JP2013098132A - Battery short circuit element, battery short circuit system, battery, and battery system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery short circuit element with which when an internal temperature or an internal pressure of a battery has risen excessively due to an abnormality, it is possible to ensure safety of the battery by causing short circuit between a positive electrode and a negative electrode with reliability to cause discharge with stability.SOLUTION: A battery short circuit element 10 connected to a battery 100 including a first electrode 131 and a second electrode 132 includes: a first electric conductor 15 that is electrically connected to a first electrode side; a second electric conductor 16 that is electrically connected to a second electrode side; and a short circuit layer 20 having an insulator 22 arranged between the first electric conductor and the second electric conductor and a low melting point alloy layer 21 arranged between the first electric conductor and the second electric conductor, wherein the short circuit layer 20 causes short circuit between the first electric conductor 15 and the second electric conductor 16 at a predetermined temperature or higher through fusion of at least a part or the whole of the low melting point alloy layer.

Description

  The present invention relates to a battery short-circuit element capable of releasing the energy of a battery by short-circuiting the positive electrode terminal and the negative electrode terminal and making the battery safe when an abnormal temperature rise occurs in the battery, and the battery short-circuit element The present invention relates to a battery and a battery system using a battery.

  In recent years, lithium ion batteries having high energy density and high safety have been demanded as batteries for electric vehicles and power storage.

  In such a lithium ion battery having a high energy density, the temperature inside the battery excessively increases or the internal pressure of the battery significantly increases and the battery case is deformed when an abnormality such as overcharge or internal short circuit occurs. There is a case. In such a case, in order to quickly secure the battery, a method of releasing energy by short-circuiting the battery can be considered.

  In Patent Document 1, a battery is provided with a short-circuit mechanism including a plate-like positive electrode terminal, a plate-like negative electrode terminal, and an insulating layer sandwiched and connected between the positive electrode terminal and the negative electrode terminal. This insulating layer has a function of electrically connecting the positive electrode terminal and the negative electrode terminal by melting at a predetermined temperature or higher. Thereby, the short circuit mechanism can make the battery safe by short-circuiting the positive electrode and the negative electrode of the battery when an abnormality occurs in the battery and the temperature exceeds a predetermined temperature.

  Moreover, in patent document 2, when the temperature of a battery rises by utilizing the NTC element whose resistance value decreases as the temperature rises as an insulating member that performs insulation between a lid plate that is a positive electrode terminal and a negative electrode terminal. The resistance of the insulating member is reduced and the positive and negative electrodes are short-circuited. Furthermore, Patent Document 2 discloses a switch that short-circuits the positive electrode terminal and the negative electrode terminal when the temperature of the battery rises by using bimetal.

  Patent Document 3 discloses a battery in which a low melting point alloy is disposed in each of a casing (battery can) electrically connected to the negative electrode and a battery lid electrically connected to the positive electrode. ing. In this battery, when an abnormality occurs in the battery and the temperature exceeds a predetermined temperature, the low-melting point alloy melts and is short-circuited by electrically connecting the housing and the battery lid.

  Patent Document 4 discloses a battery in which a low melting point alloy electrically connected to the positive electrode is disposed around the negative electrode terminal. In this battery, when an abnormality occurs in the battery and the temperature exceeds a predetermined temperature, the low melting point alloy melts to contact the negative electrode terminal, and the positive electrode and the negative electrode are electrically connected to make a short circuit.

  As in the above Patent Documents 1 to 4, when excessive heat is generated due to battery abnormality, the positive electrode terminal and the negative electrode terminal are connected and short-circuited in a short-circuit mechanism (including a low-melting-point alloy). Energy is released from the battery.

JP 2008-130458 A JP 2005-044626 A JP 2006-228520 A JP 2009-76270 A

  When the battery is abnormal, it is necessary to discharge the battery with a large current in order to quickly make the battery safe and to release the battery energy to the outside. difficult.

  In the technique such as Patent Document 1, since the insulating layer is sandwiched between the plate-like positive electrode terminal and the plate-like negative electrode terminal, the insulating layer comes off when an impact such as vibration is applied, which is unexpected. It cannot be denied that a short circuit occurs, and there is a problem in terms of vibration resistance and impact resistance. In addition, this short-circuit mechanism is based on the premise that an urging force can be applied from the outside to the positive electrode terminal and the negative electrode terminal, and even if the insulating layer melts, a melt of the insulating layer is interposed due to the urging force from the outside, The resistance value is difficult to reduce. For this reason, with this configuration, it is difficult to reliably short-circuit and discharge. Further, in the technique such as Patent Document 1, there is a problem of stability and reproducibility of the resistance value when the short circuit mechanism (short circuit element) is short-circuited, so that it is difficult to discharge urgently when the battery is abnormal.

  Further, in the technology using the NTC element of Patent Document 2, since a minute current continues to flow even during normal use, the amount of self-discharge as a battery system increases, which is not preferable.

  Similarly, in the technique using the bimetal switch of Patent Document 2, since the positive electrode terminal and the negative electrode terminal are short-circuited by the bimetal switch, the short-circuited portion is structurally one point. However, in the bimetal switch, the location where the short circuit occurs is structurally one point as described above, so that it is difficult to flow a large current and it is difficult to ensure the short circuit performance. In order to increase the area of the short-circuited portion of the bimetal switch to make the battery safer, there is a problem that the bimetal switch needs to be enlarged and the production cost increases. Further, in the case of a bimetal switch, a portion that is not originally in contact with each other is short-circuited when the temperature rises and the switch portion is deformed and contacted. That is, in applications where vibration resistance and impact resistance are required, it is difficult to obtain stable insulation performance, and it is considered that there is a problem in the reliability of the short-circuit element.

  Further, in the techniques such as Patent Document 3 and Patent Document 4, the portion where the positive electrode and the negative electrode are short-circuited is small. That is, the resistance in the short circuit path when the positive electrode and the negative electrode are short-circuited is not sufficiently small. For this reason, it is difficult to discharge with a large current from the short-circuited portion, and if a large current is to flow, it is necessary to enlarge the portion of the short-circuited portion.

  Therefore, the present invention has been made in view of such a situation, and when an abnormality occurs in the battery and the temperature inside the battery rises excessively, the positive electrode terminal and the negative electrode terminal are reliably short-circuited. It aims at providing the battery short circuit element which can be discharged stably.

  In order to achieve the above object, a battery short-circuit element according to an aspect of the present invention is a battery short-circuit element connected to a battery having a first electrode and a second electrode, and electrically connected to the first electrode side. A first electrical conductor connected to the second electrode, a second electrical conductor electrically connected to the second electrode side, and the first electrical conductor disposed between the first electrical conductor and the second electrical conductor A short-circuit layer having an insulator and a low melting point alloy layer disposed between the first electrical conductor and the second electrical conductor, the short-circuit layer being less than a predetermined temperature, One electrical conductor and the second electrical conductor are insulated, and at least a part or the whole of the low melting point alloy layer is melted at a predetermined temperature or higher, whereby the first electrical conductor and the second electrical conductor are melted. Short circuit with the body.

  According to this, the short-circuit layer is configured by the low melting point alloy layer capable of conducting current and the insulator that does not conduct current, and the low melting point alloy layer is partially or entirely at a predetermined temperature or more. By melting, the first electric conductor and the second electric conductor are directly or indirectly short-circuited. That is, when the low melting point alloy layer is melted and the melted low melting point alloy enters an opening provided in advance in the insulator or a gap formed by deformation of the insulator, the first electric conductor and the second electric conductor Is made conductive.

  For this reason, in the short circuit region, the first electric conductor and the second electric conductor can be electrically connected by melting the low melting point alloy layer. Further, since the first electric conductor and the second electric conductor are made of a foil-like member or a plate-like member, the short-circuit region can be easily enlarged. Thereby, the location where the 1st electric conductor and the 2nd electric conductor are electrically connected can be increased, and more electric current can be sent. Therefore, the positive electrode terminal and the negative electrode terminal can be reliably short-circuited and stably discharged. In addition, since the adjustment of the short-circuit region is easy, it is possible to control the resistance of the short-circuit element at the time of the short-circuit. Further, once the short circuit is started, the short circuit area is sequentially expanded by Joule heat generated from the short circuit point, so that reliable and stable short circuit performance can be obtained.

  Preferably, the insulator has an opening, and the short-circuit layer is formed by melting the low-melting-point alloy layer and flowing into the opening of the insulator. The second electrical conductor is short-circuited.

  According to this, the opening is formed in the insulator, and the first electric conductor and the second electric conductor are short-circuited by melting the low melting point alloy layer and flowing into the opening of the insulator. For this reason, the part by which the 1st electrical conductor and the 2nd electrical conductor are electrically connected can be increased, and more electric current can be sent. Therefore, the positive electrode terminal and the negative electrode terminal can be reliably short-circuited and stably discharged.

  The short-circuit layer short-circuits the first electric conductor and the second electric conductor by melting the low-melting-point alloy layer and deforming part or all of the insulator. You can also.

  According to this, when a part or all of the insulator is deformed, a gap (opening) into which the melted low melting point alloy layer flows is formed. For this reason, a short circuit layer can short-circuit a 1st electric conductor and a 2nd electric conductor efficiently, when it becomes more than predetermined temperature. Thereby, the part electrically connected with a 1st electrical conductor and a 2nd electrical conductor can be increased, and more electric current can be sent. Therefore, the positive electrode terminal and the negative electrode terminal can be reliably short-circuited and stably discharged.

  Preferably, the short-circuit layer is formed by laminating the insulator and the low melting point alloy layer.

  The short-circuit layer may be formed by coating the low melting point alloy layer with the insulator.

  Preferably, the first electric conductor and the second electric conductor are made of a foil-like member or a plate-like member.

  Further, the first electric conductor and the second electric conductor may be formed by being wound in a state of being stacked via the short-circuit layer.

  Preferably, the first electric conductor and the second electric conductor are formed by being folded into a bellows in a state of being stacked via the short-circuit layer.

  Preferably, the first electric conductor and the second electric conductor are made of a cylindrical member, and one of the first electric conductor and the second electric conductor overlaps the inside of the other. Arranged.

  Preferably, the cylindrical member disposed inside the first electric conductor and the second electric conductor is such that the plate-like metal member surrounds the central axis of the cylindrical member. It is formed by being rounded.

  In addition, the short-circuit layer includes the first low-melting-point alloy layer in which the low-melting-point alloy layer is disposed in a first short-circuit region that is a part of the short-circuit region, and the melting point is a first temperature; And a second low melting point alloy layer that is disposed in a second short circuit region that is a region different from the first short circuit region, and that has a melting point that is a second temperature different from the first temperature.

  According to this, the low melting point alloy layer is arranged in a region where two types of low melting point alloys having different melting points divide the short circuit region. That is, the first low melting point alloy layer that melts at the first temperature and the second low melting point alloy layer that melts at the second temperature are arranged side by side in the short circuit region. For this reason, the area where the first electric conductor and the second electric conductor are short-circuited can be adjusted according to the temperature. That is, the amount of current that flows when the first electrical conductor and the second electrical conductor are short-circuited according to the temperature can be adjusted stepwise. As a result, when the temperature is high, it is possible to discharge stably by flowing a large current quickly, and when the temperature is low, the discharge amount is suppressed so as not to be discharged more than necessary by short-circuiting at least. be able to.

  A battery short-circuit system according to an aspect of the present invention includes the battery short-circuit element described above, an abnormality determination unit that determines abnormality of the battery, a heating unit that increases the temperature of the short-circuit layer, and the battery. A heating instructing unit that causes the heating unit to perform heating when the abnormality determining unit determines that it is abnormal.

  According to this, the heating instruction circuit causes the heating unit to heat the short-circuit layer when the abnormality determination unit determines that the battery is abnormal. Thus, since the temperature of the short-circuit layer is increased by heating the heating unit without using the heat associated with the temperature increase of the battery at the time of abnormality, it is not necessary to place the short-circuit layer near the battery. . For this reason, the position which arrange | positions a short circuit layer can be freely set to the position etc. which are not battery vicinity. Since the position of the short-circuit layer can be freely set in this way, the short-circuit layer can be disposed in an environment where there is little influence of heat from the outside.

  Also, in order to melt the low melting point metal using the heat generated by the heating unit, for example, a low melting point metal that is a high melting point that is hardly affected by external heat is adopted, and the melting point of the adopted low melting point metal By heating to a higher temperature, the low melting point metal of the short-circuit layer can be melted at any timing to short-circuit the positive electrode and the negative electrode.

  Thereby, it is possible to prevent the positive electrode and the negative electrode of the battery from being short-circuited even when the abnormality of the battery is erroneously detected due to the influence of heat from the outside and no abnormality occurs in the battery.

  The abnormality determination unit includes a temperature detection unit that detects a temperature of the battery, and the battery is abnormal when the temperature of the battery detected by the temperature detection unit is equal to or higher than the abnormal temperature. You may judge.

  The abnormality determination unit includes a temperature detection unit that detects the temperature of the battery and a temperature change detection unit that detects a degree of change in temperature per unit time of the battery, and is detected by the temperature detection unit. The battery is abnormal when the temperature of the battery is equal to or higher than the abnormal temperature and the change in temperature of the battery per unit time detected by the temperature change detection unit is equal to or higher than a predetermined change. You may judge that.

  In addition, the abnormality determination unit includes a deformation amount detection unit that detects a deformation amount of the battery casing, and the deformation amount of the battery detected by the deformation amount detection unit is equal to or greater than a predetermined deformation amount. In this case, it may be determined that the battery is abnormal.

  The abnormality determination unit includes a deformation amount detection unit that detects a deformation amount of the battery casing, and a deformation speed detection unit that detects a deformation speed that is a deformation amount of the battery casing per unit time. And the deformation amount of the battery casing detected by the deformation amount detection unit is equal to or greater than a predetermined deformation amount, and the deformation speed of the battery detected by the deformation speed detection unit is a predetermined deformation speed. When it becomes above, you may judge that the said battery is abnormal.

  Further, the present invention can be realized not only as such a battery short-circuit element or battery short-circuit system, but also as a battery in which the battery short-circuit element or battery short-circuit system is arranged on the first electrode side and the second electrode side. . Furthermore, the present invention is realized as a battery system comprising a battery module in which a plurality of batteries are connected, and a battery short-circuit element or a battery short-circuit system that connects the first electrode side and the second electrode side of the battery module. You can also.

  According to the battery short-circuit element according to the present invention, the positive electrode terminal and the negative electrode terminal can be reliably short-circuited and stably discharged only when an abnormality occurs in the battery and the temperature inside the battery rises excessively. it can.

It is a perspective view which shows typically the external appearance of the battery containing the battery short circuiting element which concerns on Embodiment 1 of this invention. It is a perspective view which omits a part of wall part of a housing | casing and shows the inside of a battery typically. It is a perspective view which shows the structure of a battery short circuit element. It is a figure which shows the structure of the battery short circuit element in the process before setting it as a winding structure. It is sectional drawing of each component of the laminated | stacked short circuit element member in the process before setting it as a winding structure. It is an external view of an insulator film. It is an external view of the battery short circuit element of a winding structure. It is sectional drawing of the short circuit element member of the winding structure in the surface orthogonal to the longitudinal direction of a positive electrode connecting member or a negative electrode connecting member. It is sectional drawing of each component of the laminated | stacked short circuit element member in the process before setting it as the winding structure which concerns on the modification (1) of Embodiment 1. FIG. It is sectional drawing which shows an example of the short circuit layer which has a low melting-point alloy layer comprised by the low melting-point alloy of four types of different melting | fusing point which concerns on the modification (2) of Embodiment 1. It is sectional drawing which shows an example of the short circuit layer which has a low melting-point alloy layer comprised by the low melting-point alloy of four types of different melting | fusing point which concerns on the modification (2) of Embodiment 1. It is a perspective view which shows the structure of the battery short circuit element which concerns on the modification (3) of Embodiment 1. FIG. It is an external view of the short circuit element member of the laminated structure which concerns on the modification (5) of Embodiment 1. FIG. It is sectional drawing of the short circuit element member of the laminated structure in the surface which is along the longitudinal direction of the positive electrode connection member which concerns on the modification (5) of Embodiment 1, or a negative electrode connection member, and is orthogonal to a transversal direction. It is an external view of the short circuit element member of the folding structure which concerns on the modification (5) of Embodiment 1. FIG. It is sectional drawing of the short circuit element member of the folding structure in the surface orthogonal to the longitudinal direction of the positive electrode connection member which concerns on the modification (5) of Embodiment 1, or a negative electrode connection member. It is an external view of the battery short circuit element which employ | adopted the cylindrical metal member which concerns on the modification (6) of Embodiment 1 as a positive electrode connection member and a negative electrode connection member. FIG. 6 is a cross-sectional view of a surface of the battery short-circuiting element according to Modification Example (6) of Embodiment 1 that is perpendicular to the central axis of the cylinder. It is sectional drawing in the surface in alignment with the central axis of the cylinder of the battery short circuit element which concerns on the modification (6) of Embodiment 1. FIG. It is sectional drawing in a surface perpendicular | vertical to the center axis | shaft of the cylinder of the other battery short circuit element which concerns on the modification (6) of Embodiment 1. FIG. It is sectional drawing in a surface perpendicular | vertical to the center axis | shaft of the cylinder of the other battery short circuit element which concerns on the modification (6) of Embodiment 1. FIG. It is a perspective view which shows typically the external appearance of the battery containing the battery short circuit system which concerns on Embodiment 2 of this invention. (A) is sectional drawing in the surface perpendicular | vertical to the central axis of the cylinder of a short circuit action | operation part, (b) is sectional drawing in the surface in alignment with the central axis of a short circuit action part. It is a functional block diagram of a battery short circuit system. It is a functional block diagram of the battery short circuit system which concerns on the modification (1) of Embodiment 2. It is a functional block diagram of the battery short circuit system which concerns on the modification (2) of Embodiment 2. It is a functional block diagram of the battery short circuit system which concerns on the modification (3) of Embodiment 2. It is sectional drawing in the surface in alignment with the central axis of the short circuit action part which concerns on the modification (4) of Embodiment 2. FIG.

  A battery short-circuit element in an embodiment of the present invention will be described with reference to the drawings. The following embodiment is merely an example of the battery short-circuit element according to the present invention. Therefore, the scope of the present invention is defined by the wording of the claims with reference to the following embodiments, and is not limited to the following embodiments.

(Embodiment 1)
FIG. 1 is a perspective view schematically showing an overview of a battery including a battery short-circuit element. FIG. 2 is a perspective view schematically showing the inside of the battery with a part of the wall portion of the housing omitted.

  As shown in these drawings, the battery 100 is a storage battery that can charge electricity and discharge electricity, and more specifically, a non-aqueous electrolyte battery (for example, a lithium ion battery). . The battery 100 includes a power generation element 101, a housing 102, a positive electrode terminal 131 as a first electrode that is an electrode terminal 103, a negative electrode terminal 132 as a second electrode, a positive current collector 141 that is a current collector 104, and A negative electrode current collecting member 142 and a battery short-circuit element 10 are provided.

  As shown in FIG. 3, the battery short-circuit element 10 includes a positive electrode connection member 11, a negative electrode connection member 12, and a short-circuit element member 13. FIG. 3 is a perspective view showing the configuration of the battery short-circuit element 10.

  The positive electrode connection member 11 is a plate-shaped metal member that connects the positive electrode terminal 131 of the battery 100 and the short-circuit element member 13. That is, the positive electrode connection member 11 is a rectangular plate-like member that extends from the positive electrode terminal 131 to the short-circuit element member 13. The negative electrode connection member 12 is a plate-like metal member that connects the negative electrode terminal 132 of the battery 100 and the short-circuit element member 13. That is, the negative electrode connection member 12 is a rectangular plate-like member that extends from the negative electrode terminal 132 to the short-circuit element member 13. The positive electrode connecting member 11 and the negative electrode connecting member 12 are metal members, and are made of aluminum which has high thermal conductivity and excellent electrical conductivity in the present embodiment.

  Hereinafter, the battery short-circuit element 10 will be described with reference to FIGS. 4A, 4B, 4C, and 4D. FIG. 4A is a diagram illustrating a configuration of a battery short-circuit element in a process before the winding structure is formed. FIG. 4B is a cross-sectional view of the stacked components in the process before the winding structure. FIG. 4C is an external view of the insulator film. FIG. 4D is an external view of a battery short-circuit element having a winding structure. FIG. 4E is a cross-sectional view of the short-circuit element member 13 having a winding structure on a surface orthogonal to the longitudinal direction of the positive electrode connecting member or the negative electrode connecting member.

  As illustrated in FIG. 4A, the short-circuit element member 13 includes a short-circuit layer 20, a first electric conductor 15, and a second electric conductor 16. The first electric conductor 15 and the second electric conductor 16 are rectangular foil-like metal members, and are made of aluminum in the present embodiment. The positive electrode connecting member 11 is connected to all of one side of the first electric conductor 15, and the first electric conductor 15 is electrically connected to the positive electrode terminal 131 by the positive electrode connecting member 11. The negative electrode connecting member 12 is connected to all of one side of the second electric conductor 16, and the second electric conductor 16 is electrically connected to the negative electrode terminal 132 by the negative electrode connecting member 12.

  In addition, the location where the positive electrode connecting member 11 is connected to the first electric conductor 15 is not limited to all one side of the first electric conductor 15 as long as it is electrically connected. There may be. Similarly to the negative electrode connecting member 12, the portion connected to the second electrical conductor 16 is not limited to all one side of the second electrical conductor 16, but may be electrically connected. It may be a part of the side.

  As shown in FIG. 4B, the short-circuit element member 13 is stacked, as shown in FIG. 4B, the first short-circuit layer 20, the first electric conductor 15, the second short-circuit layer 20, and the second electric conductor 16. Are stacked in order. The short-circuit layer 20 also includes a low melting point alloy layer 21 and an insulating film 22, and one insulating film 22 is sandwiched and laminated between two low melting point alloy layers 21. That is, the short-circuit layer 20 has a three-layer structure. In FIG. 4A, the short-circuit layer 20 is illustrated as one layer, and a detailed configuration is omitted.

  The low melting point alloy layer 21 is preferably an alloy having a melting point of 70 to 250 ° C., and more preferably an alloy of 70 to 150 ° C. For example, a low melting point solder containing tin (Sn) or lead (Pb). Note that the alloy used for the low melting point alloy layer 21 may be 150 ° C. or higher, and for example, an alloy having a melting point of 200 ° C. is effective. The low-melting-point alloy layer 21 is an insulator film 22 that is a layer in which a low-melting-point alloy is mixed with a fluxing agent or is in contact with the low-melting-point alloy layer 21 (hereinafter referred to as “contact layer”). Or it is preferable to apply to the first electric conductor 15 and the second electric conductor 16 in advance. Thus, by using the flux agent, the wettability between the low melting point alloy layer 21 and the contact layer is improved, and the low melting point alloy layer 21 can be easily applied in layers on the surface of the contact layer. As the fluxing agent, for example, a rosin-based fluxing agent containing at least one of organic acids, amines, halides and the like as an activator can be used.

  The insulator film 22 is a thin film insulator and has a plurality of openings h. The insulator film 22 is preferably made of a material having a melting point of 150 ° C. or higher, such as silicon rubber or Teflon (registered trademark) resin. The insulator film 22 is also preferably made of silicon rubber that has wettability to the alloy of the low melting point alloy layer 21. The melting point of the insulator film 22 is preferably higher than the melting point of the low melting point metal layer 21. For example, when the material of the insulator film 22 is 70 to 250 ° C. which is the same melting point as that of the low melting point alloy layer 21, an unnecessary short circuit is caused by deformation (particularly shrinkage) at a temperature lower than the melting point. It is not preferable. The insulator film 22 is a member that substantially insulates the first electric conductor 15 and the second electric conductor 16, and therefore reliably insulates both when the temperature is lower than the intended temperature. And when it becomes more than the temperature which intends a short circuit, it is preferable to short-circuit both reliably. That is, it is preferable that the insulator film 22 is thinner and has a larger area ratio of the opening h in a state where the first electric conductor 15 and the second electric conductor 16 are reliably insulated. In order to increase the area ratio of the opening h, it is conceivable to increase the number of openings h and to increase the size of one opening h. In addition, although the insulating sheet which has the opening h was shown as the insulator film 22 here, this invention is not limited to this, What is necessary is just to have insulation and porosity, and from an insulating material A configured net, a porous mesh body (that is, a net-like material), or the like can be used.

  As shown in FIG. 4A, the short-circuit layer 20 is folded in half, and the entire first electric conductor 15 is sandwiched between the two. Thus, by arranging the second electric conductor 16 outside the first electric conductor 15 sandwiched between the short-circuit layers 20, the first electric conductor 15 and the second electric conductor 16 form the short-circuit layer 20. It is set as the state laminated | stacked through. As described above, the short-circuit layer 20 is a layer having a three-layer structure in which the insulator film 22 is sandwiched between the low melting point alloy layers 21. For this reason, by laminating the first electric conductor 15 and the second electric conductor 16 via the short-circuit layer 20, the first electric conductor 15 and the second electric conductor 16 are insulators of the short-circuit layer 20. It is insulated by the film 22. Note that the configuration in which the low melting point alloy layers 21 are provided in advance on both surfaces of the insulator film 22 as the short-circuit layer 20 has been described with reference to FIG. 4A, but the present invention is not limited to this. The form laminated | stacked in the state with which the conductor 15 or the 2nd electric conductor 16 was equipped may be sufficient. Further, in the present invention, by applying an urging force to the first electric conductor 15 and the second electric conductor 16 with a clip or the like, it is possible to obtain a stable short circuit state when the low melting point metal is melted.

  And in the state where the first electric conductor 15 and the second electric conductor 16 are laminated via the short-circuit layer 20, the short-circuit element member 13 is centered on the positive electrode connection member 11 and the negative electrode connection member 12, and The short-circuit layer 20 is formed by being wound so that one or more turns are wound on the outside.

  Further, when the short-circuit layer 20 is configured as the short-circuit element member 13, it is between the first electric conductor 15 and the second electric conductor 16, and the first electric conductor 15 and the second electric conductor. 16 is disposed at least in a region overlapping with 16 (hereinafter referred to as “short-circuit region”). By arranging the short-circuit layer 20 in this way, the first electrical conductor 15 and the second electrical conductor 16 are electrically insulated by the insulator film 22 inside the short-circuit element member 13.

  And if the short circuit layer 20 becomes more than predetermined temperature (it is 70-150 degreeC in this Embodiment, and is melting | fusing point of the low melting point alloy layer 21), the low melting point alloy layer 21 will fuse | melt and an insulator film The first electric conductor 15 and the second electric conductor 16 are short-circuited by flowing into the opening h of 22. At this time, the resistance value (Ω) of the short-circuit element member 13 is reduced by 9 digits or more as compared to before the short-circuit. That is, the short-circuit element member 13 normally needs to be substantially insulative in order to reduce the self-discharge of the battery, and more preferably has a high resistance of 1 MΩ or more. On the other hand, the short-circuit element member 13 needs to short-circuit between the terminals with a low resistance because it is necessary to rapidly discharge the battery and release the energy in the battery in the short-circuit state. The resistance at the time of this short circuit is preferably about 10 to 100 mΩ. Thus, by making the resistance change of the short-circuit element before and after the short circuit to be 9 digits or more, the self-discharge during the normal time can be reduced, and the battery can be rapidly discharged during the short-circuit.

  According to the short-circuit element member 13 in the present embodiment, the short-circuit layer 20 includes the low-melting-point alloy layer 21 that can conduct current and the insulator film 22 that does not conduct current. When the melting point alloy layer 21 is partially or wholly melted at a predetermined temperature or higher, the first electric conductor 15 and the second electric conductor 16 are directly short-circuited. That is, the low melting point alloy layer 21 is melted, and the melted low melting point alloy enters the opening h provided in the insulator film 22 in advance, thereby bringing the first electric conductor 15 and the second electric conductor 16 into a conductive state. Let

  For this reason, the first electric conductor 15 and the second electric conductor 16 can be electrically connected to each other by melting the low melting point alloy layer 21 at a plurality of locations in the short-circuit region. Moreover, since the 1st electric conductor 15 and the 2nd electric conductor 16 consist of foil-like members, a short circuit area | region can be enlarged easily. Thereby, the location where the 1st electric conductor 15 and the 2nd electric conductor 16 are electrically connected can be increased, and more electric current can be sent. Therefore, the positive electrode terminal 131 and the negative electrode terminal 132 can be reliably short-circuited and stably discharged. Further, since the adjustment of the area of the short-circuit region is easy, it is possible to control the resistance of the short-circuit element at the time of short-circuit. Further, once the short circuit is started, the short circuit area is sequentially expanded by Joule heat generated from the short circuit point, so that reliable and stable short circuit performance can be obtained.

  Further, the short-circuit element member 13 in the present embodiment is formed by being laminated and wound with the second electric conductor 16 in a state where the first electric conductor 15 is sandwiched between the short-circuit layers 20. The outer portion and the central portion of the short-circuit element member 13 tend to approach each other due to a restoring force that causes the central portion of the winding structure of the element member 13 to spread outward. That is, an urging force is applied between the first electric conductor 15 and the second electric conductor 16 so as to approach each other. When the insulator film is deformed in such a state, the first electric conductor 15 and the second electric conductor 16 can be short-circuited more reliably. Moreover, by making the short circuit element member 13 into a winding structure, it is possible to make the earthquake resistance and the impact resistance superior to those of a short circuit element member having a laminated structure or a folding structure, which will be described later.

  In addition, the short-circuit element member 13 in the present embodiment is a winding in which the first electric conductor 15, the second electric conductor 16, and the short-circuit layer 20 are wound around the positive electrode connecting member 11 and the negative electrode connecting member 12. It has a structure. Thus, by disposing the positive electrode connecting member 11 and the negative electrode connecting member 12 that conduct heat from the battery 100 at the center of the short circuit element member 13, the positive electrode connection member 11 and the negative electrode connection member 12 in the short circuit element member 13 are arranged. Heat dissipation can be prevented. For this reason, when abnormal heat | fever generate | occur | produces from the battery 100, it can reduce that the heat | fever transmitted to the short circuit element member 13 is thermally radiated, and can transmit to the short circuit layer 20 reliably. Thereby, it is possible to detect that an abnormality has occurred in the battery 100 inside the short-circuit element member 13 and to short-circuit the first electric conductor 15 and the second electric conductor 16 more reliably.

  In the short-circuit element member 13 in the present embodiment, a rectangular low-melting-point alloy layer 21 and an insulator film 22 are disposed between the rectangular first electric conductor 15 and the second electric conductor 16. Thus, the first electric conductor 15 and the second electric conductor 16 are insulated. Therefore, by adjusting the area of the first electric conductor 15, the second electric conductor 16, and the short-circuit layer 20 (that is, the contact area), the resistance value in the insulating state and the resistance value assuming the short-circuit state And can be adjusted easily. For this reason, according to the capacity | capacitance of the battery 100, it becomes easy to manufacture the short circuit element member 13 which has an optimal resistance value.

  As described above, when the battery short-circuit element 10 in the present embodiment reaches a predetermined temperature or higher, the first electric conductor 15 and the second electric conductor 16 can be reliably short-circuited, so that the battery 100 is overcharged. When the temperature becomes abnormal at times, the battery energy can be safely released while releasing the charging current.

(Modification of Embodiment 1)
(1)
In the first embodiment, the short-circuit layer 20 has a three-layer structure in which one insulating film 22 is laminated so that two low-melting-point alloy layers 21 are sandwiched therebetween, but the invention is not limited thereto. For example, as shown in FIG. 5, the short-circuit layer 20 a may be configured by coating the low melting point alloy layer 21 so as to be wrapped with the insulator coating 22 </ b> A. That is, contrary to the short-circuit layer 20 of the above-described embodiment, the short-circuit layer 20a is sandwiched between insulator coatings 22A as an insulator on the surface of the low melting point alloy layer 21. In this case, it is conceivable that the insulating coating 22A employs a material such as an insulating coating agent, a wax material, a heat shrink film, or an electrically insulating paint.

  More specifically, examples of the insulator coating agent include epoxy-based, urethane-based, silicon-based, acrylic-based, or Teflon (registered trademark) -based resins. In this case, when the short-circuit layer 20a reaches a predetermined temperature or higher, the low-melting point alloy layer 21 melts, whereby the insulating coating 22A (insulating coating agent) coated on the low-melting point alloy layer 21 is broken and collapsed. The first electric conductor 15 and the second electric conductor 16 are short-circuited when the low melting point alloy layer 21 is electrically connected.

  An example of the wax material is paraffin wax. In this case, when the short-circuit layer 20a reaches a predetermined temperature or more, the low melting point alloy layer 21 is melted, and the insulator coating 22A (brazing material) is melted after the low melting point alloy layer 21 is melted or simultaneously melted. When the molten alloy oozes out from the gap, the first electric conductor 15 and the second electric conductor 16 are short-circuited when the low melting point alloy layer 21 is electrically connected.

  An example of the heat shrink film is a polystyrene or polyester film. In this case, when the short-circuit layer 20a reaches a predetermined temperature or higher, the insulating coating 22A (heat-shrinkable film) is thermally contracted, thereby generating a gap in the insulating coating 22A. At the same time, since the low melting point alloy layer 21 is melted in the short-circuit layer 20a, the melted low melting point alloy layer 21 flows into the gap formed in the insulator coating 22A, and the first electric conductor 15 and the second electric conductor 15 The electrical conductor 16 is short-circuited when the low melting point alloy layer 21 is electrically connected.

  In the case of an electrically insulating paint, the short-circuit layer 20a acts in the same manner as in the case of the insulator coating agent, and short-circuits the first electric conductor 15 and the second electric conductor 16.

  According to the short-circuit element member 13 of the modified example (1), when a part or the whole of the insulator coating 22A is deformed, a gap into which the melted low melting point alloy layer 21 can flow into the insulator coating 22A is provided with the insulator coating. Occurs at 22A. For this reason, the short circuit layer can efficiently short-circuit the first electric conductor 15 and the second electric conductor 16 when the temperature reaches a predetermined temperature or higher. Thereby, the location where the 1st electric conductor 15 and the 2nd electric conductor 16 are electrically connected can be increased, and more electric current can be sent. Therefore, the positive electrode terminal and the negative electrode terminal can be reliably short-circuited and stably discharged. When the low melting point alloy layer 21 is coated with the insulator coating 22A as in the modification (1) to form the short circuit layer 20a, it can be manufactured at a lower cost than the short circuit layer 20 of the above embodiment.

(2)
In the first embodiment, the short-circuit layer 20 has the low melting point alloy layer 21 made of one kind of alloy, but may be made of a plurality of kinds of alloys. For example, FIG. 6 is a cross-sectional view showing an example of a short-circuit layer 20b having a low-melting point alloy layer 21A composed of four types of low-melting point alloys having different melting points. As shown in FIG. 6, the low-melting-point alloy layer 21A has four different types of first low-melting-point alloy layer 21a, second low-melting-point alloy layer 21b, third low-melting-point alloy layer 21c, and fourth low-melting-point alloy layer 21d. It is made of a low melting point alloy having a melting point. Here, the melting point of the low melting point alloy of the first low melting point alloy layer 21a is the first temperature, the melting point of the low melting point alloy of the second low melting point alloy layer 21b is the second temperature, and the third low melting point alloy layer 21c. The melting point of the low melting point alloy is the third temperature, and the melting point of the low melting point alloy of the fourth low melting point alloy layer 21d is the fourth temperature. The second temperature is higher than the first temperature, the third temperature is higher than the second temperature, and the fourth temperature is higher than the third temperature. Of course, as shown in FIG. 7, the low melting point alloy layer 21A shown in FIG. 6 may be coated with an insulator coating 22A.

  According to this, the low melting point alloy layer 21A is arranged in a region where four types of low melting point alloys having different melting points divide the short circuit region. That is, the first low melting point alloy layer 21a that melts at the first temperature, the second low melting point alloy layer 21b that melts at the second temperature, the third low melting point alloy layer 21c that melts at the third temperature, and the fourth temperature. The fourth low-melting-point alloy layer 21d that melts in is disposed side by side in the short-circuit region. For this reason, the area where the first electrical conductor and the second electrical conductor are short-circuited can be adjusted stepwise according to the temperature. That is, as the temperature becomes higher, the area where the first electric conductor 15 and the second electric conductor 16 are short-circuited by the short-circuit layer 20b increases stepwise, so the first electric conductor 15 and the second electric conductor 15 The amount of current that flows when the conductor 16 is short-circuited can be increased stepwise. As a result, when the temperature rise is large, it is possible to discharge stably by flowing a large current quickly. Can be suppressed.

(3)
Although not particularly mentioned in the first embodiment, the short-circuit element member 13 may be arranged on the negative electrode side as shown in FIG. That is, the second distance between the second electric conductor 16 and the negative electrode terminal 132 is shorter than the first distance between the first electric conductor 15 and the positive electrode terminal 131. Note that the first distance in this case is a distance in a substance that electrically (or thermally) connects the first electrical conductor 15 and the positive electrode terminal 131, and in this embodiment, the length of the positive electrode connecting member 11. It is. The same can be said for the second distance. The second distance is a distance in the material that electrically (or thermally) connects the second electric conductor 16 and the negative electrode terminal 132. In form, it is the length of the negative electrode connection member 12. In the battery 100, the negative electrode terminal 132 is often made of copper having higher thermal conductivity than the positive electrode terminal 131. Particularly in such a case, since heat generated in the battery 100 is efficiently transmitted from the negative electrode terminal, the positive electrode connecting member 11 or the negative electrode connecting member 12 is disposed by arranging the short-circuit element member 13 closer to the negative electrode terminal than the positive electrode terminal. The effect of temperature drop due to the heat released in is almost eliminated. For this reason, the short circuit element member 13 can detect that abnormal heat is generated in the battery 100 more quickly and accurately, and can short-circuit the positive electrode terminal and the negative electrode terminal of the battery 100.

  Further, the distance between the second electric conductor 16 and the negative electrode terminal 132 is not limited to be closer than the distance between the first electric conductor 15 and the positive electrode terminal 131. For example, the thermal conductivity of the negative electrode connection member 12 may be increased in order to quickly increase the temperature of the second electrical conductor 16 connected to the negative electrode terminal 132. Specifically, the negative electrode connection member 12 may be made of copper, so that the thermal conductivity of the negative electrode connection member 12 is larger than the thermal conductivity of the positive electrode connection member 11. In this case, the heat generated in the battery 100 is transmitted to the second electric conductor 16 and the temperature of the second electric conductor 16 is increased, so that the short-circuit layer 20 has a predetermined temperature or higher. is there. For this reason, the negative electrode connection member 12 that connects the second electric conductor 16 and the negative electrode terminal 132 is subjected to heat insulation treatment or heat shielding treatment in order to avoid release of heat to portions other than the second electric conductor 16. You can also.

(4)
Although not particularly mentioned in the first embodiment, the outer side of the short-circuit element member 13 may be configured to be covered with a resin member (including a laminate or the like). Thus, the short circuit element member 13 does not need to stop the edge | side of the short circuit layer 20 arrange | positioned outside by comprising the short circuit element member 13. FIG. That is, by covering the outer side of the short-circuit element member 13 with the resin member, it is possible to easily suppress it using the restoring force that works from the center of the short-circuit element member 13. Moreover, since the whole short circuit element member 13 is covered, it can prevent reliably that the 1st electrical conductor 15 and the 2nd electrical conductor 16 short-circuit unexpectedly.

(5)
In the first embodiment, the short-circuit element member 13 has the first electric conductor 15, the second electric conductor 16, and the short-circuit layer 20 stacked and wound to form a winding structure. It is not limited to a winding structure.

  For example, as shown in FIGS. 9A and 9B, a plurality of (three) first electrical conductors 15 and a plurality of (three) second electrical conductors 16 are connected via a plurality of short-circuit layers 20. It is good also as the short circuit element member 13a laminated | stacked alternately. 9A is an external view of the short-circuit element member 13a having a laminated structure, and FIG. 9B is a short-circuit of the laminated structure on a plane that is along the longitudinal direction of the positive electrode connecting member or the negative electrode connecting member and orthogonal to the short direction. It is sectional drawing of the element member 13a. In this case, the plurality of first electric conductors 15 to be stacked are brought into a conductive state by the positive electrode side connection portion 41, and the positive electrode side connection portion 41 is connected to the positive electrode connection member 11. Thereby, the plurality of first electrical conductors 15 are connected to the positive terminal 131. Similarly, the plurality of second electric conductors 16 to be stacked are brought into a conductive state by the negative electrode side connection portion 42, and the negative electrode side connection portion 42 is connected to the negative electrode connection member 12. Thereby, the plurality of second electric conductors 16 are connected to the negative terminal 132. The positive electrode side connecting portion 41 and the negative electrode side connecting portion 42 are metal members and are made of the same material as the first electric conductor 15 and the second electric conductor 16.

  Further, for example, as shown in FIGS. 10A and 10B, one foil-like first electric conductor 15 and one foil-like second electric conductor 16 are connected via one short-circuit layer 20. The sandwiched portion may be formed by stacking and folding in a bellows shape in the stacked state. 10A is an external view of the short-circuit element member 13b having a folding structure, and FIG. 10B is a cross-sectional view of the short-circuit element member 13b having a folding structure on a plane orthogonal to the longitudinal direction of the positive electrode connecting member or the negative electrode connecting member. . In this case, the positive electrode connecting member 11 is connected to one side of the first electric conductor 15, and the negative electrode connecting member 12 is connected to one side of the second electric conductor 16.

  9A and 9B or 10A and 10B, even if the short-circuit element member is configured, the short-circuit element member is configured by laminating the foil-like member and the thin-film member. When the layer 20 is heated to a predetermined temperature or higher and the low melting point alloy layer 21 is melted, the contact area between the first electric conductor 15 and the second electric conductor 16 can be increased and the short circuit can be surely performed. it can. Further, similarly to the above embodiment, the first electric conductor 15 is sandwiched by the second electric conductor 16 via the short-circuit layer 20. For this reason, it can prevent that the short circuit layer 20 (especially insulator film 22) remove | deviates by shocks, such as a vibration. For this reason, it is possible to prevent the first electric conductor 15 and the second electric conductor 16 from being short-circuited under unintended conditions.

(6)
In the battery short-circuit element 10 of the first embodiment, the positive electrode connecting member 11 and the negative electrode connecting member 12 are plate-like metal members, but not limited to a plate shape, as shown in FIGS. 11A, 11B, and 11C. A cylindrical metal member may be used. FIG. 11A is an external view of a battery short-circuiting element 10c employing cylindrical metal members as the positive electrode connecting member 11a and the negative electrode connecting member 12a. FIG. 11B is a cross-sectional view in a plane perpendicular to the central axis of the cylinder of the battery short-circuit element 10c. FIG. 11C is a cross-sectional view of a plane along the central axis of the cylinder of the battery short-circuit element 10c.

  As shown in these drawings, the positive electrode connecting member 11a and the negative electrode connecting member 12a are cylindrical metal members, and the negative electrode connecting member 12a is disposed inside the positive electrode connecting member 11a. Between the positive electrode connecting member 11a and the negative electrode connecting member 12a, a low melting point alloy layer 21B and an insulator layer 22B are laminated in layers so as to follow the cylindrical shape of both. 11B and 11C, the insulator layer 22B is laminated inside the low melting point alloy layer 21B. However, the low melting point alloy layer 21B may be laminated inside the insulator layer 22B. . Similarly, the negative electrode connection member 12a is disposed inside the positive electrode connection member 11a, but the positive electrode connection member 11a may be disposed inside the negative electrode connection member 12a. That is, the low melting point alloy layer 21B and the insulator layer 22B as the short-circuit layer 20d are laminated between the positive electrode connection member 11a and the negative electrode connection member 12a, and the short-circuit layer 20d is in contact with both. Just do it.

  In this way, by forming the positive electrode connecting member 11a and the negative electrode connecting member 12a from cylindrical metal members, even when the low melting point alloy layer 21B is melted, the molten low melting point alloy is prevented from flowing out. Can do. For this reason, when abnormality arises in the battery 100, the positive electrode connection member 11a and the negative electrode connection member 12a can be reliably short-circuited.

  As shown in FIG. 11B, the negative electrode connection member 12a disposed inside the positive electrode connection member 11a has a circular shape with a continuous cross-sectional shape, but is not limited thereto, for example, the battery short-circuit element shown in FIG. 12A As 10d, you may comprise so that the negative electrode connection member 12b arrange | positioned inside may be formed by rounding a plate-shaped metal member so that the central axis of a cylindrical member may be enclosed. Further, instead of the insulator layer 22B, a plate-like insulator layer 22C may be formed by rounding so as to surround the central axis of the cylindrical member. In this case, the insulator layer 22C forms a short circuit layer 20e in combination with the low melting point alloy layer 21B. The positive electrode connection member 11a and the low melting point alloy layer 21B, which are the components constituting the battery short-circuit element 10d other than the negative electrode connection member 12b and the insulator layer 22C, are the same as the components of the battery short-circuit element 10c. It is the composition.

  Further, as shown in FIG. 12B, in the battery short-circuiting element 10d shown in FIG. 12A, instead of the negative electrode connecting member 12b and the insulator layer 22C arranged inside the positive electrode connecting member 11a, a plate-like member is rounded to A battery short-circuiting element 10e employing a cylindrical negative electrode connecting member 12c and an insulating layer 22D that are partially overlapped may be used. In this case, the insulator layer 22D forms a short-circuit layer 20f in combination with the low melting point metal layer 21B. The positive electrode connection member 11a and the low-melting point alloy layer 21B, which are the components constituting the battery short-circuit element 10d other than the negative electrode connection member 12c and the insulator layer 22D, are the same as the components of the battery short-circuit element 10c. It is the composition.

  Moreover, the member which rounds a plate-shaped member and makes it cylindrical shape should just be a member (a negative electrode connection member in a modification (6)) arrange | positioned at least inside. Further, in the case where the battery short-circuiting elements 10d and 10e as shown in FIGS. 12A and 12B are employed, the member arranged on the outermost side (the positive electrode connecting member in the modified example (6)) has its axis. The cross section needs to be a continuous circular shape. Moreover, it is good also as a form that all the members arrange | positioned inside the positive electrode connection member 11a comprise a cylindrical member by rounding a plate-shaped member. Moreover, about the member arrange | positioned inside the positive electrode connection member 11a, when the form which comprises the cylindrical member is adopted by rounding a plate-shaped member, the member arrange | positioned from the innermost side It is necessary to form a cylindrical member by rounding a plate-like member in which a plurality of members that are continuously adjacent to each other. That is, it is not possible to take a configuration in which a cylindrical member formed by rolling a plate-like member is sandwiched between circular cylindrical members having a continuous axial cross section. 12A and 12B, the battery short-circuit elements 10d and 10e have the negative electrode connecting members 12b and 12c arranged inside the positive electrode connecting member 11a, but the positive and negative electrodes of the positive electrode connecting member and the negative electrode connecting member The roles of the positive electrode connecting member and the negative electrode connecting member may be reversed by changing the connection destination.

  As described above, since the battery short-circuit elements 10d and 10e form a cylindrical member by rounding the plate-like member, the member arranged on the inner side becomes a cylindrical member arranged on the outer side from the inner side. On the other hand, pressure by restoring force can be applied. That is, the outer diameter of the cylindrical member disposed on the inner side is formed by being inserted in a state slightly larger than the inner diameter of the cylindrical member disposed on the outer side. Thereby, a pressure can be applied to the short circuit layer between the positive electrode connection member and the negative electrode connection member, and when the abnormality occurs in the battery and the low melting point metal layer melts, the battery can be short-circuited smoothly.

(7)
In the battery short-circuit element 10 of the first embodiment, the low-melting point alloy layer 21 is melted at a predetermined temperature of 70 to 250 ° C., and the first electric conductor 15 and the second electric conductor 16 are short-circuited. For example, it is preferable that it is below the shutdown temperature of the separator used for a battery. Thereby, the battery 100 can be discharged by the short circuit of the battery short-circuit element 10 before the battery 100 is shut down by the battery separator. For this reason, the energy of the battery 100 can be released more safely.

  Moreover, in the battery short-circuit element 10 of all the above forms (Claims 1 to 10 of the present invention), the battery short-circuit element itself needs to operate by sensing heat, so that it can be disposed in the vicinity of the battery. In addition, it is desirable to install it in the vicinity of the electrode terminal where the temperature rises easily according to the temperature in the battery.

  Further, in the present invention, by applying an urging force to the first electric conductor and the second electric conductor, it is possible to obtain a short circuit state in which the low melting point metal is more stable at the time of melting.

  Although not particularly mentioned in the battery short-circuit element 10 of the above-described embodiment, heat transfer fins that promote heat dissipation to the outside air may be further provided on the surface of the short-circuit element member 13. Thereby, since the heat conducted to the short-circuit element member 13 can be radiated, the battery 100 can be prevented from being overheated. This configuration is preferably provided at a position away from the positive electrode connecting member 11 or the negative electrode connecting member 12. This is because if heat transfer fins are provided near the positive electrode connection member 11 or the negative electrode connection member 12, heat generated when an abnormality occurs in the battery 100 cannot be transmitted to the short-circuit layer 20, and the battery short-circuit element 10 can be quickly formed. This is because it becomes difficult to operate. On the other hand, the heat transfer fin is provided at a position away from the positive electrode connection member 11 or the negative electrode connection member 12, or the positive electrode connection member 11 and the negative electrode connection member 12 are arranged at the center of the short-circuit element member 13, thereby Heat generated by 100 abnormalities can be efficiently dissipated.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. FIG. 13 is a perspective view schematically showing the appearance of a battery including the battery short-circuit system according to Embodiment 2 of the present invention.

  As shown in FIG. 13, battery 200 includes a battery short-circuit system 110 instead of battery short-circuit element 10 in the first embodiment shown in FIG. 1. Since the configuration of battery 200 other than battery short-circuit system 110 is the same as that of battery 100 in the first embodiment, description thereof is omitted.

  The battery short-circuit system 110 includes a cylindrical short-circuit operating unit 120, an abnormality determination circuit 121, a positive electrode lead wire 11b connected to the positive electrode terminal 131, and a negative electrode lead wire 12b connected to the negative electrode terminal.

  14A is a cross-sectional view of a surface of the short-circuit operating unit 120 perpendicular to the central axis of the cylinder, and FIG. 14B is a cross-sectional view of a surface of the short-circuit operating unit 120 along the central axis. FIG. 15 is a functional block diagram of the battery short-circuit system.

  The short-circuit operating unit 120 includes a short-circuit element member 113, a heater 30, a heat insulating member 40, a heating instruction circuit 31, and a heating temperature sensor 32.

  The short-circuit element member 113 includes a first electric conductor 15 that is electrically connected to the positive electrode terminal 131 through the positive electrode lead wire 11b, and a second electric conductor 16 that is electrically connected to the negative electrode terminal 132 through the negative electrode lead wire 12b. And a short-circuit layer 20 sandwiched between the first electric conductor 15 and the second electric conductor 16. That is, the positive electrode lead wire 11b, the negative electrode lead wire 12b, and the short circuit element member 113 function in the same manner as the battery short circuit element 10 of the first embodiment when combined. The first electric conductor 15, the second electric conductor 16, and the short-circuit layer 20 are the same in terms of materials and functions as those described in the first embodiment, and detailed descriptions thereof are omitted. To do. Moreover, you may employ | adopt the short circuit layer 20a demonstrated in the modification (1) of Embodiment 1 instead of the short circuit layer 20. FIG.

  The heater 30 has a cylindrical shape that surrounds the short-circuit element member 113, and is configured by a heating wire that is repeatedly wound in a coil shape, for example. The heater 30 generates Joule heat when an electric current is applied, and generates more heat as the electric current is increased.

  The heat insulating member 40 is a cylindrical member arranged outside the outer surface of the heater 30 and blocks external heat. The heat insulating member 40 prevents external heat from affecting the short-circuit element member 113. Specifically, the heat insulating member 40 prevents the short-circuit element member 113 from being short-circuited by heat from the outside.

  When the heating instruction circuit 31 receives a signal indicating that the battery is abnormal from the abnormality determination circuit 121, the heating instruction circuit 31 controls the heating amount of the heater 30 based on the detection value detected by the heating temperature sensor 32.

  The heating temperature sensor 32 is a temperature sensor that detects the temperature of the short-circuit element member 113, and includes, for example, a thermistor. The heating temperature sensor 32 is disposed inside the heater 30 and in contact with the short-circuit element member 113, and detects the temperature of the short-circuit element member 113.

  The abnormality determination circuit 121 functions as an abnormality determination unit, and when it is determined that there is an abnormality in the battery, transmits a signal to that effect to the heating instruction circuit 31. The abnormality determination circuit 121 includes a battery temperature sensor 122, and determines that the battery 200 is abnormal when the temperature of the battery detected by the battery temperature sensor 122 is equal to or higher than the abnormal temperature. The “abnormal temperature” here is a temperature set in advance corresponding to the battery 200 at the time of shipment, and is a temperature at which an abnormality has occurred in the battery 200.

  The battery temperature sensor 122 is a temperature sensor that detects the temperature of the battery 200, and is formed of, for example, a thermistor. The battery temperature sensor 122 is disposed in contact with the outside of the casing 102 of the battery 200 and detects the temperature of the casing 102 of the battery 200. The position where the battery temperature sensor 122 is arranged is not limited to the above, and may be inside the housing 102.

  The heating instruction circuit 31 has a heating instruction table 31a, and performs feedback control based on the temperature detected by the heating temperature sensor 32 so that the heater 30 reaches a predetermined temperature.

  According to this, when the abnormality determination circuit 121 determines that the battery is abnormal, the heating instruction circuit 31 starts energizing the heater 30 and causes the heater 30 to heat the short-circuit layer 20. Thus, in order to raise the temperature of the short circuit layer 20 by making the heater 30 heat without using the heat | fever concerning the temperature rise of the battery 200 at the time of abnormality, the position which arrange | positions the short circuit layer 20 is in contact with the battery 200. There is no need to place it in the position to be. For this reason, the position which arrange | positions the short circuit layer 20 can be freely set to the position etc. which do not contact the battery 200. Since the position of the short-circuit layer 20 can be freely set in this way, the short-circuit layer 20 can be arranged in an environment where there is little influence of heat from the outside.

  In addition, in order to melt the low melting point alloy 21 using the heat generated by the heater 30, for example, a low melting point alloy that has a high melting point that is hardly affected by external heat is employed. By heating to a temperature higher than the melting point, the low melting point metal 21 of the short-circuit layer 20 can be melted at an arbitrary timing to short-circuit the positive electrode and the negative electrode.

  Thereby, it is possible to prevent the positive electrode and the negative electrode of the battery from being short-circuited even when the abnormality of the battery is erroneously detected due to the influence of heat from the outside and no abnormality occurs in the battery.

(Modification of Embodiment 2)
(1)
In the battery short-circuit system 110 according to the second embodiment, the abnormality determination circuit 121 includes the battery temperature sensor 122 and determines the battery abnormality by detecting the temperature of the battery. However, the present invention is not limited to this.

  For example, like the abnormality determination circuit 121a of the battery short-circuit system 110a illustrated in FIG. 16, the abnormality determination circuit 121a may further include a temperature change detection unit 123a in addition to the battery temperature sensor 122a. The battery short-circuit system 110a is similar to the battery short-circuit system 110 of the second embodiment, except for the heater 30, heating instruction circuit 31, heating table 31a, heating temperature sensor 32, and short-circuit element member 113 other than the abnormality determination circuit 121a. Since there is, explanation is omitted. Also, the battery temperature sensor 122a is the same as the battery temperature sensor 122 of the battery short-circuit system 110 of the second embodiment, and thus the description thereof is omitted.

  The temperature change detection unit 123a detects the change in temperature of the battery 200 per unit time. Specifically, the temperature change detection unit 123a detects the temperature change rate by acquiring the temperature detected by the battery temperature sensor 122a every predetermined time.

  The abnormality determination circuit 121a is configured such that the temperature of the battery 200 detected by the battery temperature sensor 122a is equal to or higher than the abnormal temperature, and the change rate of the temperature per unit time of the battery 200 is equal to or higher than a predetermined change rate (that is, temperature increase rate). Is determined to be abnormal.

  As described above, the abnormality determination circuit 121a not only determines that the temperature of the battery 200 has reached the abnormal temperature, but also determines whether or not the temperature increase rate of the battery 200 has been reached. For example, it is possible to reduce erroneous detection of an abnormality in the battery 200 such that a temperature increase due to the influence of the outside air temperature is determined as an abnormality in the battery 200. For this reason, when there is no abnormality in the battery 200, it is possible to prevent the short-circuit element member 113 from being short-circuited, and it is possible to prevent the battery 200 from wastefully releasing energy.

(2)
Further, for example, as in the abnormality determination circuit 121b of the battery short-circuit system 110b shown in FIG. 17, the deformation amount of the casing 102 of the battery 200 is detected instead of the battery temperature sensor 122 of the abnormality determination circuit 121 of the second embodiment. A strain gauge 122b as a deformation amount detection unit may be used. The battery short-circuit system 110b is similar to the battery short-circuit system 110 of the second embodiment except for the heater 30, the heating instruction circuit 31, the heating table 31a, the heating temperature sensor 32, and the short-circuit element member 113 other than the abnormality determination circuit 121b. Since there is, explanation is omitted. This is based on the fact that when an abnormality occurs in the battery 200, the pressure inside the casing 102 of the battery 200 increases and the casing 102 may expand.

  Thereby, the effect equivalent to the battery short circuit system 110 of Embodiment 2 can be acquired. The deformation amount detection unit is not limited to the strain gauge 122b. For example, the deformation amount detection unit detects a pressure applied to the housing 102 from the power generation element 101, the current collector 104, and the like inside the housing 102. It may be realized by detecting the amount of deformation of the casing 102 of the battery 200 by being provided inside the body 102.

(3)
Further, for example, as in the abnormality determination circuit 121c of the battery short-circuit system 110c illustrated in FIG. 18, the abnormality determination circuit 121c may further include a deformation speed detection unit 123c in addition to the strain gauge 122b. The battery short-circuit system 110c is similar to the battery short-circuit system 110 of the second embodiment except for the heater 30, the heating instruction circuit 31, the heating table 31a, the heating temperature sensor 32, and the short-circuit element member 113 other than the abnormality determination circuit 121c. Since there is, explanation is omitted. Further, the strain gauge 122c is the same as the strain gauge 122c of the battery short-circuit system 110b of the modification (2) of the second embodiment, and the description thereof is omitted.

  The deformation speed detection unit 123c detects a deformation speed that is a deformation amount of the casing 102 of the battery 200 per unit time. Specifically, the deformation speed detection unit 123c obtains the deformation amount of the housing 102 detected by the strain gauge 122c every predetermined time, thereby obtaining the deformation amount of the housing 102 of the battery 200 per unit time. Detect deformation speed.

  The abnormality determination circuit 121c has a deformation amount of the casing 102 of the battery 200 detected by the strain gauge 122c equal to or greater than a predetermined deformation amount, and the deformation speed of the battery 200 detected by the deformation speed detection unit 123c is a predetermined value. When the deformation speed is exceeded, it is determined that the battery 200 is abnormal.

  As described above, the abnormality determination circuit 121c not only determines whether the deformation amount of the casing 102 of the battery 200 has reached a predetermined deformation amount, but also whether or not the deformation speed of the battery 200 has been reached. Therefore, it is possible to reduce erroneous detection of an abnormality in the battery 200 such that, for example, an increase in deformation due to the influence of the outside air temperature is determined as an abnormality in the battery 200. For this reason, when there is no abnormality in the battery 200, it is possible to prevent the short-circuit element member 113 from being short-circuited, and it is possible to prevent the battery 200 from wastefully releasing energy.

(4)
Although the short-circuit layer 20 constituting the short-circuit element member 113 inside the short-circuit operating unit 120 of the second embodiment is composed of one type of low-melting-point alloy layer 21, the short-circuit layer 20 is not necessarily adopted. For example, you may employ | adopt the short circuit layer 20b or the short circuit layer 20c which has several types of low melting-point alloy which has different melting | fusing point as demonstrated in the modification (2) of Embodiment 1. FIG. FIG. 19 is a diagram illustrating the short-circuit operating unit 120a when the short-circuit layer 20c is employed. Here, the illustration in the case of employing the short-circuit layer 20b is omitted.

  If a plurality of low melting point metals having different melting points are used for the short-circuit layer 20c in the short-circuit operating unit 120a, for example, the abnormality determination circuit 121 determines the abnormality of the battery step by step, and the heating instruction circuit 31 sets the temperature of the heater 30. By controlling in steps according to the degree of abnormality, the region where the first electrical conductor 15 and the second electrical conductor 16 that are short-circuited by the short-circuit layer 20c of the short-circuit element member 113 are electrically connected is staged. Can be increased. That is, according to the temperature of the battery 200, the amount of current that flows when the first electrical conductor 15 and the second electrical conductor 16 are short-circuited can be adjusted stepwise. As a result, when the rate of temperature rise is large, it is possible to discharge stably by passing a large current quickly, and when the rate of temperature rise is small, it should be short-circuited at a minimum so as not to discharge more than necessary by flowing a small current. The amount of discharge can be suppressed.

(5)
As the battery temperature sensor 122 of the second embodiment, a thermistor is used. However, the present invention is not limited to this. For example, the short-circuit layer 20b or the short-circuit layer 20c using a plurality of low-melting-point metals having different melting points is used. You may employ | adopt the employ | adopted battery short circuit element.

(Other embodiments)
(1)
In the battery short-circuit element 10 of the above-described embodiment, the first electric conductor 15 and the second electric conductor 16 are made of aluminum. However, the present invention is not limited thereto, and any material having high thermal conductivity may be used. For example, at least one of the first electrical conductor 15 and the second electrical conductor 16 can be selected from aluminum, nickel, iron, copper, stainless steel, and other metallic materials. Similarly, the positive electrode connecting member 11 and the negative electrode connecting member 12 are made of aluminum. However, the present invention is not limited thereto, and any material having high thermal conductivity may be used. For example, at least one of the positive electrode connection member 11 and the negative electrode connection member 12 may be any one that can be selected from aluminum, nickel, iron, copper, stainless steel, and other metal materials.

(2)
The battery short-circuit element 10 of the above-described embodiment is for short-circuiting the negative electrode terminal 132 and the positive electrode terminal 131 of one battery 100. However, the battery short-circuit element 10 is not limited to one battery 100, but is a combination of a plurality of batteries. May be applied. For example, the battery short-circuit element 10 may be applied to a battery system in which a plurality of batteries are connected in series, or all of the batteries or a plurality of batteries in a battery system in which a plurality of batteries are connected in parallel. You may apply by using a short circuit element between batteries, and may apply with respect to the battery system in which the some battery was connected in series and parallel.

(3)
In the battery 100 of the above embodiment, the negative electrode terminal 132 and the positive electrode terminal 131 are connected to each other so that they can be short-circuited by one battery short-circuiting element 10. And between the positive terminal 131 and the housing 102 may be connected to each other by a single battery short-circuit element 10. The housing 102 is made of, for example, a metal member having electrical conductivity. For this reason, even in the above configuration, when abnormal heat is generated in the battery 100, the negative electrode terminal 132 and the housing 102 are short-circuited, and the positive electrode terminal 131 and the housing 102 are short-circuited. The negative electrode terminal 132 and the positive electrode terminal 131 can be short-circuited. In addition, by connecting the negative electrode terminal 132 and the positive electrode terminal 131 in such a manner that the two battery short-circuit elements 10 can be short-circuited in this way, even if one battery short-circuit element 10 is short-circuited due to some abnormality, it is normal. It is possible to prevent the battery 100 in a short state from being short-circuited and discharged.

(4)
Although not particularly mentioned in the battery short-circuit element 10 of the above-described embodiment, for example, a thermo tape whose color changes when the temperature reaches a certain temperature or more may be attached to the surface of the short-circuit element member 13. As described above, by configuring the battery short-circuit element 10, the change in color of the thermo tape is used as an index for determining whether or not the battery short-circuit element 10 is activated due to an abnormality in the battery 100. Can do.

(5)
In the battery short-circuit element 10 of the above embodiment, the first electric conductor 15 is connected to the positive electrode terminal 131 via the positive electrode connecting member 11, and the second electric conductor 16 is connected to the negative electrode terminal 132 via the negative electrode connecting member 12. However, the present invention is not limited to this, and the first electric conductor 15 may be connected to the negative terminal 132 and the second electric conductor 16 may be connected to the positive terminal 131.

  The present invention ensures that the positive electrode terminal and the negative electrode terminal are short-circuited and the battery is safe only when an abnormality occurs in the battery, the temperature inside the battery rises excessively, or the internal pressure of the battery rises excessively. It can be used as a battery short-circuit element, a battery, a battery system, etc.

10, 10a, 10b, 10c Battery short-circuit element 11, 11a Positive electrode connection member 11b Positive electrode lead wire 12, 12a Negative electrode connection member 12b Negative electrode lead wire 13, 13a, 13b, 113 Short-circuit element member 15 First electric conductor 16 Second electric Conductor 20, 20a, 20b, 20c, 20d Short-circuit layer 21, 21A, 21B Low melting point alloy layer 21a First low melting point alloy layer 21b Second low melting point alloy layer 21c Third low melting point alloy layer 21d Fourth low melting point alloy layer DESCRIPTION OF SYMBOLS 22 Insulator film 22A Insulator coating 22B Insulator layer 30 Heater 31 Heating instruction circuit 31a Heating instruction table 32 Heating temperature sensor 40 Heat insulation member 41 Positive electrode side connection part 42 Negative electrode side connection part 100, 200 Battery 101 Power generation element 102 Case 103 Electrode terminal 104 Current collecting member 131 Positive electrode terminal 132 Negative electrode terminal 41 the positive current collector 142 negative electrode current collector member

Claims (20)

A battery short-circuit element connected to a battery having a first electrode and a second electrode,
A first electrical conductor electrically connected to the first electrode side;
A second electrical conductor electrically connected to the second electrode side;
An insulator disposed between the first electrical conductor and the second electrical conductor; a low melting point alloy layer disposed between the first electrical conductor and the second electrical conductor; A short-circuit layer having
With
The short-circuit layer insulates the first electric conductor and the second electric conductor below a predetermined temperature, and at least a part or all of the low melting point alloy layer melts above the predetermined temperature, A battery short-circuit element that short-circuits the first electrical conductor and the second electrical conductor. The insulator has an opening,
The battery according to claim 1, wherein the short-circuit layer short-circuits the first electric conductor and the second electric conductor by melting the low-melting-point alloy layer and flowing into the opening of the insulator. Short circuit element. The short-circuit layer short-circuits the first electrical conductor and the second electrical conductor by melting the low-melting-point alloy layer and deforming part or all of the insulator. The battery short-circuit element according to 1. The battery short-circuit element according to any one of claims 1 to 3, wherein the short-circuit layer is formed by laminating the insulator and the low-melting-point alloy layer. The battery short-circuit element according to any one of claims 1 to 3, wherein the short-circuit layer is formed by coating the low-melting-point alloy layer with the insulator. The battery short-circuit element according to any one of claims 1 to 5, wherein the first electric conductor and the second electric conductor are formed of a foil-like member or a plate-like member. The battery short-circuit element according to claim 6, wherein the first electric conductor and the second electric conductor are formed by being wound in a state of being stacked via the short-circuit layer. The battery short-circuit element according to claim 6, wherein the first electric conductor and the second electric conductor are formed by being folded in a bellows shape in a state of being stacked via the short-circuit layer. The first electric conductor and the second electric conductor are made of a cylindrical member, and one of the first electric conductor and the second electric conductor is disposed so as to overlap the other. Item 6. The battery short-circuit element according to any one of Items 1 to 5. The cylindrical member disposed inside the first electric conductor and the second electric conductor is formed by rolling a plate-shaped metal member so as to surround the central axis of the cylindrical member. The battery short-circuit element according to claim 9. The short-circuit layer is arranged in a first short-circuit region where the low-melting-point alloy layer is a part of the short-circuit region, and a first low-melting-point alloy layer whose melting point is a first temperature, The second low-melting-point alloy layer, which is disposed in a second short-circuit region that is a region different from the first short-circuit region, and has a melting point that is a second temperature different from the first temperature. The battery short-circuit element according to any one of claims. The battery short-circuit element according to any one of claims 1 to 11,
An abnormality determination unit for determining an abnormality of the battery;
A heating unit for increasing the temperature of the short-circuit layer;
A heating instruction unit that causes the heating unit to perform heating when the abnormality determination unit determines that the battery is abnormal;
Battery short circuit system. The abnormality determination unit
A temperature detection unit for detecting the temperature of the battery;
The battery short-circuit system according to claim 12, wherein the battery is determined to be abnormal when the temperature of the battery detected by the temperature detection unit is equal to or higher than an abnormal temperature. The abnormality determination unit
A temperature detector for detecting the temperature of the battery;
A temperature change detecting unit for detecting a change in temperature per unit time of the battery,
The temperature of the battery detected by the temperature detection unit is equal to or higher than an abnormal temperature, and the change in temperature of the battery per unit time detected by the temperature change detection unit is equal to or higher than a predetermined change rate. The battery short-circuit system according to claim 12, wherein the battery is determined to be abnormal. The abnormality determination unit
A deformation amount detection unit for detecting a deformation amount of the battery case;
The battery short-circuit system according to claim 12, wherein the battery is determined to be abnormal when the deformation amount of the battery detected by the deformation amount detection unit is equal to or greater than a predetermined deformation amount. The abnormality determination unit
A deformation amount detection unit for detecting a deformation amount of the battery casing;
A deformation speed detection unit that detects a deformation speed that is a deformation amount of the battery casing per unit time, and
The deformation amount of the battery casing detected by the deformation amount detection unit is greater than or equal to a predetermined deformation amount, and the deformation rate of the battery detected by the deformation rate detection unit is greater than or equal to a predetermined deformation rate. The battery short-circuit system according to claim 12, wherein the battery is determined to be abnormal when the battery is abnormal. A first electrode;
A second electrode;
The battery short-circuit element according to any one of claims 1 to 11,
A battery comprising: A first electrode;
A second electrode;
The battery short-circuit system according to any one of claims 12 to 16,
A battery comprising: A battery group in which a plurality of batteries are connected in series and / or in parallel;
The battery short-circuit element according to any one of claims 1 to 11,
A battery system comprising: A battery group in which a plurality of batteries are connected in series and / or in parallel;
The battery short-circuit system according to any one of claims 12 to 16,
A battery system comprising:

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