JP2000090960A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery circuit interruption part having good assemblage by reducing the number of part items more than in a conventional case. SOLUTION: This battery circuit interruption part T forms a conductive passage between a battery cover 11 and a heat generating element in a battery via a diaphragm part D and a lead 18a. When the internal pressure of a battery case K rises over a preset value, the diaphragm part D displaces, thereby separating the diaphragm part D and the lead 18a for interrupting a conductive passage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rechargeable battery such as a rechargeable battery, and more particularly, to a battery in which a diaphragm or a safety valve does not operate even when an impact such as a drop is applied.

[0002]

2. Description of the Related Art Conventionally, a rechargeable lithium ion secondary battery or the like, which is sealed by injecting an organic solvent-based electrolyte into a battery case, is used as a power source for portable equipment such as a mobile phone and a personal computer. Widely used. However, if such a battery is overcharged or recharged with a current larger than the specified current when recharging the battery, an abnormality occurs in the battery, gas is generated inside the battery case, and the battery case is discharged. In some cases, the internal pressure and temperature rise, and the battery case expands, cracks, and the like, and the internal electrolyte oozes out to the outside, which may adversely affect the device in which the battery is incorporated. Even if this does not occur, if the battery is continued to be used in the abnormal state as described above, the battery may expand and the battery case may be ruptured. Had to be discontinued immediately.

A conventional battery for preventing such a rupture of the battery will be described with a circular battery as shown in FIGS. First, the battery case 1 has a battery lid 3 hermetically attached to the inside of the battery case 1 by caulking or welding or the like via a gasket 2,
Actuators 4 that can be displaced upward when the internal pressure of the battery case 1 increases are provided below the battery cover 3. A vent 3a is formed in the battery lid 3,
When the actuator 4 is displaced upward, air in a portion sandwiched between the battery lid 3 and the actuator 4 causes the air vent 3a.
From the outside.

In the actuator 4, an annular operating plate 4a is formed by drawing or the like.
A projecting portion 4b projecting downward in the figure at the center and a radial groove 4c formed on a surface around the projecting portion 4b
Part of a is formed to be thin. An insulating plate 5 is provided below the actuator 4, and a hole 5a through which the protrusion 4a of the safety valve portion 4a is inserted is formed in the center of the insulating plate 5.
A ventilation hole 5b is formed at a position distant from the hole 5a. A lead fixing member 6 is provided below the insulating plate 5. The lead fixing member 6 has a hole 6 a communicating with the hole 5 a of the insulating plate 5 and a ventilation hole 5 of the insulating plate 5.
b is provided with a ventilation hole 6b communicating with the b.

A projection 4b of an operation plate 4a is inserted into holes 5a, 6a of the insulating substrate 5 and the lead fixing member 6,
A lead 7 made of a thin metal plate is attached to the tip of the projection 4b. This thin plate-shaped lead 7
There is a joint 7a that is joined to the tip of the projection 4b by welding or the like, and the actuator 4 and the lead 7 are electrically connected. The other end of the lead 7 is connected to a power generating element
And an electric circuit is formed between the power generation element 8 and the battery lid 3. The inside of the battery case 1 is filled with an electrolytic solution (not shown). When gas is generated inside the battery case 1 due to an abnormality inside the battery and the internal pressure of the battery case 1 rises, the high-pressure gas is
Flowing from arrows b and 6b as shown by arrow A in FIG. 11, an operating force is applied to the lower surface of the operating plate 4a to push the operating plate upward.

When a concentrated stress is applied to the joint 7a of the lead 7 by the operating force applied to the operating plate 4a, and the concentrated stress becomes larger than the shear stress of the joint 7a, the joint 7a breaks or protrudes from the lead 7. The part 4b and the joint part 7a are peeled off, the electrical connection between the lead 7 and the actuator 4 is cut off, and the electric path between the power generating element 8 and the battery lid 3 is cut off. By this interruption of the electric circuit, the flow of the current inside the battery is interrupted, the pressure rise inside the battery case 1 is suppressed, and the rupture of the battery can be prevented in advance. Such conventional batteries are widely used in portable devices such as mobile phones.

[0007]

However, if such portable equipment using a conventional battery or a single battery is dropped by mistake, the battery drops into an electrolyte (not shown) inside the battery case 1. The shock is applied, and this electrolytic solution becomes tsunami-like, instantaneously moves through the vent holes 6b, 5b having a large diameter and a short distance, and a large pressure of the electrolytic solution which attempts to displace the operation plate 4a upward is generated. Join. The magnitude of the impact applied to the electrolyte varies depending on the drop height of the battery. However, when the impact is large, the operating plate 4a is pushed up at once and is inverted, and the joint 7a is broken from the lead 7 or the projection 7a is broken. The tip of the portion 4b peels off from the joint 7a. Then, the electric circuit between the power generation element 8 and the battery lid 3 is cut off, and the battery may be unusable. An object of the present invention is to provide a battery in which an electric circuit inside the battery is not interrupted even if the battery or a portable device containing the battery is accidentally dropped. And

[0008]

According to a first aspect of the present invention, there is provided a battery according to the present invention, comprising: a battery case; a battery lid for hermetically shielding the inside of the battery case;
A diaphragm portion formed on a part of this battery lid and displaceable in response to a change in the internal pressure of the battery case, or a safety valve portion that can be broken in response to a change in the internal pressure of the battery case, and in close contact with the inner surface of the battery lid. And a shielding member arranged,
A pressure transmission path having a small diameter is formed in the shielding member so as to communicate with the inside of the battery case and extend to the lower part of the diaphragm part and / or the safety valve part.

As a second means for solving the above-mentioned problems, the pressure transmission path is constituted by a groove formed on the surface of the shielding member on the side where the battery lid is in close contact.

As a third means for solving the above-mentioned problems, the pressure transmission path has a plurality of concave portions and convex portions on a wall surface of the groove, and the diameter is partially defined by the convex portions. The structure was designed to be smaller in size.

According to a fourth aspect of the present invention, the pressure transmission path is provided between an entrance of a communication part with the inside of the battery case and a lower part of the diaphragm part and / or the safety valve part. Was formed in a non-linear shape.

According to a fifth aspect of the present invention, the non-linear pressure transmission path is formed by combining a plurality of bent portions having a crank shape. An electric circuit cutoff mechanism for the battery according to the above.

According to a sixth aspect of the present invention, the pressure transmission path communicates with the battery case and the inside formed in the shielding member, and the diaphragm section and / or the safety valve. It was made up of a small bore horizontal hole extending to the lower part of the part.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a battery circuit cutoff mechanism according to the present invention. FIG. 1 is a top view according to the present invention, FIG. 2 is a sectional view of a main part according to the present invention in a state where the battery case is mounted, FIG. 3 is a bottom view according to the present invention, and FIG. FIG. 5 is an enlarged sectional view of a main part according to the present invention, and FIG.
FIG. 7 is a schematic diagram illustrating the operation of the diaphragm unit according to the present invention, FIG. 7 is a schematic diagram of a second embodiment according to the present invention, and FIG. 8 is a schematic diagram of a third embodiment according to the present invention. FIG. 9 is a schematic view of a fourth embodiment according to the present invention.

The schematic structure of the battery according to the first embodiment of the present invention will be described with reference to, for example, a rectangular battery shown in FIGS. 1 to 4.
A battery case K for accommodating a power generating element (not shown) is provided therein, and a battery cover 11 for securely shielding the inside of the battery case K is attached to the battery case K. The battery lid 11 is sandwiched between a shielding member 12 attached to the lower surface and a holding member 13 attached to the upper surface, and a rivet 14 at the center is caulked to hold the battery lid 11 and the shielding member 12 together. The member 13 is integrated. An anode terminal 15 is mounted below the rivet 14, and a conduction washer 16 is mounted above the rivet 14 simultaneously with the caulking of the rivet 14. Above the rivet 14, an external anode 17 is provided, which is connected to a conductive washer 16 and is conductive. A lead 1 is provided at one end of the shielding member 12.
A cathode terminal 18 having 8a is attached by caulking or the like.

The battery cover 11 of the above-described battery is made of a conductive metal plate such as a stainless steel material, and has a substantially rectangular outer shape as shown in FIGS.
1a and a flat bottom plate 11b formed by projecting the inside of the flange portion 11a downward by drawing or the like. A part of the bottom plate 11b of the battery cover 11 has, for example, a diaphragm portion D that can be displaced in accordance with a change in the internal pressure of the battery case 11 on the right side in the drawing and a breakable portion in accordance with a change in the internal pressure of the battery case 11 on the left side in the drawing. A safety valve portion Z is formed.

As shown in FIG. 5, the diaphragm portion D has an annular concave portion 11c formed by grinding or the like from the lower surface side of the bottom plate 11b, and is provided with a thin portion 11d. This thin portion 11d is formed into a bowl shape by pressing or the like into a battery case K.
Bulging inward. A thick portion 11e thicker than the surrounding thin portion 11d is formed at the center of the bulging thin portion 11d. The diaphragm portion D has a thin portion 11d on the outer peripheral side of the concave portion 11c.
The thick portion 11e at the center can be displaced upward with the base portion of the as a fulcrum. The safety valve portion Z includes a flat thick-walled protruding portion 11f whose outer shape is formed to protrude upward in the figure in an annular shape, and a connecting portion 11g having a thinner root portion on the outer peripheral side of the protruding portion 11f. A hollow portion 11h having a gap of a predetermined size is formed in the interior surrounded by the protruding portion 11f and the connecting portion 11g.

On the lower surface of the bottom plate 11b of the battery lid 11,
A shielding member 12 formed of an insulating material having a rectangular shape smaller than the outer shape of the battery lid 11 and having a rectangular outer shape is closely attached. The shielding member 12 communicates with an escape hole 12a formed below the thick portion 11e at the center of the diaphragm portion D, the inside of the battery case K, and a communicating portion entrance 12k of one end surface 12h through the diaphragm portion D. Recess 11c at the bottom of
When the pressure inside the battery case K rises, a high-pressure gas passes through the first pressure transmission path 12b and a concave portion of the diaphragm portion D is formed. 11c.

The other end surface 12j of the shielding member 12
A second pressure transmission path 12c having a long distance and a small diameter is formed extending from the communication portion entrance 12m to the cavity 11h below the safety valve portion Z, and when the pressure inside the battery case K increases, the high-pressure gas is released. It passes through the second pressure transmission passage 12c and enters the hollow portion 11h of the safety valve portion Z. The first and second pressure transmission passages 12b and 12c having a long distance and a small diameter are formed on the surface of the shielding member 12 on the side where the bottom plate 11b of the battery lid 11 is in close contact, for example, a U-shaped groove in cross section. It is configured. A central hole 12d through which a rivet 13 to be described later is inserted is formed in the center of the shielding member 12.
A boss portion 12e having an upper portion is formed to protrude upward. A caulking portion 12f and a positioning protrusion 12g are formed on the lower surface on the right side in the drawing of the shielding member 12 so as to protrude downward.

On the bottom plate 11b of the battery cover 11, a holding member 13 for pressing and attaching the battery cover 11 to the shielding member 12 is provided. The pressing member 13 is made of an insulating material, and has a central hole 13a formed at the center thereof for the boss 12e of the shielding member 12 to pass therethrough. A first recess 13b is formed above the diaphragm D,
A first vent 13c is formed through the upper wall of the first recess 13b so that the first recess 13b is connected to the outside. Further, above the safety valve portion Z, a safety valve portion Z
A second recess 13d in which the protrusion 11f is located is formed,
A second ventilation hole 13e is formed through the upper wall of the second concave portion 13d so that the second concave portion 13d is connected to the outside.

A rivet 14 made of aluminum or the like is inserted into the center hole 12d of the shielding member 12, and the rivet 14 has a lower head portion 14a and a caulking portion 14b projecting upward from the boss portion 12e. ing. The rivet 13 has an anode terminal 15 bent in a substantially L-shape between the head 12a and the shielding member 12, and is caulked and caulked out and has a caulking portion 14b and a holding member 13 which are spread outward in a substantially circular shape. In between, a conduction washer 16 made of a metal plate is sandwiched. The head 14 of the rivet 14
A sealing material (not shown) made of a synthetic rubber-based material is applied to the periphery of the anode terminal 15 and the shielding member 1.
2 is completely shielded. Above the caulked portion 14b of the rivet 14 which is caulked and flattened, an external anode 17 connected to both ends of the conductive washer 16 by spot welding or the like is provided. And the surface is nickel-plated. The external anode 17 and the anode terminal 15 are electrically connected via the rivet 14.

The caulking portion 12f of the shielding member 12 has
A cathode terminal 18 bent in a substantially L shape is attached. The cathode terminal 18 has a lead 18a attached to the lower surface of the shielding member 12. The lead 18a has an annular projecting portion 18 projecting upward by drawing or the like.
b is formed, and the projecting portion 18b is fitted into the escape hole 12a of the shielding member 12. The tip 18c of the protruding portion 18b is formed to be flat and thin. A thick portion 11e of the diaphragm portion D is joined by spot welding or the like near the center of the distal end portion 18c fitted into the escape hole 12a. Then, with the lead 18a joined to the diaphragm portion D, the caulking portion 12f of the shielding member 12 is caulked inside the battery case K and the shielding member 1 is formed.
2 is fixed. The lead 18a has a positioning hole 18d formed by a positioning protrusion 12g of the shielding member 12.
And the movement is regulated.

In the battery having such a configuration, as shown in FIG. 2, a flange 11a on the outer peripheral portion of the battery lid 11 is attached to an opening of the battery case K by welding or the like, and a power generating element (not shown) is provided. The inside of the battery case K in which is stored is secretly shielded. Then, an electric path is formed between the battery lid 11 and a cathode element (not shown) of the power generation element inside the battery via the diaphragm portion D and the lead 18a, and an abnormality occurs inside the battery and the inside of the battery is generated. When the pressure rises, the gas whose pressure has increased rises in the first pressure transmission path 12 of the shielding member 12.
b, penetrates into the concave portion 11c, and the diaphragm portion D
Actuating force is applied to push upward.

When the internal pressure of the battery case K rises above a predetermined value, as shown in FIG. 6, the thin portion 11d of the diaphragm D is inverted and displaced upward, and is joined to the thick portion 11e. The thin end portion 18c of the lead 18a is broken from the joint, and the electric path between the battery lid 11 and the cathode element (not shown) of the power generation element inside the battery can be cut off. At this time, the tip 18c of the lead 18a
A break hole 18e is formed in the portion where the diaphragm D was joined.
The broken piece 18f of the lead 18a is joined to the diaphragm D side displaced upward.

The interruption of the electric path formed between the battery lid 11 and the cathode element (not shown) of the power generation element inside the battery is not limited to the one in which the tip 18c of the lead 18a is broken. Depending on the strength of the spot welding, the thick portion 11e of the diaphragm portion D
Some are peeled from c (not shown). Alternatively, in some cases, the thick portion 11e of the diaphragm portion D is broken from the thin portion 11d around the thick portion 11e in a state of being joined to the distal end portion 18c of the lead 18a (not shown).

Even if the electric circuit between the battery cover 11 and the power generating element (not shown) inside the battery is cut off, the pressure inside the battery case K does not stop rising, and the internal pressure further rises. In this case, the gas that has further risen is transferred from the small-diameter die 2 pressure transmission path 12c to the cavity 1 of the safety valve section Z.
When the internal pressure of the battery case K exceeds a predetermined value, the projecting portion 11f is pushed upward, and the thinly formed connecting portion 11g is invaded. Is to be broken. The high-pressure gas inside the battery is discharged to the outside from the portion where the connecting portion 11g is broken, so that the rupture of the battery can be prevented in advance.

If the portable equipment using the battery of the present invention or the battery alone is dropped by mistake, the electrolyte in the battery case K is shocked. Tsunami-like first and second pressure transmission paths 1
2b and 12c are pushed toward the communication part entrances 12k and 12m. However, since the diameters of the first and second pressure transmission paths 12b and 12c are small and the distance is long, the tsunami-like electrolytic solution is pressed by the first and second pressures. While passing through the transmission paths 12b and 12c, the shock applied to the electrolyte is absorbed. Therefore, the electrolytic solution is supplied to the concave portion 11c of the diaphragm portion D or the safety valve portion Z.
Even if the hollow portion 11h is filled, it is possible to prevent the diaphragm portion D or the safety valve portion Z from erroneously operating.

Since the first and second pressure transmission paths 12b and 12c having a small diameter are formed in a direction parallel to the surface of the shielding member 12, the first and second pressure transmission paths 12b and 12c are formed.
Since the electrolyte that enters from the communication port entrances 12k and 12m of c moves straight in a direction parallel to the thin portion 11d of the diaphragm portion D or the projection 11f of the safety valve portion Z, the electrolyte that has entered enters the thin portion of the diaphragm portion D. The impact of the electrolyte pressure can be further reduced without directly hitting the portion 11d or the protrusion 11f of the safety valve portion Z. In the description of the present invention, first diaphragms are provided on both the diaphragm D side and the safety valve Z side.
And the second pressure transmission passages 12b and 12c are formed, but the first pressure transmission passage 1 is provided only on the diaphragm D side.
The second pressure transmission path 12c may be formed only on the side of the safety valve portion 2b. That is, the pressure transmission path 11
2b and 12c may be formed to extend to the lower part of the diaphragm part D and / or the safety valve part Z.

Further, as a second embodiment of the present invention,
As shown in FIG. 7, the pressure transmission path 22c of the shielding member 22
Has a plurality of concave portions 22d and convex portions 22e on the side wall of a U-shaped groove, for example, and the diameter of the convex portion 22e is partially reduced. Also, as a third embodiment,
The pressure transmission path 32c may have a non-linear shape between the communication port entrance 32m with the inside of the battery case K and the lower part of the diaphragm part D and / or the safety valve part Z. That is, the non-linear pressure transmission path 32c is
As shown in (1), it may be formed by combining a plurality of crank-shaped bent portions.

Further, as a fourth embodiment of the present invention,
As shown in FIG. 9, the pressure transmission path 42c is
To the inside of the battery case K, and may be constituted by a horizontal hole having a small diameter up to the diaphragm portion D and / or the lower portion of the safety valve portion Z.

[0031]

According to the battery of the present invention, a small-diameter pressure transmission path communicating with the inside of the battery case and extending to the diaphragm and / or the lower portion of the safety valve is formed in the shielding member. Even if it is dropped, the shock applied to the internal electrolyte can be absorbed by the pressure transmission path having a small diameter. Therefore, even if the battery is accidentally dropped, a battery can be provided in which the diaphragm portion or the safety valve portion does not malfunction and the internal electric circuit is cut off or the safety valve portion is not broken. .

Further, since the pressure transmission path is constituted by a groove formed on the surface of the shielding member on the side where the battery lid is in close contact, even if the battery is dropped by mistake, the thin portion of the diaphragm portion or The electrolyte enters in a direction parallel to the protrusion of the safety valve. Therefore, the intruded electrolyte does not directly hit the thin portion of the diaphragm portion or the projecting portion of the safety valve portion, so that malfunction of the diaphragm portion or the safety valve portion can be prevented.

Further, the pressure transmission path has a plurality of concave portions and convex portions on the wall surface of the groove, and the diameter of the aperture is partially reduced by the convex portions. Even if it does, the impact applied to the electrolytic solution can be absorbed by the plurality of concave portions and convex portions.

In addition, since the pressure transmission path is formed in a non-linear shape between the entrance of the communication part with the inside of the battery case and the lower part of the diaphragm part and / or the safety valve part, the battery may be erroneously inserted. Even if it falls down, the electrolyte can enter the non-linear pressure transmission path to reduce the flow rate of the electrolyte, thereby preventing malfunction of the diaphragm or the safety valve.

Further, since the non-linear pressure transmission path is formed by combining a plurality of bent portions having the shape of a crank, the flow velocity of the electrolyte which has entered the pressure transmission path can be further reduced. Malfunction of the diaphragm or the safety valve can be more reliably prevented.

Further, the pressure transmission path is formed by a small-diameter horizontal hole communicating with the inside of the battery case and extending to the diaphragm portion and / or a lower portion of the safety valve portion. The shock applied to the electrolytic solution can be absorbed.

[Brief description of the drawings]

FIG. 1 is a top view according to the present invention.

FIG. 2 is a sectional view of a main part according to the present invention.

FIG. 3 is a bottom view according to the present invention.

FIG. 4 is a side view according to the present invention.

FIG. 5 is an enlarged sectional view of a main part of a diaphragm according to the present invention.

FIG. 6 is an enlarged sectional view of a main part for explaining an operation of a diaphragm section according to the present invention.

FIG. 7 is a schematic view of a second embodiment according to the present invention.

FIG. 8 is a schematic diagram of a third embodiment according to the present invention.

FIG. 9 is a schematic diagram of a fourth embodiment according to the present invention.

FIG. 10 is a sectional view of a main part of a conventional battery.

FIG. 11 is a cross-sectional view of a main part explaining the operation of a conventional battery.

[Explanation of symbols]

 T Circuit blockage part of battery of the present invention 11 Battery lid 11a Flange 11b Bottom plate 11c Concave part 11d Thin part 11e Thick part 11f Projection part 11g Connection part 11h Cavity part 12 Shielding member 12a Escape hole 12b First pressure transmission path 12c Second Pressure transmission path 12d Central hole 12e Boss part 12f Caulking part 12g Projection 13 Pressing member 13a Central hole 13b First concave part 13c First vent 13d Second concave part 13e Second vent 14 Rivet 14a Head 14b Caulking part 15 Anode terminal 16 Conductive washer 17 External anode 18 Cathode terminal 18a Lead 18b Projection 18c Tip 18d Vent 18e Break hole 18f Fragment K Battery case D Diaphragm Z Safety valve

Claims (6)

[Claims] 1. A battery case, a battery cover for hermetically shielding the inside of the battery case, a diaphragm portion formed on a part of the battery cover and displaceable according to a change in internal pressure of the battery case, or the battery. A safety valve portion that can be broken in response to a change in the internal pressure of the case; and a shielding member disposed in close contact with the inner surface of the battery lid. The shielding member communicates with the inside of the battery case, and the diaphragm portion Or /
And a pressure transmission path having a small diameter extending to a lower portion of the safety valve portion. 2. The battery according to claim 1, wherein the pressure transmission path is formed by a groove formed on a surface of the shielding member on a side where the battery lid is in close contact. 3. The pressure transmission path has a plurality of concave portions and convex portions on a wall surface of the groove, and the diameter of the aperture is partially reduced by the convex portions. 2. The battery according to 2. 4. The pressure transmission path has a non-linear shape between an entrance of a communication part with the inside of the battery case and a lower part of the diaphragm part and / or the safety valve part. The battery according to claim 1, 2, or 3. 5. The battery according to claim 4, wherein the non-linear pressure transmission path is formed by combining a plurality of bent portions having a crank shape. 6. The pressure transmission path is formed of a small-diameter horizontal hole formed in the shielding member, communicating with the inside of the battery case, and extending to a lower portion of the diaphragm portion and / or the safety valve portion. The battery according to claim 1, wherein: