JP2997997B2 - Stepped insulating ring and method for manufacturing cylindrical nickel-metal hydride secondary battery using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stepped insulating ring and a method for manufacturing a cylindrical nickel-metal hydride rechargeable battery using the same, and more particularly, to the occurrence of an internal short-circuit accident even when a shock is applied when dropped. The present invention relates to a stepped insulating ring having a function of suppressing the occurrence of a battery, and a method for manufacturing a cylindrical nickel-metal hydride secondary battery in which a lid member (a positive electrode terminal) is hermetically disposed in a battery can using the same.

[0002]

2. Description of the Related Art A nickel-hydrogen secondary battery is a battery that operates using hydrogen as an active material, and Ni (O 2) is a positive electrode active material.
H) and Ni _{electrode 2} formed by carrying on the current collector (positive electrode), a hydrogen storage alloy electrode reversibly embodiment can hydrogen storage alloy electrochemical storage and release of hydrogen comprising supported on a current collector (Negative electrode)
A power generating element is configured by interposing an electrically insulating and liquid retaining separator between the power generating element and the power generating element, and the power generating element is housed in a conductive bottomed can that also serves as a negative electrode terminal. After the electrolyte is injected, the upper portion of the can is sealed with a lid member also serving as a positive electrode terminal.

The nickel-hydrogen secondary battery is
From its overall shape, it is roughly classified into a prismatic battery and a cylindrical battery. Among them, the cylindrical battery is generally manufactured as follows. This will be described with reference to the drawings. First, as shown in FIG. 1, a Ni electrode sheet 1b and a hydrogen storage alloy electrode sheet 1a are manufactured according to a conventional method, a separator sheet 1c is interposed between these sheets, and the hydrogen storage alloy sheet is turned outside. The whole is wound to manufacture the electrode plate group 1 having a predetermined outer diameter and height.

Then, an insulating plate 3a is laid on the bottom of a conductive bottomed cylindrical can 2 having a predetermined height and an inside diameter, and the above-described electrode plate group 1 is inserted from an upper opening 2A of the bottomed cylindrical can 2. The lower part is arranged on the insulating plate 3a. At this time, the outer diameter of the electrode group 1 and the inner diameter of the bottomed cylindrical can 2 are substantially equal, and after the electrode group 1 is inserted, the hydrogen storage alloy electrode sheet located on the outermost side of the electrode group 1 1a is the inner wall 2 of the bottomed cylindrical can 2
Thus, the bottomed cylindrical can 2 can function as a negative electrode terminal as a whole.

A current collecting tab is attached to the upper part of the Ni electrode sheet 1b of the electrode plate group 1 by spot welding.
A flexible current collecting sheet 6 is located from the current collecting tab so as to protrude upward. After inserting and disposing the electrode plate group 1 in the can, usually, a predetermined amount of a predetermined alkaline electrolyte is injected from the upper opening 2A. The injected alkaline electrolyte permeates the entire electrode group 1, and a state in which a battery reaction in the electrode group 1 is enabled is configured.

Next, usually, after a thin insulating plate 3b is laid on the upper part of the electrode plate group 1, the can wall of the bottomed cylindrical can 2 located on the insulating plate 3b is slightly constricted inward to form a shelf 2b. And a stepped insulating ring 4 is arranged on the shelf 2b as shown in FIG. This stepped insulating ring is made of, for example, an electrically insulating resin such as nylon or polypropylene. As shown in FIG. 3, the upper part has an outer diameter that is substantially equal to the inner diameter of the bottomed cylindrical can 2. 4a, the lower portion is formed as a reduced diameter foot portion 4b which is smaller in diameter than the upper portion and has an appropriate height. Therefore, a step 4c projecting toward the center is formed around the inside of the ring.

Next, a step portion 4c of the stepped insulating ring 4 is formed.
Next, as shown in FIG. 4, a peripheral portion 5a of the lid member 5 previously assembled in another process is arranged. The lid member 5 is sandwiched between a thin conductive plate 5b and a thin conductive plate 5d having a small hole 5c formed in the center in a state where a safety valve 5e made of, for example, an elastic rubber material is crimped, and the respective conductive plates 5a, 5b Is formed by caulking the peripheral edge of the peripheral edge 5a of the airtight structure.

Since the lid member 5 also serves as the positive electrode terminal of the battery, prior to disposing it on the stepped portion 4c of the stepped insulating ring, each of the tab terminals attached to the Ni electrode 1b of the electrode plate group 1 is connected to the tab terminal. The end of the current collecting sheet 6 to be connected is connected to the conductive plate 5d by, for example, spot welding.
This current collecting sheet 6 is bent by the arrangement of the lid member 5,
It will be in the state accommodated in the space inside stepped insulating ring 4.

By arranging the peripheral portion 5a of the lid member at the step 4c of the stepped insulating ring, the inner wall 2a and the shelf 2b of the upper opening of the bottomed cylindrical can 2 are provided above the bottomed cylindrical can 2.
The outer peripheral wall of the enlarged diameter upper portion 4a of the stepped insulating ring faces each other, and the inner peripheral wall including the stepped portion 4c of the stepped insulating ring and the peripheral edge portion 5a of the lid member face each other,
As a whole, a portion to be sealed is formed.

[0010] Finally, a predetermined crimping process is performed on the above-mentioned scheduled sealing portion. As a result, as shown in FIG. 5, the stepped insulating ring 4 made of resin is deformed by the caulking force, and near the upper opening of the bottomed cylindrical can 2, the inner wall 2a of the bottomed cylindrical can 2 and the shelf 2b and the outer peripheral wall of the enlarged-diameter upper portion 4a of the stepped insulating ring 4 are in close contact with each other to form a liquid-tight structure, and inside the enlarged-diameter upper portion 4a, the inner peripheral wall including the stepped portion 4c and the lid member are formed. By forming a liquid-tight structure in close contact with the peripheral edge portion 5a of the battery 5, a caulking sealing portion is formed, and the battery has a hermetically sealed structure as a whole.

The stepped insulating ring 4 functions as follows. That is, the electrode plate group 1 arranged in the bottomed cylindrical can 2 is only in a state where the outermost side (the hydrogen storage alloy electrode sheet 1a) is in surface contact with the inner wall 2a of the cylindrical can and is in close contact therewith. For example, when the assembled battery is dropped with the lid member 5 down, if the stepped insulating ring 4 is not interposed, the electrode plate group 1 is shifted toward the lid member 5 and the upper part thereof is shifted. Contact with the lid member 5 or the top of the can may cause an internal short circuit and generate heat.

However, if the stepped insulating ring 4 is interposed between the electrode plate group 1 and the cover member 5, the electrode plate group 1 is prevented from shifting toward the cover member 5, and an internal short circuit accident occurs. Will not occur.

[0013]

By the way, in the above-described manufacturing method, it is premised that the stepped insulating ring 4 is arranged on the shelf 2b before the cover member 5 is arranged. . The current collecting sheet 6 is provided on the bottom of the lid member 5.
In the case of spot welding, as shown in FIG. 6, the lid member 5 is turned sideways and automatically supplied to the vicinity of the upper opening 2A of the bottomed cylindrical can 2 sequentially using, for example, a feeder, and the conductive plate is provided. 5d (the bottom of the lid member 5) and the end of the current collecting sheet 6 projecting upward from the electrode plate group 1,
It is spot-welded.

On the other hand, after the lid member 5 is arranged on the step portion of the stepped insulating ring 4 and both are integrated in advance, the current collecting sheet may be spot-welded to the bottom of the lid member. At that time, spot welding is performed in a state as shown in FIG. That is, in a separate step, the peripheral portion 5a of the lid member 5 is arranged on the stepped portion 4c of the stepped insulating ring 4 to integrate the two, and the assembled integrated product A is turned sideways and the upper portion of the bottomed cylindrical can 2 It is arranged in the opening 2A, and the conductive plate 5d of the lid member 5 and the end of the current collecting sheet 6 are opposed to each other.

However, in this case, unlike the case shown in FIG. 6, the diameter-reduced foot 4b of the stepped insulating ring 5 is in a state of projecting beyond the conductive plate 5d of the lid member 5. The end of the electric sheet 6 cannot be in natural contact with the conductive plate 5d. Therefore, when the current collecting sheet 6 is spot-welded to the conductive plate 5d, the current collecting sheet 6 must be forcedly pushed into the inside of the reduced diameter foot portion 4b and spot-welded. Spot welding in such a state makes the welding state unstable,
This is not preferable for automation of spot welding.

According to the present invention, when spot welding is performed in the state shown in FIG. 7, the above-described problem does not occur, and the occurrence of an internal short-circuit accident against a drop impact of a battery can be suppressed. Needless to say, it is an object of the present invention to provide a stepped insulating ring that enables the current collector sheet and the bottom of the lid member to be brought into natural contact with each other, and a method of manufacturing a cylindrical nickel-metal hydride secondary battery using the same. And

[0017]

In order to achieve the above-mentioned object, according to the present invention, there are provided an enlarged diameter upper portion and a reduced diameter foot portion,
Provided is a stepped insulating ring having a stepped portion formed inside, wherein at least one portion of the reduced diameter foot portion is cut away, and a safety valve is built-in. The peripheral portion of the lid member is arranged on the step portion of the stepped insulating ring and integrated, and the integrated product is formed by an electrode plate group and an electrolytic solution to which a current collecting sheet protruding upward is attached. The current collecting sheet is disposed laterally in the vicinity of the upper opening of the bottomed cylindrical can accommodated, and the current collecting sheet passes through a notch formed in a reduced-diameter foot portion of the stepped insulating ring. After being arranged to the bottom, spot welding is performed, and then, the integrated body is inserted from the upper opening of the bottomed cylindrical can, placed on the electrode plate group, and then caulked near the upper opening to form a sealing portion. Forming a cylindrical shape Nickel-hydrogen secondary battery manufacturing method is provided.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example B of a stepped insulating ring of the present invention is shown in FIG. 8 and FIG. 9 which is a cross-sectional view taken along line IX-IX of FIG. The insulating ring B has an enlarged diameter upper part 4a and a reduced diameter foot part 4.
b, and the step portion 4c is formed inside,
This is the same as the conventional insulating ring 4 shown in FIG. The material may be the same as that of the conventional insulating ring. Specifically, nylon is preferred.

However, in the case of the insulating ring B, a portion of the reduced diameter foot 4b is cut off by a desired length to the enlarged diameter upper portion 4a, so that the cutout 4B is formed in the reduced diameter foot. I have. This notch 4B is, as shown in the figure,
It is preferable that two portions are formed at positions facing each other on the reduced diameter foot portion 4b, but only one may be provided.

The notch length of the notch 4B needs to be at least wider than the width of the current collecting sheet. This is because the current collector sheet cannot be brought into natural contact with the conductive plate of the lid member during spot welding described later. However, if the notch length is too long, the length of the arc portion of the remaining reduced-diameter foot portion 4b becomes short, and the upper portion of the electrode plate group 1 is pressed down to suppress the displacement of the electrode plate group at the time of a drop impact. Since the spacer effect is reduced, it is appropriately determined in consideration of the relationship with the width of the current collecting sheet.

By using the stepped insulating ring B,
In the present invention, the cylindrical nickel-hydrogen
The secondary battery is assembled. First, as shown in FIG.
As described above, the peripheral portion 5a of the lid member 5 is
Both are arranged in the part 4c and are integrated. Insulation ring B
A notch 4B reaching the enlarged diameter upper part 4a is formed in the reduced diameter foot 4b.
Is formed, the obtained integrated product A ₁Then the lid
The conductive plate 5d (bottom) of the member 5 can be seen through the cutout 4B.
State.

[0022] Then, as shown in FIG. 11, in a state in which the integrated product A ₁ sideways, already supplied to the upper opening 2A vicinity of the bottomed cylindrical can 1 such electrode plate group 1 is accommodated It is made to face the current collecting sheet 6. At this time, the cutout portion 4B is integrated product A ₁ so as to be positioned at the bottom of the entire ring is arranged. By taking such a positional relationship, the current collecting sheet 6 is kept upright from the notch 4B inside the reduced diameter foot 4b, despite the reduced diameter foot 4b having a certain height. Can be moved in parallel.

Therefore, next, the integrated product A ₁ is shown in FIG.
Is moved in the right direction to bring the conductive plate 5d (bottom) of the lid member 5 into contact with the end of the current collecting sheet 6, and spot welding is performed. In this case, since the current collector sheet 6 is not in a state of being forcedly in contact with the conductive plate 5d, spot welding can be stably performed.

[0024] After completion of the spot welding, integrated product of A ₁ is disposed on the insert and the shelf portion 2b from the bottomed cylindrical can 2 of the upper opening 2A, to perform the clamping process of the conventional method to the entire opening Thereby, a sealing portion is formed. At this time, the current collecting sheet 6
Is contracted to the inside of the reduced diameter foot in a bent state, as in the conventional case. In the battery manufactured in this manner, since the reduced-diameter foot portion 4b of the insulating ring 5 presses the electrode plate group 1, for example, even if a drop impact is received, the electrode group 1 Is prevented from shifting toward the lid member 5, so that an internal short circuit accident does not occur completely.

By using the insulating ring 5, if the insulating ring and the lid member are previously integrated in a separate process, spot welding can be performed on the integrated lid member as it is. Because it is possible, welding can be easily automated.

[0026]

As is clear from the above description, the stepped insulating ring of the present invention is accommodated by the function of the reduced diameter foot even when the manufactured battery is subjected to a drop impact. The electrode group does not shift toward the lid member. Therefore, an internal short circuit accident does not occur.

When this stepped insulating ring is used,
The current collecting sheet of the electrode group can be spot-welded as it is to the integrated lid member in which the lid member is integrated with the step portion, which contributes to automation of the production line.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view showing a state where an electrode group is arranged between bottomed cylinders.

FIG. 2 is an enlarged sectional view showing a state where a stepped insulating ring is arranged on a shelf.

FIG. 3 is a perspective view showing a conventional stepped insulating ring.

FIG. 4 is an enlarged sectional view showing a state in which a lid member is arranged on a stepped insulating ring.

FIG. 5 is an enlarged cross-sectional view showing a state of a crimping sealing portion after completion of crimping processing.

FIG. 6 is an enlarged cross-sectional view showing a state in which the lid member is disposed above the opening of the bottomed cylindrical tube in order to spot-weld the current collecting sheet to the lid member.

FIG. 7 is an enlarged cross-sectional view showing a state in which a conventional integrated product A is disposed above an opening of a bottomed cylindrical can.

FIG. 8 is a side view showing an example B of a stepped insulating ring of the present invention.

FIG. 9 is a sectional view taken along line IX-IX in FIG. 8;

10 is a cross-sectional view showing the integrated product A ₁ that integrates the stepped insulating ring and the lid member of the present invention.

11 is an enlarged sectional view showing a state of arranging the integrated product A ₁ in open top of the bottomed cylindrical can.

[Explanation of symbols]

Reference Signs List 1 electrode plate group 1a hydrogen storage alloy electrode sheet 1b nickel electrode sheet 1c separator sheet 2 bottomed cylindrical can 2A top opening of bottomed cylindrical can 2 2a inner wall of bottomed cylindrical can 2 2b shelf of bottomed cylindrical can 2 3a, 3b Insulating plate 4 Stepped insulating ring 4a Increased diameter upper part of stepped insulating ring 4 4b Reduced diameter foot of stepped insulating ring 4 4c Stepped portion of stepped insulating ring 4 4B Notch 5 Cover member 5a Peripheral edge of cover member 5 Part 5b, 5d Conductive plate 5c Small hole 5e Safety valve 6 Current collecting sheet A, A ₁ integrated B Stepped insulating ring

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01M 10/02-10/04 H01M 10/24-10/34 H01M 2 / 12,2 / 08

Claims (2)

(57) [Claims] 1. A stepped insulating ring having an enlarged-diameter upper portion and a reduced-diameter foot portion, and a step portion formed inside, wherein at least one portion of the reduced-diameter foot portion is notched. A stepped insulating ring. 2. The peripheral part of a lid member having a built-in safety valve is arranged and integrated on the stepped portion of the stepped insulating ring of claim 1, and the integrated product is attached to a current collecting sheet projecting upward. The electrode plate group and the electrolytic solution are placed sideways near the upper opening of the bottomed cylindrical can containing the electrolytic solution, and the current collecting sheet is formed on the reduced-diameter foot portion of the stepped insulating ring. After being arranged to the bottom of the lid member via the notch, spot welding is performed, and then the integrated body is
A cylindrical nickel-hydrogen secondary battery, wherein the cylindrical nickel-hydrogen secondary battery is inserted from the upper opening of the bottomed cylindrical can and placed on the electrode plate group, and then caulked near the upper opening to form a sealing portion. Manufacturing method.