JP2020053152A - Power storage device - Google Patents

Abstract

To provide a power storage device which allows improvement in safety.SOLUTION: A power storage device 10 provided with a power storage element 100 having an electrode body 160 comprises: a first conductive part and a second conductive part (a positive electrode terminal 120 of a power storage element 100a and a negative electrode terminal 130 of a power storage element 100b) which are paths for a current flowing through the electrode body 160 and are arranged on the outer side of the power storage element 100; a fuse part 231 which is provided in a third conductive part (an intermediate part 230) located between the first conductive part and the second conductive part, and cuts off a conductive state of the third conductive part; and a resistor 300 which keeps a conductive state between the first conductive part and the second conductive part even if a conductive state in the fuse part 231 is cut off.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power storage device including a fuse unit.

  Conventionally, a power storage element including a fuse unit has been known. For example, Patent Literature 1 discloses a secondary battery (electric storage element) that includes a fuse portion inside and outside a cell to prevent abnormal destruction inside the cell due to short circuit and improve safety. Have been.

JP 2015-5492A

  However, in the above-described conventional configuration, when the fuse portion is blown, the current path is interrupted, so that the electric capacity remains inside the power storage element, and the power storage element becomes in an unstable state. There is a risk. That is, the power storage element is often used in a power storage device (battery assembly, module), and an external short circuit may occur due to an external impact or the like. When an external short circuit occurs, a short-circuit current flows through the storage element, and the storage element enters an unsafe state. Therefore, the current path is cut off by a fuse. However, even if the current path is cut off by a fuse, another unsafe event may occur if the electric capacity remains in the storage element that has been subjected to an external impact or the like. Further, when the fuse portion is blown inside the electric storage element, there is a possibility that a spark may be generated inside the electric storage element. As described above, the inventor of the present application has found that even in the above-described conventional configuration, there is a point where safety should be further improved.

  The present invention has been made in view of the above problems, and has as its object to provide a power storage device capable of improving safety.

  In order to achieve the above object, a power storage device according to one embodiment of the present invention is a power storage device including a power storage element including an electrode body, wherein the power storage device is a path of a current flowing through the electrode body and is located outside the power storage element. A first conductive part and a second conductive part, and a fuse part provided in the third conductive part between the first conductive part and the second conductive part, for interrupting a conductive state of the third conductive part And a resistor that maintains a conductive state between the first conductive part and the second conductive part even when the conductive state in the fuse part is cut off.

  According to this, the power storage device is configured such that the first conductive portion and the second conductive portion on the outer side of the power storage element and the fuse portion that cuts off the conductive state of the third conductive portion between the first conductive portion and the second conductive portion. And a resistor that maintains a conductive state between the first conductive part and the second conductive part even when the conductive state is interrupted. As described above, even when the conduction state is cut off by the fuse portion, current can flow through the resistor to discharge the electric capacity of the power storage element, so that safety can be improved. In addition, since the fuse portion is disposed outside the power storage element, it is possible to prevent a spark from being generated inside the power storage element due to the fuse portion, thereby improving safety.

  Further, the third conductive portion is a part of a bus bar connected to an electrode terminal of the power storage element, and the resistor is connected to a position different from the third conductive portion of the bus bar. You may.

  According to this, the third conductive portion is a part of the bus bar, and the resistor is connected to a position different from the third conductive portion of the bus bar. As described above, by providing the fuse portion on the bus bar and connecting the resistor to the bus bar, safety can be improved with a simple configuration. In particular, compared to the case where a resistor is connected to a member different from the bus bar, the power storage device can be handled in a state where the resistor is connected to the bus bar at the time of manufacturing the power storage device or the like. be able to.

  The third conductive portion may be a bus bar connected to an electrode terminal of the power storage device, and the resistor may be connected to the electrode terminal.

  According to this, the third conductive portion is a bus bar, and the resistor is connected to the electrode terminal of the power storage element. As described above, by providing the fuse portion on the bus bar and connecting the resistor to the electrode terminal of the power storage element, safety can be improved with a simple configuration. In particular, even when it is difficult to connect a resistor to the bus bar, by directly connecting the resistor to the electrode terminal of the power storage element, it is not necessary to use a separate member, so that the power storage device can be easily configured. .

  Further, the bus bar may have a concave portion, and the resistor may be at least partially disposed in the concave portion.

  According to this, at least a part of the resistor is arranged in the recess of the bus bar. By arranging the resistor in the recess of the bus bar, safety can be improved while saving space.

  Further, one of the first conductive portion and the second conductive portion may be an electrode terminal of the power storage device, and the other may be an external terminal of the power storage device.

  According to this, since the electrode terminal of the power storage device and the external terminal of the power storage device correspond to the first conductive portion and the second conductive portion, the fuse portion and the resistor are connected to the electrode terminal of the power storage device and the external terminal of the power storage device. And will be arranged between them. Thereby, regardless of the arrangement or connection form of the power storage element in the power storage device, the fuse portion and the resistor are disposed on the path of the main current flowing through the power storage device, so that a simple configuration and safety can be achieved. Can be improved.

  Note that the present invention can be realized not only as such a power storage device, but also as a third conductive portion and a resistor provided with a fuse portion.

  According to the power storage device of the present invention, safety can be improved.

FIG. 3 is a perspective view illustrating an appearance of a power storage device according to an embodiment. FIG. 2 is an exploded perspective view illustrating a configuration of a power storage element according to an embodiment. FIG. 3 is a plan view showing a configuration of a bus bar and a resistor according to the embodiment. FIG. 9 is a plan view showing a configuration of a bus bar and a resistor according to a first modification of the embodiment. FIG. 9 is a plan view showing a configuration of a bus bar and a resistor according to a first modification of the embodiment. FIG. 13 is a plan view showing a configuration of a bus bar and a resistor according to a second modification of the embodiment. FIG. 13 is a plan view showing a configuration of a bus bar and a resistor according to a third modification of the embodiment. FIG. 13 is a conceptual diagram illustrating a configuration of a power storage device including a bus bar and a resistor according to Modification 4 of the embodiment. FIG. 13 is a conceptual diagram illustrating a configuration of a power storage device including a bus bar and a resistor according to Modification 4 of the embodiment. FIG. 13 is a conceptual diagram illustrating a configuration of a power storage device including a bus bar and a resistor according to Modification 4 of the embodiment. FIG. 13 is a conceptual diagram illustrating a configuration of a power storage device including a bus bar and a resistor according to Modification 4 of the embodiment.

  Hereinafter, a power storage device according to an embodiment (and a modification thereof) of the present invention will be described with reference to the drawings. Each of the embodiments described below shows a comprehensive or specific example. Numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection forms, and the like shown in the following embodiments are merely examples, and do not limit the present invention. In addition, among the components in the following embodiments, components not described in the independent claims indicating the highest concept are described as arbitrary components. In addition, each drawing is a schematic diagram, and dimensions and the like are not necessarily strictly illustrated. Further, in each drawing, the same or similar components are denoted by the same reference numerals.

  In the following description and drawings, the direction in which the electrode terminals (that is, the positive electrode terminal and the negative electrode terminal) in one power storage element are arranged, or the direction in which the short side surface of the container of the power storage element faces, is defined as the X-axis direction. In addition, the direction in which the power storage elements are arranged, the direction in which the long sides of the power storage elements face each other, the thickness direction of the container, or the extending direction of the bus bar is defined as the Y-axis direction. Further, the direction in which the exterior body main body and the lid of the power storage device are aligned, the direction in which the power storage element container main body and the lid are aligned, the longitudinal direction of the short side surface of the power storage element container, or the vertical direction is defined as the Z-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect each other (orthogonal in the present embodiment). Although the Z-axis direction may not be in the vertical direction depending on the usage mode, the Z-axis direction will be described as the vertical direction for convenience of description below. In the following description, for example, the plus side in the X-axis direction indicates the arrow direction side of the X-axis, and the minus side in the X-axis direction indicates the opposite side to the plus side in the X-axis direction. The same applies to the Y-axis direction and the Z-axis direction.

(Embodiment)
[1 General description of power storage device 10]
First, a general description of power storage device 10 in the present embodiment will be given. FIG. 1 is a perspective view showing the appearance of power storage device 10 according to the present embodiment. Note that this figure is a diagram showing the inside of the exterior body 600 as seen through the exterior body 600, and the exterior body 600 (and two external terminals 610) is indicated by broken lines.

  The power storage device 10 is a device that can charge electricity from the outside and discharge electricity to the outside. For example, the power storage device 10 is a battery module (assembled battery) used for power storage or power supply. Specifically, the power storage device 10 is, for example, a vehicle such as an electric vehicle (EV), a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV), a motorcycle, a watercraft, a snowmobile, an agricultural machine, and a construction machine. It is used as a battery for driving a moving body such as a machine or for starting an engine.

  As shown in FIG. 1, power storage device 10 includes a plurality of power storage elements 100 (six power storage elements 100 a to 100 f in the present embodiment), bus bars 200, 400 and 500, resistors 300, and these power storage elements. 100 and an exterior body 600 that accommodates the bus bar 200 and the like. The power storage device 10 includes a spacer disposed between the power storage elements 100, a restraining member or an end plate that restrains the power storage element 100, a bus bar frame for positioning the bus bar 200, and the like, and monitors a charged state and a discharged state of the power storage element 100. May also be provided, such as a circuit board and an electrical device such as a relay, but these are not shown in the drawings, and detailed description thereof is also omitted.

  The exterior body 600 is a substantially rectangular parallelepiped (box-shaped) container (module case) constituting the exterior body of the power storage device 10. That is, the exterior body 600 is disposed outside the power storage element 100 and the bus bar 200 and the like, and the power storage element 100 and the bus bar 200 and the like are disposed at predetermined positions to protect the power storage element 100 and the bus bar 200 from impact and the like. The exterior body 600 is made of, for example, an insulating material such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polyphenylene sulfide resin (PPS), polybutylene terephthalate (PBT), or ABS resin. The exterior body 600 thereby prevents the power storage element 100, the bus bar 200, and the like from coming into contact with an external metal member or the like.

  Specifically, exterior body 600 has a box-shaped main body part and a lid part, and power storage element 100, bus bar 200, and the like are housed in exterior body 600. Further, two external terminals 610 are provided on the exterior body 600. The two external terminals 610 are external connection terminals on the positive electrode side and the negative electrode side for charging electricity from outside the power storage device 10 and discharging electricity to the outside of the power storage device 10, such as aluminum or an aluminum alloy. Formed of a metal conductive member or the like. Note that exterior body 600 may include a partition plate or the like that partitions between power storage elements 100. In addition, the shape and material of the exterior body 600 are not limited to the above.

  The storage element 100 is a secondary battery (single battery) that can charge and discharge electricity, and more specifically, is a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery. . In this embodiment, six flat rectangular parallelepiped (square) power storage elements 100 (power storage elements 100a to 100f) are arranged in series.

  Note that the number of power storage elements 100 is not limited to six, and may be another number or one. Further, the shape of power storage element 100 is not limited to a rectangular parallelepiped shape (square), and may be a columnar shape, an elongated columnar shape, or a laminate type power storage element. The storage element 100 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than the non-aqueous electrolyte secondary battery or a capacitor. Further, power storage element 100 may be a primary battery that can use stored electricity without a user charging, instead of a secondary battery. Further, power storage element 100 may be a battery using a solid electrolyte. Detailed description of the configuration of power storage element 100 will be described later.

  Bus bars 200, 400 and 500 are members arranged above a plurality of power storage elements 100. Each of bus bars 200, 400, and 500 is a conductive rectangular and flat plate-shaped member, and electrically connects a plurality of power storage elements 100 and the power storage element 100 at an end to external terminal 610. For example, the bus bars 200, 400, and 500 are formed of a metal conductive member such as aluminum or an aluminum alloy. Specifically, bus bars 200 and 400 electrically connect a positive terminal or a negative terminal of one storage element 100 to a negative terminal or a positive terminal of another storage element 100 in adjacent storage elements 100. Further, bus bar 500 electrically connects the positive terminal or the negative terminal of power storage element 100 at the end to external terminal 610 on the positive or negative side. In FIG. 1, the bus bar 500 is not illustrated with a connection portion with the external terminal 610 omitted.

  For example, the bus bar 200 has one end joined to the positive terminal of the storage element 100a by welding or the like, and the other end joined to the negative terminal of the storage element 100b by welding or the like, so that the positive terminal of the storage element 100a and the storage element 100b are connected. Is electrically connected to the negative terminal. The bus bar 400 has one end joined to the positive terminal of the storage element 100b by welding or the like, and the other end joined to the negative terminal of the storage element 100c by welding or the like, so that the positive terminal of the storage element 100b and the storage element 100c are connected. Is electrically connected to the negative terminal. Similarly, bus bar 400 also sequentially connects the positive terminal and the negative terminal of power storage elements 100c to 100f. Thus, bus bars 200 and 400 connect a plurality of power storage elements 100 (power storage elements 100a to 100f) in series. Further, bus bar 500 has one end joined to the negative terminal of power storage element 100a by welding or the like, and the other end joined to external terminal 610 on the negative side by bolting or the like, so that the negative terminal of power storage element 100a and the negative electrode side are connected. Is electrically connected to the external terminal 610. Similarly, bus bar 500 electrically connects the positive terminal of power storage element 100f to external terminal 610 on the positive side.

  In addition, the material of the busbars 200, 400, and 500 is not particularly limited. For example, the busbars 200, 400, and 500 may be formed of a metal such as copper, a copper alloy, and stainless steel, or a conductive member other than the metal. Further, the shapes of busbars 200, 400, and 500 are not particularly limited. Further, bus bars 200 and 400 may be arranged so as to connect a plurality of power storage elements 100 in parallel.

  Further, a resistor 300 is connected to the bus bar 200. The resistor 300 is a member having a larger resistance value than the bus bar 200 (specifically, a fuse portion 231 of the bus bar 200 described later). Detailed descriptions of the configurations of the bus bar 200 and the resistor 300 will be described later.

[2 Detailed description of power storage element 100]
Next, power storage element 100 (power storage elements 100a to 100f) will be described in detail. Note that power storage elements 100a to 100f all have the same configuration, and thus will be described as power storage element 100 below. FIG. 2 is an exploded perspective view showing the configuration of power storage device 100 according to the present embodiment.

  As shown in FIG. 2, the power storage element 100 includes a container 110 including a container main body 111 and a lid 112, a positive terminal 120, and a negative terminal 130. The body 140, the negative electrode current collector 150, and the electrode body 160 are housed. A gasket or the like is arranged between the lid 112 and the positive electrode terminal 120 and the positive electrode current collector 140 in order to enhance insulation and airtightness, but is omitted in FIG. The same applies to the negative electrode side. An electrolytic solution (a non-aqueous electrolyte) is sealed in the container 110, but is not shown. The type of the electrolytic solution is not particularly limited as long as the performance of the electric storage element 100 is not impaired, and various types can be selected. Further, in addition to the above components, a spacer disposed on the side of the positive electrode current collector 140 and the negative electrode current collector 150, a gas discharge valve for releasing the pressure when the pressure in the container 110 increases, and An insulating film or the like that wraps around the electrolyte injection portion or the electrode body 160 may be provided.

  The container 110 includes a container body 111 having a rectangular tubular shape and having a bottom, and a lid 112 that is a plate-like member that closes an opening of the container body 111. Further, the container 110 has a structure in which the inside of the container 110 is sealed by, for example, welding the container body 111 and the lid 112 after housing the electrode body 160 and the like inside. The materials of the container body 111 and the lid 112 are not particularly limited, and may be, for example, a weldable metal such as stainless steel, aluminum, an aluminum alloy, iron, a plated steel plate, or a resin.

  The electrode body 160 is a power storage element (power generation element) formed by stacking a positive electrode plate, a negative electrode plate, and a separator. Here, the positive electrode plate included in the electrode body 160 is one in which a positive electrode active material layer is formed on a positive electrode base material layer which is a long strip-shaped current collector foil made of a metal such as aluminum or an aluminum alloy. In addition, the negative electrode plate is obtained by forming a negative electrode active material layer on a negative electrode base material layer which is a long strip-shaped current collector foil made of a metal such as copper or a copper alloy. As the positive electrode active material used for the positive electrode active material layer and the negative electrode active material used for the negative electrode active material layer, a known material can be appropriately used as long as it can store and release lithium ions.

  The positive electrode terminal 120 is an electrode terminal electrically connected to the positive electrode plate of the electrode body 160, and the negative electrode terminal 130 is an electrode terminal electrically connected to the negative electrode plate of the electrode body 160. That is, the positive electrode terminal 120 and the negative electrode terminal 130 lead the electricity stored in the electrode body 160 to the space outside the power storage element 100, and also store the electricity in the electrode body 160 inside the space inside the power storage element 100. Is a metal electrode terminal for introducing the electrode. The positive terminal 120 and the negative terminal 130 are attached to the lid 112. Specifically, the shaft of the positive electrode terminal 120 is inserted into the through-hole of the lid 112 and the through-hole of the positive electrode current collector 140 and caulked, so that the positive electrode terminal 120 is fixed to the lid 112 together with the positive electrode current collector 140. Is done. The same applies to the negative electrode terminal 130.

  The material of the positive electrode terminal 120 is not limited. For example, the positive electrode terminal 120 is formed of a metal such as aluminum or an aluminum alloy like the positive electrode base layer of the electrode body 160. Also, the material of the negative electrode terminal 130 is not limited. For example, the shaft portion is formed of a metal such as copper or a copper alloy like the negative electrode base layer of the electrode body 160, and the portion other than the shaft portion is made of aluminum. Or, it is formed of a metal such as an aluminum alloy.

  The positive electrode current collector 140 is a member having conductivity and rigidity electrically connected to the positive electrode terminal 120 and the positive electrode plate of the electrode body 160. The negative electrode current collector 150 is a member having conductivity and rigidity that is electrically connected to the negative electrode terminal 130 and the negative electrode plate of the electrode body 160. The material of the positive electrode current collector 140 is not limited. For example, the positive electrode current collector 140 is formed of a metal such as aluminum or an aluminum alloy like the positive electrode base material layer of the electrode body 160. The material of the negative electrode current collector 150 is not limited, either. For example, like the negative electrode base layer of the electrode body 160, the negative electrode current collector 150 is formed of a metal such as copper or a copper alloy.

[3 Detailed description of bus bar 200 and resistor 300]
Next, the bus bar 200 and the resistor 300 will be described in detail. FIG. 3 is a plan view showing a configuration of the bus bar 200 and the resistor 300 according to the present embodiment. Specifically, FIG. 3A is a top view of the bus bar 200 and the resistor 300 shown in FIG. 1 as viewed from the plus side in the Z-axis direction, and FIG. FIG. 3 is a side view of the resistor 300 viewed from the plus side in the X-axis direction.

  As shown in FIG. 3, the bus bar 200 has a first end 210, a second end 220, and an intermediate part 230. First end portion 210 is a rectangular and flat plate-shaped portion disposed at the end of bus bar 200 on the negative side in the Y-axis direction, and is connected (joined) to positive electrode terminal 120 of power storage element 100a by welding or the like. . That is, first end portion 210 is a portion connected to positive electrode terminal 120 of power storage element 100a (a portion including the connected portion). The second end portion 220 is a rectangular and flat plate-shaped portion arranged at the end of the bus bar 200 on the plus side in the Y-axis direction, and is connected (joined) to the negative electrode terminal 130 of the electric storage element 100b by welding or the like. . That is, the second end portion 220 is a portion connected to the negative electrode terminal 130 of the power storage element 100b (a portion including the connected portion). The intermediate part 230 is a flat part arranged between the first end 210 and the second end 220.

  As a method of connecting (joining) the first end portion 210 and the positive electrode terminal 120 of the electric storage element 100a, any welding such as resistance welding, laser welding, or ultrasonic welding may be used, and screw fastening or swaging may be used. Mechanical joining such as joining may be used. The same applies to a method of connecting (joining) the second end 220 to the negative electrode terminal 130 of the power storage device 100b.

  The positive terminal 120 of the power storage device 100a is an example of a first conductive portion, the negative terminal 130 of the power storage device 100b is an example of a second conductive portion, and the intermediate portion 230 is an example of a third conductive portion. is there. In other words, the positive terminal 120 of the power storage element 100a and the negative terminal 130 of the power storage element 100b are paths of the current flowing through the electrode body 160 and correspond to the first conductive part and the second conductive part disposed outside the power storage element 100. This is an example. Further, intermediate portion 230 is an example of a third conductive portion that is a part of bus bar 200 connected to the electrode terminal of power storage element 100. As described above, the first conductive portion, the third conductive portion, and the second conductive portion are arranged in series and continuously.

  Here, the current flowing through electrode body 160 is a charge / discharge current (main current) of power storage element 100. That is, the first conductive part and the second conductive part are arranged on the path of the charge / discharge current (main current) flowing through the power storage device 10. In addition, the first conductive portion and the second conductive portion are referred to as a positive electrode terminal 120 and a negative electrode terminal 130, instead of a portion inside the power storage element 100 such as the positive electrode current collector 140, the negative electrode current collector 150, and the electrode body 160. This is a portion on the outside of the power storage element 100 (a portion disposed outside the container 110). Note that the first end 210 and the second end 220 may be an example of a first conductive part and a second conductive part.

  The intermediate portion 230 has a fuse portion 231 at the center in the Y-axis direction. Specifically, the fuse portion 231 having a smaller cross-sectional area than other portions is formed by recessing the middle portion of the intermediate portion 230 in the positive and negative directions in the X-axis direction. Specifically, since the width of the intermediate portion 230 in the X-axis direction is reduced, the cross-sectional area of the fuse portion 231 in a plane (XZ plane) orthogonal to the current flowing direction (Y-axis direction) is reduced. 230 is a part smaller than other parts. As a result, the fuse portion 231 is blown by a large current flowing through the bus bar 200 and cuts off the conduction state of the intermediate portion 230. In other words, the fuse part 231 is provided in the third conductive part between the first conductive part and the second conductive part, and is a part that cuts off the conduction state of the third conductive part.

  In the present embodiment, the width (thickness) of the fuse portion 231 in the Z-axis direction is the same as other portions of the intermediate portion 230, but the width of the intermediate portion 230 in the Z-axis direction is also different. May be smaller than the other parts. If the cross-sectional area of fuse portion 231 is smaller than other portions of intermediate portion 230, the width of fuse portion 231 in the Z-axis direction may be larger than other portions of intermediate portion 230. . Alternatively, if the width of the fuse portion 231 in the Z-axis direction is smaller than the other portion of the intermediate portion 230 and the sectional area of the fuse portion 231 is smaller than that of the other portion of the intermediate portion 230, the fuse portion 231 may be used. May be the same as or larger than other portions of the intermediate portion 230 in the X-axis direction.

  Further, in the present embodiment, the surface of the intermediate portion 230 on the plus side in the X-axis direction is recessed from the plus surface of the first end portion 210 and the second end portion 220 on the minus side in the X-axis direction. Is located in the position. That is, since the width of the intermediate portion 230 in the X-axis direction is smaller than the widths of the first end portion 210 and the second end portion 220, the concave portion 240 is formed on the X-axis direction plus side of the intermediate portion 230. . Then, at least a part of the resistor 300 is disposed in the concave portion 240. Thus, the resistor 300 is arranged in parallel with the intermediate section 230 (fuse section 231). In the present embodiment, a portion on the negative side in the Z-axis direction of resistor 300 is arranged in concave portion 240. Note that the entire resistor 300 may be disposed in the recess 240.

  One end of the resistor 300 is connected to the first end 210 via the lead 310, and the other end is connected to the second end 220. Specifically, the end of the lead 310 connected to the negative side in the Y-axis direction of the resistor 300 is connected (joined) to the first end 210 by welding or the like, and the end of the lead 310 is connected to the negative side in the Y-axis direction. An end of the lead 310 connected to the positive side in the Y-axis direction on the positive side in the Y-axis direction is connected (joined) to the second end 220 by welding or the like. As described above, the resistor 300 is connected to a position different from the intermediate portion 230 of the bus bar 200, that is, to the first end 210 and the second end 220 sandwiching the intermediate portion 230 of the bus bar 200. That is, the resistor 300 has one end connected to the positive terminal 120 of the storage element 100a via the first end 210, and the other end connected to the negative terminal 130 of the storage element 100b via the second end 220. I have.

  The resistor 300 is arranged such that the lead 310 is connected to the upper surface (the surface on the positive side in the Z-axis direction) of the first end portion 210 and the second end portion 220. And the lower surface of the second end 220 (the surface on the negative side in the Z-axis direction). As a method of connecting (joining) the lead 310 to the first end 210 and the second end 220, any welding such as resistance welding, laser welding, ultrasonic welding, or the like may be used. Mechanical joining such as fastening or swaging may be used.

  Accordingly, even when the conduction state of the intermediate portion 230 in the fuse portion 231 is cut off, the resistor 300 maintains the conduction state between the first end portion 210 and the second end portion 220. In other words, resistor 300 maintains a conductive state between positive electrode terminal 120 of power storage element 100a and negative electrode terminal 130 of power storage element 100b even when the conductive state in fuse portion 231 is cut off. In other words, the resistor 300 is connected to a position different from the third conductive portion of the bus bar 200, and even when the conduction state in the fuse portion 231 is cut off, the resistor 300 is connected between the first conductive portion and the second conductive portion. Maintain the conduction state.

Note that when the conduction state of the intermediate unit 230 in the fuse unit 231 is interrupted due to an excessive current flowing due to an external short circuit or the like in the power storage device 10, the resistor 300 is provided within the power storage element 100 included in the power storage device 10. It has a resistance value large enough to discharge the electric capacity in a relatively short time (several hours to one day). Further, the resistor 300 has a rated voltage that does not generate a large amount of heat and does not break even at the maximum voltage of the power storage device 10 even when the conduction state in the fuse unit 231 is cut off and a current flows through the resistor 300. Body. The resistance value and the rated power (allowable power) of the resistor 300 are appropriately determined according to the magnitude of the electric capacity and voltage of the power storage device 10, the time to complete the discharge, and the like. It is preferable that the fuse portion 231 has a resistance value significantly larger than the resistance value. For example, resistor 300 is 10 several powers about twice the resistance value of the fuse portion 231, specifically, preferably has a 10 ⁹ times the resistance value (for example 1 k [Omega, about 2W～3W) . Further, since bus bar 200 is arranged outside power storage element 100, fuse portion 231 and resistor 300 are also disposed outside power storage element 100.

[4 Effect description]
As described above, according to power storage device 10 according to the embodiment of the present invention, third conductive portion (between the first conductive portion and the second conductive portion (two electrode terminals) on the outer side of power storage element 100). The fuse unit 231 interrupts the conduction state of the intermediate unit 230), and the resistor 300 maintains the conduction state between the first conductive unit and the second conductive unit even when the conduction state is interrupted. . As described above, even when the conduction state is cut off by the fuse portion 231, current can flow through the resistor 300 to discharge the electric capacity of the power storage element 100, so that safety can be improved. Further, since fuse portion 231 is arranged outside power storage element 100, it is possible to prevent sparks from being generated inside power storage element 100 due to fuse portion 231, thereby improving safety. be able to.

  Further, since the fuse portion 231 and the resistor 300 are arranged outside the power storage device 100, the safety can be easily improved without modifying the existing power storage device. Further, it is not necessary to provide the fuse portion 231 and the resistor 300 in each power storage device 100, and it is sufficient to provide a pair of fuse portions 231 and the resistor 300 for a plurality of power storage devices 100. It can be easily configured.

  The third conductive part is a part of the bus bar 200, and the resistor 300 is connected to a position different from the third conductive part of the bus bar 200. As described above, by providing the fuse portion 231 in the bus bar 200 and connecting the resistor 300 to the bus bar 200, safety can be improved with a simple configuration. In particular, compared to the case where the resistor 300 is connected to a member (such as an electrode terminal of the power storage element 100) different from the bus bar 200, the state in which the resistor 300 is connected to the bus bar 200 is used in manufacturing the power storage device 10 or the like. Therefore, the work of assembling the power storage device 10 and the like can be facilitated.

  In addition, at least a part of the resistor 300 is disposed in the recess 240 of the bus bar 200. By arranging the resistor 300 in the recess 240 of the bus bar 200 in this manner, safety can be improved while saving space.

[5 Description of Modification]
(Modification 1)
Next, a first modification of the above embodiment will be described. FIGS. 4 and 5 are plan views showing the configurations of the bus bars 201 and 202 and the resistor 300 according to the first modification of the present embodiment. Specifically, (a) and (b) of FIG. 4 are diagrams corresponding to (a) and (b) of FIG. FIG. 5 is a diagram corresponding to FIG. 3B or FIG. 4B.

  First, as illustrated in FIG. 4, the power storage device according to the present modification includes a bus bar 201 instead of the bus bar 200 of the above embodiment. The bus bar 201 has a curved intermediate portion 230a instead of the flat intermediate portion 230 of the above embodiment. Specifically, the intermediate portion 230a is a curved portion (hinge portion) provided so that the first end portion 210 and the second end portion 220 of the bus bar 201 can move in the Y-axis direction and the Z-axis direction. It is provided to protrude from the first end 210 and the second end 220 to the plus side in the Z-axis direction. In addition, the fuse part 231 is provided in the intermediate part 230a similarly to the intermediate part 230 of the above embodiment. That is, the fuse portion 231 is a curved portion of the bus bar 201 located between two portions (first end portion 210 and second end portion 220) connected to the electrode terminals of the two power storage elements 100. Are located in

  With this configuration, a concave portion 241 is formed on the minus side in the Z-axis direction of the intermediate portion 230a. That is, the bus bar 201 is formed with the concave portion 241 concaved on the positive side in the Z-axis direction, instead of the concave portion 240 concaved on the negative side in the X-axis direction as in the above embodiment.

  Then, at least a part of the resistor 300 is arranged in the recess 241. That is, the resistor 300 is at least partially disposed in the recess 241 formed inside the curved portion of the bus bar 201. Specifically, the resistor 300 is arranged such that the lead 310 is connected to the lower surface (the surface on the negative side in the Z-axis direction) of the first end 210 and the second end 220. In the present embodiment, the portion on the positive side in the Z-axis direction of the resistor 300 is arranged in the recess 241, but the entire resistor 300 may be arranged in the recess 241. . Other configurations are the same as those in the above-described embodiment, and thus detailed description is omitted.

  As illustrated in FIG. 5, the power storage device may include a bus bar 202 instead of the above-described bus bar 201. The bus bar 202 has a shape in which stepped steps 211 and 221 are formed between the intermediate portion 230a and the first end 210 and the second end 220. Thus, a concave portion 242 is formed on the minus side in the Z-axis direction of the step portions 211 and 221. With this configuration, at least a part of the resistor 300 is arranged in the recesses 241 and 242. In the present embodiment, the entire resistor 300 is disposed in the recesses 241 and 242. Other configurations are the same as those in the above-described embodiment or the above-described configuration of the bus bar 201, and thus detailed description is omitted.

  As described above, according to the power storage device of the present modification, the same effects as those of the above embodiment can be obtained. In particular, by arranging the resistor 300 inside the curved portion (intermediate portion 230a) of the bus bars 201 and 202, safety can be improved with a simple configuration while saving space. . Further, by forming the fuse portion 231 at the curved portion, the curved portion can be easily bent. The bus bar 201 can suppress an increase in height in the Z-axis direction as compared with the bus bar 202. Further, the bus bar 202 can accommodate more of the resistor 300 inside the curved portion (in the concave portion) than the bus bar 201.

(Modification 2)
Next, a second modification of the above embodiment will be described. FIG. 6 is a plan view showing the configurations of the bus bar 203 and the resistor 300 according to Modification 2 of the present embodiment. Specifically, FIGS. 6A and 6B are diagrams corresponding to FIGS. 3A and 3B.

  As shown in FIG. 6, the power storage device according to the present modification includes a bus bar 203 and a resistor 300 instead of the bus bar 200 and the resistor 300 of the above embodiment. The bus bar 203 has a plate-like intermediate portion 230b instead of the plate-like intermediate portion 230 of the above embodiment. Here, the intermediate portion 230b does not have a configuration that forms the concave portion 240 that is concave on the negative side in the X-axis direction as in the above embodiment. That is, the bus bar 203 does not have the recess 240 as in the above embodiment.

  In this configuration, one end of resistor 300 of the present modification is connected to positive electrode terminal 120 of power storage element 100a via lead 310, and the other end is connected to negative electrode terminal 130 of power storage element 100b. That is, the end of the lead 310 connected to the negative side in the Y-axis direction of the resistor 300 is connected to the surface of the positive electrode terminal 120 of the electric storage element 100a by welding or the like. In addition, the end of the lead 310 connected to the positive side in the Y-axis direction of the resistor 300 is connected to the surface of the negative electrode terminal 130 of the electric storage element 100b by welding or the like. Thus, resistor 300 is connected to the electrode terminal of power storage device 100.

  In this modification, the positive terminal 120 of the power storage device 100a is an example of a first conductive portion, and the negative terminal 130 of the power storage device 100b is an example of a second conductive portion, as in the above embodiment. Unlike the above embodiment, the bus bar 203 is an example of a third conductive portion. However, as in the above embodiment, the intermediate portion 230b may be an example of the third conductive portion. Other configurations are the same as those in the above-described embodiment, and thus detailed description is omitted.

  As described above, according to the power storage device according to the present modification, the fuse portion 231 is provided on the bus bar 203 and the resistor 300 is connected to the electrode terminal of the power storage element 100, thereby achieving a simple configuration and safety. Therefore, the same effect as in the above embodiment can be obtained. In particular, even when it is difficult to connect the resistor 300 to the bus bar 203, it is not necessary to use a separate member by directly connecting the resistor 300 to the electrode terminal of the power storage element 100. can do.

  It should be noted that the configuration of the first modification may be applied to this modification. That is, in the present modification, the intermediate portion 230b of the bus bar 203 may be formed in a curved shape, and the resistor 300 may be disposed inside (in the concave portion) of the curved intermediate portion 230b.

(Modification 3)
Next, a third modification of the above embodiment will be described. FIG. 7 is a plan view showing a configuration of the bus bar 203 and the resistor 301 according to the third modification of the present embodiment. Specifically, (a) and (b) of FIG. 7 are diagrams corresponding to (a) and (b) of FIG.

  As illustrated in FIG. 7, the power storage device according to the present modification includes a bus bar 203 and a resistor 301 instead of the bus bar 203 and the resistor 300 according to the second modification. Here, the resistor 301 is a plate-shaped resistor, and is disposed so as to overlap the intermediate portion 230 b of the bus bar 203. That is, the bus bar 203 and the resistor 301 are joined to form a clad material having the fuse portion 231 and the resistor 301. The resistor 301 is preferably disposed so as to overlap the lower surface of the bus bar 203 (the surface on the minus side in the Z-axis direction) from the viewpoint of saving space. Plane).

  As described above, the resistor 301 is connected to the first end 210 and the second end 220 without the intervention of a lead. In this modification, the positive terminal 120 of the power storage device 100a is an example of a first conductive portion, and the negative terminal 130 of the power storage device 100b is an example of a second conductive portion, as in the above embodiment. The first end 210 and the second end 220 may be an example of a first conductive part and a second conductive part. In the present modification, the intermediate portion 230b (the portion where the resistor 301 is overlapped) is an example of the third conductive portion, as in the above embodiment. Other configurations are the same as those in the above-described embodiment or Modification Example 2, and thus detailed description is omitted.

  As described above, according to the power storage device of the present modification, the same effects as those of the above embodiment can be obtained. In particular, since a configuration including the fuse portion 231 and the resistor 301 can be realized by using a clad material, the number of components can be reduced and manufacturing of the power storage device can be facilitated.

  It should be noted that the configuration of the first modification may be applied to this modification. That is, in the present modified example, the intermediate portion 230b of the bus bar 203 may be formed in a curved shape, and the curved resistor 301 may be disposed on the curved intermediate portion 230b.

(Modification 4)
Next, a fourth modification of the above embodiment will be described. 8A to 8D are conceptual diagrams illustrating the configuration of power storage devices 11, 12, 13 or 14 including bus bars 200, 510 or 620 and resistor 300 according to Modification 4 of the present embodiment.

  First, as shown in FIG. 8A, power storage device 11 in this modification includes a bus bar 200 having a fuse part 231 and a resistor 300 between power storage element 100b and power storage element 100c. For example, power storage device 11 includes bus bar 200 and resistor 300 between positive electrode terminal 120 of power storage element 100b and negative electrode terminal 130 of power storage element 100c. Thus, the bus bar 200 and the resistor 300 may be arranged at the position of the bus bar 400 in the above embodiment. Note that bus bar 200 and resistor 300 may be disposed between power storage element 100c and power storage element 100d, or may be disposed between other power storage elements 100.

  As described above, according to the power storage device 11 of the present modification, the same effects as those of the above embodiment can be obtained. In particular, since the bus bar 200 and the resistor 300 can be arranged at various positions, the degree of freedom in designing the power storage device 11 can be improved.

  As shown in FIG. 8B, power storage device 12 in the present modification includes bus bar 510 having resistor portion 511 similar to fuse portion 231 and resistor 300 between power storage element 100 a and external terminal 610. I have. For example, power storage device 12 includes bus bar 510 and resistor 300 between negative electrode terminal 130 of power storage element 100a and external terminal 610 on the negative electrode side. Thus, the bus bar 510 and the resistor 300 similar to the bus bar 200 may be arranged at the position of the bus bar 500 in the above embodiment. Note that bus bar 510 and resistor 300 may be disposed between positive electrode terminal 120 of power storage element 100f and external terminal 610 on the positive electrode side.

  As shown in FIG. 8C, power storage device 13 according to the present modification includes bus bar 510 having fuse portion 511 and resistance body 300 having a fuse portion 511 between power storage elements 100 a and 100 b connected in parallel and external terminal 610. It has. For example, the power storage device 13 includes a bus bar 510 and a resistor 300 between the negative terminal 130 of the power storage element 100a and the negative terminal 130 of the power storage element 100b and the external terminal 610 on the negative side. Thus, even when power storage elements 100 are connected in parallel, bus bar 510 and resistor 300 may be arranged on the main current path. Note that bus bar 510 and resistor 300 may be arranged between positive electrode terminal 120 of power storage element 100e and positive electrode terminal 120 of power storage element 100f and external terminal 610 on the positive electrode side. The number of power storage elements 100 connected in parallel is not limited to two, and three or more power storage elements 100 may be connected in parallel.

  As described above, in power storage devices 12 and 13 in the present modification, the electrode terminals of power storage element 100 and external terminals 610 of power storage device 12 are examples of the first conductive portion and the second conductive portion. That is, one of the first conductive portion and the second conductive portion is an electrode terminal of the power storage device 100, and the other is an external terminal 610 of the power storage device 12.

  As described above, according to the power storage devices 12 and 13 according to the present modification, the same effects as those of the above embodiment can be obtained. In particular, since the electrode terminal of the power storage element 100 and the external terminal 610 of the power storage device 10 correspond to the first conductive portion and the second conductive portion, the fuse portion 511 and the resistor 300 are connected to the electrode terminal of the power storage device 100 and the power storage device. 10 between the external terminals 610. Thus, regardless of the arrangement or connection form (series connection, parallel connection) of power storage element 100 in the power storage device, fuse portion 511 and resistor 300 are disposed on the path of the main current flowing through the power storage device. Therefore, safety can be improved with a simple configuration.

  In power storage device 13, bus bar 510 and resistor 300 may be arranged between power storage element groups connected in parallel. For example, bus bar 510 and resistor 300 may be arranged between power storage elements 100a and 100b connected in parallel and power storage elements 100c and 100d connected in parallel. In this case, the electrode terminals of the power storage element group sandwiching the bus bar 510 and the resistor 300 among the power storage element groups connected in parallel are examples of the first conductive part and the second conductive part.

  As illustrated in FIG. 8D, power storage device 14 according to the present modification includes bus bar having fuse portion 621 similar to fuse portion 231 between external terminal 610 of power storage device 10a and external terminal 610 of power storage device 10b. 620 and the resistor 300. For example, the power storage device 14 includes a bus bar 620 and the resistor 300 between the positive external terminal 610 of the power storage device 10a and the negative external terminal 610 of the power storage device 10b. Thus, even when power storage devices 10 are connected to each other, bus bar 620 and resistor 300 may be arranged in the main current path. Note that the power storage device 14 may include three or more power storage devices 10 or a plurality of power storage devices 10 may be connected in parallel.

  As described above, in the power storage device 14 according to the present modification, the external terminals 610 of two adjacent power storage devices 10 are an example of the first conductive portion and the second conductive portion. That is, the relationship between the power storage device 10 and the power storage element 100 in the above embodiment and the modifications thereof can be applied to the relationship between the power storage device 14 and the power storage device 10. Further, when a plurality of power storage devices 14 are provided to form a larger power storage device, the relationship between power storage device 14 and power storage device 10 is applied to the relationship between the large-scale power storage device and power storage device 14. can do.

  As described above, according to the power storage device 14 of the present modification, the same effects as those of the above embodiment can be obtained. In particular, even when the power storage device is increased in size, safety can be improved by arranging the bus bar 620 and the resistor 300.

  Note that the configurations of the above-described modifications 1 to 3 may be applied to this modification. That is, in this modification, the bus bars 201, 202, or 203 in the above-described modifications 1 to 3 may be applied to the bus bars 200, 510, or 620. In this modification, the configuration of the resistor 301 may be applied to the resistor 300.

(Other modifications)
As described above, the power storage device according to the embodiment of the present invention and its modified example have been described, but the present invention is not limited to this embodiment and its modified example. In other words, the embodiments and modifications thereof disclosed herein are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the appended claims, and is equivalent to the appended claims. And all changes within the meaning and scope of are included.

  For example, in the above-described embodiment and its modified example, the electrode terminal of the power storage element 100 and the external terminal 610 of the power storage device 10 and the like are illustrated as the first conductive portion and the second conductive portion, but the present invention is not limited thereto. That is, the first conductive portion and the second conductive portion may be all or a part of the conductive member arranged in the path of the main current of the power storage device, and any part on the path may be any part of the first conductive portion. And a second conductive portion. Similarly, any portion of the third conductive portion may be defined as the third conductive portion as long as the portion is provided with the fuse portion between the first conductive portion and the second conductive portion.

  In the above embodiment and its modifications, the power storage device includes only one pair of the bus bar having the fuse portion and the resistor. However, the power storage device may include a plurality of pairs of the bus bar and the resistor. In this case, the bus bar and the resistor can be installed at an arbitrary place such as the place shown in the above-described modification 4 (FIGS. 8A to 8D). By arranging a plurality of resistors as described above, a resistor having a relatively small resistance value can be used.

  Further, in the above-described embodiment and its modification, one resistor is arranged for one bus bar having a fuse portion. However, a plurality of resistors may be provided for one bus bar, or one resistor may be provided for a plurality of bus bars. When arranging a plurality of resistors for one bus bar, a resistor having a relatively small resistance value can be used. In the case where one resistor is arranged for a plurality of the bus bars, the number of resistors can be reduced and the configuration of the power storage device can be simplified.

  Further, in the above-described embodiment and its modification, the fuse section is configured by reducing the cross-sectional area of the bus bar. However, a commercially available fuse may be used as the fuse portion, or any other type of fuse may be used.

  Further, a mode constructed by arbitrarily combining the above-described embodiment and the above-described modified examples is also included in the scope of the present invention.

  Further, the present invention can be realized not only as such a power storage device, but also as a third conductive portion and a resistor provided with a fuse portion.

  The present invention can be applied to a power storage device including a power storage element such as a lithium ion secondary battery.

10, 10a, 10b, 11, 12, 13, 14 Power storage device 100, 100a to 100f Power storage element 110 Container 111 Container main body 112 Lid 120 Positive terminal 130 Negative terminal 140 Positive current collector 150 Negative current collector 160 Electrode 200 , 201, 202, 203, 400, 500, 510, 620 bus bar 210 first end 211, 221 step 220 second end 230, 230 a, 230 b middle 231, 511, 621 fuse 240, 241, 242 recess 300, 301 Resistor 310 Lead 600 Outer body 610 External terminal

Claims (5)

A power storage device including a power storage element having an electrode body,
A first conductive portion and a second conductive portion, which are paths of current flowing through the electrode body and are arranged outside the power storage element,
A fuse portion provided in the third conductive portion between the first conductive portion and the second conductive portion, and interrupting a conductive state of the third conductive portion,
And a resistor that maintains a conductive state between the first conductive part and the second conductive part even when the conductive state in the fuse part is cut off. The third conductive portion is a part of a bus bar connected to an electrode terminal of the power storage element,
The power storage device according to claim 1, wherein the resistor is connected to a position of the bus bar different from the third conductive portion. The third conductive portion is a bus bar connected to an electrode terminal of the power storage element,
The power storage device according to claim 1, wherein the resistor is connected to the electrode terminal. The bus bar has a recess,
The power storage device according to claim 2, wherein at least a part of the resistor is arranged in the recess. The power storage device according to any one of claims 1 to 4, wherein one of the first conductive portion and the second conductive portion is an electrode terminal of the power storage device, and the other is an external terminal of the power storage device. .

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