JPH08236102A - Electrochemical element - Google Patents

Abstract

PURPOSE: To provide an electrochemical element equipped with an explosion- proof mechanism which improves safety by surely operating in response to a high temperature state on the inside. CONSTITUTION: On the inside of a battery 2, one end of a positive lead plate 16 is fixed to a power generating element 12, and the other end 16a is welded to a positive terminal 4 in a connecting part 17. A shape memory member 20 arranged in the interior of the battery 2 and positioned in the vicinity of the other end 16a is formed so as to extend and deform in response to a high temperature state inside the battery 2. When the reaction of a power generating element 12 is excessively advanced and the temperance inside the battery goes high, the shape memory member 20 extends and deforms so as to press the positive lead plate 16, and thereby, the other end 16a is separated from the positive terminal in the connecting part 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrochemical device such as a battery or an electric double layer capacitor, and more particularly to an electrochemical device having an explosion-proof mechanism which operates when the temperature inside the device becomes high.

[0002]

2. Description of the Related Art Generally, in an electrochemical device such as a battery or an electric double layer capacitor, when the reaction proceeds excessively, the internal temperature rises abnormally, and gas accumulates inside the device to cause internal pressure. May rise abnormally and the element itself may burst. Therefore, the electrochemical device has conventionally been provided with an explosion-proof mechanism for preventing the above-mentioned rupture.
This explosion-proof mechanism is designed to degas the gas inside the element or to interrupt the internal conduction path to stop the electrochemical reaction when the internal pressure of the battery reaches a predetermined pressure or when the temperature becomes high. ing.

Examples of the explosion-proof mechanism are as follows. JP-A-4-24262 (hereinafter,
This is called Conventional Example 1. ), There is disclosed a valve mechanism for degassing with an open valve that operates in response to a pressure increase inside the element. Further, Japanese Patent Application Laid-Open No. 5-205727 (hereinafter, referred to as Conventional Example 2) discloses a mechanism that shuts off the internal conduction path by a bimetal that deforms according to a temperature rise. Furthermore, Japanese Laid-Open Patent Publication No. 5-266878 (hereinafter referred to as Conventional Example 3) discloses a mechanism in which a charging / discharging current is caused to flow through a temperature fuse and the current circuit is cut off due to temperature rise.

[0004]

By the way, although various explosion-proof mechanisms have been proposed which operate in response to a pressure increase in the element as seen in the above-mentioned conventional example 1, they operate when the temperature inside the battery becomes high. The typical ones are as shown in the above-mentioned conventional examples 2 and 3.

However, with the bimetal of Conventional Example 2, the conduction path may be momentarily broken due to the vibration caused by a fall or the like, and with the thermal fuse of Conventional Example 3, it is manufactured. In the process, the number of processes for connecting the thermal fuse increases, and each of the thermal fuses has various problems such as the use of one having electrolytic solution resistance as the thermal fuse. For these reasons, it has been desired to develop a simpler explosion-proof mechanism that operates by temperature.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an explosion-proof mechanism that enhances safety by operating reliably in response to a high temperature inside. To provide an electrochemical device.

[0007]

In order to achieve the above object, a first electrochemical device according to the present invention is provided with an outer shell case of the electrochemical device, and electrode terminals for conducting the inside and outside of the outer shell case. An electrochemical element housed inside the outer shell case; and a lead whose one end is welded to the electrode terminal to electrically connect the electrochemical element and the electrode terminal, A shape memory member that is disposed inside the outer shell case and that restores and deforms to its original shape when heated and reaches a predetermined temperature, and the shape memory member is expanded or contracted by the restoration deformation. The lead is engaged and the connecting portion is separated from the electrode terminal so that the lead is electrically disconnected from the electrode terminal.

Preferably, the shape memory member is stretched by the restoring deformation to press the connecting portion of the lead or its vicinity so as to peel the connecting portion of the lead from the electrode terminal.

Further, preferably, the shape memory member comprises a connecting member in which the lead is connected to one end side thereof and the electrode terminal is connected to the other end side thereof, and the connecting member is contracted by the restoring deformation. It is separated from the electrode terminal.

Further, in the second electrochemical element according to the present invention, the electrode terminal provided in the outer shell case of the electrochemical element for conducting the inside and outside of the outer shell case, and the inside of the outer shell case And the shape memory that is interposed between the electrochemical element and the electrode terminal to electrically conduct each other and to restore and deform to the original shape when heated to reach a predetermined temperature. A lead member having a function, the lead member is welded to either the electrode terminal or the electrochemical element to form a connection portion and is fixed to the other, and the lead member is restored By contracting due to deformation, it is peeled off from the connection portion and electrically disconnected from the electrode terminal.

Further, in the third electrochemical element according to the present invention, an outer shell case for accommodating the electrochemical element therein, and an inner surface of the outer shell case formed so as to penetrate therethrough. And a through hole opened on the outer surface, a closing plate provided on either the inner surface or the outer surface of the outer shell case to close the opening portion of the through hole, and the through hole provided inside the through hole and heated. A shape memory member that restores and deforms to its original shape when the temperature reaches a predetermined temperature, and an attachment member that is provided in the outer shell case and to which the shape memory member is fixedly mounted. While communicating with the inside or the outside of the shell case, a groove is formed on the surface of the closing plate, and the shape memory member expands or contracts due to the restoring deformation to press or draw in the closing plate. do it Composed so as to break the groove.

[0012] Preferably, the shape memory member or the lead member is formed in a spiral shape.

Also, preferably, the shape memory member or the lead member is made of a shape memory alloy.

Further, preferably, the shape memory member is made of shape memory plastic.

[0015]

The operation of the first electrochemical element according to the present invention will be described. The lead arranged inside the element has one end welded to the electrode terminal to connect the electrode terminal and the electrochemical element. It is conducting. When the inside of the electrochemical element is heated to a high temperature, the shape memory member is restored and deformed to its original shape.
During this restoring deformation, the shape memory member extends or contracts to engage with the lead, separate one end of the lead from the electrode terminal, and electrically disconnect the lead from the electrode terminal. As a result, the electrical connection between the electrode terminal and the electrochemical element is cut off, and the reaction in the electrochemical element is stopped. Further, after the reaction is stopped, even if the temperature is returned to the room temperature, the original shape of the shape memory member is maintained, and the electrical disconnection between the lead and the electrode terminal is maintained.

Further, in the second electrochemical element according to the present invention, the lead member, which is restored and deformed to its original shape when reaching a predetermined temperature, is welded to either the electrode terminal or the electrochemical element to be connected. A part is formed and is fixed to the other and electrically connected to each other. Similarly to the above, when the inside of the electrochemical element is heated to a high temperature, the lead member contracts to restore and deform to its original shape. Due to this contraction, the connection part that is welded is peeled off, and the lead member is electrically disconnected from the positive electrode terminal. Therefore, the electrical connection between the electrode terminal and the electrochemical element is disconnected, the reaction in the electrochemical element is stopped, and the electrical disconnection state between the lead member and the electrode terminal is maintained.

Further, in the third electrochemical element according to the present invention, the through hole formed in the outer shell case is closed by the closing plate under normal temperature conditions, and the flow inside and outside the outer shell case is blocked. Has been done. Here, similarly to the above, when the inside of the electrochemical element is in a high temperature state, the shape memory member arranged inside the through hole expands or contracts and restores and deforms to the original shape. This causes the closure plate to be pressed or retracted and broken. Therefore, the inside and the outside of the outer shell case are communicated with each other, and the gas accumulated inside the element is discharged to the outside of the element through the communicating portion.

In particular, since the shape memory member or the lead member is formed in a spiral shape, it can be easily deformed like a coil spring.

[0019]

The preferred embodiments of the electrochemical device according to the present invention will be described in detail below with reference to the accompanying drawings. The electrochemical device according to the present embodiment is, for example, a battery or an electric double layer capacitor, and is provided with an explosion-proof mechanism as a countermeasure when the reaction of the electrochemical device arranged inside thereof proceeds excessively. This explosion-proof mechanism operates in response to an abnormal rise in the internal temperature due to the excessive progress of the reaction, and it has a current interrupting mechanism that stops the reaction of the electrochemical elements and also releases the gas accumulated inside to the outside. It consists of a venting mechanism for releasing gas. Below, the battery provided with these explosion-proof mechanisms will be described in detail.

FIG. 1 shows a battery 2 according to this embodiment, and FIG. 2 is a top view of the battery 2 of FIG.
The battery 2 is a rectangular secondary battery having a rectangular cross section, and a positive electrode terminal 4 which is an electrode terminal is projected on the outer surface thereof.
A gas venting mechanism 6 described later is provided near the positive electrode terminal 4.

FIG. 3 is a sectional view of the battery 2 shown in FIG. 2 taken along the line AA, showing the upper portion thereof. The battery 2 includes a negative electrode can 8 and a terminal plate 10, and an outer shell case 3 of the battery 2 is configured by these. The negative electrode can 8 is
The terminal plate 10 is formed in the shape of a hollow bottomed cylinder having an open upper end surface, and the terminal plate 10 is disposed together with the positive electrode terminal 4 on the upper end surface of the negative electrode can 8 to seal the inside of the battery 2 in a sealed state. ing.

That is, the terminal plate 10 is formed in a concave shape, and a through hole 10a is formed in the center thereof, and the intermediate shaft portion 4a of the positive electrode terminal 4 made of aluminum is formed in the through hole 10a.
Has been inserted through. The terminal plate 10 is made of stainless steel, and its outer peripheral end is welded and integrated with the upper inner peripheral surface of the negative electrode can 8. The upper portion of the positive electrode terminal 4 serves as an enlarged head portion 4b, which projects upward from the upper surface of the outer peripheral edge of the terminal plate 10.
The insulating gasket 18 is formed such that its peripheral portion has a U-shaped cross section, and is fitted so as to sandwich the through hole 10 a of the terminal plate 10. A ring member 19 made of aluminum is arranged on the lower surface of the insulating gasket 18.
The lower shaft end 4c of the positive electrode terminal 4 is caulked to the lower surface of the. On the other hand, inside the negative electrode can 8, a power generating element 12 which is an electrochemical element is previously housed. The power generation element 12 is configured by winding two sheet-shaped positive and negative electrodes with a separator interposed therebetween. A negative electrode lead plate 14 is attached to the negative electrode of the power generation element 12, the other end of the negative electrode lead plate 14 is welded to the inner surface of the negative electrode can 8, and they are electrically connected to each other.

Further, one end of a positive electrode lead plate 16 is attached to the positive electrode of the power generating element 12, and the other end portion 16a of the positive electrode lead plate 16 is welded to the shaft end 4c of the positive electrode terminal 4 at a connecting portion 17. There is. As described above, since the positive electrode lead plate 16 is connected to the power generation element 12 and the positive electrode terminal 4, the electric energy extracted from the power generation element 12 is
It is supplied from the positive electrode terminal 4 to the external power receiving circuit through the positive electrode lead plate 16 which is a conduction path.

The battery 2 has a current cutoff mechanism as described below. The current cutoff mechanism of the first embodiment includes a coil-shaped shape memory member 20 that is restored and deformed to its original shape when heated to a predetermined temperature. The shape memory member 20 is disposed below the inside of the positive electrode terminal 4 and presses the positive electrode lead plate 16 by being restored and deformed so that the other end portion 16 a of the positive electrode lead plate 16 is separated from the connecting portion 17. ing.

The shape memory member 20 will be described in detail below. The shape memory member 20 is made of a shape memory alloy such as a Ti—Ni-based alloy or a Cu—Zn—Al-based alloy, or a shape memory plastic, and when heated to a predetermined temperature, A shape memory process is performed based on the thermoelastic martensite transformation and the reverse transformation so that the shape is restored and restored to a preset original shape. The shape memory member 20 subjected to the shape memory process is incorporated into the positive electrode terminal 4 in a state of being contracted and deformed from the set original shape. The predetermined temperature at which the shape memory member 20 is restored and deformed can be freely set within a range based on the thermoelastic martensitic transformation. In the present embodiment, the above-mentioned predetermined temperature is set to a temperature extremely higher than the normal temperature at which it is determined that the reaction of the power generation element 12 of the battery 2 has proceeded excessively, that is, about 80 ° C to 100 ° C. Therefore, when the inside of the battery reaches a predetermined temperature, the shape memory member 20 expands or contracts in accordance with the restoring deformation and operates like an actuator. The shape memory member 20 once restored and deformed to the original shape is set by the restoration deformation without being deformed again to the shape of the arranged state even if the temperature inside the battery is lowered to the normal temperature. The original shape is retained.

As described above, it is preferable that the shape memory member 20 which is deformed from the original shape and incorporated therein is formed in a shape that allows easy deformation in advance. In this embodiment, the shape memory member 20 is formed in a spiral shape, that is, a coil shape as shown in FIG. 4A, and the shape memory processing is performed in the state of the original shape and the length L _0. Has been applied. By thus forming the shape memory member 20 in a spiral shape, the shape memory member 20 having the length L ₀ can be freely expanded and contracted in the direction of the arrow D, and
The deformation operation can be easily performed. This length L ₀
The shape memory member 20 is contracted and deformed, and is arranged in the state of the length L as shown in FIG.

The shape memory member 20 having a length L is connected to the positive electrode terminal 4 by welding in accordance with the restoring deformation of the positive electrode lead plate 1.
6 is arranged so as to press downward. That is, an annular recessed housing portion 22 that extends in the axial direction from the lower end of the positive electrode terminal 4 is formed, and the coiled shape memory member 20 is housed in a contracted state inside the lower end surface of the positive electrode terminal 4. The other end portion 16a of the positive electrode lead plate 16 is welded to a portion surrounded by the concave accommodating portion 22. When the shape memory member 20 is restored and deformed due to heat generation inside the battery, the lower end of the shape memory member 20 projects from the lower end surface of the positive electrode terminal 4. The protruding shape memory member 20 engages the lower end surface of the other end portion 16a of the positive electrode lead plate 16 and presses it. Pressed other end 16a
Are separated from the positive electrode terminal 4 at the connecting portion 17 as shown in FIG. 4 (c).

Further, when the shape memory member 20 is made of a conductive material such as a shape memory alloy, in order to ensure electrical insulation between the positive electrode lead plate 16 and the positive electrode terminal 4, An insulating member 24 is provided between the shape memory member 20 and the positive electrode lead plate 16. The insulating member 24 may cover the entire outer surface of the shape memory member 20.

When the shape memory member 20 extends as described above, the positive electrode lead plate 16 and the positive electrode terminal 4 are electrically disconnected from each other, so that the reaction of the power generating element 12 is stopped. Further, even if the temperature inside the battery is lowered by the reaction to be stopped and the battery is in a normal temperature state, the shape memory member 20 does not return to the state of the length L again, and the positive electrode terminal 4 and the power generation element 12 are disconnected. The state is maintained. Therefore, the battery 2 that has once generated heat and is in a high temperature state cannot be used due to the operation of the current cutoff mechanism, and the safety of the battery 2 can be improved.

In addition to the spiral shape, the shape memory member 20 is formed into a hollow cylindrical body having an open upper end surface and a lower end surface, as shown in FIG. 5 (a). As shown in FIG. 5 (b), when the battery is housed inside the positive electrode terminal 4 in a contracted state and the temperature inside the battery rises, FIG.
It may be extended as shown in (c) to insulate the connection portion 17 between the positive electrode terminal 4 and the positive electrode lead plate 16.

Next, a second embodiment of the current interruption mechanism will be described with reference to FIG. Since the structure of the second embodiment is almost the same as that of the first embodiment, only the differences will be described below. In the second embodiment, the positive electrode terminal 4 is provided with a connecting member 28 via an annular insulating bush 26. This connecting member 28 is
It is composed of a flange portion 28a and a connecting end portion 28b which is provided so as to project from the upper end surface of the flange portion 28a and which is inserted into the insulating bush 26 and welded to the positive electrode terminal 4 at the connecting portion 17.
The positive electrode lead plate 16 is formed on the lower end surface of the connecting member 28.
Is connected to the other end 16a to electrically connect the positive electrode terminal 4 and the power generation element 12 to each other.

Similar to the shape memory member 20 of the first embodiment, the connecting member 28 is formed of the shape memory material 20 and subjected to the shape memory treatment, and when it is heated and reaches a predetermined temperature, the original shape is restored. It is designed to be deformed and restored to its shape. That is, as shown in FIG. 7A, the connecting member 28 is subjected to shape memory processing in the state of length L ₀ , and the inside of the battery has a length L as shown in FIG. 7B. It is arranged so as to be stretched and deformed. As a result, this connecting member 28
When heated and reaches a predetermined temperature, that is, a set temperature, it tries to shrink and deform according to the restoring deformation as shown in FIG. 7C. Therefore, in the connection member 28, the connection end 28b
Are separated from the positive electrode terminal 4 by being peeled off. Therefore,
The electrical continuity between the positive electrode terminal 4 and the connecting member 28 is cut off,
The reaction of the power generation element 16 is stopped. Further, since the shape memory member 20 does not deform even when the temperature inside the battery reaches the normal temperature, the safety of the battery 2 is surely secured as described above.

Further, a third embodiment of the current interruption mechanism will be described with reference to FIG. Since the structure of the third embodiment is also substantially the same as that of the first embodiment, only the differences will be described below. In the third embodiment, the positive electrode lead plate 16 itself is made of a shape memory material, and the shape memory process is performed to dispose the positive electrode lead plate 16 itself. The positive electrode lead plate 16 is extended from the power generation element 12, and the other end 16 a is welded and connected to the shaft end 4 c of the positive electrode terminal 4 at the connecting portion 17. The positive electrode lead plate 16 is
It is arranged so as to be stretched and deformed from the set shape and contracted and deformed when restored and deformed. Therefore, when the inside of the battery generates heat and reaches a high temperature state, the other end portion 16a of the positive electrode lead plate 16 is peeled off from the shaft end 4c of the positive electrode terminal 4 at the connection portion 17 that is welded and connected, as shown in FIG. Are separated. From this, the positive electrode lead plate 1
A current cutoff mechanism can be obtained by simply forming 6 with a shape memory material.

As a modification of the third embodiment, the positive electrode lead 16 is formed in a spiral shape, that is, a coil shape as shown in FIG. 10. When this is restored and deformed, it contracts and deforms as shown in FIG. The other end 16a to the positive electrode terminal 4
The insulation may be peeled off at the welded connection portion 17 by separating from the shaft end 4c. The other positive electrode lead plate 16 is formed in a rhombus cross section as shown in FIG. 12, and is configured to be expandable and contractible along the diagonal line thereof. As described above, the insulation may be peeled off at the weld connection portion 17 as described above.

On the other hand, FIG. 14 is a sectional view of the battery of FIG. 1 taken along the line BB, showing the current interruption mechanism of the third embodiment shown in FIG.
The degassing mechanism 6 is installed side by side. Only the degassing mechanism 6 will be described below. This degassing mechanism 6
As shown in FIGS. 15 (a) to 15 (c) in an enlarged manner, the terminal board 1
No. 0 through hole 30, a closing plate 32 for closing the through hole 30, a shape memory member 34 disposed inside the through hole 30, and a mounting plate to which the shape memory member 34 is fixedly installed. 36 and. The closing plate 32 is a terminal plate 10.
Is provided on the outer surface of the groove, and a groove portion 38 having a V-shaped cross section and cut out in an annular shape is formed on the lower surface thereof. The mounting plate 36 is mounted on the inner surface on the opposite side of the closing plate 32 with the terminal plate 10 interposed therebetween, and a plurality of communication holes 36a are formed therethrough. Further, a shape memory member 34 is arranged in a space defined by the closing plate 32 and the mounting plate 36 arranged on the outer surface and the inner surface of the terminal plate 10, respectively. The shape memory member 34 is formed of the shape memory material described above.

In this embodiment, the shape memory member 3 is used.
4 is formed in a spiral shape, that is, a coil shape. The lower end surface of the shape memory member 34 is joined to the surface of the mounting plate 36, and the upper end surface thereof is the annular groove portion 38 of the closing plate 32.
It is fixed inside the circle. Regarding the shape setting of the shape memory member 34, either the extension deformation or the contraction deformation may be set. FIG. 15B shows the shape memory member 3
4 shows a case in which 4 is stretched and deformed. Mounting plate 36
As the shape memory member 34 fixedly mounted on the expansion member expands due to the restoring deformation, the closing plate 32 is pressed from the side of the through hole 30 and is broken at the groove portion. When the shape memory member 34 is set to contract, FIG.
As shown in FIG. 3, the closing plate 32 is pulled in and broken as described above.

Thus, the shape memory member 34 is expanded or contracted to break the blocking plate 32, and the outside and inside of the battery 2 are communicated with the communication hole 36a through the breaking portion 40. . When the shape memory member 34 expands and deforms, the upper end surface of the shape memory member 34 does not need to be fixed to the lower surface of the closing plate 32, and the closing plate 32 is pressed and ruptured along with the restoring deformation. Just do it.

That is, when the reaction of the power generating element 12 proceeds excessively and the temperature of the inside of the battery becomes high, the shape memory member 34 arranged in the through hole 30 undergoes expansion deformation or contraction deformation, whereby the closing plate 32. Is broken through the groove 38.
The gas accumulated inside the battery is passed through the communication hole 36a that communicates the inside of the battery with the inside of the through hole, and the broken portion 4
It is released to the outside through 0. In addition, since it is possible to operate the battery before it becomes a high pressure state, the battery 2
The safety of can be further improved.

Regarding the shape memory member 34,
16 (a) to 16 (c), which are not formed in a spiral shape.
It may have a block shape as shown in FIG.

Further, the degassing mechanism 6 can be secured together with any one of the current interrupting mechanisms to ensure more reliable safety.

[0041]

As described in the above embodiments, according to the first electrochemical device of the present invention, the shape memory member incorporated in the electrochemical device expands in response to the high temperature inside the device. Also, by contracting or operating like an actuator, even if the reaction of the electrochemical element proceeds excessively, the internal conduction path is blocked and the reaction of the electrochemical element is stopped, so the safety of the electrochemical element is improved. improves.

According to the second electrochemical element of the present invention, the lead member itself for electrically connecting the electrochemical element and the electrode terminal has a shape memory function, so that the explosion-proof mechanism can be constructed very easily. Therefore, the safety of the electrochemical device is improved.

According to the third electrochemical element of the present invention, the degassing can be performed in response to the high temperature inside the electrochemical element, so that the safety of the electrochemical element is improved.

In particular, since the shape memory member or the lead member is formed in a spiral shape, it can be easily deformed like a coil spring.

[Brief description of drawings]

FIG. 1 is a perspective view showing an electrochemical device according to the present invention.

FIG. 2 is a top view of an electrochemical device according to the present invention.

3 is a sectional view of the electrochemical device shown in FIG. 1, taken along the line AA.

FIG. 4 is an enlarged view of a main part of the electrochemical device shown in FIG.

5 is an enlarged view of a main part showing another embodiment of the electrochemical device shown in FIG.

6 is a cross-sectional view showing another embodiment of the electrochemical device shown in FIG.

FIG. 7 is an enlarged view of a main part of FIG. 6;

8 is a cross-sectional view showing another embodiment of the electrochemical device shown in FIG.

9 is an enlarged view of an essential part showing a state in which an explosion-proof mechanism provided in the electrochemical device shown in FIG. 8 is activated.

10 is a cross-sectional view showing another embodiment of the explosion-proof mechanism provided in the electrochemical device shown in FIG.

11 is an enlarged view of essential parts showing a state in which an explosion-proof mechanism provided in the electrochemical device shown in FIG. 10 is in operation.

12 is a cross-sectional view showing another embodiment of the explosion-proof mechanism provided in the electrochemical device shown in FIG.

13 is an enlarged view of an essential part showing a state in which an explosion-proof mechanism provided in the electrochemical device shown in FIG. 12 is activated.

FIG. 14 is a cross-sectional view of the electrochemical device shown in FIG. 1, taken along the line BB.

15 is an enlarged view of a main part of an explosion-proof mechanism included in the electrochemical device shown in FIG.

16 is an enlarged view of a main part showing another embodiment of the explosion-proof mechanism shown in FIG.

[Explanation of symbols]

 2 Battery 19 Ring Member 3 Outer Shell Case 20 Shape Memory Member 4 Positive Terminal 22 Concave Housing 4a Intermediate Shaft 24 Insulation Member 4b Enlarged Head 26 Insulation Bushing 4c Shaft End 28 Connection Member 6 Gas Release Mechanism 28a Flange 8 Negative Can 28b Connection end portion 10 Terminal plate 30 Through hole 10a Through hole 32 Closing plate 12 Power generation element 34 Shape memory member 14 Negative electrode lead plate 36 Mounting plate 16 Positive electrode lead plate 36a Communication hole 16a Other end 38 Groove 17 Connection portion 40 Breaking portion 18 Insulation gasket

Front Page Continuation (72) Inventor Tatsuya Yamazaki 5-36-1 Shimbashi, Minato-ku, Tokyo Fuji Electric Chemical Co., Ltd. (72) Inventor Kazuo Takada 5-36-11 Shimbashi, Minato-ku, Tokyo Fuji Electric Chemical Co., Ltd. In the company

Claims (8)

[Claims] 1. An electrochemical element (2) such as a battery or an electric double layer capacitor, which is provided in an outer shell case (3) of the electrochemical element (2) to remove the inside and the outside of the outer shell case (3). An electrode terminal (4) for conduction, an electrochemical element (12) housed inside the outer shell case (3), and one end (16a) of the electrode terminal (4) are welded and connected to the electric terminal. A lead (16) for electrically conducting between the chemical element (12) and the electrode terminal (4) and a lead (16) arranged inside the outer shell case (3) and heated to reach a predetermined temperature. Then, the shape memory member (20) is restored and deformed to its original shape, and the shape memory member (20) is expanded or contracted by the restored deformation to engage with the lead (16) and its connecting portion (17). ) Is separated from the electrode terminal (4) and the lead (16 Electrochemical device characterized by comprising as to electrically disconnected from the electrode terminals (4). 2. The shape memory member (20) is stretched by the restoring deformation to press the connecting portion (17) of the lead (16) or the vicinity thereof to thereby lead (1).
The electrochemical device according to claim 1, wherein the connecting portion (17) of 6) is peeled off from the electrode terminal (4). 3. The shape memory member (20) comprises a connecting member (28) having one end connected to the lead (16) and the other end connected to the electrode terminal (4). The electrochemical element according to claim 1, wherein (28) is separated from the electrode terminal (4) by contracting due to the restoring deformation. 4. An electrochemical element such as a battery or an electric double layer capacitor, which is provided in an outer shell case (3) of the electrochemical element (2) and electrically connects the inside and outside of the outer shell case (3). The terminal (4), the electrochemical element (12) housed inside the outer shell case (3), and the electrochemical element (1)
The lead member (16) having a shape memory function interposed between the electrode terminal (4) and the electrode terminal (4) so as to be electrically connected to each other and to be restored to the original shape when heated to reach a predetermined temperature. The lead member (16) is welded to either the electrode terminal (4) or the electrochemical element (12) to form a connecting portion (17) and is fixed to the other. The lead member (16) contracts due to the restoring deformation, so that the lead member (16) is peeled off from the connecting portion (17) and electrically disconnected from the electrode terminal (4). Chemical element. 5. An electrochemical element (2) such as a battery or an electric double layer capacitor, wherein the electrochemical element (1) is provided inside.
2) An outer shell case (3) for housing the outer shell case (3), a through hole (30) penetratingly formed inside and outside the outer shell case (3) and opening on the inner and outer surfaces thereof, and the outer shell case (3). A closing plate (32) which is provided on either the inner surface or the outer surface of the through hole (30) and closes the opening of the through hole (30); A shape memory member (34) that restores and deforms to its original shape when the temperature is reached, and a mounting member (36) provided on the outer shell case (3) and fixed to the shape memory member (34). The inside of the through hole (30) communicates with the inside or the outside of the outer shell case (3), and a groove (38) is formed on the surface of the closing plate (32) to form the shape memory member. (34) is the above-mentioned closing plate which is expanded or contracted by the restoring deformation An electrochemical device characterized in that the groove (38) is broken by pressing or pulling in (32). 6. The shape memory member (20, 34) or the lead member (16) is formed in a spiral shape according to any one of claims 1, 2, 4 and 5. Electrochemical device. 7. The electrochemical device according to claim 1, wherein the shape memory member (20, 34) or the lead member (16) is made of a shape memory alloy. 8. The shape memory member (20, 34) is made of shape memory plastic.
6. The electrochemical device according to any one of 2 and 5.