Electricity storage module and electricity storage device

Abstract

To improve housing efficiency of an electricity storage module.SOLUTION: An electricity storage module includes a plurality of cells, and a bus bar. Each of the plurality of cells includes a rectangular case, an electrode terminal, and a power generation element. An outer face of the rectangular case includes a wide face in a rectangular shape and a side face. The side face crosses the wide face in a length direction. The side face is connected to the wide face in an end portion in the length direction. A plurality of cells is laminated in such a manner that mutual wide faces are opposed to each other between adjacent cells. The electrode terminal protrudes from the side face to the outside of the rectangular case in the length direction of the wide face. The electrode terminal includes an upper end portion and a lower end portion. The lower end portion is positioned inside the rectangular case. The upper end portion is positioned outside the rectangular case. In the length direction, the bus bar is connected to the electrode terminal at a position between the upper end portion of the electrode terminal and the side face of the rectangular case.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to an energy storage module and an energy storage device. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2018-106800 discloses an energy storage module formed by stacking a plurality of cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-106800 A Summary of the Invention [Problem to be solved by the invention]

[0004] The energy storage device (also referred to as a "battery pack") includes a housing and an energy storage module. The housing houses the energy storage module. The energy storage module may include a plurality of cells and a bus bar. The bus bar connects electrode terminals between two or more cells. Conventionally, the bus bar is connected to cover the upper ends of the electrode terminals. In other words, the bus bar protrudes outward from the cell case beyond the electrode terminals. The bus bar protruding outward may reduce the storage efficiency of the energy storage module within the housing. In particular, when the cell case is a rectangular case with wide faces and the electrode terminals protrude in the direction of the long sides of the wide faces, the storage efficiency of the energy storage module within the housing may be significantly reduced.

[0005] An object of the present disclosure is to improve the storage efficiency of power storage modules. [Means for solving the problem]

[0006] The technical configuration and effects of the present disclosure will be described below. However, the mechanism of action includes speculation. The mechanism of action does not limit the technical scope of the present disclosure.

[0007] 1. The energy storage module includes a plurality of cells and a bus bar. Each of the plurality of cells includes a rectangular case, an electrode terminal, and a power generation element. The rectangular case is hexahedral. The outer surface of the rectangular case includes rectangular wide faces and side faces. The side faces intersect with the long sides of the wide faces. The side faces are connected to the wide faces at their ends in the long side direction. The rectangular case houses a power generation element. A plurality of cells are stacked between adjacent cells so that the wide faces face each other. The electrode terminals protrude from the side faces along the long side direction of the wide faces to the outside of the rectangular case. The electrode terminals include an upper end and a lower end. The lower end is located inside the rectangular case. The upper end is located outside the rectangular case. The bus bar connects the electrode terminals between adjacent cells. The bus bar is connected to the electrode terminals at a position in the long side direction between the upper end of the electrode terminal and the side face of the rectangular case.

[0008] In the energy storage module of "1" above, the bus bars do not protrude beyond the electrode terminals in the long side direction (width direction) of the wide surface, which is expected to improve the storage efficiency of the energy storage module.

[0009] 2. The energy storage module described in "1" above may include, for example, the following configuration: The electrode terminal has a small diameter portion. The small diameter portion has a diameter smaller than that of the upper end portion. In the long side direction, the small diameter portion is disposed at a position between the upper end portion and the side surface. A bus bar is fitted into the small diameter portion.

[0010] By fitting the bus bar into the small diameter portion of the electrode terminal, it is expected that, for example, the connection between the electrode terminal and the bus bar will be stable.

[0011] 3. The energy storage module described in "2" above may include, for example, the following configuration: The upper end of the electrode terminal has a flange portion that extends outward beyond the small diameter portion in the radial direction of the electrode terminal, and the flange portion is welded to the bus bar.

[0012] For example, the upper end of the electrode terminal may be welded to the bus bar by irradiating the flange portion of the electrode terminal with a laser.

[0013] 4. The energy storage module according to any one of the above items "1" to "3" may include, for example, the following configuration: The electrode terminal includes a first member and a second member. The first member is in the shape of a concave lid. The first member is fitted into the second member.

[0014] Since the electrode terminal is made up of two members, the bonding area between the electrode terminal and the bus bar may increase.

[0015] 5. The energy storage module according to any one of the above items "1" to "3" may include, for example, the following configuration: The electrode terminal includes a first member and a second member. The first member is joined to the second member by a screw mechanism.

[0016] For example, the bus bar may be sandwiched between two members, and the load applied to the bus bar may be adjusted by, for example, screwing the two members together.

[0017] 6. The energy storage module according to any one of the above items "1" to "5" may include, for example, the following configuration: The energy storage module further includes an annular member. The annular member has electrical insulation properties. An electrode terminal is inserted through the annular member. A bus bar is connected between an upper end of the electrode terminal and the annular member.

[0018] If the bus bar is positioned inside the upper end of the electrode terminal, the bus bar may come into contact with the rectangular case. Contact between the bus bar and the rectangular case may cause a short circuit. To prevent a short circuit, an insulating annular member (spacer) may be placed between the bus bar and the rectangular case.

[0019] 7. A power storage device includes the power storage module according to any one of items 1 to 6 above, a housing, and an insulating member. The housing houses the power storage module and the insulating member. The upper ends of the electrode terminals face the inner surface of the housing. The insulating member is disposed between the upper ends and the inner surface.

[0020] By arranging the bus bar inside the upper end (electrode terminal), the upper end protrudes toward the inner surface of the housing. If the housing is made of metal, the upper end may come into contact with the inner surface of the housing, potentially causing a short circuit. To prevent a short circuit, an insulating member may be arranged between the upper end and the housing.

[0021] Hereinafter, one embodiment of the present disclosure (hereinafter, may be abbreviated as "the present embodiment") will be described. However, this embodiment does not limit the technical scope of the present disclosure. This embodiment is illustrative in all respects. This embodiment is non-restrictive. The technical scope of the present disclosure encompasses all modifications within the meaning and scope equivalent to the claims. For example, it is also intended from the beginning that any configuration may be extracted from this embodiment and arbitrarily combined. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a conceptual diagram showing an example of a vehicle according to an embodiment of the present invention. [Figure 2] 1 is a schematic perspective view illustrating an example of a power storage device according to an embodiment of the present invention. [Figure 3] FIG. 2 is a side view illustrating an example of the energy storage module according to the present embodiment. [Figure 4] FIG. 2 is a schematic diagram illustrating an example of a cell according to the present embodiment. [Figure 5] FIG. 2 is a first schematic cross-sectional view showing an electrode terminal in the present embodiment. [Figure 6] FIG. 2 is a second schematic cross-sectional view showing an electrode terminal in the present embodiment. [Figure 7] 1 is a first schematic plan view showing an example of a bus bar according to the present embodiment. FIG. [Figure 8]FIG. 4 is a second schematic plan view showing an example of a bus bar according to the present embodiment. [Figure 9] FIG. 10 is a third schematic plan view showing an example of the bus bar in the present embodiment. [Figure 10] FIG. 3 is a third schematic cross-sectional view showing an electrode terminal in the present embodiment. [Figure 11] FIG. 4 is a fourth schematic cross-sectional view showing an electrode terminal in the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] -Terms and phrases- "Comprise," "include," "have," and variations thereof are open-ended terms. Open-ended terms may or may not include additional elements in addition to the required elements. "Consisting of" is a closed term. However, even a structure expressed in closed terminology may include additional elements that are normally associated with the technology or that are unrelated to the technology in question. "Consisting essentially of..." is a semi-closed term. Semi-closed terminology allows for the addition of elements that do not substantially affect the basic and novel characteristics of the technology in question.

[0024] Expressions such as "may" and "may" are used in the permissive sense, meaning "to have the possibility," rather than in the obligatory sense, meaning "to have to."

[0025] Geometric terms should not be interpreted in a strict sense. Examples of geometric terms include "parallel," "perpendicular," and the like. For example, directions, angles, distances, and the like may be displaced relative to one another as long as substantially the same or similar functions are obtained. Geometric terms may include, for example, tolerances, errors, and the like in design, work, manufacturing, and the like. The dimensional relationships in each figure may not match the actual dimensional relationships. The dimensional relationships in each figure may be changed to aid the reader's understanding. For example, length, width, thickness, and the like may be changed. Some components may be omitted.

[0026] Elements described in the "singular" may also include the plural unless otherwise specified, e.g., a cell may refer to a plurality of cells (cells).

[0027] "Cell" refers to a single battery. The cell may be, for example, a lithium-ion battery. The cell may include, for example, a liquid electrolyte, a gel electrolyte, or a solid electrolyte.

[0028] "Electrode" is a general term for positive electrodes and negative electrodes. Therefore, for example, "electrode terminal" is a general term for positive electrode terminals and negative electrode terminals.

[0029] In this embodiment, a power storage module and a power storage device for a vehicle will be described. However, the use for a vehicle is merely one example of the application, and the application is arbitrary.

[0030] The thickness direction (T direction), width direction (W direction), and height direction (H direction) in each drawing are based on the T direction, W direction, and H direction of the cell. Each direction is perpendicular to one another. The T direction may be parallel to the traveling direction of the vehicle, for example, or may not be parallel to it. The T direction may be perpendicular to the traveling direction of the vehicle, for example.

[0031] -vehicle- FIG. 1 is a conceptual diagram showing an example of a vehicle in this embodiment. The vehicle 1 may be, for example, a BEV (Battery Electric Vehicle), an HEV (Hybrid Electric Vehicle), or a PHEV (Plug-in Hybrid Electric Vehicle). The vehicle 1 includes a power storage device 10. The power storage device 10 may be mounted in any position. For example, the power storage device 10 may be disposed under the floor of the vehicle 1.

[0032] -Electricity storage device- 2 is a schematic perspective view showing an example of a power storage device according to this embodiment. The power storage device 10 includes a power storage module 11, a housing 12, and an insulating member 13. The power storage device 10 may include a plurality of power storage modules 11. The power storage device 10 may include, for example, two or more, four or more, or six or more power storage modules 11. The power storage device 10 may include, for example, eight or less, six or less, or four or less power storage modules 11.

[0033] The housing 12 houses the power storage modules 11 and the insulating members 13. The housing 12 may be made of, for example, metal. The housing 12 may include, for example, an upper case 12a and a lower case 12b. There may be gaps between the power storage modules 11. For example, a partition plate (not shown) may be provided between the power storage modules 11.

[0034] The power storage device 10 may further include a cooler (not shown). The cooler can cool the power storage module 11. The cooler may include, for example, a refrigerant flow path. The cooler may be disposed, for example, between the upper case 12a and the power storage module 11. The cooler may be disposed, for example, between the lower case 12b and the power storage module 11. Inside the housing 12, the insulating member 13 is disposed between the power storage module 11 and the inner surface of the housing 12.

[0035] -Energy storage module- 3 is a side view showing an example of a power storage module according to this embodiment. The side view according to this embodiment is shown as seen from the W direction. The power storage module 11 includes a plurality of cells 100 and bus bars 200. The number of cells 100 may be, for example, 2 or more, 4 or more, 10 or more, 20 or more, 50 or more, or 100 or more. The number of cells 100 may be, for example, 100 or less, 50 or less, 20 or less, 10 or less, or 4 or less.

[0036] The multiple cells 100 are stacked in the T direction. The multiple cells 100 are stacked such that the wide surfaces 101a of adjacent cells 100 face each other. The adjacent cells 100 are inverted in the W direction, so that the positive electrode terminal 102 of one cell 100 is adjacent to the negative electrode terminal 103 of the other cell 100.

[0037] The bus bar 200 is conductive. The bus bar 200 may be made of, for example, a metal. The bus bar 200 may contain, for example, aluminum (Al), copper (Cu), or the like. The bus bar 200 connects electrode terminals between the cells 100. The bus bar 200 may connect, for example, the positive electrode terminal 102 and the negative electrode terminal 103. The bus bar 200 may connect, for example, the positive electrode terminal 102 and the positive electrode terminal 102. The bus bar 200 may connect, for example, the negative electrode terminal 103 and the negative electrode terminal 103. The bus bar 200 may be joined to the electrode terminals. For example, the bus bar 200 may be joined to the electrode terminals by resistance welding, ultrasonic welding, laser welding, or the like.

[0038] 3, bus bar 200 may be inclined in the H direction, for example. Bus bar 200 may extend parallel to the T direction, for example.

[0039] FIG. 4 is a schematic diagram showing an example of a cell in this embodiment. Each of the multiple cells 100 includes a rectangular case 101, a positive electrode terminal 102, a negative electrode terminal 103, and a power generating element 300. The rectangular case 101 houses the power generating element 300. The power generating element 300 is also referred to as an "electrode body." The power generating element 300 may include, for example, a positive electrode, a negative electrode, a separator, and an electrolyte. The power generating element 300 may be, for example, a laminated or wound type. The positive electrode and the negative electrode may be in a sheet form. The positive electrode may include, for example, lithium iron phosphate, lithium nickel composite oxide, or the like. The negative electrode may include, for example, graphite, silicon oxide, silicon, or the like.

[0040] The rectangular case 101 may be made of metal, for example. The rectangular case 101 may contain Al, for example. The rectangular case 101 may have a flat plate-like outer shape. The rectangular case 101 may be in the shape of a long plate, for example.

[0041] The width of the rectangular case 101 refers to the outer dimension in the W direction. The width of the rectangular case 101 may be, for example, 500 mm or more, 750 mm or more, or 1000 mm or more. The width of the rectangular case 101 may be, for example, 2000 mm or less, 1500 mm or less, or 1250 mm or less. The height of the rectangular case 101 refers to the outer dimension in the H direction. The height of the rectangular case 101 may be, for example, 50 mm or more, 75 mm or more, or 100 mm or more. The height of the rectangular case 101 may be, for example, 200 mm or less, 150 mm or less, 125 mm or less, or 100 mm or less. The thickness of the rectangular case 101 refers to the outer dimension in the T direction. The thickness of the rectangular case 101 may be, for example, 5 mm or more, 10 mm or more, 15 mm or more, or 20 mm or more. The thickness of rectangular case 101 may be, for example, 30 mm or less, 25 mm or less, 20 mm or less, 15 mm or less, or 10 mm or less.

[0042] The ratio of width to height (which may be referred to as the "first aspect ratio") may be, for example, 5 to 20. The ratio of width to thickness (which may be referred to as the "second aspect ratio") may be, for example, 50 to 200.

[0043] The rectangular case 101 is hexahedral. That is, the rectangular case 101 includes six faces. Each face may be flat or curved. The outer surface of the rectangular case 101 includes a pair of wide faces 101a, a pair of side faces 101b, and a pair of bottom faces 101c. Each pair of faces may have the same shape or may have different shapes. The connecting portions (corners) of each face may be angular or rounded.

[0044] The wide surface 101a is rectangular. Of the six surfaces, the wide surface 101a has the largest area. The wide surface 101a has a long side direction and a short side direction. In FIG. 4, the long side direction is the W direction. The short side direction is the H direction. The wide surface 101a extends in the long side direction. The side surface 101b intersects with the long side direction. The side surface 101b may be perpendicular to the long side direction. The side surface 101b is connected to the wide surface 101a at an end in the long side direction. The bottom surface 101c intersects with the short side direction. The bottom surface 101c may be perpendicular to the short side direction. The bottom surface 101c is connected to the wide surface 101a at an end in the short side direction.

[0045] The positive electrode terminal 102 penetrates the side surface 101b. Inside the rectangular case 101, the positive electrode terminal 102 is electrically connected to the positive electrode (power generating element 300). The positive electrode terminal 102 protrudes from the side surface 101b to the outside of the rectangular case 101 along the long side direction (W direction). Note that the "direction along the long side direction" includes all directions other than the short side direction (direction perpendicular to the long side direction). The direction along the long side direction may, for example, be parallel to the long side direction.

[0046] The negative electrode terminal 103 penetrates the side surface 101b. Inside the rectangular case 101, the negative electrode terminal 103 is electrically connected to the negative electrode (power generating element 300). In FIG. 4, the negative electrode terminal 103 protrudes in the opposite direction to the positive electrode terminal 102. In some embodiments, the negative electrode terminal 103 may protrude in the same direction as the positive electrode terminal 102. In other words, both the positive electrode terminal 102 and the negative electrode terminal 103 may be disposed on the same side surface 101b.

[0047] 4, the position of the negative electrode terminal 103 in the H direction is different from the position of the positive electrode terminal 102. The position of the negative electrode terminal 103 in the H direction may be the same as the position of the positive electrode terminal 102.

[0048] Fig. 5 is a first schematic cross-sectional view showing the electrode terminals in this embodiment. The positive electrode terminal 102 is shown in Fig. 5, Fig. 6, Fig. 10, and Fig. 11. Although not shown, the negative electrode terminal 103 may have a similar structure to the positive electrode terminal 102.

[0049] The positive electrode terminal 102 includes an upper end portion 102a and a lower end portion 102b. The lower end portion 102b is located inside the rectangular case 101. The lower end portion 102b is connected to the power generating element 300. The upper end portion 102a is located outside the rectangular case 101. The upper end portion 102a includes an end face of the positive electrode terminal 102. The end face of the positive electrode terminal 102 may be flat or curved. In the long side direction (W direction), the bus bar 200 is connected to the positive electrode terminal 102 at a position between the upper end portion 102a of the positive electrode terminal 102 and the side surface 101b of the rectangular case 101.

[0050] The positive terminal 102 may have a small diameter portion 102c. In the long side direction (W direction), the small diameter portion 102c is located between the upper end portion 102a and the side surface 101b. The small diameter portion 102c has a smaller diameter than the upper end portion 102a. The bus bar 200 may be fitted into the small diameter portion 102c. The small diameter portion 102c may have a constant diameter. The diameter of the small diameter portion 102c may vary in the axial direction of the positive terminal 102. For example, the small diameter portion 102c may be tapered or inversely tapered in the direction from the lower end portion 102b toward the upper end portion 102a.

[0051] The ratio of the diameter of small diameter portion 102c to the diameter of upper end portion 102a may be, for example, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, or 0.5 or less. The ratio of the diameter of small diameter portion 102c to the diameter of upper end portion 102a may be, for example, 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, or 0.5 or more. If the contours of upper end portion 102a and small diameter portion 102c are not circular in a cross section perpendicular to the axial direction of the electrode terminal, the diameters of each portion shall indicate the maximum diameter.

[0052] The diameter of the lower end portion 102b is arbitrary. For example, the lower end portion 102b may have the same diameter as the small diameter portion 102c. For example, the lower end portion 102b may have a larger diameter or a smaller diameter than the small diameter portion 102c.

[0053] FIG. 6 is a second schematic cross-sectional view showing an electrode terminal according to this embodiment. For example, the upper end portion 102a of the positive terminal 102 may have a shaft portion 102d and a flange portion 102e. The shaft portion 102d includes the central axis of the positive terminal 102. The flange portion 102e extends radially outward of the positive terminal 102 beyond the small diameter portion 102c. The radial direction is the H direction in FIG. 6. The flange portion 102e may be formed, for example, around the entire circumferential direction of the positive terminal 102. The flange portion 102e may extend, for example, to cover the bus bar 200. The flange portion 102e may be welded to the bus bar 200. For example, the flange portion 102e may be joined to the bus bar 200 by full-thickness welding. For example, the flange portion 102e may be welded to the bus bar 200 by irradiating the upper surface of the flange portion 102e with a laser 140. Flange portion 102e and bus bar 200 may be joined by, for example, keyhole welding.

[0054] A welded portion may be formed between the flange portion 102e and the busbar 200. For example, a first welded portion 150a extending in a layered manner along the interface between the flange portion 102e and the busbar 200 may be formed. For example, a second welded portion 150b extending in the depth direction of the flange portion 102e and the busbar 200 may be formed. The welded portion may include, for example, a constituent metal of the flange portion 102e and a constituent metal of the busbar 200. The welded portion may include, for example, an alloy of the constituent metal of the flange portion 102e and a constituent metal of the busbar 200. The welded portion may include at least one selected from the group consisting of Al, Cu, and an Al-Cu alloy. The thickness of the flange portion 102e may be, for example, 0.2 to 5 mm or 0.2 to 2 mm. The flange portion 102e may be thinner or thicker than the busbar 200.

[0055] 7 is a first schematic plan view showing an example of a bus bar in this embodiment. Bus bar 200 may be, for example, plate-shaped. Bus bar 200 may have two through holes 201. Electrode terminals may be inserted through through holes 201.

[0056] 8 is a second schematic plan view showing an example of a busbar according to this embodiment. The busbar 200 may have an opening 202. For example, the small diameter portion 102c may slide from the opening 202 to the fixed position 203. In other words, the busbar 200 may be fitted into the small diameter portion 102c. Similar to the positive electrode terminal 102, the small diameter portion of the negative electrode terminal 103 may also slide from the opening 202 to the fixed position 203.

[0057] 9 is a third schematic plan view showing an example of a busbar according to this embodiment. For example, two openings 202 may be arranged alternately with respect to the axis of busbar 200.

[0058] 5, the energy storage module 11 may further include an annular member 104 (spacer). The annular member 104 has electrical insulation properties. The annular member 104 may be made of, for example, resin or ceramic. The positive electrode terminal 102 is inserted through the annular member 104. A bus bar 200 may be connected between the upper end portion 102a and the annular member 104.

[0059] The power storage module 11 may further include a sealing material 105. The sealing material 105 provides a seal between the positive electrode terminal 102 and the rectangular case 101. The sealing material 105 may be annular. The sealing material 105 may have electrical insulating properties. The sealing material 105 may be made of, for example, rubber or resin. The sealing material 105 may have resistance to, for example, an electrolyte solution.

[0060] The upper end portion 102a faces the inner surface of the housing 12. An insulating member 13 may be disposed between the upper end portion 102a and the inner surface of the housing 12. The insulating member 13 may be, for example, plate-shaped. The insulating member 13 may be made of, for example, resin, ceramic, or the like. The insulating member 13 may fill a gap between the upper end portion 102a and the inner surface of the housing 12. The insulating member 13 may cover the upper end portion 102a. The insulating member 13 may be bonded to the upper end portion 102a. The insulating member 13 may be bonded to the inner surface of the housing 12.

[0061] The insulating member 13 may include, for example, a heat dissipation material. The insulating member 13 may include, for example, a heat insulating material. The insulating member 13 may have, for example, cushioning properties. The insulating member 13 may function as a buffer material. The insulating member 13 may be, for example, a porous material.

[0062] 10 is a third schematic cross-sectional view showing an electrode terminal in this embodiment. In an embodiment, the positive electrode terminal 102 may include a first member 1021 and a second member 1022. The first member 1021 includes an upper end portion 102a. The first member 1021 has a concave lid shape. The second member 1022 may have a columnar shape, for example. The first member 1021 may be fitted into the second member 1022. For example, the second member 1022 may be pressed into a recess in the first member 1021, thereby fitting the first member 1021 and the second member 1022 together.

[0063] 11 is a fourth schematic cross-sectional view showing an electrode terminal in this embodiment. In an embodiment, the positive electrode terminal 102 may include a first member 1021 and a second member 1022. The first member 1021 may have, for example, a male screw portion. The first member 1021 is conductive. The second member 1022 may have, for example, a female screw portion. The second member 1022 may be electrically insulating. The first member 1021 may be joined to the second member 1022 by a screw mechanism. That is, the first member 1021 may be screwed into the second member 1022.

[0064] For example, the bus bar 200 may also have a female screw portion. The positive electrode terminal 102 may be joined to the bus bar 200 by a screw mechanism. That is, the first member 1021 may be screwed into the bus bar 200. The bus bar 200 may be sandwiched between the first member 1021 and the second member 1022. [Explanation of symbols]

[0065] 1 vehicle, 10 energy storage device, 11 energy storage module, 12 housing, 12a upper case, 12b lower case, 13 insulating member, 100 cell, 101 rectangular case, 101a wide surface, 101b side surface, 101c bottom surface, 102 positive terminal, 102a upper end, 102b lower end, 102c small diameter portion, 102d shaft portion, 102e flange portion, 103 negative terminal, 104 annular member, 105 sealing material, 140 laser, 150a first welded portion, 150b second welded portion, 200 bus bar, 201 through hole, 202 opening portion, 203 fixing position, 300 power generating element, 1021 first member, 1022 second member.

Claims

1. a plurality of cells and a bus bar; Each of the plurality of cells includes a rectangular case, an electrode terminal, and a power generating element; The rectangular case is hexahedral, The outer surface of the rectangular case includes a rectangular wide surface and a side surface, the side surface intersects with the long side direction of the wide surface, the side surface is connected to the wide surface at an end in the long side direction, the rectangular case accommodates the power generating element, The plurality of cells are stacked such that the wide surfaces of the adjacent cells face each other, the electrode terminals protrude from the side surfaces to the outside of the rectangular case along the long side direction of the wide surfaces, the electrode terminal includes an upper end and a lower end; The lower end is located inside the rectangular case, The upper end is located outside the rectangular case, The bus bar connects the electrode terminals between adjacent cells, and the bus bar is connected to the electrode terminal at a position between the upper end of the electrode terminal and the side surface of the rectangular case in the long side direction. Energy storage module.

2. The electrode terminal has a small diameter portion, The small diameter portion has a diameter smaller than that of the upper end portion, In the long side direction, the small diameter portion is disposed at a position between the upper end portion and the side surface, and The bus bar is fitted into the small diameter portion. The energy storage module according to claim 1 .

3. the upper end of the electrode terminal has a flange portion that extends outward beyond the small diameter portion in the radial direction of the electrode terminal, and The flange portion is welded to the bus bar. The energy storage module according to claim 2 .

4. the electrode terminal includes a first member and a second member, The first member is a concave lid-like member, and The first member is fitted to the second member. The energy storage module according to claim 1 or 2.

5. the electrode terminal includes a first member and a second member, and The first member is joined to the second member by a screw mechanism. The energy storage module according to claim 1 or 2.

6. further comprising an annular member; the annular member has electrical insulation properties, The electrode terminal is inserted into the annular member, and the bus bar is connected between the upper end of the electrode terminal and the annular member; The energy storage module according to claim 1 or 2.

7. A power storage device comprising the power storage module according to claim 1 or 2, a housing, and an insulating member, the housing accommodates the power storage module and the insulating member, the upper end of the electrode terminal faces the inner surface of the housing, and The insulating member is disposed between the upper end portion and the inner surface. Energy storage device.

Images