JP2007149433A - Sealed battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealed battery which can prevent burst of the battery and discharge of an electrolytic liquid due to misuse certainly, and can restore battery function when the misuse state is eliminated. <P>SOLUTION: The battery is provided with a reversible current flow shut-off means (41) of pressure operation type which, when the battery internal pressure increases, is operated by the internal pressure and forms a current flow shut-off state, and when the battery internal pressure decreases to a normal pressure, can release manually or automatically the current flow shut-off state. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sealed battery in which a power generation element including an electrolytic solution is housed in a sealed state, and is particularly effective when applied to, for example, an alkaline battery having an explosion-proof function, particularly a primary battery.

  In an alkaline battery, a power generation element containing an alkaline electrolyte is hermetically sealed using a sealing gasket. However, in order to prevent an abnormal increase in the internal pressure of the battery due to charging, short-circuiting, or the like, the battery is prevented from bursting. An explosion-proof function is usually provided that allows the gas in the battery to escape to the outside by preliminarily breaking the part (for example, Patent Document 1).

  FIG. 4 shows a configuration example of a conventional alkaline battery. In an alkaline dry battery 101 shown in the figure, a power generation element 20 containing an alkaline electrolyte is accommodated in a bottomed cylindrical metal positive electrode can 15 that also serves as a positive electrode current collector and a positive electrode terminal.

  The power generation element 20 includes a positive electrode mixture 21 in which a positive electrode active material such as manganese dioxide is formed into a ring shape or a tubular shape together with a conductive additive such as graphite, a cylindrical separator 22 loaded inside the positive electrode mixture 21, A gelled negative electrode zinc 23 filled inside the separator 22 is formed.

  The opening of the positive electrode can 15 is hermetically sealed by a sealing component including the negative electrode terminal plate 26 and an electrically insulating resin sealing gasket 30. A negative electrode current collector 25 is fixedly connected to the negative electrode terminal plate 26 by spot welding or the like.

  The sealing gasket 30 integrally includes a central boss portion 31, an annular packing portion 32, an intermediate partition wall portion 33, and a thin portion 34. The central boss portion 31 is formed with a through hole through which the negative electrode current collector 25 passes in an airtight state.

  The annular packing part 32 is interposed between the open end part and the peripheral part of the negative terminal plate 26 in a pressurized state by crimping the open end part of the positive electrode can 15 inward. Form. The intermediate partition wall 33 is formed so as to be deformable when the battery internal pressure increases. The thin-walled portion 34 is formed so that when the internal pressure of the battery abnormally increases, the thin-walled portion 34 is preliminarily broken to release the gas in the battery to the outside. For this reason, the negative electrode terminal plate 26 is provided with a gas vent hole (not shown).

As described above, a sealed battery such as an alkaline battery normally has an explosion-proof function that prevents the battery from bursting by operating when the internal pressure of the battery abnormally increases and releasing the gas in the battery. Yes.
JP 2001-126694 A

  It has been found that the above-described conventional sealed battery has the following problems. That is, for example, when the explosion-proof function is activated when the internal pressure of an alkaline battery increases, it is possible to prevent the battery from bursting by letting the gas in the battery escape to the outside, but at the same time the gas escapes, The electrolyte also escapes to the outside. Electrolyte that comes out will damage the equipment. Contact with the human body may cause burns.

  On the other hand, for example, the internal pressure of an alkaline battery is increased because a primary battery whose charging is prohibited is charged when only one battery is erroneously loaded in the reverse direction. In some cases, the charger is accidentally loaded. Further, in a battery in which the negative electrode is rich (more than the amount of positive electrode electricity), gas is generated due to overdischarge, and the internal pressure increases.

  Thus, the internal pressure of the sealed battery increases even with simple misuse. If the internal pressure exceeds a certain limit due to continued misuse, the explosion-proof function is activated and the gas is vented.However, there is a problem that the electrolyte released when the gas is vented harms the equipment. It was.

  The present invention solves the above problems, and its purpose is to reliably prevent battery rupture and electrolyte discharge due to misuse, and if the misuse state is eliminated. It is an object of the present invention to provide a sealed battery that can restore the battery function.

  Other objects and configurations of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  The solution provided by the present invention is as follows.

  (1) In a sealed battery in which a power generation element including an electrolytic solution is housed in a sealed state, when the internal pressure of the battery increases, it operates at the internal pressure to form a cut-off state, while the internal pressure of the battery decreases to a normal pressure A sealed battery comprising pressure-actuated reversible energization interrupting means capable of releasing the energization interrupted state manually or automatically.

  (2) The above means (1) has a negative electrode terminal brought into contact with the negative electrode current collector in a steady state, and when the internal pressure of the battery is increased, the negative electrode terminal is reversibly deformed to form an energization cut-off state. On the other hand, when the internal pressure of the battery is reduced to a normal pressure, the negative electrode terminal is restored to its original shape, so that the negative electrode terminal and the negative electrode current collector are brought into contact again to release the energization cut-off state. A sealed battery comprising a reversible energization interruption means.

  (3) The above means (1) includes an electrically insulating movable member that protrudes from the inside of the battery to a position higher than the negative electrode terminal surface outside the battery when the internal pressure of the battery is increased. A sealed battery characterized in that the pressure-actuated reversible energization interruption means is formed by a member.

  (4) In any one of the above means (1) to (3), when the internal pressure of the battery is abnormally increased, the battery is partially broken and has an explosion-proof function for releasing the gas in the battery to the outside. A sealed battery characterized in that the operating pressure of the reversible energization interrupting means is lower than the operating pressure of the explosion-proof function.

  It is possible to provide a sealed battery that can reliably prevent battery rupture and electrolyte discharge due to misuse, and that can restore the battery function if the misuse state is resolved.

  Operations / effects other than those described above will be apparent from the description of the present specification and the accompanying drawings.

  FIG. 1 shows a first embodiment of a sealed battery according to the present invention. The sealed battery 10 shown in the figure is an LR type alkaline dry battery, and a power generation element 20 containing an alkaline electrolyte is accommodated in a bottomed cylindrical metal positive electrode can 15 which also serves as a positive electrode current collector and a positive electrode terminal. Has been.

  Although not shown in the figure, the power generation element 20 has a positive electrode mixture in which a positive electrode active material such as manganese dioxide is formed into a ring shape or a tubular shape together with a conductive auxiliary agent such as graphite, as in the case of a conventional alkaline battery, and the inside of the positive electrode mixture. And a gelled negative electrode zinc filled inside the separator.

  A rod-shaped metal negative electrode current collector 25 is inserted into the negative electrode zinc. The opening of the positive electrode can 15 is hermetically sealed by a sealing component including a negative electrode terminal plate 26, a reinforcing plate 28, an electrically insulating resin sealing gasket 30, and the like.

  The sealing gasket 30 integrally includes a central boss portion 31, an annular packing portion 32, an intermediate partition wall portion 33, and a thin portion 34. The central boss portion 31 is formed with a through hole through which the negative electrode current collector 25 passes in an airtight state.

  The annular packing part 32 is interposed between the open end part and the peripheral part of the negative terminal plate 26 in a pressurized state by crimping the open end part of the positive electrode can 15 inward. Form. The intermediate partition wall 33 is formed so as to be deformable when the battery internal pressure increases.

  The thin-walled portion 34 is formed so that when the internal pressure of the battery abnormally increases, the thin-walled portion 34 is preliminarily broken to release the gas in the battery to the outside. For this reason, the negative electrode terminal plate 26 is provided with a gas vent hole (not shown).

  As described above, the sealed battery according to the embodiment is normally provided with an explosion-proof function that prevents the battery from bursting by operating when the internal pressure of the battery abnormally increases and releasing the gas in the battery. .

  Furthermore, in the battery 10 of the embodiment, as shown in FIG. 5A, the inner center surface of the negative electrode terminal plate 26 is formed and installed so as to be in pressure contact with the head of the negative electrode current collector 25 in a steady state. ing. That is, the negative electrode terminal plate 26 and the negative electrode current collector 25 are in contact with each other in a detachable manner, not by welding.

  At the same time, an actuator 41 is interposed between the intermediate partition wall 33 of the sealing gasket 30 and the negative terminal plate 26. The actuator 41 has a rigid rod shape, a base end portion of which is supported by the intermediate partition wall portion 33, and a distal end portion of which is in contact with the inner surface of the negative electrode terminal plate 26. The actuator 41 may be formed as an independent part, but may be formed integrally with the gasket 30.

  When the sealed battery 10 is in a normal storage state or use state and the internal pressure of the battery is not high, the negative electrode terminal plate 26 is in contact with the negative electrode current collector 25 as shown in FIG. An energized state is formed between them. In this state, the battery 10 can be used normally.

  However, if the battery internal pressure increases due to misuse, the intermediate partition wall 33 of the gasket 30 is pressed upward, that is, toward the negative electrode terminal plate 26 by the increased internal pressure, as shown in FIG. Accompanying this deformation, the actuator 41 is urged to move upward, and its tip presses the negative terminal plate 26 upward. As a result, the negative electrode terminal plate 26 is elastically deformed and separated from the negative electrode current collector 25.

  In this way, when the battery internal pressure increases due to misuse, the negative electrode terminal plate is deformed to form an energization cut-off state. That is, the energization cut-off state is formed by the operation by the battery internal pressure. When energization is interrupted, gas generation in the battery 10 is stopped.

  As a result, when the battery internal pressure increases, the cause of the increase of the battery internal pressure can be automatically released before the explosion-proof function of the gasket 30 is activated. Therefore, not only the battery 10 can be ruptured due to misuse, but also leakage of the electrolyte due to the operation of the explosion-proof function can be reliably prevented.

  Thereafter, when the misuse state in which the battery internal pressure is increased is corrected, the battery internal pressure gradually decreases. However, when the battery internal pressure decreases to the normal range, as shown in FIG. When the plate 26 is elastically restored to its original shape, the negative electrode terminal plate 26 and the negative electrode current collector 25 come into contact again to release the energization cut-off state, and the battery 10 returns to the initial usable state.

  As described above, when the internal pressure of the battery increases, the sealed battery 10 described above operates at the internal pressure to form an energization cut-off state, while the energization cut-off occurs when the battery internal pressure decreases to a normal pressure. A pressure-actuated reversible energization shut-off means for automatically releasing the state is formed. As a result, battery rupture and electrolyte discharge due to misuse can be reliably prevented, and the battery function can be restored if the misuse state is resolved.

  Here, regarding the elastic deformation state of the negative electrode terminal plate 26, in the above description, the negative electrode terminal plate 26 elastically deformed by the increase in battery internal pressure automatically returns to its original shape when the battery internal pressure decreases. By doing so, the above-mentioned current interruption is automatically released, but the negative terminal plate 26 is formed so as to maintain the two shape states of FIG. 1 (a) and (b). In this case, the energization cutoff can be manually released.

  That is, the negative electrode terminal plate 26 has a first stable state in which the center surface is warped toward the inside of the battery (downward in the drawing) as shown in FIG. The center surface of the battery is configured to be in a second stable state in which the battery is warped outward (upward in the drawing).

  In this case, when the internal pressure of the battery 10 in the energized state shown in FIG. 5A is increased due to misuse, the negative electrode terminal plate 26 warps upward when the internal pressure reaches a certain limit, and FIG. ) Is turned off.

  Although this energization cut-off state is maintained even after the internal pressure of the battery is lowered, the negative electrode terminal plate 26 is warped downward by pressing the center surface of the negative electrode terminal plate 26 with a finger or the like from the outside. It is possible to manually return to the normal state shown in a).

  At this time, if the battery internal pressure remains high, the negative electrode terminal plate 26 cannot be warped downward even when pressed with a finger or the like. Thus, the user can know that the battery has become unusable due to misuse, and can easily check whether the battery that has been misused can be used or not. .

  FIG. 2 shows a second embodiment of a sealed battery according to the present invention. The sealed battery 10 shown in the figure is an LR type alkaline dry battery, and the basic configuration of the battery is the same as that of the first embodiment. Therefore, in the following description, only the features of the main part are shown.

  In the second embodiment, the negative electrode terminal plate 26 and the negative electrode current collector 25 are fixedly connected by spot welding, and a plurality of (three or more) through holes 27 are equiangular near the center surface of the negative electrode terminal plate 26. It is provided at intervals.

  As shown in FIGS. 5A and 5B, the sealing gasket 30 includes a central boss portion 31, an annular packing portion 32, an intermediate partition wall portion 33, and a thin portion 34, as well as from the through hole 27 to the negative electrode terminal plate. A projecting shaft portion 35 that can project and move to the outside (upward in the figure) of 26 is integrally formed.

  In the sealed battery 10 of this embodiment, when the inside of the battery is at normal pressure, the protruding shaft portion 35 is retracted to a steady position where it does not protrude from the outer terminal surface of the negative electrode terminal plate 26, as shown in FIG. ing.

  On the other hand, when the battery internal pressure increases beyond the normal range due to misuse or the like, the central boss portion 31 of the gasket 30 is pushed upward and moved by the internal pressure, as shown in FIG. By this movement, the protruding shaft portion 35 is pushed out to a position higher than the outer terminal surface of the negative electrode terminal plate 26. This operation is started at a battery internal pressure lower than the pressure at which the explosion-proof function by the thin portion 34 of the gasket 30 is activated.

  Thus, for example, as shown in FIG. 3A, only one of the plurality of batteries 10, 10,... Loaded in series in the battery holder 110 of the device is loaded in the reverse direction. As shown in FIG. 5B, the projecting shaft portion 35 protrudes outside the battery and is interposed between the batteries 10 and 10 as an insulating separator. The continuity is automatically cut off.

  When the misuse state is resolved and the battery internal pressure returns to normal, the projecting shaft portion 35 protruding from the terminal surface can be manually pushed to return to the original steady position.

  Thus, in the second embodiment, when the battery internal pressure increases, an electrically insulating movable member that protrudes from the inside of the battery 10 to a position higher than the negative electrode terminal surface outside the battery when the internal pressure increases is formed. The movable member forms a pressure actuated reversible energization interruption means.

  In the second embodiment, when the battery internal pressure becomes high, the central boss portion 31 of the gasket 30 is slid and moved with respect to the negative electrode current collector 25, but the pressing force acting on the central boss portion 31 by the battery internal pressure. That is, since the moving driving force is quite strong, it is not necessary to reduce the pressing force between the boss portion 31 and the negative electrode current collector 25. Therefore, even if the central boss portion 31 is slid and moved, there is no concern that the airtight state in the battery will be hindered.

  The LR type alkaline dry battery (conventional example) having the conventional configuration shown in FIG. 4, the LR type alkaline dry battery (Example 1) having the configuration of the first embodiment shown in FIG. 2, and the first type shown in FIG. LR type alkaline batteries (Example 2) having the configuration of one embodiment were respectively produced, and the following liquid leakage generation tests A to D were performed.

Test A: Four test batteries were loaded in series in the battery holder, and only one of them was loaded in reverse polarity. In this state, both ends of the four series were short-circuited for 24 hours, and the leakage occurrence state (number of leakage occurrence / number of tests) was examined.
Test B: Four test batteries were loaded in series in the correct polarity direction into the battery holder. In this state, both ends of the four series were short-circuited for 24 hours, and the leakage occurrence state (number of leakage occurrence / number of tests) was examined.
Test C: For the battery of the conventional example and Example 1, the positive electrode terminal and the negative electrode terminal of the single battery were short-circuited for 2 hours. In this case, the battery of Example 1 was turned off. Thereafter, the leakage occurrence situation (the number of leaks / the number of tests) after the two types of batteries had been placed for one month was examined.
Test D: Regarding the batteries of the conventional example and Example 1, the occurrence of leakage (the number of leaks / the number of tests) was examined when the unit cells were discharged at 10Ω for 72 hours.

Table 1 shows the results of the tests A to D.

Since tests C and D are single battery tests, the battery of Example 2 is not tested.
As is clear from Table 1, the batteries of Examples 1 and 2 were found to be very effective in preventing leakage even in a test assuming typical misuse.

  As mentioned above, although this invention was demonstrated based on the typical Example, this invention can have various aspects other than having mentioned above.

  It is possible to provide a sealed battery that can reliably prevent battery rupture and electrolyte discharge due to misuse, and that can restore the battery function if the misuse state is resolved.

It is principal part sectional drawing which shows 1st Embodiment of the sealed battery by this invention. It is principal part sectional drawing which shows 2nd Embodiment of the sealed battery by this invention. FIG. 3 is a side view of an essential part showing an operation example of the sealed battery shown in FIG. 2. It is sectional drawing which shows the structural example of the conventional sealed battery.

Explanation of symbols

10 Sealed battery (alkaline battery)
DESCRIPTION OF SYMBOLS 15 Positive electrode can 20 Power generation element 25 Negative electrode current collector 26 Negative electrode terminal board 27 Through hole 28 Reinforcement board 30 Gasket 31 Central boss part 32 Annular packing part 33 Intermediate partition part 34 Thin part 35 Projection shaft part 41 Actuator

Claims (4)

  In a sealed battery in which a power generation element containing an electrolytic solution is housed in a sealed state, when the battery internal pressure increases, it operates at that internal pressure to form a cut-off state, while the battery internal pressure decreases to a normal pressure A sealed battery comprising pressure-actuated reversible energization interruption means capable of manually or automatically releasing the energization interruption state.   2. The battery according to claim 1, wherein the battery has a negative electrode terminal that is in contact with the negative electrode current collector in a steady state, and when the internal pressure of the battery increases, the negative electrode terminal is reversibly deformed to form an energization cut-off state. When the internal pressure is reduced to normal pressure, the negative electrode terminal is restored to its original shape, so that the negative electrode terminal and the negative electrode current collector come into contact again to release the energization cut-off state. A sealed battery comprising:   The battery according to claim 1, further comprising an electrically insulating movable member that protrudes from the inside of the battery to a position higher than the negative electrode terminal surface outside the battery when the internal pressure of the battery increases, and the pressure operation is performed by the movable member. A sealed battery characterized in that a reversible energization interruption means of the type is formed. 4. The pressure-reversible reversal energizing means according to any one of claims 1 to 3, having an explosion-proof function of partially breaking when the battery internal pressure is abnormal and allowing the gas in the battery to escape to the outside. A sealed battery characterized by being lower than the operating pressure of the explosion-proof function.

Images