JP2000182675A - Non-aqueous electrolyte secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means to shut off a current of a non-aqueous electrolytic solution secondary battery in the event of abnormal rise of its temperature by sensing the temperature rise. SOLUTION: In the event of abnormal rise of the internal temp. of the can 2 of a non-aqueous electrolytic solution secondary battery, the heat is conducted to a safety device outside the can through a lid 4 from a temp. sensing member 21 made of metal and installed inside the can. That is, a temp. sensing member 21 is provided to transmit the temp. information about intra-can abnormal temp. rise to a safety device (to shut off the current with melting of a low-temp. melting member 9 so as to form a current circuit detouring the battery). Accordingly a safety device with good thermal response can be formed at a very low cost, and because the structure is simple and independent of the intra-can wirings, there is no risk of giving a structural load on the intra-can wirings nor a load in terms of assembly on the production process, and it is possible to establish a current shutoff for abnormal temp. rise upon easily sensing the intra-can temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous electrolyte secondary battery, and more particularly to a non-aqueous electrolyte secondary battery provided with a safety device for sensing battery internal temperature and shutting off battery current when a set temperature is reached. Battery.

[0002]

2. Description of the Related Art Due to its high volume energy density and its high weight energy density, lithium ion secondary batteries can be made smaller and lighter than conventional NiCd batteries and Ni-H batteries. have. In addition, since a phenomenon such as a so-called memory effect that occurs in a NiCd battery or the like does not occur, the battery has excellent features such as easy recharging during use.

[0003] However, the lithium ion secondary battery uses a combustible organic non-aqueous electrolyte as an electrolyte and an active material (eg, carbon material) used as a negative electrode material. Is that when exposed to a high temperature state due to a short circuit of the battery, etc., it generates heat intensely, and an active material used as a positive electrode material (for example, LiCoO
₂ , LiNiO ₂ , LiMn ₂ O _4, etc.), since the components constituting the battery have members that may generate heat or ignite, for example, heat generation due to a deoxygenation reaction is observed at a high temperature. It is necessary to take sufficient safety measures against ignition.

For example, since a lithium ion secondary battery uses a non-aqueous electrolyte, the ionic conductivity of lithium ions moving between the electrodes is lower than that of a water-containing electrolyte. Is formed into a sheet shape, and is wound through an extremely thin (20 to 30 μm) polymer separator to form an electrode body. For this reason, there is a problem that a micro short circuit between the electrodes is easily caused. In order to prevent such a short circuit due to a micro short circuit between the electrodes, measures are taken in the battery manufacturing process to minimize the generation of dust causing a micro short circuit. However, in spite of taking such preventive measures, the generation of dust that causes micro-shorts, which cause heat generation, cannot be inevitably generated.

[0005] In addition to the above, it is assumed that the electrodes are short-circuited due to misuse. In addition to simply taking measures against the heat generation and ignition cause of the battery, as a countermeasure after the battery is heated, if the battery generates heat to a certain temperature or more. Measures to cut off the current have been considered. For example, as in the invention described in Japanese Patent Application Laid-Open No. 6-203827, a temperature fuse is arranged at the core of the wound body of the battery body, and when the battery temperature rises to a predetermined temperature or higher, the fuse is melted. A method has been devised to cut off the electric circuit. That is, the lead wire connected to one end of the fuse element is connected to one end (positive electrode) of the electrode body, and the other end of the fuse is connected to a terminal plate of a group of sealing lids that also serves as an explosion-proof mechanism and terminals. When a chemical reaction of a substance in the battery is induced due to a short circuit of an electrode or the like, and gas generation or an excessive rise in temperature is caused, the fuse cuts off current at a predetermined operating temperature. As a result, generation of gas is stopped, an increase in the internal pressure of the battery is suppressed, and rupture is prevented.

[0006]

However, the direct installation of such a thermosensitive element inside the battery is advantageous in that it responds quickly to a rise in the temperature inside the can, but it is advantageous to install the thermosensitive element. One problem arises with the electrical connection between the electrode body and the thermal element and the lid terminal. In particular, when the battery capacity increases, the current collecting structure of the tab portion drawn out from the electrode body must increase the cross-sectional area of the current path as the current increases, so that the current collecting structure is a great constraint on the battery structure. . For example, in the case of a battery flowing a current of about 20 A, the width and thickness of the current collecting tab are, for example, 1 width.
Approximately 8 single-pole tabs are required for a tab having a thickness of 0 mm and a thickness of 0.1 mm. By electrically connecting the tab group and the thermosensitive element and storing the electrical connection means in the battery, interference with other parts, the need for a structure that avoids the danger of electrical short circuit, and There arises a problem that these connecting portions must be worked without damaging other components and causing interference during assembly, and thus there is a problem in both the structure and the manufacturing process.

An object of the present invention has been made in view of the above-mentioned problems, and it is possible to quickly sense the temperature inside a battery and apply an excessive current without giving a structural load to a current collecting structure of the battery. An object of the present invention is to provide a non-aqueous electrolyte secondary battery having a shut-off means.

[0008]

The above-mentioned object is attained as follows. The invention according to claim 1 is a non-aqueous electrolyte secondary battery configured by housing a battery main body in which a non-aqueous electrolyte is permeated between a positive electrode and a negative electrode in a can, and detects a temperature inside the can. Temperature sensing means for transmitting to the outside of the can, and current interrupting means for interrupting the battery current by melting the heat melting member by the amount of heat in the can guided to the outside of the can by the temperature sensing means. . As a result, the abnormal temperature rise inside the can is easily guided to the outside of the can, and the amount of heat melts the heat melting member outside the can, whereby the battery current is interrupted, and an emergency due to the abnormal temperature rise of the battery is anticipated. Can be prevented. According to a second aspect of the present invention, there is provided a battery body in which a positive electrode and a negative electrode are opposed to each other with a separator interposed therebetween and spirally wound to form an electrode body, and a non-aqueous electrolyte is permeated between the positive electrode and the negative electrode. A non-aqueous electrolyte secondary battery comprising: an outer can housing the battery main body; and a can lid for closing the opening of the outer can and sealing the inside of the can. A metal temperature sensing member is installed so as to be guided from the inside of the can through the can lid to the outside of the can, and by the amount of heat in the can guided by the temperature sensing member,
A safety device for interrupting a battery current by melting a heat melting member such as a solder and a thermal fuse is provided. According to such a configuration, the metal temperature sensing member installed in the can easily guides the amount of heat in the can to the outside of the can because the sensing member functions as a very good heat transport path. By the heat in the can guided by the member, the heat melting member (solder, fuse, etc.) installed outside the can and connected to the battery current path is melted, and the current path of the battery can be cut off. . Since such a safety device is mounted, it is possible to provide a nonaqueous electrolyte secondary battery that can prevent an accident with a simple structure and reliable operation. According to a third aspect of the present invention, in the non-aqueous electrolyte secondary battery according to the first or second aspect, a part of the member for detecting the temperature inside the can is a core of the wound electrode body inside the can. And the other part is connected to a heat melting member outside the can. For this reason, temperature information from a portion most suitable for temperature detection inside the battery can be easily led to the heat melting member outside the can, and a sensitive safety device can be configured. According to a fourth aspect of the present invention, in the non-aqueous electrolyte secondary battery according to the first, second or third aspect, the member for detecting the temperature inside the can includes an insertion portion inserted inside the can, And a contact portion which is screwed to the insertion portion and comes into contact with the heat melting member. Therefore, the contact portion that has been brought into contact with the heat melting member in advance can be screw-fixed to the insertion portion, and the fabrication and assemblability of the battery is improved. According to a fifth aspect of the present invention, in the non-aqueous electrolyte secondary battery according to the first, second or third aspect, a part of the member for detecting the temperature inside the can is inserted into the inside of the can and the other part is inserted into the can. Consists of a single bar that contacts the hot-melt member. Thus, since the temperature detecting member is a single material, reliable and stable heat conduction can be expected.
According to a sixth aspect of the present invention, in the non-aqueous electrolyte secondary battery according to any one of the first to fifth aspects, the member for detecting the temperature inside the can is made of copper, a copper alloy, aluminum, nickel, It is made of a heat conductive metal such as nickel-plated iron, stainless steel, and graphite. As a result, a temperature sensing member having inexpensive and reliable heat conduction performance can be obtained.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a non-aqueous electrolyte secondary battery according to the present invention equipped with a safety device having a heat-sensitive member. In this example, an embodiment of a lithium ion secondary battery will be described as a nonaqueous electrolyte secondary battery. FIG. 2 is a cross-sectional view of FIG.
FIG. 3 is a cross-sectional view of A, and FIG. 3 is another example of the lithium ion secondary battery according to the present invention equipped with a safety device having a heat-sensitive member.

In FIG. 1, reference numeral 1 denotes a battery body. The battery body 1 includes a positive electrode, a negative electrode, and a separator. The positive electrode is formed by coating a positive electrode material on both sides of a positive electrode current collector, which is an aluminum foil having a thickness of 20 μm, on both sides. The cathode material is
Positive electrode active material (for example, LiMn ₂ O ₄ , LiCoO ₂ , L
A conductive material (for example, graphite) and a resin binder (for example, PVDF (polyvinylidene fluoride)) are mixed at a W% ratio of 90: 7: 3 with iNiO _{2. The} negative electrode is a 15 μm thick foil. A negative electrode material is coated on both sides of a certain negative electrode current collector with a thickness of 80 μm on both sides.

The negative electrode material is obtained by mixing a negative electrode active material (for example, graphite, amorphous carbon) with a resin binder (for example, PVDF (polyvinylidene fluoride) at a W% ratio of 95: 5).
Between the positive and negative electrodes cut into this sheet shape,
The battery body 1 wound in a roll with a separator interposed
It is. The separator is made of a PP (polypropylene) sheet having a thickness of 20 μm, and has numerous pores on its surface. The battery body was impregnated with a non-aqueous electrolyte {a mixture of EC (ethylene carbonate) / DMC (dimethyl carbonate) at a ratio of 1: 2}. Reference numeral 2 denotes an outer can for housing the battery body, which is an aluminum can having a diameter of 54 mm and a thickness of 0.8 mm. 3 is a gasket and PP
(Polypropylene). It has a function of maintaining airtightness between the battery lid 4 and the outer can 2. Further, the gasket 3 has a peripheral portion in contact with the outer can 1 stretched into the can in order to provide an insulating function between the electrode tab and the outer can.

Reference numeral 4 denotes a battery lid, which uses PPS (polyphenylene sulfide) as a material which is not affected by the non-aqueous electrolyte. The lid 4 is provided with an insulating portion 4 to keep the heat-sensitive rod 21 insulated from the positive electrode tab 6 and the negative electrode tab 18.
a is provided around the heat-sensitive bar. Reference numeral 5 denotes a lid for sealing the safety device, and the lid and the lid 4 are hermetically sealed by ultrasonic welding. Reference numeral 6 denotes a positive electrode current collecting tab. Aluminum width 10
mm, and a ribbon having a thickness of 0.1 mm. The present battery uses eight single poles. Reference numeral 7 denotes a positive electrode terminal made of aluminum having a width of 10 mm and a thickness of 1.0 mm. Reference numeral 8 denotes a support member that is connected to the heat-sensitive bar 21 and transmits heat energy from the heat-sensitive bar 21 to the low-temperature melting member 9. Reference numeral 9 denotes solder for connecting and fixing the cup 11 and the support member 8, and the melting temperature is set to a temperature set to ensure the safety of the battery. Here, solder that melts at 90 ° C. is used. 1
Reference numeral 0 denotes a cup, which is a storage container for the solder 9 and also functions as a member for locking the switch spring 12. The space between the cup 10 and the support member 8 is supported only by the solder 9.

Reference numeral 12 denotes a switch spring, which functions as a member for connecting a circuit between the contact 13 and the contact 13a at normal temperature. When the temperature inside the can rises from a set temperature and the solder 9 melts, the contact between the contact 13 and the contact 13a is formed. It functions as a member for cutting the circuit. When the switch spring contact is in contact with the contacts 13 and 13a at normal temperature, the contact pressure greatly changes the contact resistance due to the contact pressure, so that the contact pressure is applied to the contact by the spring pressure. The application of the contact pressure of the switch contact is given by the deflection of the switch spring 12. The deflection interval is adjusted by an engagement screw between the support member 8 installed on the upper end of the heat-sensitive bar 21 and the heat-sensitive bar 21.

Reference numeral 11 denotes a switch spring contact.
A special coating is applied between the contact 3 and the contact 13a so as to keep the contact resistance stable for a long time. The contacts 13 and 13a are, like the switch spring contact 11,
Special coating prevents deterioration of the contacts.
Reference numeral 14 denotes a negative electrode terminal made of copper having a width of 10 mm and a thickness of 1.0 mm. The negative terminal 14 is connected to the contact 13,
The negative electrode circuit is connected from the terminal 14 via the contact 13 to the switch spring 12, the contact 13a, and the negative external terminal 15. Reference numeral 23 denotes a cap for guiding the heat-sensitive rod 21 installed in the can into the center pin 22 and fixing the position thereof.

Reference numeral 21 denotes a temperature sensing rod (heat sensing rod) according to the present invention provided for sensing the temperature inside the battery. The temperature sensing rod 21 is guided by the cap 6 into the winding axis of the battery body. It has been introduced to sense the temperature in the center. In a normal battery reaction, the heat generation is almost uniform in the electrode body due to the battery resistance in the electrode and the heat generated by the ion movement in the electrolyte. The generated heat moves in the direction of the center of the electrode body and in the direction of the periphery, or in the vertical direction of the axis of the electrode body. When winding the electrode,
To prevent a short circuit, the separator should be 2.
5mm longer.

Therefore, at the end of the electrode body, the separator forms a heat insulating layer of 2.5 mm, and the heat conduction in the vertical direction is hindered by this layer. In particular, at the bottom of the can, the separator is crushed by the insulator at the bottom of the can, so that there is no gap between the separators and the electrode body is sealed. On the other hand, in the axial center of the electrode body and the peripheral direction,
The heat radiated to the peripheral portion is radiated to the outside of the can through the outer can, but the heat moving in the axial direction stays because the heat radiating mechanism does not exist in the axial portion. Therefore, when the electrode body is viewed as a whole, heat is radiated in the order of the outer peripheral portion of the electrode body> upper shaft> lower shaft> axial center, and as a result, the place where heat stays most in the electrode body is This is the axis. Accordingly, the axis of the electrode body is most suitable as a portion for sensing abnormalities in the battery temperature during normal use. On the other hand, when a micro-short or some abnormal battery reaction occurs in the battery, it is generally a local reaction, so the temperature inside the can does not rise as a whole, but causes an abnormal reaction. It rises around the part where it is. However, even in such a case, the movement of the heat amount ultimately stays at the axial center of the electrode body as described above. For this reason, the axis is most suitable as the detection part of the temperature abnormality in the battery.

In the present embodiment, the temperature sensing rod 21 made of a copper material of φ5 is inserted from the upper part of the electrode body to the axial center part up to 20 mm. One end of the heat-sensitive rod 21 is thus installed in the axial space 22a of the electrode body 1, then passes through the upper space of the electrode body, penetrates the lid 4, and connects to the fastening portion 21a to the safety device. Has been inherited. Since the heat-sensitive rod 21 is formed of a copper member having a diameter of 5 mm and a length of 50 mm, in this example, a temperature change of 1.3 ° C. (0.7 ca) with respect to a temperature change in the can of 1 ° C.
Since the in-can temperature information can be transmitted to the safety device with a small amount of heat of 1), it functions as an extremely responsive sensor. In addition, even if an exothermic reaction occurs on the surface of the electrode body due to the part passing through the space above the electrode body, it is possible to quickly receive the heat generation information, so it can respond to abnormal reactions around the electrode body it can.

As described above, the heat in the can transmitted from the heat-sensitive bar 21 is transmitted to the support member 8 and changes the temperature of the support member 8. When the temperature of the supporting member 8 reaches the set temperature at which the solder 9 melts, the solder 9 melts,
The engagement force that fixed between the cup 10 and the support member 8 is lost. When the engagement force between the cup 9 and the support member 8 is lost,
The cup 9 is pushed upward by the reaction force of the switch spring 12. On the other hand, the spring 19 pushes the switch spring 12 upward from below, and until the solder 9 is melted,
Although it is fixed in a compressed state by the engagement force between the solder 9 and the support member 8, when the engagement force between the solder 9 and the support member 8 is lost, the switch spring 12 is moved upward from below by the spring elastic force. Push up. When the solder 9 is melted by these two forces and the engagement force between the cup 10 and the support member 8 is lost, the cup 9 instantaneously jumps up, and at the same time, the contacts 13 and 13a are cut off. The cup 9 further pushed upward reaches the ceiling 20 of the lid 5 and stops there.

On the other hand, the switch spring 12 is pressed from the lower end of the cup 9 reaching the ceiling 20 by the spring 19, and the pressing force applies a contact pressure of the switch spring 12 to the upper contacts 16 and 17. Thereby, the negative electrode terminal 15, the terminal 13a, the switch terminal 11, the switch spring 1
2. The switch terminal 11, the terminal 13, the negative terminal 14 in the can (not shown behind the paper in the drawing), and the circuit connected to the negative tab 18 are cut off at the contact 13 and newly bypass the circuit in the battery. Negative terminal 15, contact 16, switch spring terminal 11, switch spring 12, switch spring terminal 1
1, the contact 17 and the positive electrode terminal 7 are connected.

In the above description, the heat sensing rod, that is, the temperature sensing rod 21 is manufactured by separately processing the insertion part inserted into the can and the contact part that comes into contact with the hot-melt member, thereby manufacturing the whole battery. Although the assembling performance is improved, it may be processed as a single member, for example, a single rod, and one end may be inserted into the inside of the can and the other end may be in contact with the heat melting member. In the case of a single member, the heat conduction performance is stable.

Next, another embodiment of the present invention shown in FIG. 3 will be described. In the figure, reference numeral 23 denotes a battery main body, which is configured similarly to the electrode body described in FIG. 2
Reference numeral 4 denotes an outer can, which is an aluminum can having a diameter of 54 mm and a can thickness of 0.8 mm. Reference numeral 25 denotes a gasket, which is an airtight material made of PP. Reference numeral 26 denotes a lid formed of 4 mm thick PPS (polyphenylene sulfide). 27 is a lid material for sealing the safety device. Reference numeral 28 denotes a positive electrode tab having a width of 10
It is connected to the positive electrode terminal 29 by ultrasonic welding with a ribbon having a thickness of 0.1 mm and a thickness of 0.1 mm. Reference numeral 33 denotes a thermosensitive element according to the present invention, which is made of a copper material. Numeral 34 denotes a low-temperature melting member which uses a temperature fuse material having a width of 10 mm and a thickness of 2 mm which is melted at 90 ° C. 37 is a spring member, and 36 is a block member for housing the spring member 37.

When the electrode body 23 generates heat due to an abnormal battery reaction or the like, the generated heat moves to the battery upper space 38 through the center pin 30. Further, the heat inside the battery main body 23 is released to the space 38 through the current collecting tabs 28 and 31 by the current collector having good thermal conductivity. In this way, the temperature of the battery upper space 38 also rises along with the abnormal heat generation in the battery body 23, but the in-can temperature sensing member 33 has a small specific heat (specific heat C =
0.38 J / G · K) and a material with good conductivity (thermal conductivity κ = 403 W / m · K). In the case of this example, 0.9 J ( (0.22 cal) can be transmitted to the low-temperature melting member 34. The heat in the can is transported through the member 33 to the member 34 to increase the temperature of the member 34. When the temperature reaches the set value of 90 ° C., the member 34 melts and loses the binding force that has engaged the in-can negative terminal 32 and the external negative terminal 35. The spring member 37 urges the negative terminal 35 from the left side to the right side in the drawing.

When the low-temperature melting member 34 is in the solid state and the negative external terminal 35 is fixed in the illustrated state, the spring 37 is stored in a compressed state inside the box 36. However, when the member 34 is melted, the binding force on the negative external terminal 35 is lost, and accordingly, the spring 37 presses the negative external terminal 35 toward the wall 39.
Due to this pressing force, the negative electrode external terminal 35 moves rightward centering on the joint with the lid 27, and along with the movement, the low temperature melting member 34 is torn off near the contact point with the in-can temperature sensing member 33, and the circuit 31 → 32 → 34 → 35 are cut. When further moving toward the wall 39, the negative external terminal 35
Contacts the contact 41 of the positive external terminal 29. In response to this contact, the spring 37 applies a contact pressure to the contact portion from the left to ensure electrical connection. As a result, the circuit 35 → 34 → 32 → 31 → 30 is cut off between 35 and 32 and bypasses the battery circuit anew to 35 → 40 → 41 → 2
9 will be opened.

[0024]

As described above, according to the present invention, a member having a small specific heat and a good thermal conductivity is installed in the battery can against abnormal temperature rise in the battery can, and this member is connected to the battery via the lid. Thus, since the heat is transported to the safety device outside the can, it is possible to configure a safety device that is inexpensive and has good heat responsiveness. In addition, since the structure is simple and independent of the in-can wiring, the in-can temperature can be easily detected without applying a structural load to the in-can wiring or an assembly load in the production process. As a result, a safety device that realizes current interruption for abnormal temperature rise can be configured.

[Brief description of the drawings]

FIG. 1 is a structural sectional view showing a non-aqueous electrolyte secondary battery of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a structural sectional view showing another embodiment different from the example of FIG. 1 in the nonaqueous electrolyte secondary battery of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrode main body 2 Outer can 3 Gasket 4 Safety device lid 5 Safety device upper lid 6 Positive electrode tab 7 Positive electrode terminal 8 Support member 9 Low temperature melting solder 10 Cup 11 Switch spring contact 12 Switch spring 13 Negative contact 13a Negative contact 14 Inside negative electrode can Terminal 15 Negative external terminal 16 Negative contact 17 Positive electrode terminal 18 Negative tab 19 Bounce spring 20 Safety device lid ceiling 21 Temperature sensing rod in can 22 Center pin 22a Wound body shaft center space 23 Center cap 24 Lower insulator 25 Gasket 26 Safety Device Lid 27 Safety Device Upper Lid 28 Positive Electrode Tab 29 Positive Electrode Terminal 30 Center Pin 31 Negative Electrode Tab 32 Negative Terminal Inside Terminal 33 Can Temperature Sensing Member 34 Low Temperature Melting Member 35 Negative External Terminal 36 Spring Storage Block 37 Spring 38 Inside the Can Upper space 39 Stop wall 4 0 Negative external terminal contact 41 Positive external terminal contact 42 Outer can 43 Lower insulator

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H022 AA09 CC03 KK01 5H029 AJ12 AK03 AL07 AM03 AM05 AM07 BJ27 5H030 AA07 AA10 AS20 FF22

Claims (6)

[Claims] 1. A non-aqueous electrolyte secondary battery in which a battery main body in which a non-aqueous electrolyte is permeated between a positive electrode and a negative electrode is housed in a can. A non-aqueous electrolyte solution comprising: a temperature sensing means for transmitting the heat to the outside of the can by means of the temperature sensing means; Next battery. 2. A battery body in which a positive electrode and a negative electrode are opposed to each other with a separator interposed therebetween and spirally wound to form an electrode body, and a non-aqueous electrolyte is permeated between the positive electrode and the negative electrode. In a non-aqueous electrolyte secondary battery comprising an outer can for housing the main body and a can lid for closing the opening of the outer can and sealing the inside of the can, a metal temperature for sensing the temperature inside the battery The sensing member is installed so as to be guided from the inside of the can through the can lid portion to the outside of the can, and the heat in the can guided by the temperature sensing member is used to melt a heat melting member such as a solder and a temperature fuse. A non-aqueous electrolyte secondary battery comprising a safety device for interrupting battery current. 3. The non-aqueous electrolyte secondary battery according to claim 1, wherein the member for detecting a temperature inside the can is:
A non-aqueous electrolyte secondary battery characterized in that a tip inside a can is positioned inside a center pin of a core portion of a wound electrode body, and connected to a heat melting member outside the can. 4. The non-aqueous electrolyte secondary battery according to claim 1, wherein the member for detecting the temperature inside the can includes an insertion part inserted into the can and an insertion part inserted into the can. A non-aqueous electrolyte secondary battery, comprising: a screw-coupled contact portion that is in contact with the heat melting member. 5. The non-aqueous electrolyte secondary battery according to claim 1, 2 or 3, wherein a part of the member for detecting the temperature inside the can is inserted into the can and another part is a heat melting member. A non-aqueous electrolyte secondary battery comprising a single rod material that contacts the battery. 6. The non-aqueous electrolyte secondary battery according to claim 1, wherein the member for detecting the temperature inside the can is made of copper, copper alloy, aluminum, nickel, nickel-plated iron, A non-aqueous electrolyte secondary battery comprising a heat conductive metal such as stainless steel or graphite.