electrode substrate 7 without being bent, and the tip S is sharp, so the separator 10 is broken and reaches the region of the negative electrode plate 8.

  However, referring to FIG. 5, there is shown a state in which the tip S of the thin metal plate 32 breaks the separator 10 and reaches the region of the negative electrode plate 8 with respect to FIG. The end of the negative electrode substrate 9 of the negative electrode plate 8, that is, the upper end of the negative electrode plate 8 is configured to be sufficiently spaced from the positive electrode current collector plate 28, and further corresponds to the start of winding of the positive electrode plate 6. At the end, the metal thin plate 32 is positioned inwardly of the positive electrode substrate 7 with respect to the corner on the positive electrode current collecting plate 28 side at the connecting portion between the metal thin plate 32 and the positive electrode substrate 7. Even if the tip S on the side of the positive electrode current collector plate 28 breaks the separator 10 and reaches the region of the negative electrode plate 8, the tip S of the metal thin plate 32 does not contact the negative electrode plate 8. The part corresponding to the connection part of the metal thin plate 32 and the positive electrode substrate 7 Since blunt than the tip S, it is preferably suppressed to reach the area of the negative electrode plate 8 breaks the separator 10.

This prevents the metal thin plate 32 of the positive electrode plate 6 and the negative electrode plate 8 from being inadvertently short-circuited.
As described above, according to the cylindrical storage battery of the present invention, the end of the negative electrode substrate 9 on the positive electrode current collector plate 28 side of the negative electrode plate 8, that is, the upper end of the negative electrode plate 8 is sufficiently from the positive electrode current collector plate 28. The metal thin plate 32 is obliquely cut off at the end corresponding to the beginning of winding of the positive electrode plate 6 so that the metal thin plate 32 is connected to the positive electrode current collector at the connecting portion between the metal thin plate 32 and the positive electrode substrate 7. Since the corners on the side of the plate 28 are offset and located inward of the positive electrode substrate 7, an internal short circuit can be prevented with a simple configuration. Thereby, while being able to improve the production efficiency (yield) of a cylindrical storage battery, the safety of a cylindrical storage battery can be improved.

  In particular, with respect to the amount of cutout of the metal thin plate 32, as shown in FIG. Is set to be in the range of 60 ° to 85 °. Therefore, if the angle is less than 60 °, the positive electrode substrate 7 is likely to be cut at the connecting portion between the thin metal plate 32 and the positive electrode substrate 7, and the tip S of the thin metal plate 32 becomes too sharp and the separator 10 is easily broken. On the other hand, if the angle exceeds 85 °, there is a high possibility that the entire tip of the thin metal plate 32 penetrates the separator 10 and reaches the region of the negative electrode plate 8, but the angle is set to 60 ° to 85 °. By setting in this range, the above effect can be obtained satisfactorily without such inconvenience, and an internal short circuit can be reliably prevented.

Further, since the upper end of the negative electrode plate 8 is sufficiently separated from the positive electrode current collector plate 28 and positioned below the lower end of the thin metal plate 32, the protruding portion of the thin metal plate 32 from the connecting portion 30. Even if the metal penetrates the separator 10 and reaches the region of the negative electrode plate 8, there is no negative electrode plate 8 in this range, and the metal thin plate 32 is reliably prevented from coming into contact with the negative electrode plate 8 to prevent internal short circuit. Can do.
Furthermore, since the upper end of the separator 10 is configured to be positioned between the upper end of the negative electrode plate 8 and the positive electrode current collector plate 28, the notched side of the thin metal plate 32 hits the separator 10. It is possible to suitably prevent the portion corresponding to the connecting portion between the metal thin plate 32 and the positive electrode substrate 7 from breaking the separator 10 and reaching the region of the negative electrode plate 8.
Although the description of the cylindrical storage battery according to the present invention is finished as above, the present invention is not limited to the above embodiment.

For example, in the above embodiment, the connecting portion between the metal thin plate 32 and the positive electrode substrate 7 is not particularly covered with an insulating film such as an adhesive tape, but the connecting portion between the metal thin plate 32 and the positive electrode substrate 7 is not covered with an adhesive tape or the like. It may be reinforced by covering with an insulating coating.
Moreover, in the said embodiment, although the metal thin plate 32 is notched diagonally, the metal thin plate 32 is a positive electrode board | substrate with respect to the corner | angular part by the side of the positive electrode current collecting plate 28 in the connection part of the metal thin plate 32 and the positive electrode board | substrate 7. 7 may be cut out in a circular arc shape or a staircase shape other than diagonally.
In the above embodiment, the nickel hydride secondary battery has been described as an example. However, the present invention is not limited to this, and the present invention is applied to a nickel-cadmium secondary battery, a lithium ion secondary battery, and further to a primary battery. Is also possible.

4 Electrode group 6 Positive electrode plate 7 Positive electrode substrate 8 Negative electrode plate 9 Negative electrode substrate 10 Separator 30 Connecting part 32 Metal thin plate

Claims (4)

A cylindrical storage battery in which an electrode group formed by spirally winding a positive electrode plate and a negative electrode plate via a separator is housed in a cylindrical outer can,
Between the positive electrode plate and the positive electrode terminal of the outer can, a positive electrode current collector plate is interposed so as to be energized,
The positive electrode plate is bonded to a conductive positive electrode substrate made of a metal porous body filled with a positive electrode active material, and protrudes toward the positive electrode current collector plate at an end of the positive electrode substrate on the positive electrode current collector plate side. A strip-shaped metal thin plate, and the metal thin plate is in contact with the positive electrode current collector plate in an energizable manner;
The negative electrode plate is separated from the positive electrode current collector plate,
The thin metal plate has an end portion corresponding to the start of winding of the positive electrode plate, and a connecting portion between the thin metal plate and the positive electrode substrate is displaced inward of the positive electrode substrate with respect to a corner portion on the positive electrode current collector plate side. A cylindrical storage battery characterized by forming a cutout portion that is cut obliquely so as to be positioned.   The notch portion has a range of 60 ° to 85 ° between an angle formed by a notched side of the metal thin plate and a side of the positive electrode substrate on the positive electrode current collecting plate side when the thin metal plate is bonded to the positive electrode substrate. 2. The cylindrical storage battery according to claim 1, wherein the cylindrical storage battery is cut obliquely toward the positive electrode substrate with a corner on the positive electrode current collector plate side as a base point.   The cylindrical storage battery according to claim 1 or 2, wherein an upper end of the negative electrode plate is positioned below a lower end of the thin metal plate.   4. The cylindrical storage battery according to claim 1, wherein an upper end of the separator is located between an upper end of the negative electrode plate and the positive electrode current collector plate. 5.

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