JP2016164850A - Power storage element and mobile unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage element which comprises a case and an electrode body housed in the case which is high in safety.SOLUTION: A power storage element comprises: a positive electrode terminal; an electrode body; a positive electrode collector connected to the electrode body; and a case housing the electrode body and the positive electrode collector, and further comprises: a conductive member 300 electrically connecting the positive electrode collector and the positive electrode terminal; a projection member 820 that is disposed at a position opposite to the conductive member 300, and includes a projection 821 projecting in a direction of the conductive member 300; and a housing 810 housing the projection member 820 and a gas generating agent 850 that allows the projection member 820 to be moved in the direction of the conductive member 300 by increasing a volume under a predetermined condition.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an electricity storage device including an electrode body and a current collector connected to the electrode body housed in a container.

  In recent years, development of an electric vehicle (EV), a plug-in hybrid electric vehicle (PHEV), a hybrid electric vehicle (HEV), and the like using a power storage element such as a lithium ion secondary battery as a power source has been promoted. Such an electricity storage element generally includes an electrode body having a positive electrode and a negative electrode, and a container for housing the electrode body.

  In addition, in a power storage element such as a lithium ion secondary battery, for example, due to overcharging, a part of the electrolytic solution in the container is vaporized, which may increase the internal pressure of the container.

  In the storage battery safety device disclosed in Patent Document 1, the pressure sensitive means is reversed when the internal pressure of the exterior case increases. As a result, the charge / discharge lead connecting the electrode element and the positive electrode terminal is cut. As a result, the subsequent increase in internal pressure is prevented. Further, the charge / discharge lead is composed of a brittle substrate made of glass or the like and a conductor printed on the brittle substrate, thereby enabling easy cutting of the charge / discharge lead.

JP-A-8-162094

  When a brittle base material such as glass is used as the base material for the charge / discharge lead as in the above conventional technique, the charge / discharge lead can be easily or reliably cut, but against vibration or impact. Problems with resistance can arise.

  For this reason, for example, a storage battery safety device according to the above-described conventional technology is not suitable for a storage element placed in an environment where intense vibration or strong impact can be applied, such as a storage element mounted on an automobile.

  Also, when a material with high mechanical strength is used as the base material of the conductive member that is cut by the member that reverses due to the internal pressure of the container (reversing member), for example, by increasing the thickness of the reversing member It is necessary to increase the force generated by the reversal of the member. However, in this case, there arises a problem that the reversing member is not easily reversed.

  Further, in the structure in which the conductive member is cut by directly using the force generated when the reversing member is reversed, the reversing operation varies depending on the rising speed or amount of the internal pressure. Variations are likely to occur in cutting timing or success or failure.

  In consideration of the above-described conventional problems, the present invention provides a power storage element including a container and an electrode body accommodated in the container, and provides a highly safe power storage element and a mobile body including the power storage element. With the goal.

  In order to achieve the above object, a power storage element according to one embodiment of the present invention houses an electrode terminal, an electrode body, a current collector connected to the electrode body, the electrode body, and the current collector. A power storage element including a container, the conductive member electrically connecting the current collector and the electrode terminal, and a protrusion disposed in a position facing the conductive member and projecting in the direction of the conductive member A protrusion member; and a housing that houses the protrusion member and a substance that moves the protrusion member in the direction of the conductive member by increasing the volume under a predetermined condition.

  According to this configuration, the protruding member having the protrusion directed toward the conductive member is disposed at a position facing the conductive member that electrically connects the current collector and the electrode terminal. The protruding member is accommodated in the casing, and the substance in the casing is moved in the direction of the conductive member by increasing the volume under a predetermined condition. Thereby, the protrusion of the protruding member can protrude from, for example, a hole of the housing and push the conductive member, and as a result, the conductive member is broken.

  That is, for example, the electrical connection between the electrode body and the electrode terminal can be mechanically disconnected by utilizing the expansion of the volume of a substance (such as a gas generating agent) whose volume is increased by a chemical reaction. Therefore, even when the strength of the conductive member is relatively large, the conductive member can be broken. Further, for example, the conductive member can be broken with a constant force that does not depend on the amount of increase or the rate of increase of the internal pressure of the container.

  Therefore, according to the electricity storage device according to this aspect, it is possible to maintain or improve the reliability of the conductive member during normal use and to mechanically cut off the continuity in an emergency.

  Thus, the power storage device according to this aspect is a power storage device including a container and an electrode body accommodated in the container, and is a highly safe power storage device.

  In the power storage element according to one embodiment of the present invention, the housing may further include a heat generating portion, and the substance may increase the volume when the heat generating portion generates heat.

  According to this structure, the element (heat generating part) for increasing the volume of the substance accommodated in the housing can be realized with a simple structure such as a nichrome coil.

  The power storage device according to one embodiment of the present invention further includes a displacement portion that is displaced by receiving an internal pressure of the container, and a switch portion that supplies current to the heat generating portion by the displacement portion being displaced. It may be provided.

  According to this configuration, for example, when the internal pressure of the container rises due to overcharge, the displacement part is displaced, so that a current is supplied to the heat generating part by the switch part. The member is broken.

  That is, the power storage element can detect the change in its own state and execute the breaking of the conductive member. Further, since the increase in the internal pressure is only used for the operation of the switch part, for example, the displacement part can be provided in a shape and size that easily reacts to the increase in the internal pressure. Thereby, for example, the conductive member can be reliably broken when the internal pressure of the container increases.

  Further, in the power storage device according to one aspect of the present invention, the switch unit is two contact units arranged at a predetermined interval, and one of the two contact units is connected to the heat generating unit. The switch part is a state in which the displacement part displaced by the internal pressure of the container comes into contact with the two contact parts, so that one of the currents flowing between the electrode body and the electrode terminal is Part may be supplied to the heat generating part.

  According to this structure, the displacement part which received the internal pressure of the container and was displaced functions as a member which conducts two contact points. That is, the displacement unit can turn on the switch unit. In addition, since the switch unit supplies a part of the current flowing in the power storage element to the heat generating unit, the power storage element mechanically connects the electrode body and the electrode terminal using, for example, power stored in itself. Can be cut.

  Further, in the energy storage device according to one embodiment of the present invention, the switch unit includes two contact portions that are arranged at a predetermined interval and are electrically connected to the heat generating unit, and the switch unit includes: Even if a part of the current flowing through the conductive member is supplied to the heat generating portion by the displacement portion displaced by receiving the internal pressure of the container, the two contact portions are in contact with the conductive member. Good.

  According to this structure, the displacement part which received the internal pressure and was displaced functions as a member which conducts an electroconductive member and two contact points. That is, the displacement part displaced by the internal pressure can turn on the switch part. In addition, since the switch unit supplies a part of the current flowing in the power storage element to the heat generating unit, the power storage element mechanically connects the electrode body and the electrode terminal using, for example, power stored in itself. Can be cut.

  Further, in the energy storage device according to one embodiment of the present invention, the protrusion is further provided between a portion of the conductive member that is pressed by the protrusion and an electrical connection portion of the current collector or the electrode terminal. It is good also as providing the contact part contact | abutted to the said electrically-conductive member from the opposite side.

  According to this configuration, the contact portion that contacts the conductive member is disposed on the side of the conductive member opposite to the protruding member. The position of the contact portion is a position corresponding to the side of the portion pressed by the protrusion of the protrusion member in the conduction direction of the conductive member.

  That is, a load from the protrusion of the protrusion member is applied to a part of the conductive member, and the position of the side part of the part is restricted by contacting the contact part.

  Accordingly, the conductive member can be efficiently broken (shear broken) by the protrusion and the contact portion of the protrusion member. Therefore, it is possible to ensure the breaking of the conductive member (mechanical cutting of conduction) when the protruding member moves.

  Further, in the energy storage device according to one embodiment of the present invention, the conductive member is weak in a part between an electrical connection portion with the current collector and an electrical connection portion with the electrode terminal. It may have a part.

  According to this structure, a weak part is provided in a part of electrically-conductive member, and, thereby, the fracture | rupture of the electrically-conductive member when a protrusion member moves is ensured more.

  In addition, it becomes possible to limit the position where the conductive member is broken to the position of the fragile portion.From this, for example, when the conductive member is pushed by a protrusion, the conductive member cracks at an unexpected position, Thereby, generation | occurrence | production of malfunctions, such as failure of a fracture | rupture of an electrically-conductive member, is suppressed.

  A moving body according to one embodiment of the present invention includes the power storage element according to any one of the above embodiments and an airbag, and the substance increases the volume when the airbag is activated.

  According to this configuration, the conductive member included in the power storage element can be broken in conjunction with the airbag. Accordingly, when an event such as a collision accident that causes the airbag to operate occurs in the moving body, it is possible to prevent occurrence of problems such as abnormal heat generation of the power storage element.

  ADVANTAGE OF THE INVENTION According to this invention, it is an electrical storage element provided with a container and the electrode body accommodated in the container, Comprising: A highly safe electrical storage element and a mobile body provided with the said electrical storage element can be provided.

It is a perspective view which shows the external appearance of the electrical storage element in embodiment. It is a perspective view which shows each component with which the main body of the container of the electrical storage element in embodiment isolate | separated and with which an electrical storage element is provided. It is sectional drawing which shows the structure of the periphery of the positive electrode terminal of the electrical storage element in embodiment. It is a disassembled perspective view which shows the structure of the periphery of the positive electrode terminal of the electrical storage element in embodiment. It is a perspective view which shows the external appearance of the electrically-conductive member in embodiment. It is sectional drawing which shows the structure outline | summary of the safety mechanism in embodiment. It is a 1st figure which shows the operation example of the safety mechanism in embodiment. It is a 2nd figure which shows the operation example of the safety mechanism in embodiment. It is sectional drawing which shows the structure outline | summary of the safety mechanism in the modification of embodiment. It is a 1st figure which shows the operation example of the safety mechanism in the modification of embodiment. It is a 2nd figure which shows the operation example of the safety mechanism in the modification of embodiment.

  Hereinafter, a power storage device according to an embodiment of the present invention will be described with reference to the drawings. Each figure is a schematic diagram and is not necessarily illustrated exactly.

  In addition, each of the embodiments and modifications thereof described below shows a specific example of the present invention. The shapes, materials, constituent elements, arrangement positions and connecting forms of constituent elements, order of manufacturing steps, and the like shown in the following embodiments and modifications thereof are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments and modifications thereof, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

  Furthermore, in the following description and drawings, the winding axis direction of the electrode body of the electricity storage element is defined as the X-axis direction. That is, the X-axis direction can be defined as the direction in which the current collectors or electrode terminals are arranged or the direction in which the short side surface of the container faces. Further, the vertical direction of the power storage element is defined as the Z-axis direction. That is, the Z-axis direction can be defined as the direction in which the legs of the current collector extend or the longitudinal direction of the short side surface of the container. A direction intersecting with the X-axis direction and the Z-axis direction is defined as a Y-axis direction. That is, the Y-axis direction can be defined as the opposing direction of the long side of the container, the short direction of the short side of the container, or the thickness direction of the container.

  First, with reference to FIGS. 1 and 2, a general description of the power storage element 10 in the embodiment will be given.

  FIG. 1 is a perspective view showing an external appearance of a power storage element 10 according to the embodiment. FIG. 2 is a perspective view showing each component included in power storage device 10 by separating main body 120 of container 100 of power storage device 10 in the embodiment.

  The power storage element 10 is a secondary battery that can charge electricity and discharge electricity, and more specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery.

  The power storage element 10 is mounted on, for example, an electric vehicle (EV), a plug-in hybrid electric vehicle (PHEV), a hybrid electric vehicle (HEV), or the like.

  In addition, the electrical storage element 10 is not limited to a nonaqueous electrolyte secondary battery, A secondary battery other than a nonaqueous electrolyte secondary battery may be sufficient, and a capacitor may be sufficient as it.

  As shown in these drawings, the electricity storage device 10 includes a container 100, a positive electrode terminal 200, a negative electrode terminal 400, and upper insulating members 250 and 450. In addition, the positive electrode current collector 500, the negative electrode current collector 600, and the electrode body 700 are accommodated in the internal space S <b> 1 of the container 100.

  In addition, a liquid such as an electrolytic solution (non-aqueous electrolyte) is sealed inside the container 100 of the electricity storage element 10, but the illustration of the liquid is omitted. In addition, as long as it does not impair the performance of the electrical storage element 10, as the electrolyte solution enclosed with the container 100, there is no restriction | limiting in particular and various things can be selected.

  The container 100 includes a main body 120 having a rectangular cylindrical shape and a bottom, and a lid 110 that is a plate-like member that closes the opening of the main body 120. In addition, the container 100 can be hermetically sealed by welding the lid body 110 and the main body 120 after the electrode body 700 and the like are accommodated therein. In addition, although the kind of material which forms the cover body 110 and the main body 120 is not specifically limited, For example, it is preferable that they are weldable metals, such as stainless steel, aluminum, and aluminum alloy.

  The electrode body 700 includes a positive electrode, a negative electrode, and a separator, and is a member that can store electricity. In the positive electrode, a positive electrode active material layer is formed on a positive electrode base material layer which is a long strip-shaped metal foil made of aluminum or an aluminum alloy. Further, the negative electrode is obtained by forming a negative electrode active material layer on a negative electrode base material layer that is a long strip-shaped metal foil made of copper, a copper alloy, or the like. The separator is a microporous sheet made of resin.

  As the positive electrode active material used for the positive electrode active material layer or the negative electrode active material layer used for the negative electrode active material layer, any known material can be used as long as it is a positive electrode active material or negative electrode active material capable of occluding and releasing lithium ions. .

  The electrode body 700 is formed by winding a core (not shown) in a layered manner so that a separator is sandwiched between a positive electrode and a negative electrode. That is, in the present embodiment, the electrode body 700 is a wound electrode body. In FIG. 2, the shape of the electrode body 700 is oval, but it may be circular or elliptical. Further, the shape of the electrode body 700 is not limited to the winding type, and may be a shape in which flat plate plates are laminated.

  The electrode body 700 includes a positive electrode connection portion 701 that is an end portion on the positive electrode side and a negative electrode connection portion 702 that is an end portion on the negative electrode side. The positive electrode connecting portion 701 is an end portion on the positive electrode side of the electrode body 700 in which the positive electrode active material layer non-forming portions are stacked and bundled, and the negative electrode connecting portion 702 is a negative electrode active material layer non-forming portion laminated. This is the end of the electrode body 700 on the negative electrode side that is bundled.

  The positive electrode active material layer non-forming portion is a portion of the positive electrode where the positive electrode active material is not coated and the positive electrode base material layer is exposed, and the negative electrode active material layer non-forming portion is a negative electrode of the negative electrode. The active material is not applied and the negative electrode base material layer is exposed.

  Further, the positive terminal 200 is attached to the lid 110 via the upper insulating member 250. The negative terminal 400 is attached to the lid 110 via the upper insulating member 450.

  The upper insulating members 250 and 450 are disposed between the electrode terminals and the container 100 and are insulating members that insulate the electrode terminals from the container 100. Specifically, the upper insulating member 250 is disposed between the positive electrode terminal 200 and the lid body 110 of the container 100, and the upper insulating member 450 is disposed between the negative electrode terminal 400 and the lid body 110. The upper insulating members 250 and 450 are made of a resin such as polyphenylene sulfide (PPS) or polypropylene (PP), for example.

  The upper insulating member 250 in the present embodiment includes a first insulating member 260 and a second insulating member 270. Between the first insulating member 260 and the second insulating member 270, a conductive member that can be broken or melted is disposed, and a mechanism (safety mechanism) that includes the conductive member and breaks the conduction path in the electric storage element 10 is provided. It is disposed below the positive electrode terminal 200. Details of the safety mechanism in the present embodiment will be described later with reference to FIGS.

  The positive electrode current collector 500 is disposed between the positive electrode of the electrode body 700 and the side wall of the main body 120 of the container 100, and has electrical conductivity and rigidity that are electrically connected to the positive electrode terminal 200 and the positive electrode of the electrode body 700. It is a member provided. The positive electrode current collector 500 is formed of aluminum, an aluminum alloy, or the like, like the positive electrode base material layer of the electrode body 700.

  The negative electrode current collector 600 is disposed between the negative electrode of the electrode body 700 and the side wall of the main body 120 of the container 100, and has conductivity and rigidity that are electrically connected to the negative electrode terminal 400 and the negative electrode of the electrode body 700. It is a member provided. The negative electrode current collector 600 is formed of copper, a copper alloy, or the like, like the negative electrode base material layer of the electrode body 700.

  A lower insulating member is disposed on the opposite side of the upper insulating members 250 and 450 with the lid 110 interposed therebetween, so that the positive electrode current collector 500 and the negative electrode current collector 600 and the container 100 are electrically connected. Is electrically insulated.

  Next, a safety mechanism and its surrounding structure, which are features of the electricity storage device 10 in the embodiment, will be described with reference to FIGS. In the present embodiment, since a safety mechanism is arranged on the positive electrode side, only the structure around the positive electrode terminal 200 will be described below. About the structure of the periphery of the negative electrode terminal 400, the same structure as the past may be employ | adopted, and the same structure as the periphery of the positive electrode terminal 200 demonstrated below may be employ | adopted.

  FIG. 3 is a cross-sectional view illustrating a structure around the positive electrode terminal 200 of the electricity storage device 10 according to the embodiment. Specifically, FIG. 3 illustrates a III-III cross section of the electricity storage device 10 illustrated in FIG. 2, and the electrode body 700 is not illustrated.

  FIG. 4 is an exploded perspective view showing a structure around the positive electrode terminal 200 of the electricity storage device 10 according to the embodiment.

  FIG. 5 is a perspective view showing an external appearance of the conductive member 300 in the embodiment, and FIG. 6 is a cross-sectional view showing a configuration outline of the safety mechanism 180 in the embodiment.

  FIG. 6 shows an enlarged view of a part of the cross section at the same position as the cross section shown in FIG. Further, the safety device 800 is simply illustrated for explanation of the operation principle, and a conduction path through which a current for operation flows is illustrated by a dotted line. 6 are applied also to FIGS. 7 and 8 described later, and FIGS. 9 to 11 showing a safety mechanism 181 according to a modification of the present embodiment.

  The power storage element 10 in the present embodiment includes a safety mechanism 180 that is a mechanism that cuts off a conduction path of the power storage element 10. The safety mechanism 180 includes a conductive member 300 and a safety device 800.

  Specifically, as shown in FIGS. 3 and 4, in the power storage element 10, the positive electrode current collector 500 and the positive electrode terminal 200 are electrically connected via the conductive member 300 and the discharge terminal 290. .

  A safety device 800 is disposed at a position facing the conductive member 300. The safety device 800 operates to cause the protrusion 821 to project when the displacement portion 281 disposed below the safety device 800 is displaced, whereby the conductive member 300 is broken. As a result, the continuity between the positive electrode current collector 500 and the positive electrode terminal 200 is cut off, and for example, charging of the power storage element 10 that has fallen into an overcharge state is stopped.

  The safety mechanism 180 operating in this way and the surrounding structure will be described in detail below.

  In the electricity storage device 10 of the present exemplary embodiment, the upper insulating member 250 including the first insulating member 260 and the second insulating member 270 is disposed on the top of the lid 110, and the positive electrode terminal is disposed on the upper surface of the second insulating member 270. 200 is arranged.

  A fixing part 116 projects from the lid 110, and the fixing part 116 is caulked while passing through the through hole 264 of the first insulating member 260. Thereby, the first insulating member 260 is fixed to the lid 110. In FIG. 4, the fixed portion 116 is shown after being swaged.

  The first insulating member 260 is provided with a plurality of protrusions 261, and each of the plurality of protrusions 261 penetrates the through hole 271 of the second insulating member 270 and the through hole 201 of the positive electrode terminal 200. It is heat squeezed in the state. Thereby, the second insulating member 270 is fixed to the first insulating member 260. FIG. 4 shows a state after each of the plurality of projecting portions 261 has been subjected to heat caulking.

  The first insulating member 260 is further provided with a breaking opening 263 that forms a space in which the safety device 800 is disposed.

  Further, between the first insulating member 260 and the second insulating member 270, the discharging terminal 290 and the conductive member 300 are disposed.

  The discharge terminal 290 is a member that is electrically connected to the positive electrode current collector 500 and at least a part of which is disposed outside the container 100. The discharge terminal 290 is used to discharge the electric power accumulated in the electrode body 700 when the conduction between the electrode body 700 and the positive electrode terminal 200 is interrupted by breaking the conductive member 300 or the like. Terminal. The upper insulating member 250 covering the discharge terminal 290 is provided with a discharge opening 265 so that the discharge terminal 290 can be accessed from the outside.

  That is, since the discharge terminal 290 used as an emergency electrode terminal plays a role of electrical connection between the positive electrode current collector 500 and the conductive member 300, for example, without complicating the structure of the power storage element 10. A mechanism for eliminating the overcharge state can be provided.

  Similarly to the positive electrode base material layer of the electrode body 700, the discharge terminal 290 is a member formed of aluminum or an aluminum alloy, the first connection portion 291 connected to the conductive member 300, and the positive electrode current collector. 500 and a second connection portion 292 connected to 500.

  The first connection portion 291 and the first end portion 301 that is one end portion of both ends in the conduction direction of the conductive member 300 (same as the longitudinal direction of the conductive member 300 in the present embodiment) are joined, Thereby, the discharge terminal 290 and the conductive member 300 are mechanically and electrically connected.

  The second connection portion 292 is connected to a through hole (not shown) provided in the first insulating member 260, a through hole 113 provided in the lid 110, and the terminal connection portion 510 of the positive electrode current collector 500. It penetrates the provided through-hole 511 and is caulked in this state. Thereby, the positive electrode current collector 500 and the discharge terminal 290 are mechanically and electrically connected. In FIG. 4, the second connecting portion 292 is shown after being swaged.

  Further, as shown in FIG. 3, a lower insulating member 255 is disposed between the terminal connecting portion 510 and the lid 110, whereby the positive electrode current collector 500 and the lid 110 (container 100) are electrically connected. Insulated.

  The positive electrode current collector 500 has a pair of leg portions 520 extending from the terminal connection portion 510 in the direction of the electrode body 700, and the pair of leg portions 520 and the positive electrode connection portion 701 (see FIG. 2) is joined by ultrasonic welding or the like. Thereby, the positive electrode current collector 500 and the electrode body 700 are mechanically and electrically connected.

  Of the both ends in the conduction direction of the conductive member 300, the second end 302, which is the end opposite to the first end 301, passes through the conduction opening 272 provided in the second insulating member 270. The positive electrode terminal 200 is joined. Thereby, the conductive member 300 and the positive electrode terminal 200 are mechanically and electrically connected.

  Note that various methods such as laser welding, spot welding, and clinch bonding may be employed as a method for joining the discharge terminal 290 and the conductive member 300 and a method for joining the conductive member 300 and the positive electrode terminal 200. .

  In the present embodiment, a conductive path between the positive electrode current collector 500 and the positive electrode terminal 200 is formed by the above structure, and a part of the conductive path is formed by the conductive member 300.

  Specifically, the conductive member 300 is a member that electrically connects the positive electrode current collector 500 and the positive electrode terminal 200, and is disposed outside the container 100.

  The conductive member 300 is made of a metal such as aluminum or an aluminum alloy, has a predetermined strength as a whole, and partially has a fragile portion 305.

  Specifically, the conductive member 300 includes an electrical connection portion between the positive electrode current collector 500 (first end portion 301 in this embodiment) and an electrical connection portion between the positive electrode terminal 200 (this embodiment). In a form, it has the weak part 305 with a smaller cross-sectional area than the other part in a part between 2nd ends 302).

  More specifically, as shown in FIG. 5, the conductive member 300 has a plate shape, and the thickness of the fragile portion 305 is smaller than the thickness of other portions. That is, the weak part 305 which is a mechanically weak part is provided by making a part of metal conductive member 300 thin.

  In the present embodiment, the fragile portion 305 is provided with a groove 305a on the upper surface 300a of the conductive member 300 opposite to the safety device 800, as shown in FIGS. 3 and 5, for example. It is formed with.

  That is, by forming the groove 305 a extending in the direction intersecting the conduction direction in the conductive member 300 on the upper surface 300 a of the conductive member 300, the linear fragile portion 305 is provided in the conductive member 300.

  In this way, by forming the weakened portion 305 by the groove 305a provided in the conductive member 300, for example, the position where the conductive member 300 is divided can be controlled. Therefore, for example, when the safety device 800 is operated, a crack is generated in the conductive member 300 at an unexpected position, thereby suppressing the occurrence of problems such as failure of the conductive member 300 to break.

  In the present embodiment, the width of the conductive member 300 (the length in the direction orthogonal to the conduction direction and the thickness direction) is also narrower than the other portions at the position of the fragile portion 305. The cross-sectional area of the fragile part 305 is made smaller than the other parts.

  In addition, the weak part 305 in this Embodiment is orthogonal to the conduction direction provided in a part of conduction path (between the first end part 301 and the second end part 302) formed by the conductive member 300. It can also be said that the cross-sectional area is the smallest part.

  In power storage element 10 according to the present embodiment, as shown in FIG. 6, safety device 800 that breaks conductive member 300 under a predetermined condition is provided at a position facing conductive member 300.

  The safety device 800 includes a protruding member 820 disposed at a position facing the conductive member 300, and a housing 810 that houses the protruding member 820. The protruding member 820 has a protrusion 821 protruding in the direction of the conductive member 300.

  More specifically, the housing 810 includes a protrusion member 820 and a substance that moves the protrusion member 820 in the direction of the conductive member 300 by increasing the volume under a predetermined condition (in this embodiment, a gas generating agent). 850) A member to be accommodated. In addition, the housing 810 in this embodiment includes a protrusion hole 811 through which the protrusion 821 passes. In the present embodiment, the predetermined condition is, for example, when heat equal to or higher than a threshold is given to the gas generating agent 850.

  In the present embodiment, the housing 810 further includes a heat generating portion 830, and the gas generating agent 850 increases the volume when the heat generating portion 830 generates heat.

  The heat generating portion 830 is realized by, for example, a coil formed of nichrome wire, and heat (Joule heat) is generated by energizing the heat generating portion 830, and this heat causes a chemical reaction to the gas generating agent 850. Wake up to increase volume.

  More specifically, an igniting agent (not shown) is combusted by the heat generation unit 830 generating heat, whereby the gas generating agent 850 is ignited, and as a result, a gas such as carbon dioxide gas is generated.

  In addition, the kind of gas generating agent 850 is not limited to a specific kind, For example, it can select suitably from the various gas generating agents 850 used for the airbag of a motor vehicle.

  In addition, as materials of the housing 810 and the protruding member 820, strength and heat resistance are considered from various materials such as metal whose surface is subjected to insulation treatment such as resin coating, or resin having high heat resistance. To be selected.

  In FIG. 6, the gas generating agent 850 accommodated in the housing 810 is schematically represented by a region with dots. However, the gas generating agent 850 is in a state of, for example, pellets or powder in the housing. Housed in body 810.

  In the present embodiment, as a mechanism for flowing an electric current to the heat generating unit 830, a displacement unit 281 that is displaced by receiving the internal pressure of the container 100, and a switch unit that supplies current to the heat generating unit 830 when the displacement unit 281 is displaced. 833 is provided in the electric storage element 10.

  The displacement part 281 is provided in the power storage element 10 as a part of the reversing part 280 that is deformed by receiving the internal pressure of the container 100. The inversion part 280 is formed in a convex shape toward the inside of the container 100, and when the internal pressure of the container 100 rises, it is deformed so as to be convex toward the outside of the container 100. Thereby, the displacement part 281 is displaced in the direction of the switch part 833.

  In the present embodiment, the reversing unit 280 is manufactured as a separate component from the container 100 and is disposed so as to close the hole provided in the container 100. Specifically, the inversion part 280 is disposed so as to close the attachment hole 114 provided in the lid 110.

  As shown in FIGS. 3 and 4, the reversing unit 280 is made of a material having elasticity and conductivity, such as stainless steel, aluminum, and aluminum alloy, as a whole with a convex shape (the surface of the container 100). It is produced by molding so as to be concave.

  Moreover, the periphery of the inversion part 280 and the periphery of the attachment hole 114 are joined by laser welding, for example, and thereby the airtightness of the container 100 at the position of the inversion part 280 is maintained.

  That is, the reversing unit 280 is a member (a part of the container 100) that constitutes a part of the container 100 and receives a pressure difference between the internal space S <b> 1 of the container 100 and the outside of the container 100.

  Therefore, for example, when a part of the electrolytic solution is vaporized due to overcharging of the power storage element 10 (electrode body 700), and thereby the internal pressure of the container 100 is increased, the reversing unit 280 is directed toward the outside of the container 100. To be reversed.

  That is, the displacement part 281 forming the central part of the reversing part 280 moves in the direction of the switch part 833 by receiving the internal pressure of the container 100 and contacts the two contact parts constituting the switch part 833.

  As shown in FIG. 6, the switch portion 833 in the present embodiment has two contact portions 831a and 832a that are arranged at a predetermined interval. The contact portion 831 a is an end portion of the first conduction portion 831 connected to the conductive member 300, and the contact portion 832 a is an end portion of the second conduction portion 832 connected to the conductive member 300.

  Each of the first conducting portion 831 and the second conducting portion 832 is a lead wire or a lead plate that is disposed in the housing 810 and has one end connected to the conductive member 300. In addition, a heat generating portion 830 is disposed in the middle of the second conducting portion 832, and the contact portion 832 a is connected to the heat generating portion 830.

  Moreover, in normal time, as shown in FIG. 6, the 1st conduction | electrical_connection part 831 and the 2nd conduction | electrical_connection part 832 are not electrically connected, and an electric current does not flow.

  However, when the displacement part 281 comes into contact with the two contact parts 831a and 832a constituting the switch part 833, the first conduction part 831 and the second conduction part 832 are electrically connected. As a result, a current is supplied to the heat generating portion 830, and as a result, the safety device 800 is activated and the conductive member 300 is broken. Specifically, the safety mechanism 180 in the present embodiment operates as shown in FIGS. 7 and 8, thereby mechanically disconnecting the electrical connection between the electrode body 700 and the positive electrode terminal 200.

  FIG. 7 is a first diagram illustrating an operation example of the safety mechanism 180 in the embodiment, and FIG. 8 is a second diagram illustrating an operation example of the safety mechanism 180 in the embodiment.

  For example, when the internal pressure of the container 100 (pressure in the internal space S1) rises due to the electrode body 700 falling into an overcharged state, as shown in FIG. In response, the safety device 800 is displaced in the direction of the housing 810.

  As a result, the displacement portion 281 comes into contact with the two contact portions 831a and 832a, whereby the two contact portions 831a and 832a are electrically connected by the displacement portion 281 having conductivity.

  In other words, the switch unit 833 has a current flowing between the electrode body 700 and the positive terminal 200 when the displacement unit 281 displaced by the internal pressure of the container 100 comes into contact with the two contact units 831a and 832a. Is supplied to the heat generating portion 830.

  More specifically, the heat generating portion 830 is connected in parallel with the conductive member 300 by electrically connecting the contact portions 831 a and 832 a by the displacement portion 281. Therefore, a part of the current flowing between the electrode body 700 and the positive electrode terminal 200 is supplied to the heat generating unit 830, and the heat generating unit 830 generates heat.

  As a result, the gas generating agent 850 causes a chemical reaction to generate gas (the volume of the gas generating agent 850 increases). In the present embodiment, the housing space for the gas generating agent 850 is isolated from the inside of the housing 810 by the inner surface of the housing 810 and the protruding member 820. Further, the protruding member 820 is held by the housing 810 in a state in which the protruding member 820 can move in the vertical direction (Z-axis direction).

  Therefore, the protruding member 820 moves in the direction of the conductive member 300 due to the pressure of the gas generated when the gas generating agent 850 causes a chemical reaction. As a result, the protrusion 821 exposed from the protrusion hole 811 presses a part of the conductive member 300, thereby breaking the conductive member 300.

  Specifically, in the present embodiment, the conductive member 300 has a fragile portion 305, and the fragile portion 305 is a side portion of the conductive member 300 that is pressed by the protrusion 821, that is, a side where the protrusion 821 collides. Is provided.

  Therefore, the conductive member 300 is broken at the fragile portion 305, and as shown in FIG. 8, a portion including the second end portion 302 (portion on the electrode terminal side) and a portion including the first end portion 301 (collection) It is divided into two parts on the electric side.

  Note that, since the protrusion 821 and the conductive member 300 are disposed apart from each other in a normal state, the protrusion 821 contacts (collises) with the conductive member 300 after starting acceleration. Can be shocked. This is advantageous for ensuring the fracture of the conductive member 300. In addition, since the protrusion 821 and the conductive member 300 are arranged apart from each other, for example, when vibration is applied to the power storage element 10 in a normal state, interference between the protrusion 821 and the conductive member 300 is suppressed.

  In the present embodiment, the weakened portion 305 is formed by the groove 305a provided on the upper surface 300a of the conductive member 300, and the conductive member 300 is pushed up by the protrusion 821 from the opposite side of the upper surface 300a.

  Therefore, the conductive member 300 is deformed so as to increase the width of the groove 305a (the width of the upper surface 300a in the direction orthogonal to the extending direction of the groove 305a). Thereby, the fracture | rupture of the bottom part (part thinned thickness) of the groove | channel 305a is performed efficiently. That is, the fracture at the fragile portion 305 is further ensured.

  Further, in the present embodiment, the width of the conductive member 300 is narrow at the position of the fragile portion 305. Therefore, stress tends to concentrate on the fragile portion 305, and this also ensures the breakage in the fragile portion 305.

  Note that the housing 810 and the protrusion 821 of the safety device 800 maintain a state where they are in contact with the two parts (the electrode terminal side part and the current collector side part) after the breaking even after the conductive member 300 is broken. There are cases (see, for example, FIG. 8). However, since the housing 810 and the protrusion 821 have electrical insulation at least in a portion in contact with the conductive member 300, the electrode body 700 and the positive terminal 200 via the safety device 800 after the conductive member 300 is broken. There is no conduction between the two.

  Further, since the weakened portion 305 is a portion having a small cross-sectional area in this embodiment, it functions as a portion that is most easily melted in the conductive member 300 when a large current flows.

  For example, a case is assumed in which an external short circuit occurs in the power storage element 10 due to an external factor such as a collision accident of an automobile on which the power storage element 10 is mounted. In this case, it is conceivable that the differential pressure inside and outside the container 100 does not increase to the extent that the displacement portion 281 is displaced.

  However, the fragile portion 305 is a portion having a small cross-sectional area in the metal conductive member 300 and becomes high heat when a large current flows. As a result, the conductive member 300 is fused at the position of the fragile portion 305. Thereby, the flow of current in power storage element 10 is stopped, and further temperature increase of power storage element 10 can be suppressed.

  As described above, the safety mechanism 180 including the conductive member 300 and the safety device 800 in the present embodiment is different from each other, for example, an increase in internal pressure due to overcharge and generation of a large current due to an external short circuit. It can function as a mechanism for safety measures corresponding to two events.

  Further, in the present embodiment, the movement of the conductive member 300 in the direction is restricted by the second insulating member 270 arranged in the direction pushed by the protrusion 821.

  Specifically, for example, as illustrated in FIG. 3, the second insulating member 270 includes a contact portion 275 and a pressing portion 276.

  The contact portion 275 is a portion that contacts the conductive member 300 from the side opposite to the protrusion 821. In the present embodiment, the contact portion 275 is disposed on the opposite side of the portion pressed by the protrusion 821 across the fragile portion 305 of the conductive member 300 in plan view (when viewed from the positive direction of the Z axis). Is done.

  That is, the fragile portion 305 is positioned between the portion pressed by the protrusion 821 and the portion where the contact portion 275 contacts in the conductive member 300. Further, the current collector side portion of the conductive member 300 is pressed by the pressing portion 276.

  Therefore, when the protrusion 821 moves (protrudes) in the direction of the conductive member 300 due to the pressure of the gas generated by the gas generating agent 850, the conductive member 300 can be efficiently sheared by the protrusion 821 and the contact portion 275.

  More specifically, the conductive member 300 is subjected to a load from the reversing portion 280 on one side with the fragile portion 305 as the center, and the other side is regulated by the contact portion 275.

  As a result, the fragile portion 305 is more reliably broken (sheared) by the protrusion 821 protruding in the direction of the conductive member 300. Therefore, for example, even when the stroke of the protrusion 821 (maximum displacement of the protrusion 821) is relatively small, the conductive member 300 can be broken by the protrusion 821. That is, the safety device 800 can be reduced in size, which is advantageous for reducing the size of the power storage device 10.

  As described above, the storage element 10 according to the present embodiment is disposed at the position facing the conductive member 300 and the conductive member 300 that electrically connects the positive electrode current collector 500 and the positive electrode terminal 200, and the direction of the conductive member 300. And a protrusion member 820 having a protrusion 821 protruding from the bottom. The power storage element 10 further includes a housing 810 that houses the protruding member 820 and the gas generating agent 850 and has a protruding hole 811 through which the protrusion 821 passes.

  The gas generating agent 850 is an example of a substance that moves the protruding member 820 in the direction of the conductive member 300 by increasing the volume under a predetermined condition.

  In the electricity storage device 10 having the above structure, the protrusion 821 moves in the direction of the conductive member 300 due to an increase in the volume of the gas generating agent 850, and a part of the conductive member 300 can be pushed by the protrusion 821.

  That is, the protrusion 821 can be pressed against the conductive member 300 using the pressure of the gas generated in the housing 810 of the safety device 800 included in the power storage element 10. Therefore, for example, the conductive member 300 can be broken with a predetermined force that does not depend on the magnitude of the internal pressure of the container 100 or the like.

  Therefore, for example, the entire conductive member 300 is made of a metal such as aluminum, so that the conductive member 300 is resistant to vibration or impact, and the conductive device 300 can be broken by the safety device 800. It can be.

  In the present embodiment, since conductive member 300 is disposed outside container 100, safety mechanism 180 can be disposed in power storage element 10 in a manner that does not substantially consume the internal capacity of container 100. . Further, even if a foreign material such as a metal piece or spatter is generated by breaking or fusing the conductive member 300, the foreign material does not enter the inside of the electrode body 700, for example. That is, the occurrence of an internal short circuit in the power storage element 10 that can be caused by a foreign matter generated by dividing the metal conductive member 300 is suppressed.

  Further, the conductive member 300 is covered with the upper insulating member 250. Therefore, for example, in the case where a plurality of power storage elements 10 are arranged to form a power storage module, even if the conductive member 300 of one power storage element 10 is divided, the foreign matter generated by the division is separated from other power storage elements 10. And other components are not adversely affected.

  In addition, the electricity storage element 10 includes a heat generating portion 830 that generates heat, and uses the heat generated by the heat generating portion 830 to cause a chemical reaction (gas generation) to the gas generating agent 850. The heat generating portion 830 can be realized by a simple mechanism such as a coil formed of nichrome wire, for example.

  Furthermore, the power storage element 10 includes a displacement portion 281 that is displaced by receiving the internal pressure of the container 100 and a switch portion 833 that supplies current to the heat generating portion 830 when the displacement portion 281 is displaced.

  Thereby, for example, when the internal pressure of the container 100 rises due to overcharge, the heat generation of the heat generating portion 830 and the subsequent operation of the safety mechanism 180 (the movement of the protrusion 821 by the gas pressure, the conduction by the moved protrusion 821). The breakage of the member 300 can be automatically caused.

  Further, since the internal pressure itself of the container 100 is only used for moving the displacement portion 281, before the internal pressure of the container 100 increases to such an extent that the metal conductive member 300 can be broken, for example, The conductive member 300 can be broken by the protrusion 821.

  Therefore, for example, when the container 100 is provided with a safety valve (not shown), before the safety valve is opened, the safety device 800 is operated using the increased internal pressure to break the conductive member 300, thereby It is also possible to stop the increase in internal pressure. That is, it is possible to reduce the possibility of opening of the safety valve (gas release to the outside) due to overcharge or the like.

  In addition, a part of the current flowing between the electrode body 700 and the positive electrode terminal 200 is supplied to the heat generating unit 830 through the displacement unit 281 that contacts the two contact units 831a and 832a configuring the switch unit 833. .

  That is, in the electricity storage device 10 of the present embodiment, for example, the gas generating agent 850 can be ignited using the electric power stored in the electrode body 700, so that the operation of the safety device 800 in an emergency is more reliable. Is done. Further, since the supply of current to the heat generating portion 830 is stopped due to the breakage of the conductive member 300, the heat generation of the heat generating portion 830 is also stopped. Note that when the heat generating portion 830 generates heat, the heat generating portion 830 may be broken (for example, blown out) by the heat.

  As described above, the power storage element 10 in the present embodiment is a power storage element 10 including the container 100 and the electrode body 700 housed in the container 100, and is a highly safe power storage element 10.

  In addition, the electrical storage element 10 may have a different safety mechanism from the safety mechanism 180 illustrated in FIGS. Therefore, in the following, a modified example related to the safety mechanism 180 in the embodiment will be described focusing on differences from the above embodiment.

(Modification)
FIG. 9 is a cross-sectional view showing a configuration outline of a safety mechanism 181 in a modification of the embodiment. FIG. 10 is a first diagram illustrating an operation example of the safety mechanism 181 in the modification of the embodiment, and FIG. 11 is a second diagram illustrating an operation example of the safety mechanism 181 in the modification of the embodiment. is there.

  The safety mechanism 181 shown in FIGS. 9 to 11 is different from the safety mechanism 180 in the above embodiment in the mechanism for supplying current to the heat generating unit 830 of the safety device 860.

  Specifically, the power storage element 10 in the present modification includes a safety mechanism 181, and the safety mechanism 181 includes a conductive member 300 and a safety device 860 that moves in accordance with the displacement of the displacement portion 281.

  The safety device 860 includes a protruding member 820 disposed at a position facing the conductive member 300, a protruding member 820, and a substance that moves the protruding member 820 in the direction of the conductive member 300 by increasing the volume under a predetermined condition. Has a housing 870 containing the.

  The protrusion member 820 has a protrusion 821 protruding in the direction of the conductive member 300, and the housing 870 has a protrusion hole 871 through which the protrusion 821 passes. In the present modification, the substance that increases the volume under a predetermined condition and is accommodated in the housing 870 is the gas generating agent 850 as in the above embodiment.

  The safety mechanism 181 in the present modification is characterized in that a switch unit 833 is disposed on the conductive member 300 side of the safety device 860. The switch part 833 has two contact parts 831b and 832b arranged at a predetermined interval.

  The two contact portions 831b and 832b are end portions of the first conductive portion 831 and the second conductive portion 832 on the conductive member 300 side, respectively. Further, as shown in FIG. 9, a heat generating portion 830 is disposed between the first conducting portion 831 and the second conducting portion 832. That is, the two contact portions 831b and 832b are connected to the heat generating portion 830.

  Further, as shown in FIG. 9, since the two contact portions 831 b and 832 b configuring the switch portion 833 are present at positions away from the conductive member 300 in the normal state, no current flows through the heat generating portion 830.

  However, for example, when the internal pressure of the container 100 increases due to overcharge, and the displacement portion 281 is displaced in the direction of the conductive member 300, the switch portion 833 moves in the direction of the conductive member 300 along with this displacement. Moving. As a result, as shown in FIG. 10, the switch portion 833 and the conductive member 300 come into contact with each other.

  That is, the two contact portions 831 b and 832 b are connected to the conductive member 300, whereby the heat generating portion 830 is connected in parallel to the conductive member 300. As a result, a part of the current flowing between the electrode body 700 and the positive electrode terminal 200 is supplied to the heat generating unit 830.

  As described above, the heat generating portion 830 is a coil or the like formed of a nichrome wire and generates heat when a current is passed. As a result, the gas generating agent 850 causes a chemical reaction to generate gas.

  When gas is generated in the housing 870, as shown in FIG. 11, the projection member 820 moves in the direction of the conductive member 300 due to the pressure of the gas, and the projection 821 in a state of penetrating the projection hole 871 becomes the conductive member. It is pressed against 300. As a result, the conductive member 300 is broken.

  As described above, in the safety mechanism 181 according to this modification, the two contact portions 831 b and 832 b are in contact with the conductive member 300 by the displacement portion 281 that is displaced by receiving the internal pressure of the container 100.

  Thereby, the switch unit 833 can supply a part of the current flowing through the conductive member 300 to the heat generating unit 830. As a result, the safety device 860 is activated and the conductive member 300 is broken. Further, since the supply of current to the heat generating portion 830 is stopped due to the breakage of the conductive member 300, the heat generation of the heat generating portion 830 is also stopped. Note that when the heat generating portion 830 generates heat, the heat generating portion 830 may be broken (for example, blown out) by the heat.

  As described above, the safety mechanism 181 in the present modified example is similar to the safety mechanism 180 in the above embodiment, in the case where a problem such as overcharging occurs in the power storage element 10, the electrode body 700 and the positive terminal 200. Can be mechanically interrupted. Therefore, the safety mechanism 181 in the present modification can be improved in the safety of the power storage element 10 by being provided in the power storage element 10.

(Other embodiments)
In the above, the electrical storage element in this invention was demonstrated based on embodiment and its modification. However, the present invention is not limited to the embodiment and its modifications. Without departing from the spirit of the present invention, various modifications conceived by those skilled in the art may be applied to the embodiment or its modifications, or a structure constructed by combining a plurality of the above-described constituent elements may be applied to the present invention. It is included in the range.

  For example, the volume of the gas generating agent 850 may be increased under conditions other than the heat generation of the heat generating unit 830. For example, when the electricity storage element 10 abnormally generates heat, the gas generating agent 850 may be ignited by the heat directly or via an ignition agent.

  Further, the current for generating heat by the heat generating unit 830 may not be a part of the current flowing between the electrode body 700 and the positive electrode terminal 200. For example, the heat generating unit 830 may generate heat by receiving supply of current from an external device that is not involved in charging and discharging of the power storage element 10.

  In this case, the safety device 800 or 860 starts the operation triggered by the supply of current from the external device. That is, the trigger for starting the operation of the safety device 800 or 860 may be other than the displacement portion 281 being displaced. For example, the safety device 800 or 860 may be operated in conjunction with an airbag provided in an automobile that is an example of a moving object on which the power storage element 10 is mounted. That is, when the airbag is activated, the volume of the substance (for example, the gas generating agent 850) included in the safety device 800 or 860 may be increased. Such a mechanism includes, for example, a detection unit that detects the operation of the airbag, and the heat output that is output from the detection unit and that heats the substance in response to the signal indicating that the airbag has been activated or activated. It may be realized by the unit 830 or the like. Moreover, this detection part may detect the collision of a motor vehicle instead of detecting the operation | movement of an airbag itself. That is, for example, when detecting a shock of a predetermined magnitude, the detection unit may operate the safety device 800 or 860 by operating the airbag and causing the heat generation unit to generate heat.

  As described above, when the safety device 800 or 860 included in the power storage element 10 is operated in conjunction with the airbag, for example, when an event that causes the airbag to operate, such as a collision accident, occurs. The occurrence of problems such as abnormal heat generation can be prevented in advance. In addition, as such a mobile body, a truck, a bus, a two-wheeled vehicle, etc. other than a general passenger car are illustrated.

  In addition, the substance that increases the volume under a predetermined condition and is accommodated in the housing 810 or 870 may be composed of a plurality of different types of substances.

  For example, two kinds of substances that increase in volume by being mixed are accommodated in the housing 810 or 870 in a state where they are separated by a partition that is destroyed by impact. Thereby, for example, when a car on which the power storage element 10 is mounted collides, the partition is destroyed by the impact of the collision, and these two kinds of substances are mixed.

  As a result, the total volume of the two types of substances increases, and thereby the protrusion 821 moves in the direction of the conductive member 300. Even with such a configuration, the conductive member 300 can be broken in an emergency. In this case, the predetermined condition for increasing the volume of the substance accommodated in the casing 810 or 870 (total volume of two kinds of substances) is, for example, when the casing 810 or 870 moves at an acceleration equal to or higher than a threshold value. Can be expressed as

  Moreover, the inversion part 280 does not need to be formed in a convex shape toward the inside of the container 100, and when the internal pressure of the container 100 rises, the inversion part 280 becomes a convex shape toward the outside of the container 100. It does not have to be deformed.

  The inversion part 280 may be formed substantially flat with respect to the inner surface or outer surface of the container 100, for example. That is, if the reversing part 280 is formed so that the displacement part 281 that is a part of the reversing part 280 is displaced by receiving the internal pressure of the container 100, the displacement part 281 is displaced when the internal pressure of the container 100 increases. Thus, the switch portion 833 can be contacted. That is, it is possible to supply current to the heat generating unit 830 through the displacement unit 281.

  Moreover, although stainless steel, aluminum, an aluminum alloy, etc. were illustrated as a material of the inversion part 280, since the inversion part 280 is a different body from the container 100, strength and displacement of the displacement part 281 are selected from various materials. It is only necessary to select an appropriate material for the reversing unit 280 by paying attention to easiness.

  For example, even when the reversing part 280 itself is formed of a material having an insulating property, the displaceable part 281 comes into contact with the switch part 833 by disposing a conductive member on the displaceable part 281. Operation of the device 800 is possible.

  Moreover, the inversion part 280 does not need to be a separate body from the container 100, and may be provided in the container 100 by processing a part of the container 100, for example.

  For example, the shape of the lid 110 may be adjusted by press working when forming the metal lid 110, and a portion corresponding to the reversing portion 280 may be formed in a part thereof. Thereby, the increase in the number of parts of the electrical storage element 10 is suppressed, for example. Further, for example, there is no problem with airtightness around the reversing part 280 in the container 100.

  In addition, the contact portion 275 that contacts the conductive member 300 from the side opposite to the protrusion 821 may not be disposed. Even in this case, it is possible to break the conductive member 300 by the safety device 800 or 860 that generates a relatively large force by using the gas pressure.

  Further, the shape of the conductive member 300 is not limited to the shape shown in FIG. For example, the conductive member 300 may not have the fragile portion 305.

  Even in this case, for example, by reducing the distance between the contact portion 275 and the portion pressed by the protrusion 821 of the conductive member 300 in a plan view, the shear stress generated in the conductive member 300 can be reduced within a narrow range. Thus, the conductive member 300 can be reliably broken.

  That is, in short, the conductive member 300 is cut by causing the protrusion 821 that contacts the conductive member 300 and the contact portion 275 to function as the two blades of the scissors with respect to the conductive member 300. can do.

  In the above embodiment, the conduction path between the positive electrode current collector 500 and the positive electrode terminal 200 is formed by the discharge terminal 290 and the conductive member 300, but the discharge terminal 290 is connected to the conduction path. It is not necessary to form a part. That is, the conductive member 300 and the positive electrode current collector 500 may be directly connected.

  A part of the conduction path may be formed by a member other than the discharge terminal 290 and the conductive member 300. For example, another metal member may be connected between the conductive member 300 and the positive electrode terminal 200.

  The present invention can provide a power storage element having a container and an electrode body housed in the container, and having a high safety. Therefore, the power storage element of the present invention is useful as a power storage element mounted on an automobile or the like that requires a large current for a long time.

DESCRIPTION OF SYMBOLS 10 Power storage element 100 Container 110 Cover body 113, 201, 264, 271, 511 Through hole 114 Mounting hole 116 Fixing part 120 Main body 180,181 Safety mechanism 200 Positive electrode terminal 250, 450 Upper insulating member 255 Lower insulating member 260 First insulating member 261 Projection 263 Breaking opening 265 Discharging opening 270 Second insulating member 272 Conducting opening 275 Contacting part 276 Pressing part 280 Reversing part 281 Displacement part 290 Discharging terminal 291 First connecting part 292 Second connecting part 300 Conducting member 300a Upper surface 301 First end portion 302 Second end portion 305 Fragile portion 305a Groove 400 Negative electrode terminal 500 Positive electrode current collector 510 Terminal connection portion 520 Leg portion 600 Negative electrode current collector 700 Electrode body 701 Positive electrode connection portion 702 Negative electrode connection portion 800, 860 Safety device 810, 870 housing Body 811, 871 Projection hole 820 Projection member 821 Projection 830 Heat generating part 831 First conduction part 831 a, 831 b, 832 a, 832 b Contact part 832 Second conduction part 833 Switch part 850 Gas generating agent

Claims (8)

An electrical storage element comprising an electrode terminal, an electrode body, a current collector connected to the electrode body, and a container for housing the electrode body and the current collector,
A conductive member for electrically connecting the current collector and the electrode terminal;
A protruding member disposed at a position facing the conductive member and having a protrusion protruding in the direction of the conductive member;
An energy storage device comprising: the protruding member; and a housing that houses a substance that moves the protruding member in the direction of the conductive member by increasing the volume under a predetermined condition. The power storage device according to claim 1, wherein the housing further includes a heat generating portion, and the substance increases the volume when the heat generating portion generates heat. Furthermore, a displacement part that is displaced by receiving the internal pressure of the container,
The power storage device according to claim 2, further comprising: a switch unit that supplies current to the heat generating unit when the displacement unit is displaced. The switch part is two contact parts arranged at a predetermined interval, one of which has two contact parts connected to the heat generating part,
The switch part is in a state in which the displacement part displaced by receiving the internal pressure of the container is in contact with the two contact parts, and a part of the current flowing between the electrode body and the electrode terminal is The power storage device according to claim 3, wherein the power storage device is supplied to the heat generating portion. The switch part is arranged with a predetermined interval, and has two contact parts electrically connected to the heat generating part,
The switch part is in a state in which the two contact parts are in contact with the conductive member due to the displacement part displaced by the internal pressure of the container, so that a part of the current flowing through the conductive member is changed to the heat generating part. The power storage device according to claim 3, wherein the power storage device is supplied to the power storage device. Further, a contact of the conductive member that contacts the conductive member from a side opposite to the protrusion between a portion pressed by the protrusion and an electrical connection portion of the current collector or the electrode terminal. The electrical storage element of any one of Claims 1-5 provided with a part. The conductive member has a fragile portion in a part between an electrical connection portion with the current collector and an electrical connection portion with the electrode terminal. The electrical storage element as described in. The electricity storage device according to any one of claims 1 to 7,
With an airbag,
The substance increases the volume when the airbag is activated.

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