JP2018056097A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device including multiple power storage elements, in which safety is improved.SOLUTION: A power storage device 10 includes a power storage element unit 350 having multiple power storage elements 300, a first conductive member 800 disposed at a position facing a lateral face of one power storage element 300 of the multiple power storage elements 300, and a second conductive member 900 disposed oppositely to the first conductive member 800 while being spaced apart therefrom, at a position at an opposite side to the lateral face with the first conductive member 800 interposed therebetween. The first conductive member 800 is connected with one of a positive electrode or a negative electrode of the power storage element unit 350, and the second conductive member 900 is connected with the other of the positive electrode or the negative electrode of the power storage element unit 350.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a power storage device including a plurality of power storage elements.

  Conventionally, a power storage device including a plurality of power storage elements is known. Each of the plurality of power storage elements includes, for example, a container, an electrode body and an electrolytic solution accommodated in the container. In some cases, a flammable organic liquid is used as the electrolytic solution included in the power storage element, and various safety measures are taken for the power storage element.

  For example, Patent Document 1 discloses a configuration in which a short-circuit member is disposed between two adjacent secondary batteries in a battery module including a plurality of secondary batteries. Each of the plurality of short-circuit members is pressurized and deformed by swelling one of the two secondary batteries on both sides of the short-circuit member. As a result, the short-circuit member contacts the electrode terminals of the two secondary batteries, thereby causing a short circuit. The heat generated by the short circuit melts the connecting member that connects the two secondary batteries, and the charging or discharging of the two secondary batteries is interrupted.

Japanese Patent No. 5186650

  Here, in a power storage device including a plurality of power storage elements, for example, when a safety mechanism is arranged between power storage elements as in the conventional technique, the size and weight of the power storage device are increased. In addition, for example, when one power storage element expands to a high temperature due to overcharge or the like, even if charging or discharging of the power storage element stops, the heat is given to the other power storage element, and as a result, the power storage device May become more unstable.

  In view of the above-described conventional problems, an object of the present invention is to provide a power storage device including a plurality of power storage elements and having improved safety.

  To achieve the above object, a power storage device according to one embodiment of the present invention includes a power storage element unit including a plurality of power storage elements, and a position facing a side surface of one of the plurality of power storage elements. And a second conductive member disposed opposite to the first conductive member at a position opposite to the side surface across the first conductive member, and the second conductive member The first conductive member is connected to one of a positive electrode and a negative electrode of the power storage element unit, and the second conductive member is connected to the other of the positive electrode and the negative electrode of the power storage element unit.

  According to this configuration, for example, when the power storage element included in the power storage element unit becomes unstable due to overcharge or the like, the side surface expands as the internal pressure increases. At this time, the first conductive member is brought into contact with the second conductive member by being moved (or deformed) by receiving a force due to the swelling of the power storage element. As a result, the plurality of power storage elements included in the power storage element unit are in a state in which a discharge path is generated collectively. Thereby, the electrical energy of a some electrical storage element is consumed at an early stage, and relaxation of an unsafe event is achieved. That is, it is possible to suppress the deterioration of the situation when an abnormality occurs. Thus, the power storage device according to this aspect is a power storage device with improved safety.

  Further, for example, as compared to the case where the safety mechanism is arranged between two adjacent power storage elements as in the conventional technique, the space consumed for the arrangement of the safety mechanism is small. This is advantageous from the viewpoint of increasing the storage capacity (improvement of energy density) of the power storage device.

  In the power storage device according to one embodiment of the present invention, the first conductive member is disposed at a position facing the long side surface of the one power storage element, which is the side surface, which is the side surface. It is good also as.

  The long side surface of the power storage element is a portion that easily swells as the internal pressure of the power storage element increases. Therefore, when the power storage element is in an unstable state and swells, the formation of a discharge path (external short circuit) for suppressing the deterioration of the situation can be generated more reliably or earlier. That is, the effect of suppressing the deterioration of the situation at the time of occurrence of abnormality by the first conductive member and the second conductive member can be obtained more reliably.

  In the power storage device according to one embodiment of the present invention, the first conductive member is disposed at a position facing the side surface in the stacking direction of the electrode plates in the electrode body included in the one power storage element, which is the side surface. It is good as well.

  Here, in general, the size of the electrode body having the stacked electrode plates when viewed from the stacking direction of the electrode plates is larger than the size when viewed from the direction orthogonal to the stacking direction. That is, among the plurality of side surfaces of the electricity storage element, the side surface in the stacking direction of the electrode plates of the electrode body is a side surface having a relatively large area. That is, the side surface is a portion that easily swells as the internal pressure of the power storage element increases, and the first conductive member is arranged at a position facing the side surface, thereby forming a discharge path when an abnormality occurs (external Short circuit) can occur more reliably or earlier. Therefore, the effect of suppressing the deterioration of the situation at the time of occurrence of abnormality by the first conductive member and the second conductive member can be obtained more reliably.

  In the power storage device according to one embodiment of the present invention, the plurality of power storage elements are arranged in a predetermined direction, and the first conductive member is an end surface of the plurality of power storage elements in the predetermined direction. It is good also as arrange | positioning in the position facing the said side which is.

  According to this configuration, since the first conductive member is arranged at a position facing the side surface that is the end face of the row of the plurality of power storage elements, when any one of the power storage elements is swollen, the influence of the swollenness In response, the side surface moves in a predetermined direction, whereby the first conductive member can be pushed. Further, for example, when a plurality of power storage elements swell at the same time, the side surface moves under the influence of the accumulation of the bulges, so that an external short-circuit for suppressing the deterioration of the situation is more reliably or earlier. Can be executed.

  The power storage device according to one embodiment of the present invention may further include an exterior body disposed outside the power storage element unit, and the second conductive member may be disposed on an inner surface of the exterior body. .

  According to this configuration, since the second conductive member is arranged on the inner surface of the exterior body, for example, the stability of the position of the second conductive member can be obtained. Further, for example, the positioning of the second conductive member with respect to the first conductive member is facilitated.

  In the power storage device according to one embodiment of the present invention, the first conductive member may be fixed to an insulating member arranged between the side surface and the first conductive member.

  According to this configuration, for example, the first conductive member and the container of the power storage element are electrically insulated by fixing the first conductive member to the side surface of the power storage element with an adhesive such as silicone resin that is an insulating member. However, the position of the first conductive member at the normal time can be stabilized. For example, when a displacement in a direction approaching the second conductive member occurs on the side surface, the first conductive member can be moved so as to follow the displacement by interposing the insulating member. For example, the same effect can be obtained by fixing the first conductive member to a spacer which is an insulating member arranged on the side of the power storage element.

  In the power storage device according to one embodiment of the present invention, at least one of the first conductive member and the second conductive member is connected to the positive electrode or the negative electrode of the power storage element unit via a resistor. It is good also as.

  According to this configuration, for example, when the first conductive member and the second conductive member are conducted, the possibility that the current flowing through the power storage element unit becomes excessive is reduced.

  According to the present invention, it is possible to provide a power storage device that includes a plurality of power storage elements and that has improved safety.

It is a perspective view which shows the external appearance of the electrical storage apparatus which concerns on embodiment. It is a disassembled perspective view which shows each component at the time of decomposing | disassembling the electrical storage apparatus which concerns on embodiment. It is a perspective view which shows the external appearance of the electrical storage element which concerns on embodiment. It is a perspective view which isolate | separates and shows the electrical storage element which concerns on embodiment, the container cover part and container main body of a container. It is a top view for demonstrating the arrangement position of the 1st conductive member which concerns on embodiment, and a 2nd conductive member. It is a top view which shows the state which the 1st electroconductive member and the 2nd electroconductive member electrically connected. It is a top view which shows the one part structure of the electrical storage apparatus which concerns on the modification 1 of embodiment. FIG. 7 is a plan view showing a partial structure of the power storage device according to the second modification of the embodiment. FIG. 8 is a plan view showing a state in which the reversing portion of the first conductive member according to the second modification of the embodiment is reversed.

  Embodiments of the present invention and modifications thereof will be described below with reference to the drawings. Each of the embodiments and modifications thereof described below is a comprehensive or specific example. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, connection forms, processes, order of processes, 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 arbitrary constituent elements.

  Each figure is a schematic diagram and is not necessarily illustrated strictly. Moreover, in each figure, the same code | symbol is attached | subjected to the substantially same structure, The overlapping description may be abbreviate | omitted or simplified.

(Embodiment)
First, the configuration of the power storage device 10 will be described. FIG. 1 is a perspective view showing an external appearance of a power storage device 10 according to an embodiment. FIG. 2 is an exploded perspective view showing each component when the power storage device 10 according to the embodiment is disassembled.

  In these figures, the Z-axis direction is shown as the vertical direction, and the Z-axis direction will be described below as the vertical direction. However, depending on the usage, the Z-axis direction may not be the vertical direction. The axial direction is not limited to the vertical direction. The same applies to the following drawings.

  The power storage device 10 is a device that can charge electricity from the outside and discharge electricity to the outside. The power storage device 10 is a battery module used for power storage applications, power supply applications, and the like. The power storage device 10 may be used as a battery for starting an engine or a battery for driving an assist motor in a vehicle such as a two-wheeled vehicle or a four-wheeled vehicle. The power storage device 10 is used as a power source (power storage device for driving a driving motor for driving) such as an electric vehicle (EV), a plug-in hybrid electric vehicle (PHEV), and a hybrid electric vehicle (HEV). There is also.

  As shown in FIGS. 1 and 2, the power storage device 10 includes a power storage element unit 350 including a plurality of power storage elements 300 and an exterior body 11 that covers the power storage element unit 350. In the present embodiment, the plurality of power storage elements 300 included in power storage element unit 350 are connected in series by bus bar 400, and the most negative power storage element in the direction in which the plurality of power storage elements 300 are arranged (X-axis direction). 300 positive electrode terminal 320 is treated as positive electrode terminal 351 of power storage element unit 350. In addition, the negative electrode terminal 330 of the most storage element 300 in the X-axis direction functions as the negative electrode terminal 352 of the storage element unit 350.

  The exterior body 11 is a rectangular (box-shaped) container (module case) that constitutes the exterior body of the power storage device 10. The exterior body 11 covers the power storage element unit 350 and can protect the power storage element 300 and the like from an impact or the like. The package 11 is made of an insulating resin material such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polyphenylene sulfide resin (PPS), polybutylene terephthalate (PBT), or ABS resin.

  Here, the exterior body 11 includes an exterior body main body 100 that houses the power storage element unit 350 and a lid body 200 that closes the opening of the exterior body main body 100.

  The exterior body main body 100 is a member that constitutes the body portion of the exterior body 11, and specifically, is a bottomed rectangular cylindrical housing having an opening formed in the upper portion. A plurality of power storage elements 300 are inserted from the openings and accommodated in the exterior body main body 100. In the exterior body 100, for example, ribs or partition plates (not shown) for restricting the positions of the plurality of power storage elements 300 are arranged.

  The lid body 200 is a flat rectangular cover member that closes the opening of the exterior body main body 100. The lid 200 is provided with a positive external terminal 210 and a negative external terminal 220. The power storage device 10 charges electricity from the outside via the positive electrode external terminal 210 and the negative electrode external terminal 220 and discharges electricity to the outside.

  Specifically, as shown in FIG. 2, the positive electrode lead plate 410 and the positive electrode external terminal 210 joined to the positive electrode terminal 351 of the power storage element unit 350 are electrically connected to a conductive member such as a bus bar (illustrated schematically by a broken line in FIG. ). Further, the negative electrode lead plate 420 joined to the negative electrode terminal 352 of the power storage element unit 350 and the negative electrode external terminal 220 are connected by a conductive member such as a bus bar (conceptually shown by a two-dot chain line in FIG. 2).

  In addition, the exterior body main body 100 and the lid body 200 may be formed of members of the same material, or may be formed of members of different materials. Further, for example, an electric device such as a circuit board or a relay that controls charging and discharging of the power storage element unit 350 may be disposed inside the lid 200.

  In the present embodiment, a first conductive member 800 and a second conductive member 900 are provided in the exterior body 11. The first conductive member 800 has a connection portion 810, and the connection portion 810 is connected to, for example, the positive electrode lead plate 410, whereby the first conductive member 800 is connected to the positive electrode of the power storage element unit 350. In addition, the second conductive member 900 has a connection portion 910, and the connection portion 910 is connected to, for example, the negative electrode lead plate 420, so that the second conductive member 900 is electrically connected to the negative electrode of the power storage element unit 350. Is done.

  In the present embodiment, the first conductive member 800 is fixed to the side surface of one power storage element 300 via the insulating member 700. The second conductive member 900 is provided with an insulating coating 930 on portions other than the connection portion 910 and the contact portion 920, and is disposed on the inner surface of the exterior body 11 (the exterior body body 100). The contact portion 920 is disposed at a position facing the first conductive member 800. The effects of these two conductive members will be described later with reference to FIGS.

  The power storage element 300 is a secondary battery (unit cell) that can charge and discharge electricity, and more specifically, a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery. . The power storage element 300 has a flat rectangular shape, and in the present embodiment, eight power storage elements 300 are arranged in the X-axis direction and accommodated in the exterior body 11. The storage element 300 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than the non-aqueous electrolyte secondary battery (for example, a nickel-cadmium battery and a nickel-hydrogen battery). Alternatively, it may be a capacitor. Further, the battery may be a primary battery that can use the stored electricity without being charged by the user.

  Further, the number of power storage elements 300 included in the power storage device 10 is not limited to eight. For example, the number of power storage elements 300 can be adjusted according to an output voltage required for the power storage device 10.

  Bus bar 400 is a conductive plate-like member such as a metal that is disposed above a plurality of power storage elements 300 and electrically connects the plurality of power storage elements 300 to each other. Specifically, bus bar 400 connects positive electrode terminal 320 of one power storage device 300 and negative electrode terminal 330 of another power storage device 300 in adjacent power storage devices 300. In the present embodiment, eight power storage elements 300 are connected in series by seven bus bars 400, so that a power storage element unit 350 including eight power storage elements 300 is configured.

  Note that the manner of electrical connection of the plurality of power storage elements 300 in the power storage element unit 350 is not limited to series. For example, when two power storage elements 300 connected in parallel are used as subunits, one power storage element unit 350 may be configured by connecting four subunits in series.

  Next, the structure of the electrical storage element 300 is demonstrated using FIG. 3A and 3B. FIG. 3A is a perspective view showing an external appearance of power storage device 300 according to the embodiment. FIG. 3B is a perspective view showing the electricity storage device 300 with the container lid 314 and the container main body 315 of the container 310 separated.

  As illustrated in FIGS. 3A and 3B, the power storage device 300 includes a container 310, a positive electrode terminal 320, and a negative electrode terminal 330. Inside the container 310, an electrode body (storage element) 280, a positive electrode current collector 240, a negative electrode current collector 250, and the like are disposed, and an electrolytic solution (non-aqueous electrolyte, not shown) is enclosed. .

  The container 310 includes a bottom surface portion 311 on the negative side in the Z-axis direction, a long side surface portion 312 on the side surfaces on both sides in the X-axis direction, a short side surface portion 313 on the side surfaces on both sides in the Y-axis direction, and a container on the positive side in the Z-axis direction. This is a rectangular parallelepiped (square) container having a lid 314. The bottom surface portion 311 is a rectangular portion that forms the bottom surface of the container 310, the long side surface portion 312 is a rectangular portion that forms the long side surface of the container 310, and the short side surface portion 313 is a short portion of the container 310. It is a rectangular part which forms a side surface. The container lid portion 314 is a rectangular member that constitutes the lid of the container 310.

  That is, in the container 310, the bottom surface portion 311, the two long side surface portions 312, and the two short side surface portions 313 constitute a container main body 315 having a rectangular cylindrical shape and a bottom, and the opening of the container main body 315 is opened to the container lid portion 314. Is configured to close. Specifically, the container 310 has a structure that can seal the inside by accommodating the electrode body 280 and the like inside the container body 315 and then welding the container body 315 and the container lid 314. Have.

  The material of the container 310 (the container body 315 and the container lid 314) is not particularly limited, but is preferably a weldable metal such as stainless steel, aluminum, or aluminum alloy. In addition, the container lid 314 is provided with a gas discharge valve 319 for releasing the pressure inside the container 310.

  In the present embodiment, electrode body 280 accommodated in container 310 is a wound electrode body formed by winding electrode plate 285 around winding axis W. More specifically, the electrode body 280 includes a negative electrode plate and a positive electrode plate as the electrode plate 285. In addition, the electrode body 280 is formed by winding the negative electrode plate, the positive electrode plate, and the two separators so that the negative electrode plate and the positive electrode plate are stacked with the separator interposed therebetween.

  3B represents the winding axis of the electrode body 280. In FIG. The winding axis W is a virtual axis serving as a central axis when winding the electrode plate 285 and the like, and is a straight line passing through the center of the electrode body 280 and parallel to the Y axis in the present embodiment.

  The electrode body 280 has a flat shape in a direction orthogonal to the winding axis W (in the present embodiment, the X-axis direction). That is, when viewed from the direction of the winding axis W, the electrode body 280 has an oval shape as a whole, the oval straight portion becomes a flat shape, and the oval curved portion is curved. Become. That is, the electrode body 280 has curved portions at both ends in the Z-axis direction, and has a flat portion between the two curved portions. When the electrode body 280 is accommodated in the container 310, the long side surface portions 312 of the container body 315 are positioned on both sides of the flat portion of the electrode body 280, and the container body is disposed on both sides in the direction of the winding axis W of the electrode body 280. The short side surface portion 313 of 315 is located.

  The type of electrode body 280 is not limited to the wound type. The electrode body 280 may be, for example, a stacked electrode body in which flat plate plates are stacked, and, for example, a long strip-shaped electrode plate is stacked in a bellows shape by repeating mountain folding and valley folding. It may be an electrode body having a structure.

  As the positive electrode active material or the negative electrode active material used for the electrode body 280, a known material can be used as appropriate as long as the performance of the power storage element 300 is not impaired. In addition, as the electrolytic solution sealed in the container 310, there is no particular limitation on the type thereof as long as it does not impair the performance of the power storage device 300, and various types can be selected.

  The positive electrode terminal 320 is an electrode terminal electrically connected to the positive electrode of the electrode body 280 via the positive electrode current collector 240, and the negative electrode terminal 330 is electrically connected to the negative electrode of the electrode body 280 via the negative electrode current collector 250. Connected electrode terminals, both of which are attached to the container lid 314.

  In power storage device 10 according to the present embodiment, power storage element unit 350 configured by connecting eight power storage elements 300 having the above-described configuration is housed in exterior body 11. As shown in FIG. 2, the positive electrode (positive electrode terminal 351) and the negative electrode (negative electrode terminal 352) of the electricity storage element unit 350 are connected to the external terminals (210, 220) of the exterior body 11, and two conductive members ( 800, 900). These two conductive members (800, 900) function as members that suppress deterioration of the situation when an abnormality occurs in the power storage element unit 350.

  Hereinafter, in the present embodiment, configurations and effects of the two conductive members (800, 900) arranged on the exterior body 11 will be described with reference to FIGS.

  FIG. 4 is a plan view for explaining arrangement positions of the first conductive member 800 and the second conductive member 900 according to the embodiment. FIG. 5 is a plan view showing a state in which the first conductive member 800 and the second conductive member 900 are electrically connected. 4 and 5, the lid 200 and the like are not shown so that the positions of the first conductive member 800 and the second conductive member 900 are clear, and the opening end surface of the exterior body main body 100, The one conductive member 800, the second conductive member 900, and the insulating member 700 are shown with dots or diagonal lines. These supplementary matters regarding FIGS. 4 and 5 also apply to FIGS. 6 to 9 described later.

  As shown in FIGS. 4 and 5, power storage device 10 according to the present embodiment includes power storage element unit 350 including a plurality of power storage elements 300, first conductive member 800, and second conductive member 900. First conductive member 800 is disposed at a position facing the side surface of one of the plurality of power storage elements 300. The second conductive member 900 is disposed opposite to and spaced from the first conductive member 800 at a position opposite to the side surface with the first conductive member 800 interposed therebetween. The first conductive member 800 is connected to the positive electrode of the power storage element unit 350, and the second conductive member 900 is connected to the negative electrode of the power storage element unit 350.

  More specifically, the first conductive member 800 is connected to the positive electrode of the power storage element unit 350 by electrically connecting the connection portion 810 of the first conductive member 800 and the positive electrode terminal 351 of the power storage element unit 350. Is done. Further, the second conductive member 900 is connected to the negative electrode of the power storage element unit 350 by electrically connecting the connecting portion 910 of the second conductive member 900 and the negative electrode terminal 352 of the power storage element unit 350.

  Moreover, in this Embodiment, the 1st conductive member 800 and the 2nd conductive member 900 are metal plate-shaped members, such as aluminum, aluminum alloy, copper, or a copper alloy, for example, and thickness is about 1 mm, for example. is there. The second conductive member 900 has a contact portion 920 that is not provided with an insulating coating 930 (see FIG. 2) and has a metal surface exposed at a position facing the first conductive member 800. That is, for example, when the first conductive member 800 is moved or deformed so as to contact the contact portion 920, the first conductive member 800 and the second conductive member 900 are electrically connected.

  In the power storage device 10 having the above configuration, for example, when one of the plurality of power storage devices 300 is overcharged due to a malfunction of a device connected to the power storage device 10 or the like. Suppose. In this case, the power storage element 300 generates heat due to overcharging, and the evaporation of the electrolyte proceeds, and the container 310 expands due to the increase in internal pressure. At this time, the first conductive member 800 contacts with the contact portion 920 of the second conductive member 900 by moving (or deforming) in response to the force due to the side surface swelling. As a result, the plurality of power storage elements 300 included in the power storage element unit 350 are collectively in a state where a discharge path is generated. As a result, the electrical energy of the plurality of power storage elements 300 is consumed at an early stage, thereby mitigating unsafe events. That is, when an abnormality occurs in one power storage element 300, the electric energy of each of all the power storage elements 300 included in the power storage device 10 can be rapidly reduced, thereby reducing the situation when the abnormality occurs. Can be suppressed. Thus, power storage device 10 according to the present embodiment is power storage device 10 with improved safety.

  Further, for example, as compared to the case where the safety mechanism is arranged between two adjacent power storage elements as in the conventional technique, the space consumed for the arrangement of the safety mechanism is small. This is advantageous from the viewpoint of increasing the storage capacity (improvement of energy density) of the power storage device 10. Further, it is advantageous from the viewpoint of suppressing the manufacturing cost of the power storage device 10.

  Note that FIG. 5 illustrates a state in which the container 310 of the leftmost power storage element 300 is swollen. However, when any of the plurality of power storage elements 300 is swollen, the leftmost power storage element 300 is Displaces to the left under the influence. More specifically, each of the plurality of power storage elements 300 is free to move in the XY plane due to the presence of a restraining force due to, for example, a rib (not shown) included in the bus bar 400 and the exterior body main body 100. Absent. However, when at least one power storage element 300 swells, the other one or more power storage elements 300 and each element such as the bus bar 400 are deformed. As a result, for example, the leftmost power storage element 300 has a leftward movement. Displacement occurs. As a result, the first conductive member 800 that has moved (deformed) in response to the displacement comes into contact with the second conductive member 900. As a result, as described above, the plurality of power storage elements 300 are collectively connected to the discharge path. It can be set as the state which arose (state where the external short circuit arose).

  In addition, the various effects described above are exhibited even when the first conductive member 800 is connected to the negative electrode of the power storage element unit 350 and the second conductive member 900 is connected to the positive electrode of the power storage element unit 350. That is, first conductive member 800 may be connected to one of the positive electrode and the negative electrode of power storage element unit 350, and second conductive member 900 may be connected to the other of the positive electrode and the negative electrode of power storage element unit 350.

  Further, in power storage device 10 according to the present embodiment, each power storage element 300 does not have to include a member or a device for causing an external short circuit. Therefore, for example, a conventional power storage element can be employed as the power storage element 300 constituting the power storage element unit 350.

  In the present embodiment, first conductive member 800 is disposed at a position facing the long side surface of the long side surface and the short side surface of one power storage element 300. Specifically, the first conductive member 800 is disposed at a position facing the long side surface portion 312 that forms the long side surface of the container 310 of the power storage element 300.

  Here, the long side surface formed by the long side surface portion 312 of the electricity storage device 300 is the side surface having the largest area among the plurality of side surfaces of the container 310. Therefore, the long side surface portion 312 is a portion that easily swells as the internal pressure of the power storage element 300 (container 310) increases. In addition, the first conductive member 800 is disposed at a position where the first conductive member 800 is easily moved by receiving the force due to the swelling. Therefore, according to power storage device 10 according to the present embodiment, the formation of a discharge path (external short circuit) for suppressing the deterioration of the situation can be generated more reliably or earlier. That is, the effect of suppressing the deterioration of the situation at the time of occurrence of abnormality by the first conductive member 800 and the second conductive member 900 can be obtained more reliably.

  Further, in the present embodiment, the first conductive member 800 is disposed on the side surface of the power storage element 300 and facing the side surface in the stacking direction of the electrode plate 285 in the electrode body 280 included in the one power storage element 300. It is good as it is.

  Here, in general, the size of the electrode body having the stacked electrode plates when viewed from the stacking direction of the electrode plates is larger than the size when viewed from the direction orthogonal to the stacking direction. The size of the electrode body 280 according to the present embodiment when viewed from the X direction, which is one of the lamination directions of the electrode plates 285, is a direction orthogonal to the lamination direction (for example, the direction of the winding axis W (FIG. 3B In other words, the side surface in the stacking direction of the electrode plate 285 of the electrode body 280 (the long side surface in this embodiment) among the plurality of side surfaces of the container 310 of the power storage element 300. In other words, the long side surface portion 312 forming the side surface is a portion that easily swells as the internal pressure of the power storage element 300 (container 310) increases, as described above. For this reason, when the first conductive member 800 is disposed at a position facing the long side surface portion 312, when the power storage element 300 is in an unstable state, formation of a discharge path for suppressing deterioration of the situation ( More accurate external short circuit) Or more can be generated at an early stage. Therefore, according to the first conductive member 800 and the second conductive member 900, it is possible to obtain the effect of suppressing the deterioration of the situation at the time of occurrence of abnormality more reliably.

  In the present embodiment, the plurality of power storage elements 300 are arranged in a predetermined direction (the X-axis direction in the present embodiment), and the first conductive member 800 includes the X of the plurality of power storage elements 300. It arrange | positions in the position facing the side surface which is an end surface in an axial direction.

  More specifically, as shown in FIGS. 4 and 5, the plurality of power storage elements 300 included in the power storage element unit 350 are arranged side by side in the X-axis direction. The first conductive member 800 is an end surface in the X-axis direction of the plurality of power storage elements 300, and is the left side (most X-axis direction minus side) of the left-hand power storage element 300 (X-axis direction minus side facing the side surface). ) Is disposed at a position facing the long side surface portion 312.

  According to this configuration, the first conductive member 800 is arranged at a position facing the side surface that is the end surface of the row of the plurality of power storage elements 300. Therefore, when any one of the power storage elements 300 swells, the side surface can move to the negative side in the X-axis direction under the influence of the bulge, so that the side surface can press the first conductive member 800. . In addition, for example, when a plurality of power storage elements 300 swell at the same time, the side surface moves under the influence of the accumulation of the bulges and pushes the first conductive member 800, so that the deterioration of the situation is suppressed. The external short circuit can be executed more reliably or earlier.

  The power storage device 10 according to the present embodiment includes an exterior body 11 disposed outside the electrical storage element unit 350, and the second conductive member 900 is disposed on the inner surface of the exterior body 11.

  Specifically, in the present embodiment, as shown in FIG. 4, the second conductive member 900 is fixed to the inner surface 112 b of the side wall 112 and the inner surface 113 b of the side wall 113 of the exterior body main body 100. Thereby, for example, the stability of the position of the second conductive member 900 is obtained. Further, for example, the positioning of the second conductive member 900 with respect to the first conductive member 800 is facilitated.

  The second conductive member 900 only needs to have at least a portion in contact with the first conductive member 800 (contact portion 920 in the present embodiment). For example, one flat metal plate is disposed as a second conductive member 900 at a position facing the first conductive member 800, and the second conductive member 900 and the negative electrode terminal 352 of the power storage element unit 350 are connected to the cable. Or you may connect with a bus bar etc.

  In the present embodiment, first conductive member 800 is fixed to insulating member 700 disposed between the side surface of power storage element 300 and first conductive member 800.

  Specifically, the insulating member 700 according to the present embodiment is formed of an adhesive material such as silicone resin, and the first conductive member 800 is connected to the long side surface portion 312 of the power storage element 300 via the insulating member 700. It is fixed to.

  According to this configuration, for example, the position of the first conductive member 800 in a normal state can be stabilized while electrically insulating the first conductive member 800 and the container 310 of the power storage element 300. Further, for example, when a displacement in a direction approaching the second conductive member 900 occurs in the long side surface portion 312, the first conductive member 800 is moved so as to follow the displacement by interposing the insulating member 700. be able to.

  Note that the insulating member 700 disposed between the first conductive member 800 and the power storage element 300 may not be fixed to the side surface of the power storage element 300. For example, when a spacer that is a plate-like insulating member is disposed between two adjacent power storage elements 300, the first conductive member 800 may be fixed to the spacer. Even in this case, the effects such as the stabilization of the position of the first conductive member 800 in the normal state can be obtained.

  The power storage device 10 according to the embodiment has been described above, but the power storage device 10 may include the first conductive member 800 and the second conductive member 900 in a mode different from the modes illustrated in FIGS. . Therefore, hereinafter, a modified example of the structure related to the first conductive member 800 and the second conductive member 900 in the power storage device 10 will be described focusing on differences from the above-described embodiment.

(Modification 1)
FIG. 6 is a plan view showing a partial structure of power storage device 10a according to the first modification of the embodiment. In the power storage device 10a shown in FIG. 6, the first conductive member 800 disposed at a position facing the side surface of the power storage element 300 and the first conductive member at a position opposite to the side surface with the first conductive member 800 interposed therebetween. A second conductive member 900 that is opposed to and spaced apart from the member 800. Although not shown in FIG. 6, the first conductive member 800 is connected to the positive electrode of the power storage element unit 350, and the second conductive member 900 is connected to the negative electrode of the power storage element unit 350. These points are common to the above embodiment.

  However, in the power storage device 10a according to the present modification, the first conductive member 800 is disposed at a position facing the short side surface 313 instead of the long side surface 312 of the power storage element 300, and in this respect, the above embodiment is described. Is different. That is, the first conductive member 800 comes into contact with the second conductive member 900 when the short side surface portion 313 swells, whereby a plurality of power storage elements 300 are collectively discharged (external short circuit). A state in which the above occurs.

  According to this configuration, for example, an abnormality (swelling of the container 310) of at least one power storage element 300 in an intermediate portion in the arrangement direction among the plurality of power storage elements 300 arranged in a row is easily detected. That is, when at least one power storage element 300 in the middle portion of the row of power storage elements 300 swells, the first conductive member 800 can directly receive the swell. As a result, it is possible to more surely or earlier to form a collective discharge path (external short circuit) for the plurality of power storage elements 300 to suppress the deterioration of the situation.

  In addition, the first conductive member 800 can be disposed at a position facing the short side surface portion 313 of each of the plurality of power storage elements 300 (two power storage elements 300 in FIG. 6). Therefore, when any short side surface portion 313 of the plurality of power storage elements 300 swells, the first conductive member 800 can directly receive the swell.

(Modification 2)
FIG. 7 is a plan view showing a partial structure of power storage device 10b according to the second modification of the embodiment. FIG. 8 is a plan view showing a state where the reversing unit 820 included in the first conductive member 800 according to the second modification of the embodiment is reversed.

  In the power storage device 10a shown in FIGS. 7 and 8, the first conductive member 800 disposed at a position facing the side surface of the power storage element 300, and the position opposite to the side surface across the first conductive member 800, A second conductive member 900 disposed opposite to and spaced apart from the first conductive member 800. Although not shown in FIGS. 7 and 8, the first conductive member 800 is connected to the positive electrode of the power storage element unit 350, and the second conductive member 900 is connected to the negative electrode of the power storage element unit 350. ing. These points are common to the above embodiment.

  However, the first conductive member 800 included in the power storage device 10b according to the present modification includes the reversing portion 820 that bulges toward the power storage element 300, and this is different from the above embodiment.

  When the power storage element 300 swells, the first conductive member 800 according to this modification contacts the second conductive member 900 by reversing the reversing unit 820. Specifically, for example, as shown in FIG. 8, when the long side surface portion 312 of the power storage element 300 swells, the reversing portion 820 is pushed by the long side surface portion 312 via the insulating member 700. At this time, a portion of the first conductive member 800 around the reversing portion 820 is moved in the direction of the second conductive member 900 by the insulating member 750 disposed between the first conductive member 800 and the second conductive member 900. Movement is restricted. In this case, the pressing force by the long side surface portion 312 is efficiently applied to the reversing unit 820, and as a result, the reversing unit 820 is reversed. That is, the inversion part 820 changes to a state where it bulges toward the second conductive member 900. Thereby, the inversion part 820 contacts the 2nd conductive member 900, and the 1st conductive member 800 and the 2nd conductive member 900 conduct | electrically_connect.

  As described above, the first conductive member 800 may include the reversing part 820 that bulges toward the power storage element 300 and that reverses when receiving a pressing force by the side surface of the power storage element 300. When the first conductive member 800 includes the reversing portion 820, for example, the first conductive member 800 is larger than the amount of swelling of the power storage element 300 (the amount of displacement in the X-axis direction in FIG. 8), and a part of the first conductive member 800 (the reversing portion 820). The central part) can be displaced. As a result, for example, when normal conduction between the first conductive member 800 and the second conductive member 900 hardly occurs and the power storage element 300 swells, the first conductive member 800 and the second conductive member It becomes easy for electric conduction to 900 to occur.

  In the case where the first conductive member 800 includes the reversing portion 820, for example, a convex portion that protrudes toward the second conductive member 900 may be provided at the center of the reversing portion 820. Thereby, for example, when the reversing part 820 is reversed, the reversing part 820 and the second conductive member 900 can be more reliably brought into contact with each other.

  Further, for example, a protruding portion that protrudes toward the reversing portion 820 may be provided at a position of the insulating member 700 that contacts the reversing portion 820. Thereby, for example, when the power storage element 300 swells, the pressure (pressing force per unit area) applied to the inversion portion 820 by the insulating member 700 can be improved.

  Further, the reversing unit 820 may be disposed at a position facing the short side surface portion 313 instead of the long side surface portion 312 of the power storage element 300. That is, the first conductive member 800 according to this modification may be employed in the power storage device 10a according to Modification 1.

(Other embodiments)
The power storage device 10 according to the embodiment of the present invention and the modification thereof has been described above, but the present invention is not limited to the above-described embodiment and the modification.

  For example, in the above-described embodiment, the first conductive member 800 is disposed at a position facing the long side surface portion 312 that forms the end surface in the X-axis direction of the plurality of power storage elements 300. That is, the first conductive member 800 is arranged at the end of the row of the power storage elements 300 formed by the plurality of power storage elements 300. However, the first conductive member 800 may be disposed, for example, between the long side surface portion 312 of one of the two adjacent power storage devices 300 and the long side surface 312 of the other power storage device 300. Good.

  For example, the first conductive member 800 is fixed to the long side surface portion 312 of the left power storage element 300 of the two power storage elements 300 adjacent on the left and right via the insulating member 700. Further, the second conductive member 900 (more specifically, the contact portion 920) is fixed to the long side surface portion 312 of the right storage element 300 via the insulating member 700. Further, first conductive member 800 is connected to the positive electrode of power storage element unit 350, and second conductive member 900 is connected to the negative electrode of power storage element unit 350.

  According to this configuration, for example, when one of the one or more power storage elements 300 on the left side of the first conductive member 800 swells, the first conductive member 800 is influenced by the bulge and approaches the second conductive member 900. Displace in the direction. For example, when one of the one or more power storage elements 300 on the right side of the second conductive member 900 swells, the second conductive member 900 is displaced in a direction approaching the first conductive member 800 under the influence of the bulge. . In either case, the first conductive member 800 and the second conductive member 900 can be brought into contact with each other. In this case, the same effect as that obtained by the power storage device 10a according to the modification can be obtained. That is, when at least one power storage element 300 in the middle part of the row of power storage elements 300 swells, the first conductive member 800 can directly receive the swell. As a result, it is possible to more surely or earlier to form a collective discharge path (external short circuit) for the plurality of power storage elements 300 to suppress the deterioration of the situation.

  Further, in the power storage device 10 described above, each of the first conductive member 800 and the second conductive member 900 may not be directly connected to the negative electrode or the positive electrode of the power storage element unit 350. For example, at least one of the first conductive member 800 and the second conductive member 900 may be connected to the positive electrode or the negative electrode of the power storage element unit 350 via a resistor.

  For example, a resistor having an electrical resistance element may be disposed between the positive electrode of the power storage element unit 350 and the first conductive member 800. Further, for example, a wiring material having a relatively high electrical resistance may be disposed in at least a part of the conduction path between the positive electrode of the power storage element unit 350 and the first conductive member 800, for example. The same applies to the negative electrode of the electricity storage element unit 350 and the second conductive member 900.

  Thus, by interposing a resistor in the electrical connection between at least one of the first conductive member 800 and the second conductive member 900 and the electric element unit 350, the first conductive member 800 and the second conductive member 900 are When conducting, the possibility that the current flowing through the power storage element unit 350 becomes excessive is reduced.

  In the above embodiment, each of the plurality of power storage elements 300 included in the power storage device 10 is, for example, a rectangular lithium ion secondary battery. However, the type and shape of the battery employed as the power storage element 300 are not limited to a specific type and shape.

  For example, a cylindrical battery may be employed as the power storage element 300. In addition, a laminated battery in which the electrode body is sealed with a laminate may be employed as the power storage element 300. In any case, by disposing the first conductive member 800 and the second conductive member 900 as described above, it is possible to suppress deterioration of the situation at the time of occurrence of abnormality, thereby improving safety. Is done.

  Specifically, in any case of a cylindrical battery and a laminated battery, for example, the side surface located in the stacking direction of the electrode plates tends to swell when the internal pressure in the battery container increases. Therefore, it is preferable to arrange the first conductive member 800 and the second conductive member 900 at a position facing the side surface.

  In the above embodiment, all (eight) power storage elements 300 included in the power storage device 10 are electrically connected as one power storage element unit 350. However, a part of all the power storage elements 300 included in the power storage device 10 and two or more power storage elements 300 may be handled as one power storage element unit.

  Further, the material of the first conductive member 800 and the second conductive member 900 is not limited to metal. For example, the first conductive member 800 or the second conductive member 900 may be formed of a conductive resin containing a conductive filler. In this case, for example, the degree of freedom of the shape of the first conductive member 800 or the second conductive member 900 formed of a conductive resin is increased.

  In the exterior body 11, the position of the inner surface where the second conductive member 900 is disposed is not limited to the side wall 112 or 113. For example, a part of the second conductive member 900 may be disposed on the inner surface of the lid body 200 of the exterior body 11.

  In addition, embodiments constructed by arbitrarily combining the constituent elements included in the above-described embodiment and its modifications are also included in the scope of the present invention. For example, you may add the structure of a modification to the structure of embodiment.

  The present invention can be applied to a power storage device including a plurality of power storage elements such as lithium ion secondary batteries.

10, 10 a, 10 b Power storage device 11 Exterior body 100 Exterior body body 112, 113 Side wall 112 b, 113 b Inner surface 200 Lid body 210 Positive electrode external terminal 220 Negative electrode external terminal 240 Positive electrode current collector 250 Negative electrode current collector 280 Electrode body 285 Electrode plate 300 Power storage element 310 Container 311 Bottom surface portion 312 Long side surface portion 313 Short side surface portion 314 Container lid portion 315 Container body 319 Gas exhaust valve 320, 351 Positive electrode terminal 330, 352 Negative electrode terminal 350 Power storage device unit 400 Bus bar 410 Positive electrode lead plate 420 Negative electrode lead plate 700, 750 Insulating member 800 First conductive member 810, 910 Connection portion 820 Inversion portion 900 Second conductive member 920 Contact portion 930 Insulation coating

Claims (7)

A power storage element unit including a plurality of power storage elements;
A first conductive member disposed at a position facing a side surface of one of the plurality of power storage elements;
A second conductive member disposed at a position opposite to the side surface across the first conductive member, and facing the first conductive member and spaced apart;
The first conductive member is connected to one of a positive electrode and a negative electrode of the power storage element unit,
The power storage device, wherein the second conductive member is connected to the other of the positive electrode and the negative electrode of the power storage element unit. The power storage device according to claim 1, wherein the first conductive member is disposed at a position facing the long side surface of the long side surface and the short side surface of the one power storage element, which is the side surface. The power storage device according to claim 1, wherein the first conductive member is disposed at a position facing the side surface in the stacking direction of the electrode plates in the electrode body of the one power storage element. The plurality of power storage elements are arranged side by side in a predetermined direction,
The power storage device according to any one of claims 1 to 3, wherein the first conductive member is disposed at a position facing the side surface that is an end surface in the predetermined direction of the plurality of power storage elements. Furthermore, an exterior body disposed outside the electricity storage element unit is provided,
The power storage device according to claim 1, wherein the second conductive member is disposed on an inner surface of the exterior body. The power storage device according to claim 1, wherein the first conductive member is fixed to an insulating member disposed between the side surface and the first conductive member. The power storage according to any one of claims 1 to 6, wherein at least one of the first conductive member and the second conductive is connected to the positive electrode or the negative electrode of the power storage element unit via a resistor. apparatus.

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