Electricity storage device

Abstract

A power storage device mounted on a vehicle is provided with a power storage unit, an inter-module fuse, a first external terminal, and a second external terminal. The power storage unit includes a first power storage module having a first electrode and a second power storage module having a second electrode. The first electrode includes a first terminal electrically connected to the first external terminal and a second terminal. The second electrode includes a third terminal electrically connected to the second external terminal and a fourth terminal, and the second terminal is electrically connected to the fourth terminal. The inter-module fuse is provided in an electrical path between the second terminal and the fourth terminal.

Description

Technical Field

[0001] The present disclosure relates to a power storage device. Background Art

[0002] For example, Japanese Patent Application Laid-Open No. 2023-046977 discloses a power storage device including an upper case, a lower case, and a power storage unit comprising a plurality of power storage modules. The power storage modules include a plurality of secondary cells having smoke exhaust ports and are housed in the case (the upper case and the lower case). Summary of the Invention

[0003] In a power storage device, from the viewpoint of electrical protection, for example, a fuse may be provided in the battery pack structure.

[0004] For example, the fuse may be disposed between the external terminal of the power storage device and the power storage module as a safety device for preventing a large current exceeding the specification from flowing through an electronic device connected to the power storage device.

[0005] In the above-described power storage device, when the power storage modules generate heat, exhaust may be generated from the heated power storage modules.

[0006] Furthermore, the exhaust from the heated storage module may cause a short circuit between the heated storage module and an adjacent storage module, thereby forming a short circuit within the storage unit.

[0007] On the other hand, since the fuse is provided between the external terminal and the power storage unit, even if a short circuit as described above is formed, the current interruption function cannot be achieved.

[0008] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a power storage device including power storage cells including a plurality of power storage modules, which can exhibit a current interruption function even if a short circuit occurs in the power storage cells.

[0009] A power storage device is mounted on a vehicle, the power storage device comprising a power storage unit, an inter-module fuse, a first external terminal, and a second external terminal. The power storage unit includes a first power storage module and a second power storage module, the first power storage module having a first electrode, the second power storage module being arranged adjacent to the first power storage module in a width direction, and the second power storage module having a second electrode, the first electrode being arranged at one end of the power storage unit in the width direction, the first electrode including a first terminal and a second terminal, the first terminal being electrically connected to the first external terminal, the second electrode being arranged at the other end of the power storage unit in the width direction, the second electrode including a third terminal and a fourth terminal, the third terminal being electrically connected to the second external terminal, and the second terminal being electrically connected to the fourth terminal, and the inter-module fuse being provided in an electrical path between the second terminal and the fourth terminal.

[0010] A power storage device further includes a terminal fuse provided in an electrical path between a second external terminal and a third terminal.

[0011] A power storage device includes a power storage unit including a connecting bracket connecting a first power storage module and a second power storage module, wherein the connecting bracket is formed to protrude upward from the first power storage module and the second power storage module.

[0012] A power storage device further includes a third power storage module, the third power storage module being arranged in an arrangement direction intersecting the width direction relative to the power storage cells, the third power storage module being arranged between one end and the other end in the width direction, and the inter-module fuse being arranged at a position adjacent to the third power storage module in the width direction.

[0013] A power storage device is provided with a heat insulating member disposed above an inter-module fuse.

[0014] A power storage device is provided in which an opening communicating with a space inside the power storage device is formed in a heat insulating material.

[0015] A power storage device further includes a bottom case, wherein the inter-module fuse is arranged on the bottom case with a heat conduction member interposed therebetween.

[0016] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a plan view schematically showing the power storage device according to this embodiment.

[0018] Figure 2 It is a perspective view schematically showing the power storage module according to this embodiment.

[0019] Figure 3 yes Figure 2 An exploded perspective view of the power storage module shown.

[0020] Figure 4 It is a side view schematically showing the power storage cell according to this embodiment.

[0021] Figure 5 It is a perspective view schematically showing the power storage unit according to this embodiment.

[0022] Figure 6 It will Figure 5 An enlarged perspective view of the periphery of the connecting bracket portion is shown.

[0023] Figure 7 Show Figure 1 Cross-sectional view at section VII-VII.

[0024] Figure 8 Show Figure 1 Cross-sectional view at section VIII-VIII of .

[0025] Figure 9 Show Figure 1 Cross-sectional view at section IX-IX of FIG. DETAILED DESCRIPTION

[0026] The embodiments of the present disclosure will be described with reference to the accompanying drawings. In the drawings referred to below, the same or corresponding components are denoted by the same reference numerals.

[0027] Figure 1 It is a plan view showing the power storage device according to this embodiment. Figure 1 The longitudinal direction L, width direction W, and vertical direction H shown represent the longitudinal direction, width direction, and vertical direction of the power storage device, respectively. The power storage device 100 is, for example, a device for storing electric power for driving an electric vehicle (not shown). The width direction W is an example of a "first direction" in this disclosure, and the longitudinal direction L is an example of a "second direction" in this disclosure.

[0028] The power storage device 100 includes a case 10 , power storage modules 90 , bus bars 40 , a junction box 50 , external terminals 55 , and an inter-module fuse 70 .

[0029] The housing 10 houses the power storage assembly 90 , the junction box 50 , the protective cover 60 , and the inter-module fuse 70 . The housing 10 includes a bottom case 11 and a top cover 12 (not shown). The housing 10 forms the outer shell of the power storage device 100 .

[0030] The bottom case 11 is formed to open upward. When the top cover 12 is viewed from a position away from the top cover 12 in the vertical direction H, the top cover 12 has the same outer shape as the bottom case 11. The bottom case 11 and the top cover 12 are connected to form a space R1.

[0031] The bottom case 11 includes a bottom plate and peripheral walls formed to stand upward from the outer peripheral edge of the bottom plate. The peripheral walls include a front wall and a rear wall arranged in the longitudinal direction L, and a right wall and a left wall arranged in the width direction W.

[0032] The power storage assembly 90 includes a plurality of power storage cells 80 and a power storage module 21 .

[0033] The plurality of storage cells 80 are arranged in a longitudinal direction L. Each storage cell 80 includes one end face and another end face aligned in the width direction W. Each storage cell 80 includes a storage module 20 aligned in the width direction W and a connecting bracket 30 connecting adjacent storage modules 20 in the width direction W.

[0034] The power storage module 21 is arranged adjacent to the plurality of power storage cells 80 in the longitudinal direction L. For example, the power storage module 21 is provided on the rear side relative to the plurality of power storage cells 80 .

[0035] The electricity storage module 21 is arranged at the center of the electricity storage unit 80 in the width direction W. Therefore, the electricity storage module 21 is located between one end surface and the other end surface of the electricity storage unit 80 in the width direction W.

[0036] In conjunction with this, for example, a dead space is formed by the electricity storage unit 80 and the electricity storage module 21 at a position adjacent to the electricity storage module 21 in the width direction W.

[0037] The junction box 50 is provided adjacent to the electricity storage module 90 in the longitudinal direction L. For example, the junction box 50 is arranged in front of the electricity storage module 90. The junction box 50 is arranged on the inner surface side of the front wall of the bottom case 11.

[0038] The external terminal 55 is provided on the front wall of the bottom case 11 . The external terminal 55 is provided on the outer surface of the front wall of the bottom case 11 .

[0039] The inter-module fuse 70 is arranged adjacent to the power storage module 21 in the width direction W.

[0040] The plurality of bus bars 40 connect the plurality of power storage modules 20 to one another and connect the power storage modules 20 to the inter-module fuses 70 .

[0041] Power storage device 100 is connected to a PCU (power control unit) or the like of the electric vehicle via a power line or the like connected to external terminal 55 .

[0042] Figure 2 A perspective view schematically illustrates a storage module according to this embodiment. The storage module 20 is a rectangular parallelepiped extending in the width direction W. The storage module 20 includes a module case 2 and an electrode 3. The module case 2 has notches 2a and 2b at one end of a pair of walls aligned along the width direction W. The electrode 3 consists of a terminal 3a and a terminal 3b. Terminal 3a is exposed through notch 2a of the module case 2, and terminal 3b is exposed through notch 2b of the module case 2.

[0043] Figure 3 Show Figure 2 The illustrated diagram is an exploded perspective view of a power storage module 20 . The power storage module 20 includes a plurality of power storage cells 1 housed in a module case 2 .

[0044] Figure 4A side view of a storage cell is shown. Storage cell 1 is formed to extend in width direction W. Storage cell 1 has electrode terminals 1a and 1b at both ends in width direction W. In width direction W, electrode terminal 1a is located at one end of storage cell 1, and electrode terminal 1b is located at the other end. For example, electrode terminal 1a is a positive electrode terminal, and electrode terminal 1b is a negative electrode terminal.

[0045] Refer again Figure 3 The plurality of storage cells 1 are arranged in the longitudinal direction L. When the plurality of storage cells 1 are viewed from a position away from the storage cells 1 in the width direction W, the electrode terminals 1a and 1b of the storage cells 1 are arranged alternately in the longitudinal direction L.

[0046] Furthermore, in the longitudinal direction L, the electrode terminals 1a and 1b are arranged such that one end is electrode terminal 1a, and the other end is electrode terminal 1b. The electrode terminals 1a and 1b of adjacent storage cells 1 are electrically connected in series via busbar 40. Furthermore, in the plurality of storage cells 1 electrically connected in series, the electrode terminal 1a at one end of the conductive path corresponds to the terminal 3a of the storage module 20, and the electrode terminal 1b at the other end corresponds to the terminal 3b of the storage module 20.

[0047] The module case 2 includes an upper frame 4 , a lower frame 5 , insulating covers 6 a and 6 b , and end plates 7 .

[0048] The upper frame 4 is arranged to cover the plurality of electricity storage cells 1 from above. A plurality of gas discharge holes 4a are formed in the upper frame 4. Gas generated from the electricity storage cells 1 is discharged through the gas discharge holes 4a.

[0049] The lower frame 5 is formed to cover the lower surface of the plurality of electricity storage cells 1 and a pair of side surfaces arranged in the longitudinal direction L. The lower frame 5 supports the plurality of electricity storage cells 1 from below. The lower frame 5 is formed to sandwich the plurality of electricity storage cells 1 in the longitudinal direction L.

[0050] The pair of insulating covers 6 a and 6 b are arranged so as to sandwich the plurality of power storage cells 1 in the width direction W.

[0051] The insulating cover 6a is disposed on a surface provided with electrode terminals 1a and 1b corresponding to the terminals 3a and 3b in the width direction W. The insulating cover 6a is formed so as to cover the plurality of power storage cells 1 when viewed from a position away from the insulating cover 6a in the width direction W, and has notches 2a and 2b formed therein to expose the terminals 3a and 3b.

[0052] The insulating cover 6b is disposed at a position facing the insulating cover 6a across the plurality of storage cells 1. The insulating cover 6b is formed so as to cover the plurality of storage cells 1 when viewed from a position away from the insulating cover 6b in the width direction W.

[0053] The end plate 7 is arranged adjacent to the insulating cover 6 b in the width direction W.

[0054] Figure 5 A perspective view of a storage unit is shown. The storage unit 80 includes a pair of storage modules 20 and a connecting bracket 30. The storage modules 20 are arranged in the width direction W. The storage unit 80 is configured such that insulating covers 6a are provided at both ends in the width direction W. As a result, in the storage unit 80, the end plates 7 of the pair of storage modules 20 are arranged facing each other. In the storage unit 80, the pair of storage modules 20 are connected by fastening the facing end plates 7 together with the connecting bracket 30.

[0055] Figure 6 Shown extracted and enlarged by Figure 5 A three-dimensional view of the portion formed by a pair of end plates, a connecting bracket, and bolts.

[0056] The end plate 7 has notches 7a at its four corners when viewed from a position away from the end plate 7 in the width direction W. Through holes 7b are formed in the end plate 7 so as to penetrate between the notches 7a arranged in the vertical direction H.

[0057] The connecting bracket 30 includes an upper member 31 and a pair of lower members 34 .

[0058] The upper member 31 is formed to extend in the longitudinal direction L. The upper member 31 is formed to cover the pair of end plates 7 of the electricity storage unit 80 . The upper member 31 is formed of a top plate 32 and a pair of end members 33 .

[0059] The top plate 32 is formed to extend in the longitudinal direction L. The top plate 32 is formed to cover the upper surface of the end plate 7 .

[0060] The pair of end members 33 are arranged in the longitudinal direction L. The pair of end members 33 are connected by the top plate 32. The end members 33 are arranged on the upper surfaces of the notches 7a of the pair of end plates 7. Two through holes 33a are formed in each of the pair of end members 33 so as to extend in the vertical direction H.

[0061] The pair of lower members 34 are each located below the end member 33 and formed to be received in the notch 7a of the end plate 7. The lower members 34 have two internal threads 34a formed therein extending in the vertical direction H. Threads are formed on the side surfaces of the holes forming the internal threads 34a.

[0062] Figure 7 yes Figure 1 The through hole 7b of the end plate 7, the through hole 33a of the end member 33, and the internal thread portion 34a of the lower member 34 are formed coaxially.

[0063] Bolt 35 consists of a bolt head 35a and a shaft 35b. Shaft 35b is inserted into the hole formed by through-holes 7b and 33a and internal thread 34a. Bolt 35 is fastened to lower member 34, sandwiching upper member 31 and end plates 7. This secures the pair of end plates 7 to the connecting bracket 30.

[0064] The plurality of electricity storage modules 20 are supported from below by the bottom case 11. The upper member 31 of the connection bracket 30 is in contact with the end plate 7 in the up-down direction H without a gap therebetween.

[0065] The upper surface 32a of the top plate 32 of the connecting bracket 30 is formed above the upper surface 4b of the upper frame 4. Similarly, the upper surface 33b of the end member 33 of the connecting bracket 30 is formed above the upper surface 4b of the upper frame 4. In other words, the upper surfaces 32a and 33b of the connecting bracket 30 protrude upward from the upper surface 4b of the power storage module 20. Furthermore, the thermal insulator 36 is positioned to fill the gap between the top cover 12 and the top plate 32. Alternatively, the thermal insulator 36 may be integrally formed with the top plate 32.

[0066] Refer again Figure 1 The bus bar 40 electrically connects the junction box 50, intermodule fuse 70, storage module 90, and external terminal 55 of the power storage device 100. Thus, an electrical path having the first external terminal 55a and the second external terminal 55b at its ends is formed within the power storage device 100.

[0067] Specifically, the bus bar 40 electrically connects the storage cells 80 arranged in the longitudinal direction L. More specifically, the bus bar 40 electrically connects the terminal 3 a of the storage module 20 constituting the storage cell 80 and the terminal 3 b of the storage module 20 adjacent in the longitudinal direction L.

[0068] Among the plurality of storage cells 80 arranged in the longitudinal direction L, the storage cell 81 at one end is connected to the first external terminal 55 a and the second external terminal 55 b . The storage cell 82 at the other end is electrically connected to the storage module 21 .

[0069] More specifically, in the storage unit 81 , the terminal 3 a of one storage module 22 arranged in the width direction W is electrically connected to the first external terminal 55 a , and the terminal 3 b of the other storage module 23 arranged in the width direction W is electrically connected to the second external terminal 55 b .

[0070] Furthermore, in the storage unit 82 located at the other end, the terminal 3b of the storage module 24 on one side in the width direction W is electrically connected to the terminal 3a of the storage module 21. The terminal 3a of the storage module 25 on the other side in the width direction W is electrically connected to the terminal 3b of the storage module 21. Thus, the storage module 21 is disposed on an electrical path formed by the electrical connection between the terminal 3b of the storage module 22 and the terminal 3a of the storage module 23.

[0071] The junction box 50 houses electrical equipment such as the SMRs and fuses in the power storage device 100. For example, a terminal fuse 51 is provided in the junction box 50. Terminal fuse 51 is provided in the electrical path between terminal 3b of the power storage module 23 included in the power storage unit 81 and the second external terminal 55b. Terminal fuse 51 melts when a large current flows when the drive system electronic equipment, etc., is connected to the external terminal 55 to form a closed circuit.

[0072] The power storage device 100 further includes a protective cover 60. The protective cover 60 is provided to prevent conductive foreign matter from adhering to the busbar 40. The protective cover 60 is formed to extend along the longitudinal direction L. The protective cover 60 is arranged so as to be aligned in the width direction W. The protective cover 60 is arranged to cover the busbar 40 that electrically connects the power storage cells 80 to each other.

[0073] The inter-module fuse 70 is provided on the electrical path between the terminal 3 b of the power storage module 21 and the terminal 3 a of the power storage module 25 .

[0074] Figure 8 Show Figure 1 A cross-sectional view of section VIII-VIII.

[0075] The inter-module fuse 70 is housed in a fuse housing 71 . The inter-module fuse 70 is fixed to the lower surface of the fuse housing 71 .

[0076] The fuse housing 71 is formed to surround the inter-module fuse 70. The fuse housing 71 may also be formed with ventilation holes (not shown) for heat exchange between the inter-module fuse 70 and the ambient air surrounding the fuse housing 71. The fuse housing 71 is disposed on the bottom case 11, sandwiching (intervening) a heat-conducting member 72. The fuse housing 71 includes a fixing member 73 extending from the fuse housing 71. The fixing member 73 connects the fuse housing 71 to the reinforcement member 11a fixed to the bottom case 11. This secures the fuse housing 71 to the bottom case 11.

[0077] Figure 9 Show Figure 1IX-IX cross-sectional view of FIG. A heat insulator 74 is arranged above the fuse housing 71. A cover 75 is arranged on the upper portion of the heat insulator 74 so as to cover the heat insulator 74. An opening 74a is formed in the heat insulator 74.

[0078] The opening 74 a connects, in the width direction W, a space R2 where the fuse case 71 is covered by the heat insulator 74 and a space R1 formed by the bottom case 11 and the top cover 12 .

[0079] The bus bar 40 connected to the inter-module fuse 70 is connected to the electrode 3 through the opening 74 a.

[0080] In the above embodiment, the power storage device 100 includes an inter-module fuse 70 disposed in the electrical path between the power storage module 24 and the power storage module 25. This configuration allows the power storage device 100 to be provided in such a manner that, even if power storage modules 20 adjacent in the width direction W of the power storage unit 80 are electrically connected and a short circuit occurs within the power storage device 100, the inter-module fuse 70 can be opened to interrupt a large current.

[0081] In the above embodiment, the electricity storage unit 80 includes the connecting bracket 30. The upper member 31 of the connecting bracket 30 is in contact with the end plate 7 without a gap in the vertical direction H. This configuration prevents smoke exhausted from the gas exhaust holes 4a of the upper frame 4 from passing between the upper member 31 and the end plate 7. This prevents the flow of smoke in the width direction W within the electricity storage unit 80.

[0082] Furthermore, the upper surface 32a of the top plate 32 of the upper member 31 and the upper surface 33b of the end member 33 are positioned above the upper surface 4b of the upper frame 4. This configuration prevents smoke exhausted from the gas exhaust holes 4a of the upper frame 4 from passing over the top of the top plate 32 and the end member 33. This prevents the flow of smoke in the width direction W of the power storage unit 80.

[0083] In the above embodiment, the heat insulator 36 is disposed so as to fill the gap between the top cover 12 and the top plate 32. With this configuration, the flow of smoke in the width direction W in the electricity storage unit 80 can be suppressed.

[0084] In the above embodiment, the power storage module 21 is arranged in the longitudinal direction L at one end of a plurality of power storage cells 80 arranged in the longitudinal direction L. Furthermore, the power storage module 21 is positioned between one end and the other end of the power storage cells 80 in the width direction W. Furthermore, the inter-module fuse 70 is arranged adjacent to the power storage module 21 in the width direction W. This configuration effectively utilizes the dead space (unused space) created at adjacent positions of the power storage modules 21 in the width direction.

[0085] In the above embodiment, the heat insulator 74 is disposed above the inter-module fuse 70. With this configuration, the inter-module fuse 70 can be protected from the high-temperature exhaust smoke generated from the power storage module 20.

[0086] Furthermore, an opening 74a that connects space R1 and space R2 is formed in heat insulator 74. With this configuration, cool air in space R1 flows into space R2 through opening 74a, thereby cooling inter-module fuse 70.

[0087] In the above embodiment, the inter-module fuse 70 is disposed in a fuse housing 71. Furthermore, the fuse housing 71 is disposed on the bottom case 11 with a heat conducting member 72 interposed therebetween. The bottom case 11 has a greater heat capacity than the fuse housing 71. This configuration allows heat from the inter-module fuse 70 to be dissipated to the bottom case 11 via the fuse housing 71 and the heat conducting member 72.

[0088] In the above embodiment, an example is shown in which the gap between the top cover 12 and the top plate 32 is filled with the heat insulating member 36, but the present disclosure is not limited to this. For example, the heat insulating member 36 may be omitted, and a gap may be provided between the top cover 12 and the top plate 32. Alternatively, the upper surface 32a of the top plate 32 and the upper surface 33b of the end member 33 are each formed to be located above the upper surface 4b of the upper frame 4 of the storage module 20. By configuring in this manner, it is possible to prevent smoke exhausted from the gas exhaust hole 4a of the upper frame 4 from passing above the connecting bracket 30. As a result, the flow of smoke in the width direction W in the storage cell 80 can be suppressed.

[0089] While the embodiments of the present invention have been described, the embodiments disclosed herein are to be construed as illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, and is intended to encompass all modifications within the meaning and scope of the claims and equivalents thereof.

Claims

1. A power storage device mounted on a vehicle, The power storage device includes a power storage unit, an inter-module fuse, a first external terminal, and a second external terminal. The power storage unit includes a first power storage module and a second power storage module, the first power storage module having a first electrode, the second power storage module being arranged adjacent to the first power storage module in a first direction, and the second power storage module having a second electrode. The first electrode is arranged at one end of the power storage unit in the first direction. The first electrode includes a first terminal and a second terminal, the first terminal is electrically connected to the first external terminal, The second electrode is arranged at the other end of the power storage unit in the first direction, The second electrode includes a third terminal and a fourth terminal, the third terminal is electrically connected to the second external terminal, The second terminal is electrically connected to the fourth terminal, The inter-module fuse is provided in the electrical path between the second terminal and the fourth terminal.

2. The power storage device according to claim 1, The power storage device further includes a terminal fuse. The terminal fuse is provided in an electrical path between the second external terminal and the third terminal.

3. The power storage device according to claim 1 or 2, The electricity storage unit includes a connecting bracket connecting the first electricity storage module and the second electricity storage module. The connecting bracket is formed to protrude upward from the first electricity storage module and the second electricity storage module.

4. The power storage device according to claim 1, The power storage device further includes a third power storage module. The third power storage module is arranged in a second direction intersecting the first direction with respect to the power storage unit. The third power storage module is arranged between the one end and the other end in the first direction. The inter-module fuse is arranged at a position adjacent to the third power storage module in the first direction.

5. The power storage device according to claim 1, A heat insulator is disposed above the inter-module fuse.

6. The power storage device according to claim 5, The heat insulator has an opening formed therein that communicates with the internal space of the power storage device.

7. The power storage device according to claim 1, The power storage device further includes a bottom case. The inter-module fuse is arranged on the bottom case with a heat conduction member interposed therebetween.

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