Energy storage module

Abstract

We provide energy storage modules with excellent interchangeability. [Solution] The energy storage module 1 comprises a first energy storage cell 11 having a first external terminal 30, a second energy storage cell 12 having a second external terminal 40, a busbar 20 for electrically connecting the first external terminal 30 and the second external terminal 40, and current interruption devices 50 disposed between the busbar 20 and the first external terminal 30, and between the busbar 20 and the second external terminal 40, wherein each current interruption device 50 includes a first conductive member that contacts the busbar 20, a second conductive member disposed at a distance from the first conductive member and contacting the first external terminal or the second external terminal, and a current interruption structure disposed between the first conductive member and the second conductive member.

Description

Technical Field

[0001] The present disclosure relates to a power storage module.

Background Art

[0002] As a conventional power storage module, Japanese Unexamined Patent Application Publication No. 2024-86555 discloses a power storage module including a plurality of power storage cells and a bus bar assembly that electrically connects the plurality of power storage cells.

[0003] The bus bar assembly includes a conductive sheet incorporated in an upper cover detachably connected to a tray that houses a plurality of power storage cells therein, a contact member detachably and electrically connected to an external terminal of the power storage cell, and an elastic member disposed between the conductive member and the contact member.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the power storage module described in Patent Document 1, the bus bar assembly is not provided with a current interruption device, and a conductive sheet having the function of a bus bar is incorporated in the upper cover. Therefore, when an abnormality occurs in any of the plurality of power storage cells and an abnormal current flows through the conductive sheet, the conductive sheet may deteriorate or an excessive load may be applied to the plurality of power storage cells.

[0006] When the conductive sheet deteriorates, it is difficult to replace the conductive sheet alone, and the entire upper cover in which the conductive sheet is incorporated needs to be replaced. In addition, when an excessive load is applied to the plurality of power storage cells, other power storage cells in addition to the power storage cell in which the abnormality has occurred need to be replaced.

[0007] This disclosure has been made in view of the above-mentioned problems, and the purpose of this disclosure is to provide an energy storage module with excellent interchangeability. [Means for solving the problem]

[0008] A battery storage module according to this disclosure comprises a first battery storage cell having a first external terminal, a second battery storage cell having a second external terminal, a busbar for electrically connecting the first external terminal and the second external terminal, and current interruption devices disposed between the busbar and the first external terminal, and between the busbar and the second external terminal. Each current interruption device includes a first conductive member in contact with the busbar, a second conductive member disposed at a distance from the first conductive member and in contact with the first external terminal or the second external terminal, and a current interruption structure disposed between the first conductive member and the second conductive member.

[0009] According to the above configuration, current interruption devices are provided on both the first and second energy storage cells in the current path between the adjacent first and second energy storage cells. Therefore, if an abnormality occurs in one of the first or second energy storage cells and the abnormal current flows toward the other energy storage cell, the current interruption structure located on the side of the first or second energy storage cell will activate. This prevents deterioration of the busbar, the current interruption device on the other energy storage cell, and the other energy storage cell, which are located downstream of the activated current interruption device in the path through which the abnormal current flows.

[0010] In addition, the current interruption structure is sandwiched between the busbar and the first external terminal or the second external terminal, and is not welded to the busbar or the first external terminal or the second external terminal. This allows a deteriorated energy storage cell to be removed and replaced individually. Furthermore, if an abnormality occurs in either the first or second energy storage cell, the abnormal energy storage cell and the current interruption structure that was activated by the abnormality can be replaced. In this way, either the energy storage cell itself, or the energy storage cell and the interruption mechanism that contacts the energy storage cell can be replaced, thus improving replaceability.

[0011] In the energy storage module based on the above disclosure, the current interruption structure may include a first rigid conductor disposed in contact with the first conductive member, a second rigid conductor disposed at a distance from the first rigid conductor in contact with the second conductive member, a conductive molten member that connects the first rigid conductor and the second rigid conductor and melts with heat, and a rigid insulator that maintains the distance between the first rigid conductor and the second rigid conductor.

[0012] According to the above configuration, if an abnormality occurs in one of the two energy storage cells, the heat from the abnormal energy storage cell will melt the molten material. This will interrupt the electrical connection between the first rigid conductor and the second rigid conductor, thereby blocking the abnormal current flow from the abnormal energy storage cell toward the busbar and the other energy storage cell.

[0013] In the energy storage module based on the above disclosure, the current interruption structure may include a first rigid conductor disposed in contact with the first conductive member, a second rigid conductor disposed at a distance from the first rigid conductor in contact with the second conductive member, a connecting conductor that connects the first rigid conductor and the second rigid conductor and is provided to be breakable, and an insulator that is thermally expandable and located between the first rigid conductor and the second rigid conductor, and fixed to one of the rigid conductors, the first rigid conductor and the second rigid conductor.

[0014] According to the above configuration, if an abnormality occurs in one of the two energy storage cells, the insulator will expand due to the heat generated from the abnormal energy storage cell. This causes the connecting conductor to break, and the electrical connection between the first rigid conductor and the second rigid conductor is interrupted. As a result, the abnormal current flow from the abnormal energy storage cell toward the busbar and the other energy storage cell can be interrupted. [Effects of the Invention]

[0015] According to this disclosure, it is possible to provide an energy storage module with excellent interchangeability. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic perspective view showing a portion of the energy storage module according to Embodiment 1, as well as a partially disassembled state. [Figure 2] This is an exploded perspective view of the current interruption device according to Embodiment 1. [Figure 3] This is a perspective view showing the state after the current interruption device according to Embodiment 1 has been activated. [Figure 4] This is a schematic perspective view showing a portion of the energy storage module according to Embodiment 2, as well as a partially disassembled state. [Figure 5] This is a perspective view showing the busbar related to the first modified example. [Figure 6] This is a perspective view showing the current interruption structure according to Embodiment 3. [Figure 7] This is a perspective view showing the state after the current interruption structure according to Embodiment 3 has been activated. [Modes for carrying out the invention]

[0017] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference numerals in the drawings, and their descriptions will not be repeated.

[0018] (Embodiment 1) FIG. 1 is a schematic perspective view partially showing a power storage module according to Embodiment 1 and showing a partially disassembled state. Referring to FIG. 1, the power storage module 1 according to Embodiment 1 will be described.

[0019] The power storage module 1 according to Embodiment 1 is mounted on a hybrid vehicle capable of traveling using the power of at least one of a motor and an engine, or an electric vehicle traveling with a driving force obtained from electric energy.

[0020] As shown in FIG. 1, the power storage module 1 includes a plurality of power storage cells 10, a plurality of bus bars 20, and a plurality of current cutoff devices 50.

[0021] The plurality of power storage cells 10 are arranged in the first direction DR1. The plurality of power storage cells 10 are arranged in a state where the largest side surfaces of the power storage cells 10 face each other. A cooling plate or a buffer plate (not shown) may be arranged in the gap between two adjacent power storage cells 10. The plurality of power storage cells 10 includes a first power storage cell 11 and a second power storage cell 12 adjacent to each other in the first direction DR1.

[0022] Each power storage cell 10 has a pair of external terminals 30 and 40. In the present embodiment, a case where the external terminal 30 is a positive electrode terminal and the external terminal 40 is a negative electrode terminal is exemplified, but it is not limited thereto. The external terminal 30 may be a negative electrode terminal and the external terminal 40 may be a positive electrode terminal.

[0023] The plurality of power storage cells 10 are arranged one by one in an inverted manner so that the external terminals 30 and the external terminals 40 are alternately arranged in the first direction DR1. The external terminal 30 of the first power storage cell 11 and the external terminal 40 of the second power storage cell 12 are arranged adjacent to each other. The external terminal 30 of the first power storage cell 11 corresponds to the first external terminal, and the external terminal 40 of the second power storage cell 12 corresponds to the second external terminal.

[0024] Multiple energy storage cells 10 are electrically connected in series by multiple current interruption devices 50 and multiple busbars 20.

[0025] Each energy storage cell 10 is a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The energy storage cell 10 may use a liquid electrolyte or a solid electrolyte. The energy storage cell 10 may also be a rechargeable capacitor.

[0026] Each energy storage cell 10 has a case 15. Inside the case 15 are electrodes and an electrolyte (not shown). The case 15 is made of a metal such as aluminum.

[0027] The case 15 includes a main body 16 and a lid 17. The main body 16 has a substantially box shape that is open upwards. The lid 17 closes the opening of the main body 16. A pair of external terminals 30 and 40 are fixed to the lid 17. The pair of external terminals 30 and 40 are spaced apart in a second direction DR2 that is perpendicular to the first direction DR1. At least one of the pair of external terminals 30 and 40 is insulated from the lid 17 by an insulator. Alternatively, both of the pair of external terminals 30 and 40 may be insulated from the lid 17 by insulators.

[0028] The busbar 20 is a conductive member for electrically connecting adjacent energy storage cells 10. The busbar 20 has, for example, a plate shape. The busbar 20 has one end 20a located on one side of the first direction DR1 and the other end 20b located on the other side of the first direction DR1.

[0029] The busbar 20 is positioned so as to overlap the external terminal 30 of one of two adjacent energy storage cells 10 and the external terminal 40 of the other energy storage cell.

[0030] A current interruption device 50 is located on each of the external terminals 30 and 40. When considering a single busbar 20 for electrically connecting two adjacent energy storage cells 10, the current interruption device 50 located on one of the two adjacent energy storage cells 10 is located between the external terminal 30 of that energy storage cell 10 and the busbar 20. Similarly, when considering a single busbar 20 for electrically connecting two adjacent energy storage cells 10, the current interruption device 50 located on the other of the two adjacent energy storage cells 10 is located between the external terminal 40 of the other energy storage cell 10 and the busbar 20.

[0031] More specifically, the current interruption device 50 located on the external terminal 30 of the first energy storage cell 11 is positioned between one end 20a of the busbar 20 for electrically connecting the first energy storage cell 11 and the second energy storage cell 12, and the external terminal 30. The current interruption device 50 located on the external terminal 40 of the second energy storage cell 12 is positioned between the other end 20b of the busbar for electrically connecting the first energy storage cell 11 and the second energy storage cell 12, and the external terminal 40.

[0032] Multiple current interruption devices 50 are held between the busbars 20 and external terminals 30 and 40, for example, by a pressing member (not shown) which presses the busbars 20 toward the multiple energy storage cells 10. The pressing member can be, for example, the upper cover of the housing case that houses the energy storage module 1.

[0033] The current interruption device 50 is not welded or bonded to the busbar 20 or the external terminals 30 and 40. The current interruption device 50 is detachable from the busbar 20, or from the external terminals 30 or 40.

[0034] Figure 2 is an exploded perspective view of the current interruption device according to Embodiment 1. The details of the current interruption device 50 according to Embodiment 1 will be described with reference to Figure 2.

[0035] As shown in Figure 2, the current interruption device 50 includes a first conductive member 51, a second conductive member 52, and a current interruption structure 53.

[0036] The first conductive member 51 is in contact with the busbar 20. The first conductive member 51 is formed in a plate shape. The first conductive member 51 is elastic. As described above, when the current interruption device 50 is sandwiched between the busbar and the external terminal 30 or external terminal 40, the first conductive member 51 is compressed or deformed and comes into close contact with the busbar 20. This ensures electrical conductivity between the busbar 20 and the first conductive member 51.

[0037] The second conductive member 52 is positioned at a distance from the first conductive member 51. The first conductive member 51 and the second conductive member 52 are arranged in a third direction DR3 that is perpendicular to the first direction DR1 and the second direction DR2. The third direction DR3 is, for example, parallel to the vertical direction.

[0038] The second conductive member 52 contacts the external terminal 30 or external terminal 40. The first conductive member 51 is formed in a plate shape. The second conductive member 52 is elastic. As described above, when the current interruption device 50 is sandwiched between the busbar 20 and the external terminal 30 or external terminal 40, the second conductive member 52 is compressed or deformed to make close contact with the external terminal 30 or external terminal 40. This ensures electrical conductivity between the external terminal 30 or external terminal 40 and the second conductive member 52.

[0039] The first conductive member 51 and the second conductive member 52 have sufficient heat resistance to maintain their shape even when the current interruption structure 53 is activated. The first conductive member 51 and the second conductive member 52 can be, for example, silicon mixed with a conductive filler, conductive polypyrrole, or a conductive elastomer, but are not limited to these. Furthermore, the first conductive member 51 and the second conductive member 52 may be the same material or different materials.

[0040] The current interruption structure 53 has a simple fuse-like mechanism. The current interruption structure 53 is positioned between the first conductive member 51 and the second conductive member 52. The current interruption structure 53 includes, for example, a first rigid conductor 531, a second rigid conductor 532, a molten member 533, and a rigid insulator 534.

[0041] The first rigid conductor 531 has a plate-like shape. The first rigid conductor 531 has substantially the same shape as the first conductive member 51. The first rigid conductor 531 is positioned in contact with the first conductive member 51. The first rigid conductor 531 is in surface contact with the lower surface 51a of the first conductive member 51. The first rigid conductor 531 is made of a metal material such as copper, iron, or aluminum, and has rigidity. The first rigid conductor 531 has higher rigidity than the first conductive member 51.

[0042] The second rigid conductor 532 has a plate-like shape. The second rigid conductor 532 is positioned spaced apart from the first rigid conductor 531 in the third direction. The second rigid conductor 532 has substantially the same shape as the second conductive member 52. The second rigid conductor 532 is in surface contact with the upper surface 52b of the second conductive member 52. The second rigid conductor 532 is made of a metal material such as copper, iron, or aluminum, and has rigidity. The second rigid conductor 532 has higher rigidity than the second conductive member 52.

[0043] The molten member 533 is electrically conductive. The molten member 533 is formed, for example, in a columnar shape. When not molten, the molten member 533 electrically connects the first rigid conductor 531 and the second rigid conductor 532. The molten member 533 is provided so as to be meltable by heat.

[0044] As the molten member 533 that melts due to heat in the event of an abnormality such as overheating of the energy storage cell 10, a tin-bismuth alloy or an indium-bismuth alloy can be used, but is not limited to these. As long as it does not melt under normal operating conditions, melts in the event of an abnormality in the energy storage cell 10, and has a melting temperature lower than that of the first conductive member 51, the second conductive member 52, the first rigid conductor 531, the second rigid conductor 532, and the rigid insulator 534 described above, the molten member 533 can be set as appropriate.

[0045] Furthermore, if the molten member 533 is a tin-bismuth alloy, the melting temperature of the molten member 533 is approximately 138°C. If the first conductive member 51 and the second conductive member 52 described above are conductive silicone rubber, the melting temperatures of the first conductive member 51 and the second conductive member 52 are 200°C or higher. Also, if the first rigid conductor 531 and the second rigid conductor 532 are copper, the melting temperatures of the first rigid conductor 531 and the second rigid conductor 532 are 1000°C or higher. In addition, if the rigid insulator 534 described later is made of ceramic, the melting temperature of the rigid insulator 534 is 1000°C or higher.

[0046] Multiple rigid insulators 534 are provided. The rigid insulators 534 are made of ceramic. The rigid insulators 534 have, for example, a columnar shape. The rigid insulators 534 are arranged around the molten member 533. The rigid insulators 534 maintain the distance between the first rigid conductor 531 and the second rigid conductor 532. The rigid insulators 534 connect the first rigid conductor 531 and the second rigid conductor 532.

[0047] In this embodiment, the case in which four rigid insulators 534 are arranged is illustrated, but the number of rigid insulators 534 is not particularly limited as long as the rigid insulators 534 can maintain the distance between the first rigid conductor 531 and the second rigid conductor 532. The number of rigid insulators 534 may be one or two or more.

[0048] Furthermore, the rigid insulator 534 may have a cylindrical shape surrounding the molten member 533. Alternatively, the molten member 533 may have a cylindrical shape, and the rigid insulator 534 may be positioned inside the cylindrical molten member 533.

[0049] Figure 3 is a perspective view showing the state after the current interruption device according to Embodiment 1 has been activated. As shown in Figure 3, if the energy storage cell 10 overheats abnormally, or if an abnormal current flows to the molten member 533 due to such overheating or a short circuit, the molten member 533 melts due to the heat. On the other hand, the first rigid conductor 531 and the second rigid conductor 532 are kept at a certain distance apart by the rigid insulator 534. As a result, the electrical connection between the first rigid conductor 531 and the second rigid conductor 532 is interrupted.

[0050] As described above, in the energy storage module 1 according to Embodiment 1, current interruption devices 50 are provided on both the first energy storage cell 11 side and the second energy storage cell 12 side in the current path between the adjacent first energy storage cell 11 and second energy storage cell 12. Therefore, if an abnormality occurs in one of the energy storage cells, the abnormal current flows toward the other energy storage cell, the current interruption device 50 located on the side of the one energy storage cell will activate. As a result, deterioration of the busbar, the current interruption device on the other energy storage cell side, and the other energy storage cell, which are located downstream of the activated current interruption device 50 in the path through which the abnormal current flows, can be suppressed.

[0051] In addition, the current interruption device 50 is sandwiched between the busbar 20 and the external terminal 30 or external terminal 40, and is not welded to the busbar 20 or the external terminal 30 or external terminal 40. This allows a deteriorated energy storage cell to be removed and replaced individually. Furthermore, if an abnormality occurs in one of the first energy storage cells 11 or the second energy storage cell 12, the abnormal energy storage cell and the current interruption device 50 that was activated by the abnormality can be replaced. In this way, either the energy storage cell itself, or the energy storage cell and the current interruption device 50 that contacts the energy storage cell can be replaced, thus improving replaceability. Moreover, by replacing the deteriorated energy storage cell itself, or the abnormal energy storage cell 10 and the current interruption device 50, stable and long-term use of the energy storage module 1 becomes possible.

[0052] Examples of the aforementioned deterioration include aging. Due to aging, individual differences in cell capacity and voltage may widen, and the state of deterioration may differ from cell to cell. The energy storage module 1 is equipped with a monitoring system (not shown) that detects the voltage of multiple energy storage cells 10. Energy storage cells that have deteriorated are detected by the vehicle's cell monitoring system when they reach the lower voltage limit. In this case, as described above, since the first conductive member 51 and the second conductive member 52 are not welded, bonded, or soldered to the busbar 20 and the external terminal 30 or external terminal 40, only the deteriorated energy storage cell 10 can be replaced without replacing the entire energy storage module 1.

[0053] In the above-described embodiment 1, the first conductive member 51, the second conductive member 52, and the first rigid conductor 531 and the second rigid conductor 532 are exemplified as having a rectangular flat plate shape in plan view, but their shapes are not limited thereto. The first conductive member 51, the second conductive member 52, and the first rigid conductor 531 and the second rigid conductor 532 may have flat plate shapes such as circular, elliptical, or track-shaped in plan view. Furthermore, the molten member 533 and the rigid insulator 534 are exemplified as being substantially cylindrical, but are not limited thereto. The molten member 533 and the rigid insulator 534 may have a prismatic shape. Moreover, the overall shape of the current interruption device 50 is not limited to a rectangular parallelepiped shape, but may be cylindrical, prismatic, or spherical.

[0054] (Embodiment 2) Figure 4 is a schematic perspective view showing a portion of the energy storage module according to Embodiment 2, as well as a partially disassembled state. The energy storage module 1A according to Embodiment 2 will be described with reference to Figure 4.

[0055] As shown in Figure 4, the energy storage module 1A according to Embodiment 2 differs from the energy storage module 1 according to Embodiment 1 in the shape of the busbar 20A. The other shapes are almost the same.

[0056] The busbar 20A has a plate-like shape. The busbar 20A is provided with openings 21h and 22h at positions corresponding to the external terminals 30 and 40 to which it is connected. The openings 21h and 22h are provided through the busbar 20A in the thickness direction.

[0057] A current interruption device 50, positioned on the external terminal 30, is press-fitted into opening 21h, and a current interruption device 50, positioned on the external terminal 40, is press-fitted into opening 22h. This fixes the busbar 20A to the current interruption device 50.

[0058] The end faces of the busbars 20A that define the openings 21h and 22h are in contact with the circumferential end faces of the first conductive member 51 of the current interruption device 50. This electrically connects the first conductive member 51 and the busbars 20A. The first conductive member 51 is positioned inside the openings 21h and 22h.

[0059] Even in this configuration, the energy storage module 1A according to Embodiment 2 provides substantially the same effects as the energy storage module 1 according to Embodiment 1.

[0060] (First variation) Figure 5 is a perspective view showing the busbar according to the first modified example. The busbar 20X according to the first modified example will be described with reference to Figure 5.

[0061] The busbar 20X differs in shape from the busbar 20A according to Embodiment 2. The busbar 20X is provided with notches 21c and 22c instead of openings 21h and 22h.

[0062] A current interruption device 50, positioned on the external terminal 30, is press-fitted into the notch 21c, and a current interruption device 50, positioned on the external terminal 40, is press-fitted into the notch 22c. This fixes the busbar 20A to the current interruption devices 50.

[0063] The end faces of the busbars 20A that define the notches 21c and 22c are in contact with the circumferential end faces of the first conductive member 51 of the current interruption device 50. This electrically connects the first conductive member 51 and the busbars 20A. The first conductive member 51 is positioned inside the notches 21c and 22c.

[0064] Even when using the busbar 20X according to this modified example 1, substantially the same effects as the energy storage module 1A according to embodiment 2 can be obtained.

[0065] (Embodiment 3) Figure 6 is a perspective view showing the current interruption structure according to Embodiment 3. The current interruption structure 53B according to Embodiment 3 will be described with reference to Figure 6. The current interruption structure 53B according to Embodiment 3 can be used in the energy storage modules 1 and 1A according to Embodiments 1 and 2.

[0066] The current interruption structure 53B differs from the current interruption structure 53 according to Embodiment 1 in that a breakable connecting conductor 533B is used instead of the molten member 533, and a thermally expandable insulator 534B is used instead of the rigid insulator 534.

[0067] The connecting conductor 533B is designed to be breakable. For example, the connecting conductor 533B can be made of silicon mixed with a conductive filler, conductive polypyrrole, or a conductive elastomer. Furthermore, the connecting conductor 533B can be made of a metal with less thermal expansion than the insulator 534B. For example, the connecting conductor 533B can be made of a thin aluminum wire with a diameter of 1 mm or less, which is easily broken by the thermal expansion of the insulator 534B. Additionally, the connecting conductor 533B may have a weak point, such as a notch, that is easily broken by the thermal expansion of the insulator 534B.

[0068] The thermally expandable insulator 534B is configured to expand with heat and not deform at room temperature. The insulator 534B is fixed to the second rigid conductor 532, for example, by adhesive or welding. A portion of the insulator 534B may be embedded inside the second rigid conductor 532. At room temperature, the tip of the insulator 534B located on the first rigid conductor 531 side does not come into contact with the first rigid conductor 531.

[0069] The insulator 534B may be fixed to the first rigid conductor 531 side so as not to contact the second rigid conductor 532 at room temperature. In other words, the insulator 534B should be fixed to the other rigid conductor of the first rigid conductor 531 and the second rigid conductor 532 so as not to contact one of the rigid conductors of the first rigid conductor 531 and the second rigid conductor 532 at room temperature. The insulator 534B is located between the first rigid conductor 531 and the second rigid conductor 532 and is fixed to one of the rigid conductors of the first rigid conductor 531 and the second rigid conductor 532.

[0070] The insulator 534B has a considerable degree of rigidity. As such a rigid insulator with thermal expansion properties, materials such as expandable mica and vermiculite can be used, which expand several to tens of times their original size from room temperature to, for example, around 100°C, and remain stable.

[0071] Figure 7 is a perspective view showing the state after the current interruption structure according to Embodiment 3 has been activated. As shown in Figure 7, if the energy storage cell 10 overheats abnormally, or if an abnormal current flows due to such overheating or a short circuit, heat is transferred to the second rigid conductor 532 via the current path, and then from the second rigid conductor 532 to the insulator 534B. As a result, the insulator 534B expands due to the heat, pressing the first rigid conductor 531 away from the second rigid conductor 532, and increasing the distance between the first rigid conductor 531 and the second rigid conductor 532. Consequently, the connecting conductor 533B breaks, and the electrical connection between the first rigid conductor 531 and the second rigid conductor 532 is interrupted.

[0072] Even in a power storage module employing the current interruption structure 53B described above, almost the same effects as those of the power storage modules 1 and 1A according to Embodiments 1 and 2 can be obtained.

[0073] In addition, because the first conductive member 51 and the second conductive member 52 are elastic, the stress acting from the insulator 534B to the busbar 20 and external terminals 30 and 40 when the insulator 534B undergoes thermal expansion can be relieved by the deformation of the first conductive member 51 and the second conductive member 52.

[0074] In the above-described embodiment 2, the example given is that the insulator 534B is fixed to the first rigid conductor 531 or the second rigid conductor 532, but the invention is not limited thereto. The insulator 534B may also be fixed to the first conductive member 51 or the second conductive member 52. When the insulator 534B is fixed to the first conductive member 51, the first rigid conductor 531 is provided with a notch or through hole so as not to interfere with the insulator 534B. When the insulator 534B is fixed to the second conductive member 52, the second rigid conductor 532 is provided with a notch or through hole so as not to interfere with the insulator 534B.

[0075] The embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, and all modifications are within the meaning and scope equivalent to the claims. [Explanation of Symbols]

[0076] 1, 1A energy storage module, 10 energy storage cell, 11 first energy storage cell, 12 second energy storage cell, 15 case, 16 main body, 17 lid, 20, 20A, 20X busbar, 20a one end, 20b other end, 21c, 22c notch, 21h, 22h opening, 30, 40 external terminals, 50 current interruption device, 51 first conductive member, 51a bottom surface, 52 second conductive member, 52b top surface, 53, 53B current interruption structure, 531 first rigid conductor, 532 second rigid conductor, 533 molten member, 533B connecting conductor, 534 rigid insulator, 534B insulator.

Claims

1. A first energy storage cell having a first external terminal, A second energy storage cell having a second external terminal, A busbar for electrically connecting the first external terminal and the second external terminal, The system includes current interruption devices disposed between the busbar and the first external terminal, and between the busbar and the second external terminal, Each current interruption device is a power storage module comprising a first conductive member that contacts the busbar, a second conductive member that is positioned at a distance from the first conductive member and contacts the first external terminal or the second external terminal, and a current interruption structure positioned between the first conductive member and the second conductive member.

2. The current interruption structure comprises a first rigid conductor disposed in contact with the first conductive member, a second rigid conductor disposed at a distance from the first rigid conductor in contact with the second conductive member, a molten member having conductivity that connects the first rigid conductor and the second rigid conductor and melts with heat, and a rigid insulator that maintains the distance between the first rigid conductor and the second rigid conductor, according to claim 1, the energy storage module.

3. The current interruption structure comprises a first rigid conductor disposed in contact with the first conductive member, a second rigid conductor disposed at a distance from the first rigid conductor in contact with the second conductive member, a connecting conductor provided to connect the first rigid conductor and the second rigid conductor and to be breakable, and an insulator having thermal expansion properties and located between the first rigid conductor and the second rigid conductor, and fixed to one of the rigid conductors, the energy storage module according to claim 1.

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