JP2825868B2 - Cylindrical alkaline battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a cylindrical alkaline battery having a sealing member provided with a thin portion for explosion proof.

[Conventional technology]

In a cylindrical alkaline battery, when charged or erroneously charged, gas is generated inside the battery, the pressure inside the battery rises abnormally, and the battery bursts under high pressure.

Therefore, as shown in FIG. 2, a thin portion (63a) is provided in the sealing body (6), and when the pressure inside the battery rises and reaches a predetermined pressure, the thin portion (63a) is broken and the battery (63a) is broken. The gas inside is released from the gas vent (9a) of the negative electrode terminal plate (9) to the outside of the battery via the gas vent (7a) of the annular support (7), and the battery ruptures under high pressure, so-called. It has been practiced to prevent explosions (for example, see Jpn.
issue).

[Problems to be solved by the invention]

However, in the above battery, when the internal pressure of the battery rises and the thin portion (63a) of the sealing body (6) is broken to release the gas inside the battery to the outside of the battery, the negative electrode composed of paste zinc is used. The agent (2) flows to reach the negative electrode terminal plate (9) and fills the space between the sealing member (6), closes the gas vent hole (7a) of the annular support (7), and removes the battery. The internal pressure may rise again, causing the battery to burst under high pressure.

Accordingly, the present invention provides a highly safe cylindrical alkaline battery in which the gas vent hole (7a) of the annular support (7) is prevented from being blocked by the negative electrode agent (2) and the explosion-proof function is reliably operated. The purpose is to:

[Means for solving the problem]

The means for solving the above problems will be described with reference to FIG. 1 corresponding to the embodiment. According to the present invention, by disposing an annular resin lid (10) above the negative electrode agent (2), The purpose has been achieved.

That is, when the internal pressure of the battery rises and the thin portion (63a) of the sealing body (6) is ruptured and gas inside the battery is released to the outside of the battery, the negative electrode agent (2) is formed by the resin lid (10).
Is prevented from flowing, and the blockage of the vent hole (7a) of the annular support (7) by the negative electrode agent (2) is not closed. The gas inside the battery passes through the separator (3) and exits above the resin lid (10).
The operation of the explosion-proof function is not hindered by the resin lid (10).

In the present invention, a closing member (8) is provided on the upper part of the annular support (7) to prevent moisture outside the battery from reaching the thin portion (63a) of the sealing body (6). Department (6
3a) In order not to reduce the strength due to moisture absorption,
Prevent thin section (63a) from breaking under normal pressure,
Has improved leakage resistance.

That is, in the cylindrical alkaline battery described above, in order to improve the liquid leakage resistance, the sealing body (6) is made of nylon which has a high compressive stress and can seal the opening of the positive electrode can (4) with a high tightening pressure. However, since this nylon has a strong hygroscopic property, in a high-temperature and high-humidity atmosphere, the thin portion (63a) of the sealing body (6) is formed by the gas vent (9a) of the negative electrode terminal plate (9) and the annular support. Absorbs moisture that has entered from the outside of the battery through the gas vent hole (7a) of (7), and the strength of the thin portion (63a) is reduced. The thin portion (63a) is broken below a set pressure. As a result, there is a problem that the electrolyte inside the battery leaks to the outside rain of the battery.

Therefore, in the present invention, as described above, the annular closing member (8) is disposed above the annular support (7), and the gas vent hole (7a) of the annular support (7) is closed by the closing member (8). 8), and the moisture outside the battery is reduced by the thin portion (63a) of the sealing body (6).
To prevent the thin portion (63a) from breaking under normal pressure conditions by preventing the strength from being reduced due to moisture absorption of the thin portion (63a).

The annular closing member (8) normally serves as a lid for closing the gas vent hole (7a) of the annular support (7), and the battery closes from the gas vent hole (9a) of the negative electrode terminal plate (9). Since the water (water vapor) invading the inside is blocked, the water outside the battery does not reach the thin portion (63a) of the sealing body (6), so the thin portion (63a) absorbs moisture and the strength is reduced. Will not cause.

On the other hand, gas is generated inside the battery due to an abnormal situation such as charging or over-discharging, and the pressure inside the battery increases, and the sealing body (6)
When the thin portion (63a) is broken, the gas passes through the vent hole (7a) of the annular support (7) and pushes up the closing member (8), and the inner peripheral edge of the closing member (8) A gap is created at the contact surface between the outer peripheral surface of the thick portion (61) of the sealing body (6) and
Since the gas passes through the gap and is further discharged out of the battery through the gas vent hole (9a) of the negative electrode terminal plate (9), the closing member (8) does not hinder the operation of the explosion-proof function.

〔Example〕

 Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing one embodiment of the cylindrical alkaline battery of the present invention.

In the figure, (1) is a positive electrode mixture, (2) is a negative electrode agent, (3) is a separator, (4) is a positive electrode can, (5) is a negative electrode current collector,
(6) is a sealing body, (7) is an annular support, (8) is an annular closing member, (9) is a negative electrode terminal plate, (10) is a resin cover, (1)
1) is an exterior body.

The positive electrode mixture (1) uses manganese dioxide as a positive electrode active material,
A powder mainly composed of manganese dioxide and graphite as a conductive additive is formed into a cylindrical shape under pressure. The negative electrode agent (2) is obtained by mixing a binder such as sodium polyacrylate and a zinc fluoride powder in an alkaline electrolyte in which potassium hydroxide and zinc oxide for preventing self-corrosion of zinc are dissolved. It is made of paste zinc. The separator (3) is made of a nonwoven fabric mainly composed of vinylon, has a bottomed cylindrical shape, and separates the positive electrode mixture (1) and the negative electrode agent (2).

The positive electrode can (4) is made of iron and nickel-plated on the surface. The positive electrode mixture (1), the negative electrode agent (2), the separator (3), the electrolytic solution (the electrolytic solution is the negative electrode agent as described above) (2) It is not only contained in (2) but also impregnated in separator (3) and positive electrode mixture (1)).
Such a power generation element is housed in the positive electrode can (4).

The negative electrode current collector (9) is made of brass and is inserted into the through hole (64) of the shaft (5a) of the sealing body (6), and the lower part of the shaft (5a) passes through the through hole (64). Then, it reaches the inside of the negative electrode agent (2), and its head (5b) is welded to the center of the negative electrode terminal plate (9),
An electrical connection between the negative electrode current collector (5) and the negative electrode terminal plate (9) can be obtained.

The sealing body (6) has an annular thick portion (61) having a through hole (64) into which a shaft portion (5a) of the negative electrode current collector (5) is inserted at the center, and a positive electrode can (4). A thick outer peripheral portion (62) that comes into contact with the inner peripheral surface of the open end (4a), and a connecting portion (63) that connects the thick portion (61) and the outer peripheral edge (62). The connecting portion (63) has an explosion-proof thin portion (63a) near the thick portion (61) and guides the opening end of the separator (3) near the outer peripheral edge (62). V-shaped part with role (63
b).

The annular support (7) is made of iron, has a gas vent (7a), and is fitted between the thick portion (61) of the sealing body (6) and the outer peripheral edge (62). And is arranged above the connecting portion (63).

The annular closing member (8) is made of, for example, hard vinyl chloride resin or polyethylene, and is disposed on the annular support (7).
And the outer peripheral edge of the annular support (7),
Its inner peripheral edge is in close contact with the outer peripheral surface of the thick portion (61) of the sealing body (6). In this specification, the upper side means that the battery is located on the upper side when the battery is arranged such that the negative electrode terminal plate (9) is located at the upper end of the battery as shown in FIG. An annular closing member (8) is attached to an annular support (7).
In the arrangement above, at least a part of the closing member (8) is arranged on the negative electrode terminal plate (9) side of the annular support (7) while contacting the annular support (7). Means that.

The negative electrode terminal plate (9) is made of iron and nickel-plated on the surface, has a hat-like shape with a peripheral edge formed in a flange shape, and has a peripheral wall portion that moves from the ceiling to the flange-shaped peripheral edge portion. The gas vent hole (9a) is provided, the head (5b) of the negative electrode current collector (5) is welded to the center of the ceiling as described above, and the peripheral part is the opening of the positive electrode can (4). By inwardly bending the upper end of the end (4a), the annular support (7) is joined to the outer peripheral edge of the annular closing member (8) by the upper end of the outer peripheral edge (62) of the sealing body (6). ) Is pressed and fixed to the outer periphery.

The annular resin lid (10) is made of a vinyl chloride resin sheet, a polypropylene sheet, or the like. In the present embodiment, the one made of a vinyl chloride resin is used, and is disposed on the negative electrode agent (2). The inner peripheral surface is in close contact with the shaft (5a) of the negative electrode current collector (5), and the outer peripheral surface is in close contact with the inner peripheral surface of the separator (3).

The exterior body (11) is made of a sheet obtained by depositing aluminum on a vinyl chloride resin sheet, and insulates the outer periphery of the positive electrode can (4). A groove (4b) having a bottom protruding toward the inside of the battery is provided near the opening of the positive electrode can (4), and an outer peripheral portion (62) of the opening (6) is formed at the bottom of the groove (4b). ) Supports the lower part.

 This battery is manufactured, for example, as follows.

The positive electrode mixture (1) formed on a cylinder is inserted into the positive electrode can (4), a rod is inserted into the hollow portion of the positive electrode mixture (1), and the positive electrode mixture (1) is pressed from above with a pressing member. After pressing, the outer peripheral surface of the positive electrode mixture (1) is brought into close contact with the inner peripheral surface of the positive electrode can (4), and after removing the pressing member and the rod, the separator (3) is inserted, and the electrolyte is injected. After impregnating the separator (3) and the positive electrode mixture (1) with the electrolytic solution, the negative electrode agent (2) is filled into the hollow of the separator (3), and then the groove (5) is formed near the opening end of the positive electrode can (4). 4b) is formed.

An annular support (7) is previously fitted between the thick portion (61) and the outer peripheral edge (62) of the sealing body (6), and an annular closing member is mounted on the annular support (7). (8) is arranged.

The head (5b) of the negative electrode current collector (5) and the negative electrode terminal plate (9) are welded in advance, and the shaft (5a) of the negative electrode current collector (5) is attached to the sealing body (6) in the above state. ), The resin cover (10) is fitted into the shaft (5a) of the negative electrode current collector (5), and the sealing body (6) in this state is inserted into the positive electrode can (4).
And the opening end (4a) of the positive electrode can (4) is tightened inward so that the upper end thereof is bent inward, and the opening of the positive electrode can (4) is sealed with the sealing body (6). ) And the negative electrode current collector (5), and the exterior body (11) is disposed so as to cover the outer periphery of the positive electrode can (4). In addition, the resin lid (10)
As described above, it is not only fitted into the shaft portion (5a) of the negative electrode current collector (5), but also disposed in advance on the negative electrode agent (2), and The shaft (5a) may be inserted.

The tip of the shaft (5a) of the negative electrode current collector (5) is formed sharply like a needle, but the diameter of the portion in contact with the sealing body (6) is slightly larger than the diameter of the through hole (64). By inserting the negative electrode current collector (5) into the through-hole (64), the thick portion (61) around the through-hole is pressed radially outward, and the annular support (7) becomes thicker. Since the meat part (61) is pressed in the radial direction,
The degree of close contact between the shaft (5a) of the negative electrode current collector (5) and the sealing body (6) is kept high. In addition, on the outer peripheral surface of the outer peripheral edge (62) of the sealing body (6), the open end (4a) of the positive electrode can (4) is provided.
Opening end (4a) of positive electrode can (4) by tightening inside
And the density of the contact surface between the sealing body (6) and the positive electrode can (4) is kept high, so that leakage of the electrolytic solution to the outside of the battery is prevented.

The upper end of the positive electrode can (4) is fixed to the peripheral edge of the negative electrode terminal plate (9) by inward bending of the upper end when the inward opening (4a) is tightened. Accordingly, the outer peripheral edge of the annular closing member (8) is fixed to the peripheral edge of the negative electrode terminal plate (9) and the outer peripheral edge of the annular support (7), and the inner peripheral edge of the closing member (8). Is the shaft (5a) of the negative electrode current collector (5)
When the is inserted into the through hole (64), the thick portion (61) on the inner periphery of the through hole (64) expands radially outward and comes into close contact with the outer peripheral surface of the thick portion (61). .

Therefore, in this battery, at normal pressure, the closing portion (8) closes the vent hole (7a) of the annular support (7), so that even if the battery is placed in a high-temperature, high-humidity atmosphere, The moisture outside the battery is blocked by the closing member (8) and does not reach the thin portion (63a) of the sealing body (6).
Therefore, the thin portion (63a) of the sealing body (6) does not absorb the moisture and cause a decrease in strength, and the thin portion (63a) is broken under normal use conditions and causes leakage of the electrolyte. There is no such thing.

When the battery is overcharged or overdischarged and gas is generated inside the battery, the pressure inside the battery increases and the thin portion (63a) is broken, the resin cover (1
0) prevents the flow of the negative electrode agent (2), so that the negative electrode agent (2) does not block the vent holes (7a) of the annular support (7), preventing the internal pressure of the battery from rising again. You. At this time, the gas passes through the separator (3) and passes through the resin lid (10).
Since it goes upward, the operation of the explosion-proof function is not hindered by the resin lid (10). Further, when the thin portion (63a) is broken due to an increase in the internal pressure of the battery, the gas passing through the thin portion (63a) and the hole (7a) of the annular support (7) pushes up the closing member (8). The inner peripheral edge of the closing member (8) is the thick portion (61) of the sealing body (6).
For example, a gap is formed in the contact surface between the closing member (8), the inner peripheral edge portion, and the outer peripheral surface of the thick portion (61) of the sealing body (6), and gas inside the battery passes through the gap. Furthermore, it goes out of the battery through the gas vent hole (9a) of the negative electrode terminal plate (9). Therefore, the explosion-proof function by destruction of the thin portion (63a) operates cleanly without being hindered by the closing member (8).

Normally, the closing member (8) closes the gas vent hole (7a) of the annular support (7), and the pressure inside the battery increases, so that the thin portion (63a) of the sealing body (6) is closed. When it is torn, a gap must be created between the inner peripheral edge and the outer peripheral surface of the thick portion (61) of the sealing body (6) to act to discharge gas inside the battery to the outside of the battery. However, in order to perform such an action, it is hard enough to have a certain degree of self-shape retention, and is pushed up at a pressure equal to or less than the breaking pressure of the thin portion (63a), and its inner peripheral edge is It is necessary that the closing member be capable of being deformed so as to form a gap at the contact surface between the thick portion (61) and the outer peripheral surface of the sealing member (6). Thin plate of synthetic resin with low water absorption such as hard vinyl chloride resin, polyethylene, polypropylene etc., moisture proof (E.g., laminated paper laminated with polyethylene film on both sides of the paper),
A thin metal plate such as stainless steel or aluminum having a thickness of about 0.4 to 0.6 mm is used. In other words, if the closing member (8) is formed of the above-described one, it can maintain a predetermined shape without deforming from the set state at normal times. (63
The breaking pressure of a) is set to about 40 to 60 kg / cm ² , but the pressure (for example, 5 to 7 kg) which is lower than the breaking pressure of the thin portion (63a) is set.
/ cm ² ) and is deformed so as to form a gap between the inner peripheral edge thereof and the outer peripheral surface of the thick portion (61) of the sealing body (6).

As for the outer diameter and inner diameter of the closing member (8), the outer diameter of the closing member (8) is determined by connecting the outer peripheral edge to the negative electrode terminal plate (9).
It is sufficient if it is set so as to be able to be sandwiched between the peripheral edge of the annular support (7) and the outer peripheral edge of the annular support (7). 64), the thickness of the thick portion (61) around the translucent portion is set to be slightly smaller than the dimension when expanded to the radially outward side, and preferably about 0.05 to 0.2 mm.

The height of the thick portion (61) of the sealing body (6) is adjusted so that a gap is formed between the upper end and the lower surface of the head (5b) of the negative electrode current collector (5) as shown in the figure. When set, when the pressure inside the battery rises and the thin portion (63a) is broken, the inner peripheral edge of the closing member (8) comes out above the thick portion (61),
The inner peripheral edge of the closing member (8) and the thick portion (6) of the sealing body (6)
Since a large gap is generated between 1) and 1), the operation of the explosion-proof function by the destruction of the thin portion (63a) proceeds smoothly as planned, which is preferable. The upper end position of the thick portion (61) of the sealing body (6) is slightly higher than the portion where the closing member (8) comes into contact with the outer peripheral surface of the thick portion (61), for example, 0.1 mm.
It is preferable to set the height to about 3 to 1.5 mm. In the embodiment, the upper end position of the thick portion (61) of the sealing body (6) is set at 1.1 from the portion where the closing member (8) contacts the outer peripheral surface of the thick portion (61).
0 mm higher, and as a result, the thicker portion (6
There is a gap of 0.6 mm between the upper end of 1) and the lower surface of the head (5b) of the negative electrode current collector (5).

As the ring-shaped resin lid (10), for example, a hard plastic resin such as a hard vinyl chloride resin, polyethylene, or polypropylene having a low absorbency may be used.
Usually, a size of about 0.3 to 1.0 mm is preferable.

Next, the difference between the safety of the battery A of the present invention shown in the above embodiment and the battery B of the conventional structure shown in FIG. 2 during the operation of the explosion-proof function and the resistance to liquid leakage when stored in a high-temperature, high-humidity atmosphere. Are shown in Table 1.

All batteries are AA batteries with an outer diameter of 14.5 mm and a total height of 50.5 mm. The sealing body (6) is made of nylon 66 and has a thin portion (63
The thickness of a) is 0.20 mm. In the battery A of the present invention, an annular member having a thickness of 0.5 mm, an outer diameter of 11.0 mm and an inner diameter of 2.5 mm is used as the closing member (8), and the resin cover (10) is made of a hard vinyl chloride resin. Made of vinyl resin, 0.5mm thick,
An annular body with an outer diameter of 7.8 mm and an inner diameter of 1.5 mm is used. The shaft (5) of the negative electrode current collector (5) is inserted into the through hole (64) of the sealing body (6).
The outer diameter of the thick portion (61) at the time of insertion of the thick portion (61) is inserted into the through-hole (64) by inserting the shaft portion (5a) of the negative electrode current collector (5) as described above. The outer peripheral surface of (61) expands radially outward and the outer diameter becomes larger) is 2.6 mm, which is 0.1 mm larger than the inner diameter of the closing member (8). The peripheral portion is in close contact with the outer peripheral surface of the thick portion (61) of the sealing body (6).

The safety at the time of the operation of the explosion-proof function is as follows. For 10 batteries each of battery A and battery B, the battery is forcibly charged for 20 minutes at a constant current of DC 1 amp to generate gas inside the battery (by the above-described charging). The electrolytic solution causes electrolysis and oxygen gas is generated on the positive electrode can side, and hydrogen gas is generated on the negative electrode side), and the thin portion (63a) of the sealing body (6) is broken, and the gas inside the battery is discharged. When the gas was discharged to the outside, the gas discharge did not proceed smoothly, and the battery was ruptured.

In addition, the leak-resistant battery stores batteries for 50 batteries A and B each for a predetermined period in an atmosphere at 60 ° C. and a total humidity of 90%, and a battery that leaks with each storage period. The number was checked.

In Table 1, the safety during the operation of the explosion-proof function is indicated by the number of ruptured batteries, and the leak resistance is indicated by the number of leaked batteries.

As shown in Table 1, in the battery A of the present invention, there was no rupture, and the thin portion (63a) of the sealing body (6) was not found.
This indicates that the resin cover (10) prevents the gas vent (7a) of the annular support (7) from being blocked by the negative electrode agent (2) when the explosion-proof function is activated due to the destruction of the resin. Was. Further, the battery A of the present invention has a temperature of 60 ° C. and a relative humidity of 60 ° C.
No leakage was observed even after storage at 890% of high temperature and high humidity for 60 days. From this result, it was confirmed that the product has a leakage resistance that can withstand storage for 5 to 6 years under normal use conditions. Presumed.

In the case of the battery B, which is a conventional battery, one that ruptured occurred because the negative electrode agent (2) flowed when the explosion-proof function was activated by rupture of the thin portion (63a) of the sealing body (6). This is probably because the gas vent hole (7a) of the support (7) was closed. In the battery B, the reason why the leakage occurred with the increase of the storage period was that the thin portion (63a) of the sealing body (6) absorbed moisture during storage and caused a decrease in strength. On the other hand, the reason why no leakage of the battery A of the present invention occurred was that the water outside the battery did not reach the thin portion (63a) due to the closing member (8), and the water in the thin portion (63a) did not. This is considered to be the result of preventing the strength from being reduced by absorption.

The materials of the respective constituent members exemplified in the above-described embodiment are merely those used in the embodiment. For example, for the sealing body (6), in addition to nylon 66, nylon 6, nylon 610, nylon 11, Materials other than the examples can be used for the material of each component such as nylon 12 or the like.

〔The invention's effect〕

As described above, in the present invention, since the annular resin lid (10) is provided on the negative electrode agent (2), when the explosion-proof function is activated by the destruction of the thin portion (63a) of the sealing body (6), The negative electrode agent (2) was prevented from closing the gas vent hole (7a) of the annular support (7), the explosion-proof function could be operated cleanly, and the safety of the battery could be improved.

In the present invention, since the gas vent hole (7a) of the annular support (7) is closed by the annular closing member (8), moisture outside the battery reaches the thin portion (63a) of the sealing body (6). As a result, the strength of the thin portion (63a) due to moisture absorption was prevented from being reduced, and the liquid leakage resistance of the battery could be improved.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing one embodiment of the cylindrical alkaline battery of the present invention. FIG. 2 is a partial sectional view showing a conventional cylindrical alkaline battery. (1) Positive electrode mixture, (2) negative electrode agent, (3) separator, (4) positive electrode can, (4a) open end, (5) negative electrode current collector , (5a)… shaft part, (5b)… head part, (6)… sealing body, (61)… thick part, (62)… outer peripheral edge part, (63)… connecting part , (63a) ... thin portion, (63a) ... thin portion, (64) ... through-hole, (7) ... annular support, (7a) ... gas vent hole,
(8) ... closing member, (9) ... negative electrode terminal plate, (9a) ...
... gas vent hole, (10) ... resin lid

Continuation of front page (72) Inventor Mitsutoshi Watanabe 1-1-88 Ushitora, Ibaraki-shi, Osaka Hitachi Maxell, Ltd. (56) References JP-A-59-98452 (JP, A) (58) Fields investigated ( Int.Cl. ⁶ , DB name) H01M 2/12

Claims (1)

(57) [Claims] A positive electrode mixture (1), a negative electrode agent (2), an electrolytic solution, a separator (3), a positive electrode can (4), a negative electrode current collector (5), and a sealing body (6). ), An annular support (7), and a negative electrode terminal plate (9). The positive electrode mixture (1), the negative electrode agent (2), the electrolyte solution, and the separator (3) are placed in a positive electrode can (4). The shaft (5a) of the negative electrode current collector (5) is inserted into the through hole (64) of the sealing body (6), and the lower part of the shaft (5a) is
The sealing body (6) penetrates through the through hole (64) and reaches the inside of the negative electrode agent (2). The sealing body (6) has an annular thick portion (61) having the through hole (64) at the center and a positive electrode can ( An outer peripheral edge (62) that comes into contact with the inner peripheral surface of the open end (4a) of (4), and a connecting part (63) that connects the thick part (61) and the outer peripheral edge (62). The connecting portion (63) of the sealing body (6) has an explosion-proof thin portion (63a), the annular support (7) has a gas vent hole (7a), and the sealing body (63). The negative electrode terminal plate (9) is fitted between the thick portion (61) and the outer peripheral edge portion (62) and is disposed above the connecting portion (63). A central portion thereof comes into contact with a head (5b) of the negative electrode current collector (5), and an opening of the positive electrode can (4) fits the sealing body (6). Tube closed by tightening the open end (4a) of the positive electrode can (4) inward In the alkaline battery, an annular resin lid (10) is provided on the negative electrode agent (2), and an annular closing member (8) is provided on the annular support (7). The gas vent hole (7a) of the annular support (7) is closed with the closing member (8), and the periphery of the negative electrode terminal plate (9) is arranged on the outer periphery of the closing member (8). The upper end of the open end (4a) of the positive electrode can (4) is pressed inward and fixed to the outer peripheral edge of the annular support (7) together with the outer peripheral edge of the closing member (8) by inward bending. A cylindrical alkaline battery.