JP3249883B2 - Battery with current path cutoff function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention detects the deformation of the wall by the battery internal gas pressure, such as rechargeable Li-ion secondary battery used in cellular phones or the like, leading to one electrode of the battery
About the current path blocking function batteries so as to interrupt the current path.

[0002]

2. Description of the Related Art Conventionally, as a sensor related to an article deformation detecting sensor, there is a sensor for detecting the displacement of an article. In this case, a pressure sensor is fixed to the article and the output of the pressure sensor is detected. There is known a sensor for detecting a displacement amount. In addition, in Li (lithium) ion secondary batteries and the like, if the storage battery is overcharged or overdischarged, the gas pressure inside the battery rises, and the storage battery may explode. There has been proposed a device provided with a safety valve for exhausting the gas in the battery when the pressure of the battery is reduced. Here, the Li-ion secondary battery will be described. The principle of operation is as follows. At the time of charging, electrons are fed into the carbonaceous material of the negative electrode, and L
The i ions are desorbed and occluded in the negative electrode, causing a potential difference.
Conversely, at the time of discharge, the Li occluded in the carbon material of the negative electrode
The ions are desorbed and occluded in the positive electrode, sending out electrons and causing current to flow in an external circuit.

The inside of a Li-ion secondary battery has a spiral structure in which a sheet-like positive electrode and a sheet-like negative electrode are spirally wound with a polyolefin-based separator interposed therebetween. For the positive electrode, a composite metal oxide composed of Li ions and a specific metal is used as an active material,
A specific carbonaceous material was used for the negative electrode. L for both positive and negative electrodes
Contains i in the form of ions and has low reactivity to air and moisture. For this reason, the Li-ion secondary battery can be manufactured under a normal atmosphere. An aprotic organic solvent in which a Li salt is dissolved is used as the electrolyte. High ionic conductivity and stable voltage. Li in the electrolyte during charging and discharging
The ion concentration does not change. Further, the safety valve is provided to exhaust gas when the internal pressure rises due to an abnormality in the battery.

[0004]

However, in the prior art, the structure of the safety device was complicated, and the mounting work was troublesome. Further, it is not preferable to use a storage battery in which an abnormality has occurred and the internal pressure has increased, again. But,
In the prior art, when a predetermined pressure is reached by the safety valve, the gas in the battery is only exhausted, and there is a possibility that the storage battery may be used again by mistake.

[0005] The purpose of the present invention, a simple structure is to provide a current path blocking function batteries that can simultaneously detecting the varying <br/> form of wall interrupts the current path of the battery .

[0006]

The Purpose Means for Solving the Problems], the internal gas
Directly or indirectly on the outer wall that expands and deforms due to increased pressure
Formed in contact with and can be broken by the stress of the deformation
The conductive pattern with low toughness is connected to one electrode of the battery and the external circuit.
This is achieved by being connected between a road . The conductive pattern is flexible insulation that bends under the deformation stress of the outer wall of the battery
It is formed on the substrate or on the outer wall of the battery.
An epoxy-based conductive adhesive formed by direct contact.
May be.

[0007] The Purpose is rectangular with its upper part open
Shaped housing, facing the top of the housing across the opening
It is hung between the inner walls and destroyed by the deformation stress of the wall.
Insulating substrate having a low toughness and having a rectangular shape in plan view, and the insulating substrate
Formed on one side from one side to the other side .
Low toughness conductive pattern connected between electrode and external circuit
This is also achieved by having Conductive putter
Is tough enough to break under the stress of the outer wall of the battery.
Formed on a low insulating substrate or faces a battery on an insulating substrate
May be formed on the surface opposite to the surface
The conductive pattern is formed on the surface on which the conductive pattern is formed.
Grooves may be formed that extend across, or conductive patterns may be interrupted.
Meandering shape crossing the groove formed on the edge substrate surface multiple times
On the bottom of the groove on the insulating substrate.
A transmission member that transmits stress by contact is provided.
Is also good .

[0008]

[Function] The wall expands and deforms due to the rise of the internal gas pressure.
The toughness formed directly or indirectly on the wall
Because the low conductive pattern breaks under the deformation stress,
The current path between one electrode of the pond and the external circuit is interrupted
You. The conductive pattern breaks due to the deformation stress on the outer wall of the battery.
If formed on an insulating substrate with low toughness that can be broken,
It becomes easier to cut off the flow path .

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 are views for explaining a first embodiment of the present invention. FIG. 1 is an exploded perspective view of the first embodiment, FIG. 2 is a sectional view of the first embodiment, and FIG. Circuit diagram of the first embodiment,
FIG. 4 is an explanatory view showing a cracked state of the ceramic substrate of the first embodiment, FIG. 5 is a perspective view showing a first modification of the ceramic substrate of the first embodiment, and FIGS. It is a perspective view which shows the modification examples 2 and 3 of the ceramic substrate of 1st Example.

In these figures, reference numeral 8 denotes a battery.
Is the Li ion secondary battery described above, and the battery 8 has the first
-3 electrodes 5, 6, 7 are provided. Electromotive force E is that occur between the second electrode 6 and the third electrode 7. Reference numeral 1 denotes a substrate having low toughness, such as a ceramic substrate, and a conductive pattern 2 is formed on the surface of the ceramic substrate 1 by printing. The conductive pattern 2 is a composite type conductive pattern containing silver using a thermoplastic resin as a binder and has low toughness. Further, on the lower side of the ceramic substrate 1, the grooves 3 of the V-shape is formed me over a period of the entire width of the substrate 1. The conductive pattern 2 may be of a composite type in which a metal component such as ruthenium oxide is mixed with a glass component as a binder.

Reference numeral 4 denotes a terminal made of a metal material obtained by plating Ag on phosphor bronze. The second leg 4c and the first electrode 5 or 7 of the battery 8
And a cut-and-raised portion 4d that fits into the electrode 5 or 7 is provided, and has a substantially U-shape as a whole. As shown in FIG.
And the ceramic substrate 1 placed on the battery 8 is sandwiched. The second leg 4c need not be provided.

Next, the operation of the first embodiment will be described. Normally, this unit is incorporated in an electric appliance (not shown), and the second electrode 6 and the first electrode 5 of the battery 8 are used as power terminals of the electric appliance (not shown). Here, overcharging or overdischarging is performed as described above, and the battery 8
When the storage battery internal pressure rises of expanding deformation, as shown in FIG. 4, the ceramic substrate 1 is cracking, even breakage conductive pattern 2 at the same time. A indicates an expanded portion of the battery 8. Thus, the circuit shown in FIG. 3 because the disconnection, overcharge or overdischarge of the battery is stopped. Therefore, the battery does not further expand and burst.

Here, a modification of the ceramic substrate 1 of the first embodiment will be described with reference to FIGS. In a first modification of the ceramic substrate 1, as shown in FIG. 5, both sides are cut out, and the cutouts 10, 10 are provided so as to reach the conductive pattern 2.

In a second modification of the ceramic substrate 1,
As shown in FIG. 6A, a groove 1 is formed on the conductive pattern forming surface side.
1 is provided, and the groove 11 is not provided only near the end face.
1 is provided. In a third modification of the ceramic substrate 1, as shown in FIG. 6B, the groove 12 is provided over the entire width on the conductive pattern forming surface side, and the conductive pattern 22 is formed.
Has a meandering shape that simultaneously crosses the groove 12 multiple times. A groove 13 is provided across the entire width of the lower surface of the ceramic substrate 1 so as to face the groove 12.

The shape of the broken portion formed in the ceramic substrate 1 may be a shape in which a through hole is provided in a chain line shape. In the case of this shape or the shape shown in FIG. Can be secured as needed.

In the first embodiment thus constructed, the low toughness ceramic substrate 1 which can be broken by the deformation stress of the battery 8 and the low toughness conductive material formed on the ceramic substrate 1 Since it has the pattern 2 and the electrodes 6 and 7 which are connected to the conductive pattern 2 and are arranged at least with the destructed portion of the ceramic substrate 1 interposed therebetween, the storage battery has a simple structure.
Safety device can be provided. In addition, the modified example
In the 3, since the conductive pattern 22 is formed in a meandering shape through multiple grooves 12 is the destruction of the ceramic substrate 1, since one of them may be at least breaking,
The reliability of the interruption can be increased.

[0017] The In the first embodiment, since the power storage pond 8 which faces the ceramic substrate 1 provided with the conductive pattern 2 on the opposite surface, the ceramic substrate 1 expands strange <br/> when broken by shape, as compared with the case of providing the conductive pattern 2 on the lower surface, since the conductive pattern 2 receives a greater tensile force is reliably cut off, overcharge or overdischarge of the battery is stopped, 蓄 battery There does not have to be ruptured by further expansion. In the first embodiment, a groove 3 extending in a direction perpendicular to a line connecting the electrodes 6 and 7 of the ceramic substrate 1 is formed, and a conductive pattern 2 is formed on a surface opposite to a surface on which the groove 3 is formed. When the ceramic substrate 1 is cracked, the conductive pattern 2 is surely cut off.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a front view of the second embodiment. As this difference from the first embodiment in the second embodiment is directly formed conductive pattern 25 in the power storage battery 8, which the conductive pattern 25 was extended respectively to the electrode 5 and 7 of a charge reservoir pond 8 The other parts are the same as in the first embodiment. The conductive pattern 25 in the second embodiment
It is to be used a conductive adhesive or the like of the epoxy.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 8 is a perspective view of a substrate according to the third embodiment. Difference from the first embodiment in the third embodiment is only an insulating substrate and the conductive pattern, the other portions are the same. Insulation substrate 30 shown in FIG. 8 is PET, a flexible film of polyimide or the like, the conductive pattern 31 formed on the insulating substrate 30 is ITO film. In the third embodiment, since the conductive pattern 31 can be cut by bending the insulating substrate 30 without breaking the insulating substrate 30, the conductive pattern 31 can be broken with a small pressure.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 9 is an exploded perspective view of the fourth embodiment, and FIG. 10 is an enlarged sectional view of a main part of the fourth embodiment.
The fourth embodiment is an example relating to a storage battery of a type different from the above-described storage battery. That is, the fourth embodiment, the metal casing 40 was taken out a negative electrode (casing 40 is in the negative electrode), an electrode 41 located at the top of the said casing 40, take out the positive electrode Type. The holder 42 is made of an insulating resin, and has grooves 43 at both ends thereof. An insulating substrate 44 is inserted between the grooves 43, 43, and an elastic contact plate 45 made of a metal such as phosphor bronze is elastically held between the insulating substrate 44 and the holder 42. This bullet contact plate 4
5 are provided with two elongated through-holes 46 at one end thereof. Projections 48, 48 projecting from the lower surface of the terminal electrode 47 made of brass are inserted into the through-holes 46, 46 through the holder 42. Through the through holes 54, 54. The elastic contact plate 45 is folded back, and the other end is the insulating substrate 44.
It is in elastic contact with one end of the upper conductive pattern 49.

A through hole 50 is provided at the other end of the insulating substrate 44, and an overhang portion 52 of a conductive plate 51 provided on the lower surface side of the insulating substrate 44 is inserted into the through hole 50 and fixed by soldering 56. The overhang 52 and the conductive pattern 49 are made conductive. The lower end of the conductive plate 51 is in pressure contact with the electrodes 41 of the electric storage battery 55. The substrate holder 5 is provided in the metal casing 40.
7 and 57 are formed, the holder 42 is placed on both substrate holders 57 and 57, and an adhesive 53 is applied to the peripheral surface of the holder 42 and fixed to the metal casing 40. A gap 58 is provided between the insulating substrate 44 and the holder 42 so that the insulating substrate 44 can be deformed.

In the fourth embodiment constructed as described above, the electric storage device having the metal casing 40 and drawing out the internal electric energy to the outside through the first and second electrodes (40, 41). a pond 55, insulating substrate 44 disposed thereon
And the other end of the conductive pattern 49 on the insulating substrate 44
Through the conductive plate 51 is connected to the first electrode 41 of the electric storage battery 55, the second electrode 40 of the electric storage battery 55 and on the insulating substrate 44
The terminal electrode 47 connected to one end of the conductive pattern 49 is used as an extraction electrode of the storage battery, and the insulating substrate 44 is
Holder 42 for holding is placed in contact with the metal casing 40, insulating substrate 44 is formed of a low toughness material deformation stress can destroy undergoing metal casing 40, a lower conductive pattern toughness on the insulating substrate 44 Formed
The current path can be cut off simultaneously with the detection of the deformation of the storage battery.

Next, a fifth embodiment of the present invention will be described with reference to FIGS. FIG. 11 is a perspective view of the pressure disconnection element of the fifth embodiment, and FIG. 12 is a plan view, a longitudinal sectional view, and a bottom view of the pressure disconnection element of the fifth embodiment. 11 and 12, reference numeral 60 denotes an insulating substrate.
The ends 60a and 60b are incorporated into the holder 61 by snap-in and are clamped. A terminal electrode 62 is attached to the insulating substrate 60, and one end of the terminal electrode 62 is formed in a clip shape and is in elastic contact with a conductive pattern 63 formed on the insulating substrate 60. At the center of the lower surface of the terminal electrode 62, a storage section 65 for storing a transmission member 64 such as urethane is provided. The conductive pattern 63 of the insulating substrate 60 is in elastic contact with the terminal electrode 62 and is conductive .

A gap 66 is provided between the upper surface of the insulating substrate 60 and the holder 61, and a space for deforming the insulating substrate 60 until the conductive pattern 63 is disconnected is secured. 67 is a metal lead, and one end of the metal lead 67
Conductive pattern 6 but are disposed to the upper surface of the insulating substrate 60
Folded on the lower surface of which is connected to the third end Rutotomoni insulating substrate 60 to cover the transmission member 64 has reached the vicinity of the other end.
A plurality of slits 68 are provided at positions corresponding to the transmission members 64 of the metal leads 67. Reference numeral 69 denotes a groove provided over the entire upper surface of the insulating substrate 60. A rubber conductive connector may be interposed between the terminal electrode 62 and the conductive pattern 63.

Further, the transmission member 64, the terminal electrodes 62 causes pressure contact with the positive electrode of蓄<br/> batteries, since the deformation of the electric storage battery is required to convey the insulating substrate 60, and some suitable softness Hardness is required. In this embodiment, urethane is used as the transmission member 64, but rubber or the like can be used as long as it has appropriate hardness. The fifth embodiment thus configured
In this embodiment, the same operation and effect as those of the above embodiments can be obtained. The insulating substrate shown in FIGS . 9 and 11 can be replaced with the substrate described in the first embodiment.

[0026]

According to the first aspect of the present invention, the deformation stress
Low toughness conductive pattern on the outer wall
It is formed in direct or indirect contact with one electrode of the battery.
Because it is connected between external circuits,
The battery current path is detected at the same time as the wall deformation is detected.
It is possible to cross. According to the second aspect of the present invention, guide
Flexibility to bend the electric pattern under the deformation stress of the outer wall surface of the battery
Since it was formed on a conductive insulating substrate, the conductive
Turns can be cut, so conductive patterns can be formed with small pressure
Can be broken . According to the invention described in claim 6,
Place the conductive pattern on the opposite side of the surface of the insulating substrate facing the battery .
Having formed on the surface, when the insulating substrate is split and deformed to expand, from moving in a direction where the conductive pattern are separated, Ru can be reliably cut off the conductive patterns. According to the invention of claim 7, the conductive pattern of the insulating substrate is formed.
On the surface, a concave groove extending across the conductive pattern was formed.
When the insulating substrate is broken, the conductive pattern is reliably cut off
It is Ru can be. According to the eighth aspect of the present invention, the insulation
Make a meandering shape by traversing the groove formed on the substrate surface multiple times
Since the formation of the conductive pattern, one of the conductive pattern of the meander shape across more than once it may be at least break
From, it is possible to increase the reliability of the current path blocking.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the first embodiment of the present invention.

FIG. 3 is a circuit diagram of a first embodiment of the present invention.

FIG. 4 is an explanatory view showing a cracked state of the ceramic substrate according to the first embodiment of the present invention.

FIG. 5 is a perspective view showing a first modification of the ceramic substrate of the first embodiment of the present invention.

FIG. 6 is a perspective view showing Modification Examples 2 and 3 of the ceramic substrate according to the first embodiment of the present invention.

FIG. 7 is a front view of a second embodiment of the present invention.

FIG. 8 is a perspective view of a substrate according to a third embodiment of the present invention.

FIG. 9 is an exploded perspective view of a fourth embodiment of the present invention.

FIG. 10 is an enlarged explanatory view of a main part of a fourth embodiment of the present invention.

FIG. 11 is a perspective view of a pressure disconnection element according to a fifth embodiment of the present invention.

FIG. 12 is a plan view, a longitudinal sectional view, and a bottom view of a pressure disconnection element according to a fifth embodiment of the present invention.

[Explanation of symbols]

1 ceramic substrate 2, 21,22,25,31,49,63 conductive pattern 6 second electrode 7 third electrode 11, 12 groove 40 the metal casing 30, 44, 60 insulating substrate 8, 55 power storage ponds

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01M 2/34 H01M 2/02 H01M 2/12 H01M 10/42-10/48

Claims (10)

(57) [Claims] 1. Expansion and deformation caused by an increase in internal gas pressure.
That are formed directly or indirectly in contact with the outer wall surface, a lower conductive pattern toughness that obtained by destroying under stress of the deformation,
A battery with a current path interruption function, which is connected between one electrode of the battery and an external circuit . 2. The conductive pattern has a deformation stress on the outer wall surface of the battery.
The electrode with a current path interrupting function according to claim 1, wherein the electrode is formed on a flexible insulating substrate that bends in response to the electric current.
Pond . 3. The conductive pattern is in direct contact with the outer wall surface of the battery.
2. The battery according to claim 1, wherein the battery is an epoxy-based conductive adhesive . 4. A rectangular parallelepiped housing having an open upper part,
Across the opening and between the opposing inner walls above the housing
Flatness with low toughness that can be broken by the deformation stress of the wall
A square insulating substrate, and one side of the insulating substrate
Is formed on the other side, and one electrode and the external circuit
This <br/> a current path blocking function battery, characterized in having connected a low toughness conductive patterns between. 5. The conductive pattern was formed on the outer wall surface of the deformation stress that obtained by destroying undergoing toughness low insulating substrate of the battery
Electrodeposition of claim 1 or 4, wherein the those
Battery with flow path cutoff function . 6. The conductive pattern is opposed to the battery on the insulating substrate.
6. The device according to claim 5, wherein the second surface is formed on a surface opposite to the first surface.
Current path blocking function batteries according. 7. A surface of an insulating substrate on which a conductive pattern is formed.
Forming a groove extending across the conductive pattern.
Claim 5 or 6 current path blocking function batteries according, characterized in that the. 8. A conductive pattern is formed on an insulating substrate surface.
Formed in a meandering shape by traversing the concave groove several times.
Current path with blocking function according to claim 7, wherein the that
Batteries. 9. A stress is generated by contacting a lower side of a concave groove of an insulating substrate.
A transmitting member for transmitting is provided, and on the insulating substrate surface
A conductive pattern is formed in a meandering shape by traversing the formed groove a plurality of times.
Current path blocking function batteries according to claim 7, characterized in that the formation of the turns. 10. The battery is a storage battery.
Current path blocking function batteries according to any one of claims 1 to 9.