Power storage module

Abstract

To more firmly attach a bus bar to an electrode external terminal with a simpler structure.SOLUTION: In the power storage module disclosed herein, the plurality of power storage devices are arranged such that the first surfaces of the cases of the power storage devices face each other. The bus bar electrically connects two power storage devices adjacent to each other in a direction in which the plurality of power storage devices are arranged. The bus bar has two non-through holes on the same surface. The positive electrode external terminal of one of the two adjacent power storage devices is fitted into one of the two non-through holes. The negative electrode external terminal of the other power storage device of the two adjacent power storage devices is fitted into the other non-through hole of the two non-through holes, so that the bus bar electrically connects the two adjacent power storage devices.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] An example of a power storage module is a power storage module including a secondary battery such as a lithium-ion secondary battery. In recent years, this type of power storage module has been suitably used as a power source for driving vehicles such as electric vehicles (BEVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs).

[0003] Japanese Patent Application Laid-Open Publication No. 2016-85961 discloses a battery terminal having a shaft portion and a flange portion extending radially from the shaft portion. The battery terminal is composed of a clad material in which at least a first metal layer and a second metal layer are bonded. Each of the shaft portion and the flange portion is composed of the first metal layer on one side in the axial direction of the shaft portion and the second metal layer on the other side. The first metal layer of the shaft portion has a portion that protrudes in the other axial direction beyond the surface of the first metal layer of the flange portion on the other axial direction. The publication states that this configuration can increase the bonding strength between the first metal layer and the second metal layer.

[0004] Japanese Patent Application Laid-Open Publication No. 2012-79456 discloses a battery pack in which a cell having an electrode terminal is connected to the electrode terminal of another adjacent cell by an electrode terminal connecting member. The electrode terminal is formed in a cone shape whose width decreases from the tip toward the battery container. The electrode terminal extends from the tip toward the battery container and has grooves that divide at least the tip portion into multiple segments and recesses formed on the outer circumferential surface. The electrode terminal connecting member has fitting holes into which electrode terminals, which are arranged so that the segments are close to each other, are pressed and fitted into the recesses. The publication states that this configuration enables the electrode terminals and the electrode terminal connecting member to be securely connected over a long period of time.

[0005] The battery module disclosed in JP 2015-49930 A includes a plurality of battery cells each having a substantially columnar positive electrode post and a negative electrode post extending in a predetermined direction, and a conductive electrode connector connecting the positive electrode post to the negative electrode post of an adjacent battery cell. In the battery module, juxtaposed battery cells are connected in series by the electrode connector. The battery module includes an opening in the electrode connector that allows the insertion of the positive electrode post and the negative electrode post. The battery module includes a deformation means in either the positive electrode post and the negative electrode post or the electrode connector that deforms the portion of the opening facing the positive electrode post and the negative electrode post in a direction substantially perpendicular to the predetermined direction. The publication states that this configuration ensures stable connection between adjacent battery cells without compromising assembly. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2016-85961 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-79456 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-49930 Summary of the Invention [Problem to be solved by the invention]

[0007] The present inventors have been thinking about how to attach bus bars to external electrode terminals more firmly with a simpler structure. [Means for solving the problem]

[0008] The technology disclosed herein provides an energy storage module including a plurality of energy storage devices and a bus bar. The plurality of energy storage devices include a case having a pair of opposing rectangular first surfaces, and a positive electrode external terminal and a negative electrode external terminal on the outer surface of the case. The plurality of energy storage devices are arranged so that the first surfaces of the energy storage devices face each other. The bus bar is a member that electrically connects two adjacent energy storage devices in the arrangement direction of the plurality of energy storage devices. The bus bar has two blind holes on the same surface. The positive electrode external terminal of one of the two adjacent energy storage devices is fitted into one of the two blind holes. The negative electrode external terminal of the other of the two adjacent energy storage devices is fitted into the other of the two blind holes, thereby electrically connecting the two adjacent energy storage devices. This configuration allows the bus bar to be attached to the electrode external terminals more firmly with a simpler structure. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of the energy storage module 100. FIG. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Figure 3] FIG. 3 is a bottom view of the bus bar 14. FIG. [Figure 4] FIG. 4 is a cross-sectional view of the bus bar 14. [Figure 5] FIG. 5 is a graph showing the correlation between residual compressive force and resistance value. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the energy storage device disclosed herein is described below. The embodiment described herein does not particularly limit the technology disclosed herein. The technology disclosed herein is not limited to the embodiment described herein unless otherwise specified. The drawings are schematic and do not necessarily reflect the actual product. Components and parts that perform the same function are appropriately designated with the same reference numerals, and redundant explanations may be omitted. The reference numerals "R," "L," "U," "D," "F," and "Rr" in the drawings represent "right," "left," "up," "down," "front," and "rear," respectively. The notation "A to B" indicating a numerical range means "greater than A and less than B" unless otherwise specified, and also encompasses the meaning of "greater than A and less than B."

[0011] In this specification, the term "electricity storage device" refers to a device in which charge and discharge occur by the movement of charge carriers between a pair of electrodes (positive and negative electrodes) via an electrolyte. Electricity storage devices include secondary batteries such as lithium ion secondary batteries, nickel-metal hydride batteries, and nickel-cadmium batteries; and capacitors such as lithium ion capacitors and electric double layer capacitors. The electricity storage device may be, for example, a lithium ion secondary battery.

[0012] FIG. 1 is a perspective view of an energy storage module 100. As shown in FIG. 1, the energy storage module 100 includes a plurality of energy storage devices 12 and a bus bar 14. The energy storage devices 12 are arranged in a first direction P. In the embodiment shown in FIG. 1, the energy storage device 12 includes a rectangular parallelepiped case 30 having a pair of opposing first surfaces 30a, a pair of opposing second surfaces 30b, and a bottom surface 30c. The first surfaces 30a are rectangular and are the largest surfaces of the case 30. As shown in FIG. 1, the pair of opposing first surfaces 30a extend from a pair of opposing long sides of the bottom surface 30c. The second surfaces 30b are rectangular and are sandwiched between the pair of opposing first surfaces 30a. As shown in FIG. 1, the pair of opposing second surfaces 30b extend from a pair of opposing short sides of the bottom surface 30c. 1, the power storage devices 12 are arranged so that their first surfaces 30a face each other. The "first direction P" here refers to the direction from one first surface 30a of the power storage device 12 to the other first surface 30a, that is, the direction from the rear (Rr) side to the front (F) side in FIG.

[0013] The electricity storage device 12 includes, for example, a case 30, an electrode assembly (not shown) housed in the case 30, and an electrolyte (not shown). As shown in FIG. 1, the case 30 includes a main body 31 and a sealing plate 32. The main body 31 is a member that houses, for example, the electrode assembly and the electrolyte. Here, the main body 31 has a rectangular parallelepiped shape with one side open. In the embodiment shown in FIG. 1, the main body 31 has a pair of opposing first faces 30a, a pair of opposing second faces 30b, and a bottom face 30c. Here, the bottom face 30c faces the opening. The sealing plate 32 is, for example, a member that closes the opening of the main body 31. The sealing plate 32 has a shape corresponding to the opening of the main body 31, and here is rectangular (including a substantially rectangular shape; the same applies below). The sealing plate 32 has a first through hole 321 (see FIG. 2) and a second through hole (not shown). Here, the first through hole 321 is a through hole through which the positive electrode external terminal 40 is inserted. Here, the second through hole is a through hole through which the negative electrode external terminal 50 is inserted. Note that, as the electrode body and the electrolyte of the electricity storage device 12, the electrode body and the electrolyte of this type of electricity storage device (for example, a lithium ion secondary battery) can be used without any particular limitation.

[0014] FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. FIG. 2 shows an enlarged cross section of the vicinity of the connection portion between the bus bar 14 and the positive external terminal 40. In this embodiment, the electricity storage device 12 is provided with a positive external terminal 40 and a negative external terminal 50 on its outer surface. In the embodiment shown in FIGS. 1 and 2, the electricity storage device 12 is provided with a positive external terminal 40 and a negative external terminal 50 on the upper surface 32u of the sealing plate 32. The positive external terminal 40 is, for example, a member electrically connected to the positive electrode of the electrode assembly. The positive external terminal 40 passes through the first through-hole 321 and has a portion disposed inside the case 30 and a portion disposed outside the case 30. The portion disposed inside the case 30 is connected to the positive electrode of the electrode assembly. The portion disposed outside the case 30 is connected to the bus bar 14, which will be described later. The positive external terminal 40 may be made of, for example, aluminum or an aluminum alloy.

[0015] In this embodiment, the positive electrode external terminal 40 has a shaft portion 41, a flange portion 42, and a crimped portion 43. The shaft portion 41 is, for example, a portion that is inserted through the first through-hole 321 of the sealing plate 32, and separates the positive electrode external terminal 40 into a portion that is arranged inside the case 30 and a portion that is arranged outside the case 30. In this embodiment, the shaft portion 41 is cylindrical. As shown in FIG. 2 , the crimped portion 43 is provided at the lower end of the shaft portion 41. The flange portion 42 is provided at the upper end of the shaft portion 41. In the embodiment shown in FIG. 2 , the portion of the positive electrode external terminal 40 that is arranged inside the case 30 is the crimped portion 43. The portion of the positive electrode external terminal 40 that is arranged outside the case 30 is the flange portion 42.

[0016] The flange portion 42 is a portion that is connected to, for example, the bus bar 14. For this reason, as described above, the flange portion 42 is disposed outside the case 30. In this embodiment, the flange portion 42 has a disk shape that widens from the shaft portion 41 as its center. The diameter of the flange portion 42 is, for example, larger than the diameter of the shaft portion 41. In the embodiment shown in FIG. 2, the flange portion 42 is fitted into the first non-through hole 14h1 of the bus bar 14. Here, the flange portion 42 is disposed inside the first non-through hole 14h1. The crimped portion 43 is a portion that is connected to, for example, the positive electrode internal terminal 60. For this reason, as described above, the crimped portion 43 is disposed inside the case 30. In this embodiment, the crimped portion 43 is a portion that is formed by crimping the lower end of the shaft portion 41 to the positive electrode internal terminal 60.

[0017] The negative external terminal 50 may have the same structure as the positive external terminal 40. In this embodiment, a flange portion (not shown) of the negative external terminal 50 is fitted into the second non-through hole 14h2 (see FIGS. 3 and 4) of the bus bar 14. The flange portion of the negative external terminal 50 is disposed within the second non-through hole 14h2. Other details of the structure of the negative external terminal 50 will not be described here. The negative external terminal 50 may be made of, for example, copper or a copper alloy.

[0018] As shown in FIG. 2, the electricity storage device 12 includes an insulating member 70. The insulating member 70 is a member that provides insulation between, for example, the bus bar 14, the sealing plate 32, the positive electrode external terminal 40, and the positive electrode internal terminal 60. In this embodiment, the insulating member 70 is disposed between the bus bar 14 and the sealing plate 32, between the flange portion 42 and the sealing plate 32, between the shaft portion 41 and the sealing plate 32 (in FIG. 2, on the inner wall of the first through hole 321), and between the sealing plate 32 and the positive electrode internal terminal 60. As the insulating member 70, any insulating member that is included in this type of electricity storage device (for example, a lithium ion secondary battery) can be used without any particular limitation. Although not shown, the electricity storage device also includes an insulating member similar to the insulating member 70 on the negative electrode side.

[0019] The bus bar 14 is, for example, a member that electrically connects two adjacent power storage devices 12. As shown in Fig. 1 , the bus bar 14 is bridged across two adjacent power storage devices 12 in a first direction P. In this embodiment, the bus bar 14 is bridged across the positive external terminal 40 of one of the two adjacent power storage devices 12 in the first direction P and the negative external terminal 50 of the other power storage device 12.

[0020] FIG. 3 is a bottom view of the busbar 14. FIG. 4 is a cross-sectional view of the busbar 14. FIG. 3 shows the structure of the bottom surface 142 of the busbar 14. In this embodiment, as shown in FIG. 2, the surface of the busbar 14 facing the power storage device 12 is the bottom surface 142, and the surface opposite the bottom surface 142 is the top surface 141. As shown in FIGS. 3 and 4, the busbar 14 has a first non-through hole 14h1 and a second non-through hole 14h2 on the bottom surface 142. The first non-through hole 14h1 is, for example, a portion into which the positive electrode external terminal 40 is fitted. The second non-through hole 14h2 is, for example, a portion into which the negative electrode external terminal 50 is fitted. In this embodiment, of two adjacent power storage devices 12 in the first direction P, the positive external terminal 40 of one of the power storage devices 12 is fitted into the first non-through hole 14h1, and the negative external terminal 50 of the other power storage device 12 is fitted into the second non-through hole 14h2.

[0021] As shown in Figures 2 and 4, first non-through hole 14h1 has opening 14a and bottom 14b on the lower surface 142 side. In the embodiment shown in Figures 2, 3, and 4, first non-through hole 14h1 has protrusion 14p1 on the inner wall. As shown in Figures 3 and 4, protrusion 14p1 is provided continuously along the circumferential direction of first non-through hole 14h1. As shown in Figures 2 and 4, protrusion 14p1 is provided on the periphery of opening 14a.

[0022] As shown in Fig. 2, the tip of the positive electrode external terminal 40 is positioned closer to the bottom 14b of the first non-through hole 14h1 than the protrusion 14p1. In the embodiment shown in Fig. 2, the flange 42 of the positive electrode external terminal 40 is positioned closer to the bottom 14b of the first non-through hole 14h1 than the protrusion 14p1. Here, the upper end surface 421 of the flange 42 is in contact with the bottom 14b. The side surface 422 of the flange 42 is in contact with the inner wall of the first non-through hole 14h1.

[0023] 4, a diameter R2 of the portion of the first non-through hole 14h1 where the protrusion 14p1 is provided (in this embodiment, the diameter R2 of the opening 14a) is smaller than a diameter R1 of the portion of the first non-through hole 14h1 excluding the protrusion 14p1 (in this embodiment, the diameter R1 of the bottom 14b). From the viewpoint of more stably holding the positive electrode external terminal 40 in the first non-through hole 14h1, when the diameter R1 is 1, the diameter R2 is, for example, 0.8 to 0.99, preferably 0.85 to 0.97, and more preferably 0.9 to 0.95, although this is not particularly limited. From the viewpoint of achieving better electrical connectivity between the positive electrode external terminal 40 and the bus bar 14, when the diameter of the flange portion 42 is taken as 1, the diameter R1 is, for example, 0.9 to 1.1, preferably 0.95 to 1.05, and more preferably 0.95 to 1.0 or 0.95 to 0.99.

[0024] In this embodiment, the residual compressive force from the first non-through hole 14h1 to the flange portion 42 of the positive electrode external terminal 40 is 0.3 N / mm 2From the viewpoint of improving the electrical connection between the bus bar 14 and the positive electrode external terminal 40, the residual compressive force is set to a value greater than 0.4 N / mm 2 More than 0.5N / mm 2 More than 0.6N / mm is preferable. 2 More preferably, 0.7N / mm 2 More preferably, 0.8N / mm 2 The above is particularly preferable. Although not particularly limited, the residual compressive force is approximately 2 N / mm 2 It is preferable that the value is equal to or less than 1.8N / mm 2 less than 1.6N / mm 2 The following is preferable: Such residual compressive force can be achieved, for example, by appropriately setting the dimensional relationship between the diameters R1 and R2 and the diameter of the flange 42 of the positive electrode external terminal 40. The relationship between the dimensional relationship between the diameters R1 and R2 and the diameter of the flange 42 of the positive electrode external terminal 40 and the residual compressive force can be set, for example, by CAE (Computer Aided Engineering) analysis.

[0025] The first non-through hole 14h1 may be formed, for example, using a cutting machine (for example, a machining center) equipped with a cutting tool (for example, an end mill) used for this type of application. The protrusion 14p1 in the first non-through hole 14h1 may also be formed, for example, using such a cutting machine.

[0026] Busbar 14 is made of, for example, aluminum or an aluminum alloy. From the viewpoint of better achieving the effects of the technology disclosed herein, busbar 14 is preferably made of, for example, pure aluminum. More preferably, busbar 14 is made of pure aluminum and annealed O material (e.g., A1050-O material, A1070-O material, etc.). In this embodiment, an aluminum alloy is one in which 70% by mass or more but less than 90% by mass of the constituent elements is aluminum, an aluminum alloy is one in which 90% by mass or more of the constituent elements is aluminum, and an aluminum alloy is one in which 99% by mass of the constituent elements is aluminum.

[0027] The same applies to copper. In this embodiment, a material in which 70% by mass or more and less than 90% by mass of the constituent elements are copper is referred to as a "copper alloy," a material in which 90% by mass or more of the constituent elements are copper is referred to as "copper," and a material in which 99% by mass of the constituent elements are copper is referred to as "pure copper."

[0028] As shown in FIG. 1 , in the energy storage module 100, the multiple energy storage devices 12 are restrained in a first direction P. The energy storage module 100 includes a spacer 11 and a pair of end plates 17. The spacer 11 is disposed between adjacent energy storage devices 12 in the first direction P. The end plates 17 are disposed at both ends of the multiple energy storage devices 12 arranged in the first direction P, and restrain the multiple energy storage devices 12. The end plates 17 are bridged by metal restraint bands 18. Ends of the restraint bands 18 are fixed with screws 19.

[0029] The power storage module 100 can be used for a variety of purposes, and is particularly suitable as a power source (driving power source) for motors mounted on vehicles such as passenger cars, trucks, etc. The type of vehicle is not particularly limited, but suitable examples include plug-in hybrid electric vehicles (PHEVs), hybrid electric vehicles (HEVs), and battery electric vehicles (BEVs).

[0030] As described above, the energy storage module 100 includes a plurality of energy storage devices 12 and a bus bar 14. The plurality of energy storage devices 12 include a case 30 having a pair of opposing rectangular first surfaces 30a, and a positive electrode external terminal 40 and a negative electrode external terminal 50 on the outer surface of the case 30. The plurality of energy storage devices 12 are arranged such that the first surfaces 30a of the energy storage devices 12 face each other. The bus bar 14 is a member that electrically connects two adjacent energy storage devices 12 in a first direction P in which the plurality of energy storage devices 12 are arranged. The bus bar 14 has two non-through holes (here, a first non-through hole 14h1 and a second non-through hole 14h2) on the same surface (here, the lower surface 142). The positive electrode external terminal 40 of one of the two adjacent energy storage devices 12 is fitted into one of the two non-through holes (here, the first non-through hole 14h1). The negative external terminal 50 of the other of the two adjacent energy storage devices 12 is fitted into the other of the two non-through holes (here, the second non-through hole 14h2), thereby electrically connecting the bus bar 14 between the two adjacent energy storage devices 12.

[0031] In other words, in the energy storage module 100, the positive electrode external terminal 40 of one of two energy storage devices 12 adjacent in the first direction P is fitted into each of the two non-through holes provided in the bus bar 14, and the negative electrode external terminal 50 of the other energy storage device 12 is fitted into each of the two non-through holes provided in the bus bar 14, thereby achieving electrical connection. By fitting the electrode external terminals into the non-through holes provided in the bus bar 14, the connection between them can be made stronger. In addition, there is no need to weld the electrode external terminals and the bus bar 14. This makes it possible to attach the bus bar 14 to the electrode external terminals more firmly with a simpler structure.

[0032] The positive external terminal 40 may have a shaft portion 41 and a disk-shaped flange portion 42 that widens from the shaft portion 41. At least the flange portion 42 may be disposed inside the first non-through hole 14h1. This allows for a more appropriate fit.

[0033] The first non-through hole 14h1 may have a protrusion 14p1 on the inner wall. The tip of the positive external terminal 40 may be disposed closer to the bottom 14b of the first non-through hole 14h1 than the protrusion 14p1. This allows the first non-through hole 14h1 and the positive external terminal 40 to be fitted together more stably.

[0034] The protrusion 14p1 may be provided continuously along the circumferential direction of the first non-through hole 14h1, thereby making it possible to further stabilize the fit.

[0035] The residual compressive force from the first non-through hole 14h1 to the portion of the positive electrode external terminal 40 disposed inside the first non-through hole 14h1 (here, the flange portion 42) is 0.3 N / mm 2 This allows for a more appropriate fit and reduces the resistance between the bus bar 14 and the positive external terminal 40.

[0036] Busbar 14 may be made of pure aluminum, which is 99% or more of its constituent elements. Pure aluminum is softer and easier to process. This makes it easier to fit busbar 14 to the external electrode terminals and to achieve a desired connection strength.

[0037] The fitting between the first non-through hole 14h1 of the bus bar 14 and the positive external terminal 40 has been described above, but the same applies to the fitting between the second non-through hole 14h2 and the negative external terminal 50. Therefore, a description of the negative side will be omitted here. In addition, in Figures 3 and 4, the symbol "14p2" indicates a protrusion provided in the second non-through hole 14h2.

[0038] As described above, one embodiment of the technology disclosed herein has been described. The technology disclosed herein may include modifications and variations of the above-described embodiment, as long as the effects of the technology disclosed herein can be achieved. For example, in the above embodiment, the protrusion 14p1 is provided on the periphery of the opening 14a. However, the location of the protrusion can be changed as appropriate, for example, depending on the thickness of the flange 42. The protrusion may be provided, for example, between the opening 14a and the bottom 14b. Alternatively, in the above embodiment, the protrusion 14p1 is provided continuously along the circumferential direction of the first non-through hole 14h1. However, the shape of the protrusion is not limited thereto. For example, multiple protrusions may be provided on the inner wall of the first non-through hole 14h1. The multiple protrusions may be provided scattered circumferentially on the inner wall of the first non-through hole 14h1.

[0039] Test examples relating to the technology disclosed herein will be described below, but it is not intended that the technology disclosed herein be limited to those shown in the following test examples.

[0040] Two aluminum test pieces were prepared. The aluminum test pieces were made of A1050-O material. The two aluminum test pieces were overlapped so that an area of ​​10 mm x 10 mm was in contact with each other, and the resistance value (μΩ) between the test pieces was measured while applying a load to the overlapping portion of the two aluminum test pieces using an Autograph (registered trademark) (Shimadzu Corporation). CAE analysis was then performed based on the measured data to determine the residual compressive force (N / mm 2 The correlation between the residual compressive force (N / mm) and the resistance value was obtained. The results are shown in Figure 5. Figure 5 is a graph showing the correlation between the residual compressive force and the resistance value. Figure 5 shows the relationship between the residual compressive force (N / mm) and the resistance value. 2 ) (X-axis) and the resistance value (μΩ) (Y-axis) between the test pieces.

[0041] As shown in Figure 5, the residual compressive force between the two aluminum specimens was 0.3 N / mm 2A significant reduction in resistance was confirmed in a range larger than the above range. As described above, the configuration of the technology disclosed herein enables the bus bar to be more strongly connected to the electrode external terminal with a simpler structure. In addition, the results shown in FIG. 5 show that, in addition to the above effect, the resistance between the bus bar and the electrode external terminal can be reduced by, for example, appropriately setting the residual compressive force on the electrode external terminal from the non-through holes provided in the bus bar.

[0042] The techniques disclosed herein may include the techniques described in the following sections. Section 1: a plurality of electricity storage devices each including a case having a pair of opposing rectangular first surfaces and a positive electrode external terminal and a negative electrode external terminal on an outer surface of the case, the plurality of electricity storage devices being arranged so that the first surfaces of the electricity storage devices face each other; a bus bar that electrically connects two adjacent power storage devices in a direction in which the plurality of power storage devices are arranged; A power storage module comprising: the bus bar has two blind holes on the same surface; the positive external terminal of one of the two adjacent energy storage devices is fitted into one of the two non-through holes, and the negative external terminal of the other of the two adjacent energy storage devices is fitted into the other of the two non-through holes, thereby causing the bus bar to electrically connect the two adjacent energy storage devices. Section 2: Item 2. The energy storage module according to item 1, wherein the positive electrode external terminal and the negative electrode external terminal each have a shaft portion and a disk-shaped flange portion that expands from the shaft portion as a center, and at least the flange portion is disposed inside the non-through hole. Section 3: Item 3. The energy storage module according to item 1 or 2, wherein the non-through hole has a convex portion on an inner wall, and the tip of the positive electrode external terminal or the tip of the negative electrode external terminal is disposed closer to the bottom of the non-through hole than the convex portion. Section 4: Item 4. The energy storage module according to item 3, wherein the protrusion is provided continuously along the circumferential direction of the non-through hole. Section 5: The residual compressive force from the non-through hole to the portion of the positive electrode external terminal or the negative electrode external terminal that is disposed inside the non-through hole is 0.3 N / mm 2 5. The electricity storage module according to any one of items 1 to 4, wherein the voltage Vcc is greater than 100 V. Item 6: 6. The electricity storage module according to any one of items 1 to 5, wherein the bus bar is made of pure aluminum, 99% or more of whose constituent elements is aluminum. [Explanation of symbols]

[0043] 12 Energy storage devices 14 Busbar 14h1 1st non-through hole 14p1 convex part 30 cases 30a 1st page 40 Positive external terminal 41 Shaft 42 Tsuba 43 Crimping part 50 Negative external terminal 100 Energy Storage Module P 1st direction

Claims

1. a plurality of electricity storage devices each including a case having a pair of opposing rectangular first surfaces and a positive electrode external terminal and a negative electrode external terminal on an outer surface of the case, the plurality of electricity storage devices being arranged such that the first surfaces of the electricity storage devices face each other; a bus bar that electrically connects two adjacent power storage devices in a direction in which the plurality of power storage devices are arranged; A power storage module comprising: the bus bar has two blind holes on the same surface; the positive external terminal of one of the two adjacent energy storage devices is fitted into one of the two non-through holes, and the negative external terminal of the other of the two adjacent energy storage devices is fitted into the other of the two non-through holes, thereby causing the bus bar to electrically connect the two adjacent energy storage devices.

2. 2. The energy storage module according to claim 1, wherein the positive electrode external terminal and the negative electrode external terminal each have a shaft portion and a disk-shaped flange portion that widens from the shaft portion as a center, and at least the flange portion is disposed inside the non-through hole.

3. 3. The energy storage module according to claim 1, wherein the non-through hole has a protrusion on an inner wall, and a tip of the positive electrode external terminal or a tip of the negative electrode external terminal is disposed closer to a bottom of the non-through hole than the protrusion.

4. The energy storage module according to claim 3 , wherein the protrusion is provided continuously along a circumferential direction of the non-through hole.

5. The residual compressive force from the non-through hole to the portion of the positive electrode external terminal or the negative electrode external terminal that is disposed inside the non-through hole is 0.3 N / mm ２ The energy storage module according to claim 1 or 2, wherein the energy storage module is greater than

6. The energy storage module according to claim 1 or 2, wherein the bus bar is made of pure aluminum having aluminum as its constituent elements at least at 99%.

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