Power storage module

Abstract

A power storage module is provided with: a plurality of power storage devices (2) arranged in a first direction (X); and a separator (4) that is disposed between two adjacent power storage devices (2) and insulates the two power storage devices (2) from each other. A power storage device (2) is provided with: an outer tank (10) having an opening (12); a sealing plate (16) for sealing the opening (12); and a joint part (20) between the outer can (10) and the sealing plate (16). The partition plate (4) has: a contact region in contact with the surface of the outer can (10) facing the first direction (X); and a separation region (48) that overlaps with the joining portion (20) when viewed from the first direction (X) and is recessed further away from the outer can (10) than the contact region.

Description

[0001] This application is a divisional application of application No. 201980076916.6 entitled “Power Storage Module” filed with the State Intellectual Property Office of China on November 26, 2019. Technical Field

[0002] The present invention relates to a power storage module. Background Art

[0003] For example, as a power source for vehicles and the like requiring a high output voltage, a power storage module is known in which a plurality of power storage devices (e.g., batteries) are connected in series. Generally, a power storage module includes: a plurality of power storage devices; a plurality of partitions arranged between adjacent power storage devices; a pair of end plates arranged at both ends of the arrangement direction of the power storage devices; and a binding bar (binding bar) that is installed between the pair of end plates and constrains the plurality of power storage devices in the arrangement direction.

[0004] In addition, generally, the power storage device includes: an outer can with an opening; an electrode body housed in the outer can; and a sealing plate that seals the opening of the outer can. Such a power storage device has a tendency to expand as it is charged. The expansion of the power storage device is caused by the increase in gas pressure in the outer can or the expansion of the electrode body. In the conventional power storage module, the expansion is suppressed by the end plate and the connecting bar.

[0005] Regarding such a storage module, Patent Document 1 discloses a battery pack, which includes a flat angular secondary electromagnet and spacers arranged on both sides of the secondary battery in the thickness direction. In this battery pack, the secondary battery has a middle area overlapping with the electrode mixture layer on the wide side, and a peripheral area around the middle area. In addition, the spacer has an abutting portion abutting the peripheral area of ​​the wide side, and a hollow portion adjacent to the middle area of ​​the wide side. Moreover, the dimension of the hollow portion in the thickness direction is greater than the expansion amount of the wide side when the secondary battery is fully charged. The battery pack of Patent Document 1 prevents the middle area of ​​the wide side from receiving a reaction force from the spacer when the battery expands by providing a gap between the middle area of ​​the wide side of the container and the spacer.

[0006] [Prior art literature]

[0007] [Patent Literature]

[0008] Patent Document 1: Japanese Patent Application Publication No. 2016-152203 Summary of the invention

[0009] [Problems to be solved by the invention]

[0010] In recent years, there is a demand for further higher capacity of the power storage module, and in order to meet this demand, the higher capacity of the power storage device is developing. However, if the power storage device has a higher capacity, the amount of expansion of the power storage device may increase. In the previous power storage module in which the peripheral portion of the outer tank of the power storage device is pressed by a spacer, if the amount of expansion of the power storage device increases, the load applied to the joint between the outer tank and the sealing plate during expansion becomes too large, which may cause damage to the joint. In addition, in the structure in which the peripheral portion of the outer tank is pressed by a spacer, when the power storage module is assembled, a large load is applied to the joint when the power storage device is constrained by the connecting bar, which may cause damage to the joint. Since the damage to the joint leads to a decrease in the reliability of the power storage module, it is desired to avoid it.

[0011] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technology for improving the reliability of a power storage module.

[0012] [Technical solutions for solving technical problems]

[0013] One scheme of the present invention is a storage module. The storage module includes: a plurality of storage devices arranged along a first direction; and a partition disposed between two adjacent storage devices to insulate the two storage devices. The storage device includes: an outer can with an opening; a sealing plate that seals the opening; and a joint between the outer can and the sealing plate. The partition includes: an abutment region that contacts the surface of the outer can facing the first direction; and a separation region that overlaps with the joint when viewed from the first direction and is recessed in a direction away from the outer can than the abutment region.

[0014] Optional combinations of the above-described constituting elements and embodiments in which the present invention is expressed in the form of methods, apparatuses, systems, and the like may also be practiced as additional embodiments of the present invention.

[0015] [Effects of the Invention]

[0016] According to the present invention, the reliability of the power storage module can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a perspective view of the power storage module according to the first embodiment.

[0018] Figure 2 This is an exploded perspective view of the power storage device and the separator.

[0019] Figure 3 It is a three-dimensional diagram of the partition.

[0020] Figure 4 It is a perspective view showing a part of the partition in an enlarged manner.

[0021] Figure 5 This is a cross-sectional view of a portion of the power storage module.

[0022] Figure 6 It is a cross-sectional view showing a part of the upper portion of the power storage module in an enlarged manner.

[0023] Figure 7 This is a cross-sectional view showing a part of the lower portion of the power storage module in an enlarged manner.

[0024] Figure 8 This is a cross-sectional view showing an enlarged portion of an upper portion of the power storage module according to the second embodiment.

[0025] Fig. 9 It is a perspective view of a power storage module according to Embodiment 3.

[0026] Fig.10 This is an exploded perspective view of the power storage device and the separator.

[0027] Fig.11 It is a three-dimensional diagram of the partition.

[0028] Fig.12 It is a perspective view showing a part of the partition in an enlarged manner.

[0029] Fig.13 This is a cross-sectional view of a portion of the power storage module.

[0030] Fig.14 It is a cross-sectional view showing a part of the upper portion of the power storage module in an enlarged manner.

[0031] Fig.15 This is a cross-sectional view showing a part of the lower portion of the power storage module in an enlarged manner.

[0032] Fig.16 This is a cross-sectional view showing an enlarged portion of a lower portion of the power storage module according to the fourth embodiment.

[0033] Fig.17 This is a cross-sectional view showing an enlarged portion of a lower portion of the power storage module according to the fifth embodiment.

[0034] Fig.18 This is a cross-sectional view showing an enlarged portion of a lower portion of the power storage module according to Modification 1. DETAILED DESCRIPTION

[0035] Hereinafter, the present invention will be described based on a preferred embodiment and with reference to the accompanying drawings. The embodiment does not limit the invention but is an illustration, and all the features and combinations thereof described in the embodiment are not necessarily the essential contents of the invention. The same or equivalent components, members, and processes shown in the drawings are marked with the same figure numerals, and repeated descriptions are appropriately omitted. In addition, for ease of description, the scales and shapes of the various parts shown in the figures are conveniently set, and no restrictive interpretation is made unless otherwise specified. In addition, when the terms "first", "second", etc. are used in this specification or the claims, unless otherwise specified, the terms do not indicate any order or importance, but are terms used to distinguish a certain structure from other structures. In addition, in each of the drawings, on the basis of describing the embodiment, a part of the unimportant components is omitted from display.

[0036] (Implementation method 1)

[0037] Figure 1 This is a perspective view of the power storage module according to the first embodiment. Figure 2 The power storage module 1 includes a plurality of power storage devices 2 , a plurality of separators 4 , a pair of end plates 6 , and a pair of restraining members 8 .

[0038] Each power storage device 2 is a rechargeable secondary battery such as a lithium ion battery, a nickel-metal hydride battery, or a nickel-cadmium battery. The power storage device 2 is a so-called rectangular battery and has an outer can 10 in a flat rectangular parallelepiped shape. The outer can 10 has a rectangular opening 12 on one surface (see Figure 5 ), an electrode assembly 14 including a positive electrode and a negative electrode is housed in the outer can 10 through the opening 12 (see Figure 5 ) and electrolyte, etc. The opening 12 is provided with a sealing plate 16 for sealing the opening 12 and sealing the outer can 10. The sealing plate 16 is, for example, a rectangular plate.

[0039] The outer can 10 has a bottom surface 10a opposite to the sealing plate 16. In addition, the outer can 10 has four side surfaces connecting the opening 12 and the bottom surface 10a. Two of the four side surfaces are a pair of long side surfaces 10b connected to two long sides opposite to the opening 12. Each long side surface 10b is the surface with the largest area among the surfaces of the outer can 10, that is, the main surface. The remaining two side surfaces except the two long side surfaces 10b are a pair of short side surfaces connected to the opening 12 of the outer can 10 and the short sides of the bottom surface 10a.

[0040] The sealing plate 16 is provided with an output terminal 18 electrically connected to the positive electrode of the electrode body 14 at one end near the longitudinal direction, and an output terminal 18 electrically connected to the negative electrode of the electrode body 14 is provided near the other end. Hereinafter, the output terminal 18 connected to the positive electrode is appropriately referred to as the positive terminal 18a, and the output terminal 18 connected to the negative electrode is referred to as the negative terminal 18b. In addition, when there is no need to distinguish the polarity of the output terminal 18, the positive terminal 18a and the negative terminal 18b are collectively referred to as the output terminal 18. The outer can 10 and the sealing plate 16 are conductive bodies, for example, made of metals such as aluminum, iron, and stainless steel. The sealing plate 16 and the outer can 10 are joined, for example, by laser. Therefore, the power storage device 2 has a joint 20 of the outer can 10 and the sealing plate 16. As an example, the joint 20 is provided in the entire periphery of the sealing plate 16. In addition, in addition to laser, the sealing plate 16 and the outer can 10 can also be joined by friction stir welding or brazing.

[0041] In the description of this embodiment, for convenience, the surface on the side where the sealing plate 16 is provided is regarded as the upper surface of the power storage device 2. In addition, the bottom surface 10a of the outer can 10 is regarded as the bottom surface of the power storage device 2, the long side surface 10b of the outer can 10 is regarded as the long side surface of the power storage device 2, and the short side surface of the outer can 10 is regarded as the short side surface of the power storage device 2. In addition, in the power storage module 1, the surface on the upper surface side of the power storage device 2 is regarded as the upper surface of the power storage module 1, the surface on the bottom surface side of the power storage device 2 is regarded as the bottom surface of the power storage module 1, and the surface on the short side surface side of the power storage device 2 is regarded as the side surface of the power storage module 1. In addition, the upper surface side of the power storage module 1 is regarded as the upper side in the vertical direction, and the bottom surface side of the power storage module 1 is regarded as the lower side in the vertical direction. These directions and positions are defined for convenience. Therefore, for example, in the present invention, the portion defined as the upper surface does not necessarily mean that it is located above the portion defined as the bottom surface. Therefore, the sealing plate 16 is not limited to be located above the bottom surface 10 a of the exterior can 10 .

[0042] A safety valve 22 is provided between a pair of output terminals 18 on the sealing plate 16. The safety valve 22 is configured to open when the internal pressure of the outer tank 10 rises to a predetermined value or more, and to release the gas inside the outer tank 10. The safety valve 22 of each power storage device 2 is connected to a gas conduit (not shown), and the gas inside the power storage device 2 is discharged from the safety valve 22 to the gas conduit. The safety valve 22 is configured, for example, by a thin-walled portion having a thickness thinner than other portions provided on a portion of the sealing plate 16 and a linear groove formed on the surface of the thin-walled portion. In this configuration, if the internal pressure of the outer tank 10 rises, the thin-walled portion is ruptured starting from the groove, and the safety valve 22 is opened.

[0043] A plurality of power storage devices 2 are arranged side by side at a predetermined interval so that the long sides 10b of adjacent power storage devices 2 are opposite to each other to form an assembly. In the present embodiment, the direction in which the plurality of power storage devices 2 are arranged is set as the first direction X. In addition, the direction in which the sealing plate 16 extends is set as the second direction Y, and the direction in which the sealing plate 16 and the bottom surface 10a are arranged is set as the third direction Z. In addition, the output terminals 18 of each power storage device 2 are arranged in a manner facing the same direction as each other. In the present embodiment, for convenience, the output terminals 18 of each power storage device 2 are arranged in a manner facing upward in the vertical direction. In addition, the output terminals 18 of each power storage device 2 may also be arranged in a manner facing different directions.

[0044] Two adjacent power storage devices 2 are stacked in such a manner that the positive terminal 18a of one power storage device 2 is adjacent to the negative terminal 18b of the other power storage device 2. The positive terminal 18a and the negative terminal 18b are connected in series via a bus bar (not shown). In addition, the output terminals 18 of the same polarity in a plurality of adjacent power storage devices 2 may be connected in parallel via a bus bar to form a power storage device block, and the power storage device blocks may be connected in series.

[0045] The partition 4 is also called an insulating spacer, and is disposed between two adjacent power storage devices 2 to electrically insulate the two power storage devices 2. The partition 4 of this embodiment includes a frame 24 and a heat conduction suppressing portion 26. The frame 24 is made of, for example, an insulating resin. Examples of the resin constituting the frame 24 include thermoplastic resins such as polypropylene (PP), polybutylene terephthalate (PBT), polycarbonate (PC), and Noyl (registered trademark) resin (modified PPE).

[0046] The frame 24 has a locking portion 27 interposed between the long side surfaces 10b of the two adjacent power storage devices 2. The existence of the locking portion 27 insulates the two adjacent power storage devices 2. The frame 24 is a polygonal ring (a quadrangular ring in the present embodiment) corresponding to the shape of the long side surface 10b, and the inner side of the frame or ring corresponds to the center side of the power storage module 1 in the YZ plane, and the outer side of the frame or ring corresponds to the outer side of the power storage module 1 in the YZ plane. The YZ plane is a plane extending along the second direction Y and the third direction Z.

[0047] In addition, the frame portion 24 has a wall portion 28. The wall portion 28 is connected to the outer peripheral surface of the locking portion 27 and extends in the first direction X, covering the upper surface, short side surface and bottom surface of the power storage device 2. As a result, the creepage distance between adjacent power storage devices 2 or between the power storage device 2 and the end plate 6 can be ensured. In addition, the position of the power storage device 2 in the second direction Y and the third direction Z can be restricted. In addition, each power storage device 2 can be electrically insulated from the restraining member 8. In the present embodiment, the locking portion 27 and the wall portion 28 are integrally formed.

[0048] A cutout 30 is provided at a position of the wall portion 28 corresponding to the output terminal 18 so as to expose the output terminal 18. In addition, a pair of protruding wall portions 32 are provided on the wall portion 28 so as to protrude in the third direction Z in which the sealing plate 16 and the bottom surface 10a are arranged. The pair of protruding wall portions 32 are arranged in the second direction Y in which the sealing plate 16 extends, in other words, in the second direction Y in which the two output terminals 18 are arranged, so as to sandwich the cutout 30.

[0049] In addition, an opening portion 34 is provided at a position of the wall portion 28 corresponding to the safety valve 22 so as to expose the safety valve 22. A tubular conduit portion 36 is provided around the opening portion 34 so as to protrude from the wall portion 28 in the third direction Z. The conduit portion 36 surrounds the entire circumference of the opening portion 34. The conduit portion 36 connects the safety valve 22 and a gas conduit (not shown). In addition, a cutout portion 38 is provided at a position of the wall portion 28 corresponding to the bottom surface 10a of the outer tank 10 so as to expose a portion of the bottom surface 10a. As an example, the cooling plate is thermally connected to the bottom surface 10a of the power storage device 2.

[0050] The heat conduction suppression portion 26 is interposed between the long side surfaces 10b of two adjacent power storage devices 2, and suppresses heat conduction between the two power storage devices 2. Thus, even if the temperature of any power storage device 2 rises excessively during use of the power storage module 1, the heat can be suppressed from being transferred to the adjacent power storage device 2. Therefore, the chain reaction of overheating (chain reaction of thermal runaway) can be suppressed. In addition, the heat conduction suppression portion 26 has insulating properties. The heat conduction suppression portion 26 is plate-shaped or sheet-shaped, and is composed of a heat insulating material and a laminate film as an example. The thickness of the heat conduction suppression portion 26 is, for example, 1 to 2 mm.

[0051] The thermal insulation material is in sheet form and has a structure in which a porous material such as silica dry gel is carried between fibers of a fiber sheet composed of non-woven fabric or the like. Silica dry gel has a nano-sized void structure that restricts the movement of air molecules and has a low thermal conductivity. The thermal conductivity of the thermal insulation material is about 0.018~0.024W / m·K. The thermal insulation material is particularly useful as a thermal insulation material used in a narrow space. The thermal conductivity of the thermal insulation material is lower than the thermal conductivity of air. Therefore, by providing a thermal conduction suppression portion 26, the heat conduction between the two adjacent power storage devices 2 can be further suppressed compared to the case where only an air layer exists between the two adjacent power storage devices 2. In addition, the thermal conductivity of the thermal conduction suppression portion 26 is lower than that of the frame portion 24.

[0052] In addition, the silica dry gel has a high structural stability against external pressure. Therefore, the thermal insulation performance of the thermal insulation material can be stably maintained. Therefore, the power storage module 1 can further stably suppress the heat conduction between the power storage devices 2 by including the heat conduction suppression unit 26. Furthermore, the thermal conductivity of the thermal insulation material is lower than that of the air, so the same degree of thermal insulation effect can be obtained with a thinner layer thickness than the air layer. As a result, the size of the power storage module 1 can be suppressed.

[0053] The laminate film is a member for wrapping the entire heat insulating material and protecting it. The laminate film can prevent the porous material in the heat insulating material from falling off from the fiber sheet. In addition, by covering the heat insulating material with the laminate film, the heat conduction suppressing portion 26 can be easily embedded in the frame portion 24 when assembling the power storage module 1. The laminate film is made of, for example, polyethylene terephthalate (PET) or the like.

[0054] The heat resistance of the heat conduction suppressing portion 26 is higher than that of the frame 24. More specifically, the heat resistance of the heat insulating material is higher than that of the frame 24. More specifically, the fiber sheet contains fibers having a higher melting point than that of the frame 24, or the porous material is composed of a substance having a higher melting point than that of the frame 24, or both. For example, the melting point of the heat insulating material is above 300°C. Specifically, the melting point of the fiber sheet and / or the porous material constituting the heat insulating material is above 300°C. In particular, it is preferred that the melting point of the fibers constituting the fiber sheet is above 300°C. Thus, even when the heat insulating material is exposed to high temperature, the fiber sheet can maintain a state of being loaded with the porous material.

[0055] Since the heat resistance of heat conduction suppressing portion 26 is higher than that of frame portion 24, heat conduction suppressing portion 26 can remain even when frame portion 24 melts due to heat generated by power storage device 2. Therefore, even when frame portion 24 melts, insulation between power storage devices 2 can be maintained by heat conduction suppressing portion 26. In addition, the state in which heat conduction between adjacent power storage devices 2 is suppressed can be maintained for a long time.

[0056] The plurality of power storage devices 2 and the plurality of partitions 4 arranged in parallel are clamped in the first direction X by a pair of end plates 6. As an example, a partition without a heat conduction suppressing portion 26 is arranged between the pair of end plates 6 and the power storage devices 2 located at both ends in the first direction X. In this way, the power storage device 2 and the end plates 6 can be electrically insulated, and interference with heat dissipation of the power storage device 2 through the end plates 6 can be avoided. In addition, the partition preferably has a separation area 48 described later. The end plate 6 is made of, for example, a metal plate. On the surface of the end plate 6 opposite to the long side surface 10b of the outer can 10, a threaded hole (not shown) for screwing the screw 40 is provided.

[0057] A pair of restraining members 8, also called connecting bars, are long strip-shaped members with the first direction X as the length direction. The pair of restraining members 8 are arranged in a manner opposite to each other in the second direction Y where the pair of output terminals 18 are arranged. There are a plurality of power storage devices 2, a plurality of partitions 4, and a pair of end plates 6 between the pair of restraining members 8. Each restraining member 8 has a rectangular plane portion 8a extending parallel to the short side of the power storage device 2 and four shelter portions 8b protruding from each end edge of the plane portion 8a toward the power storage device 2. Two shelter portions 8b facing each other in the first direction X are provided with through holes (not shown) for inserting screws 40.

[0058] In a state where a plurality of power storage devices 2 and a plurality of partitions 4 are alternately arranged and clamped by a pair of end plates 6 in the first direction X, they are clamped by a pair of restraining members 8 in the second direction Y. Each restraining member 8 is positioned in such a way that the through hole of the shelter 8b overlaps with the threaded hole of the end plate 6. In addition, the screw 40 is inserted through the through hole and screwed into the threaded hole. In this way, the plurality of power storage devices 2 are restrained by the engagement of a pair of restraining members 8 with a pair of end plates 6. The plurality of power storage devices 2 and the plurality of partitions 4 are fastened by the restraining members 8 in a state where a predetermined pressure is applied along the first direction X.

[0059] The plurality of power storage devices 2 are fastened in the first direction X by the constrained member 8, thereby being positioned in the first direction X. In addition, the upper surface and the bottom surface of the plurality of power storage devices 2 are in contact with two shelters 8b arranged on the upper surface and the bottom surface and facing each other in the third direction Z via the wall portion 28 of the partition plate 4. Thus, the plurality of power storage devices 2 are positioned in the third direction Z. As an example, after these positionings are completed, a bus bar is mounted on the output terminal 18 of each power storage device 2, and the output terminals 18 of the plurality of power storage devices 2 are electrically connected to each other. For example, the bus bar is fixed to the output terminal 18 by welding.

[0060] The upper surfaces of the plurality of power storage devices 2 are covered by a cover member (not shown). The cover member is supported by the protruding wall portion 32. The cover member prevents condensation water, dust, etc. from contacting the output terminal 18, bus bar, safety valve 22, etc. of the power storage device 2. The cover member is made of, for example, an insulating resin.

[0061] Figure 3 It is a three-dimensional diagram of the partition. Figure 4 It is a perspective view showing a part of the partition in an enlarged manner. Figure 5 This is a cross-sectional view of a portion of the power storage module. Figure 6 It is a cross-sectional view showing a part of the upper portion of the power storage module in an enlarged manner. Figure 7 FIG. 2 is a cross-sectional view showing a part of the lower portion of the power storage module in an enlarged manner. Figure 3 and Figure 4 The heat conduction suppressing portion 26 is omitted in the figure. Figure 5~Figure 7In FIG. 1 , two arbitrary power storage devices 2 and a separator 4 disposed therebetween are shown as a part of the power storage module 1. In addition, the internal structure of the power storage device 2 is schematically shown.

[0062] As described above, the partition 4 includes the frame portion 24 and the heat conduction suppressing portion 26. The locking portion 27 of the frame portion 24 is interposed between two adjacent power storage devices 2, and includes the hole 42 extending between the two power storage devices 2. In addition, when viewed from the first direction X in which the power storage devices 2 are arranged, the frame portion 24 extends along the peripheral portion of the outer can 10. Therefore, the hole 42 overlaps with the central portion of the outer can 10 when viewed from the first direction X. In other words, the hole 42 is a through hole that penetrates the partition 4 along the first direction X.

[0063] The heat conduction inhibiting portion 26 is arranged so as to block the hole 42. The locking portion 27 of the frame portion 24 has a predetermined thickness in the first direction X, and has a groove portion 44 on the inner peripheral surface facing the hole 42 side of the frame portion 24. The groove portion 44 extends over the entire circumference of the hole 42. The heat conduction inhibiting portion 26 is supported by the frame portion 24 by fitting the peripheral portion into the groove portion 44. In addition, the groove portion 44 may not extend over the entire circumference of the hole 42. For example, the groove portion 44 may be formed only at both ends of the heat conduction inhibiting portion 26 to hold the both ends of the heat conduction inhibiting portion 26.

[0064] As a method of providing the heat conduction suppressing portion 26 on the frame 24, in other words, as a method of assembling the partition 4, the following method is exemplified. For example, the frame 24 is divided into a plurality of (for example, two) parts in the second direction Y or the third direction Z. Then, the divided parts are arranged with the heat conduction suppressing portion 26 interposed therebetween, and after the end of the heat conduction suppressing portion 26 is aligned with the groove 44 of each part, the parts are brought close to each other. After the parts touch each other, they are fixed, for example, by bonding. Thus, the peripheral edge of the heat conduction suppressing portion 26 is inserted into the groove 44 and supported by the frame 24. Alternatively, a slit for inserting the heat conduction suppressing portion 26 into the hole 42 may be provided on the frame 24, and the heat conduction suppressing portion 26 may be inserted into the frame 24 through the slit. In addition, the frame 24 may be divided in the first direction X, and the partition 4 may be assembled by sandwiching the heat conduction suppressing portion 26 between the parts in the first direction X. Alternatively, the partition plate 4 may be formed by integrally molding the frame portion 24 and the heat conduction suppressing portion 26 .

[0065] In addition, the partition 4 has a contact area 46 and a separation area 48. In the present embodiment, the contact area 46 and the separation area 48 are arranged on the frame portion 24. More specifically, the contact area 46 and the separation area 48 are arranged on both side surfaces in the first direction X of the locking portion 27 of the frame portion 24 that are arranged toward the power storage device 2. The contact area 46 contacts the surface of each outer tank 10 facing the first direction X, that is, the long side surface 10b. As a result, each power storage device 2 is positioned in the first direction X. In addition, the expansion of the outer tank 10 is squeezed. The contact area 46 of the present embodiment contacts three edges of the long side surface 10b, namely, the edge adjacent to the bottom surface 10a and the edge adjacent to a pair of short side surfaces. Therefore, when viewed from the first direction X, the contact area 46 is roughly U-shaped.

[0066] The separation region 48 has a shape that is recessed in a direction away from the outer can 10 compared to the contact region 46. Furthermore, the separation region 48 is arranged so as to overlap with the joint portion 20 when viewed from the first direction X. The long side surface 10b of the present embodiment is rectangular, the contact region 46 overlaps with three of the four end sides of the long side surface 10b facing the first direction X, and the separation region 48 overlaps with the remaining end side of the four end sides.

[0067] A gap 50 is provided between the separation area 48 of the frame 24 and the long side surface 10b of the outer can 10. Since the frame 24 has the separation area 48, it is possible to prevent the joint 20 from being pressed by the frame 24 when the storage battery module 1 is assembled. As a result, it is possible to reduce the load applied to the joint 20 due to the pressure from the partition 4 when the storage battery module 1 is assembled. In addition, the separation area 48 may be provided so as to extend intermittently in the second direction Y or the third direction Z.

[0068] In addition, at the initial stage of expansion of the outer can 10, the region near the joint 20 in the outer can 10 expands without being pressed by the frame 24. When the outer can 10 expands by a predetermined amount, the outer can 10 abuts against the separation region 48, and further expansion of the outer can 10 is suppressed. Thus, excessive deformation of the joint 20 is suppressed. As a result, the load applied to the joint 20 due to the deformation can be reduced.

[0069] In addition, the separation area 48 of the present embodiment extends over the entirety of the locking portion 27 in the second direction Y in which the sealing plate 16 extends. That is, both ends of the separation area 48 in the second direction Y are in contact with the wall portion 28 extending parallel to the short side surface of the power storage device 2. Therefore, when viewed from the first direction X, the separation area 48 overlaps the entirety of the joint portion 20 in the second direction Y in which the sealing plate 16 extends. Thus, the load applied to the joint portion 20 can be reliably reduced. In addition, both ends of the separation area 48 in the second direction Y can also be connected to the portion of the abutment area 46 extending in the third direction Z. In this case, the mechanical strength of the frame portion 24 is improved, and the reliability related to the retention of the power storage device 2 is improved.

[0070] In addition, the separation area 48 overlaps with the entirety of the joint 20 in the thickness direction of the sealing plate 16, that is, the third direction Z. In other words, the separation area 48 extends from the surface of the sealing plate 16 facing the outside of the power storage device 2 to the surface facing the internal space side of the power storage device 2. As a result, the load applied to the joint 20 can be further reliably reduced. Furthermore, the separation area 48 protrudes from the sealing plate 16 toward the side of the surface of the outer can 10 opposite to the sealing plate 16, that is, the bottom surface 10a side. That is, the separation area 48 extends further toward the bottom surface 10a side than the surface of the sealing plate 16 facing the internal space side of the power storage device 2. As a result, the load applied to the joint 20 can also be further reliably reduced.

[0071] Furthermore, in the present embodiment, the portion of the frame 24 extending along the joint 20, that is, the portion where the separation region 48 is arranged, is arranged outside the electrode body 14 when viewed from the first direction X. The expansion of the outer can 10 is mainly caused by the expansion of the electrode body 14. Therefore, by arranging this portion of the frame 24 outside the electrode body 14, the separation region 48 does not overlap with the electrode body 14, and the load applied to the joint 20 can be further reliably reduced.

[0072] In addition, the peripheral portion of the heat conduction inhibiting portion 26 is fitted into the groove portion 44 of the frame portion 24. That is, the frame portion 24 supports the heat conduction inhibiting portion 26 by sandwiching the peripheral portion of the heat conduction inhibiting portion 26 in the first direction X. Therefore, a part of the frame portion 24 exists between the peripheral portion of the heat conduction inhibiting portion 26 and the long side surface 10b of the outer can 10. Thus, a gap 52 is formed between the central portion of the heat conduction inhibiting portion 26 and the central portion of the long side surface 10b.

[0073] By providing the gap 52, at least in the initial stage of expansion of the outer can 10, the central part of the outer can 10 expands without touching the heat conduction suppression part 26. That is, the gap 52 functions as a space that allows a predetermined amount of expansion of the outer can 10. Thus, it is possible to suppress deformation of the heat conduction suppression part 26 due to the expansion of the outer can 10, in other words, to suppress compression in the first direction X. As a result, it is possible to suppress reduction in the heat insulation performance of the heat conduction suppression part 26. In addition, it is possible to reduce the load applied to the end plate 6 or the restraining member 8. Thus, as a countermeasure against the increase in the amount of expansion of the power storage device 2, it is possible to avoid increasing the strength of the end plate 6 or the restraining member 8. As a result, it is possible to suppress an increase in the cost of the power storage module 1 and a decrease in the processability of the end plate 6 and the restraining member 8. The size of the gap 52 in the first direction X may be equal to or greater than the size of the gap 50 in the first direction X. With this configuration, it is possible to provide the separation area 48 and ensure a space for the expansion of the outer can 10.

[0074] As described above, the power storage module 1 of the present embodiment includes: a plurality of power storage devices 2; and a partition 4 disposed between two adjacent power storage devices 2 to insulate the two power storage devices 2. The power storage device 2 includes: an outer can 10 having an opening 12; a sealing plate 16 that blocks the opening 12; and a joint 20 between the outer can 10 and the sealing plate 16. The partition 4 includes: a contact region 46 that contacts the surface of the outer can 10 in the first direction X in which the power storage devices 2 are arranged; and a separation region 48 that overlaps with the joint 20 when viewed from the first direction X and is recessed in a direction away from the outer can 10 than the contact region 46.

[0075] Since the separator 4 has the separation area 48, when the plurality of power storage devices 2 and the plurality of separators 4 are compressed in the first direction X and constrained by the constraining member 8 during assembly of the power storage module 1, the load applied to the joint 20 can be reduced. In addition, the load repeatedly applied to the joint 20 when the outer can 10 expands can be reduced. In addition, when the outer can 10 expands to a predetermined size, the outer can 10 abuts against the separation area 48, and further expansion of the outer can 10 is suppressed. As a result, excessive deformation of the joint 20 can be suppressed, and the load applied to the joint 20 due to the deformation can be reduced.

[0076] Thus, according to the power storage module 1 of this embodiment, the possibility of damage to the joint 20 between the outer can 10 and the sealing plate 16 can be reduced, thereby improving the reliability of the power storage device 2 and the power storage module 1. In addition, the power storage module 1 can maintain its reliability and achieve a higher capacity.

[0077] In addition, when viewed from the first direction X, the separation region 48 overlaps the entirety of the joint portion 20 in the second direction Y in which the sealing plate 16 extends. In addition, the separation region 48 overlaps the entirety of the joint portion 20 in the thickness direction of the sealing plate 16. Furthermore, the separation region 48 protrudes toward the bottom surface 10a side of the outer can 10 from the sealing plate 16. Thus, the load applied to the joint portion 20 when the outer can 10 expands or when the power storage device 2 is fastened by the restraining member 8 can be further reliably reduced.

[0078] In addition, the partition plate 4 of the present embodiment includes a frame portion 24 and a heat conduction suppressing portion 26. The frame portion 24 is interposed between two adjacent power storage devices 2, and defines a hole extending between the two power storage devices 2. In addition, the heat conduction suppressing portion 26 is configured to block the hole 42. Furthermore, the abutting area 46 and the separation area 48 are configured in the frame portion 24. By interposing the heat conduction suppressing portion 26 between the two adjacent power storage devices 2, even if the temperature of any power storage device 2 rises excessively during use of the power storage module 1, the heat can be suppressed from being transferred to the adjacent power storage device 2. Therefore, the chain of overheating can be suppressed.

[0079] (Implementation method 2)

[0080] Embodiment 2 has the same configuration as Embodiment 1 except for the shape of frame portion 24. Hereinafter, this embodiment will be described mainly focusing on the configuration different from Embodiment 1, and the common configuration will be briefly described or omitted. Figure 8 FIG. 2 is a cross-sectional view showing an enlarged portion of an upper portion of a power storage module according to Embodiment 2. Figure 8 , the internal structure of the power storage device 2 is schematically illustrated.

[0081] The separator 4 included in the power storage module 1 of the present embodiment has the contact region 46 and the separation region 48 similarly to the first embodiment. In the present embodiment as well, the contact region 46 and the separation region 48 are arranged in the frame portion 24 .

[0082] The separation area 48 of the present embodiment has an inclined surface 48a. The inclined surface 48a is inclined so as to be away from the outer can 10 as it moves from the sealing plate 16 toward the bottom surface 10a side of the outer can 10 opposite to the sealing plate 16. The inclined surface 48a is arranged at the end of the portion extending along the joint 20 of the frame 24 on the side of the hole 42. Therefore, the portion extending along the joint 20 of the frame 24 has a tapered portion in which the thickness (the size in the first direction X) becomes thinner from the outside of the power storage module 1 to the center.

[0083] Therefore, the gap 50 provided between the separation area 48 and the long side surface 10b gradually expands from the outside to the center side of the storage module 1 in the area where the inclined surface 48a extends. The amount of expansion of the central portion of the outer tank 10 is greater than that of the peripheral portion. In contrast, by having the inclined surface 48a in the separation area 48, the expansion of the outer tank 10 can be further reliably allowed. As a result, the load applied to the joint 20 can be further reliably reduced. In addition, the possibility of the frame 24 being pressed against the outer tank 10 and causing damage such as dents on the outer tank 10 or the insulating tape covering the outer surface of the outer tank 10 can be reduced. In addition, the inclined surface 48a can also extend over the entire separation area 48 in the third direction Z.

[0084] (Implementation method 3)

[0085] In a conventional power storage module in which a heat conduction suppression portion is arranged between adjacent power storage devices, if the amount of expansion of the power storage device increases, the heat conduction suppression portion is excessively compressed in the arrangement direction of the power storage device and its size in the arrangement direction is reduced, and there is a possibility that the heat insulation performance is reduced due to the shortening of the heat transfer path in the arrangement direction. The reduction in the heat insulation performance of the heat conduction suppression portion will lead to a reduction in the reliability of the power storage module, and it is therefore desirable to avoid this.

[0086] Fig. 9 It is a perspective view of a power storage module according to Embodiment 3. Fig.10 The power storage module 1 includes a plurality of power storage devices 2 , a plurality of separators 4 , a pair of end plates 6 , and a pair of restraining members 8 .

[0087] Each power storage device 2 is a rechargeable secondary battery such as a lithium ion battery, a nickel-metal hydride battery, or a nickel-cadmium battery. The power storage device 2 is a so-called rectangular battery and has an outer can 10 in a flat rectangular parallelepiped shape. The outer can 10 has a rectangular opening 12 on one surface (see Fig.13 ), an electrode assembly 14 including a positive electrode and a negative electrode is housed in the outer can 10 through the opening 12 (see Fig.13 ) and electrolyte, etc. The opening 12 is provided with a sealing plate 16 for sealing the opening 12 and sealing the outer can 10. The sealing plate 16 is, for example, a rectangular plate.

[0088] The outer can 10 has a bottom surface 10a opposite to the sealing plate 16. In addition, the outer can 10 has four side surfaces connecting the opening 12 and the bottom surface 10a. Two of the four side surfaces are a pair of long side surfaces 10b connected to two long sides opposite to the opening 12. Each long side surface 10b is the surface with the largest area among the surfaces of the outer can 10, that is, the main surface. The remaining two side surfaces except the two long side surfaces 10b are a pair of short side surfaces connected to the opening 12 of the outer can 10 and the short sides of the bottom surface 10a.

[0089] The sealing plate 16 is provided with an output terminal 18 electrically connected to the positive electrode of the electrode body 14 at one end near the longitudinal direction, and an output terminal 18 electrically connected to the negative electrode of the electrode body 14 is provided near the other end. Hereinafter, the output terminal 18 connected to the positive electrode is appropriately referred to as the positive terminal 18a, and the output terminal 18 connected to the negative electrode is referred to as the negative terminal 18b. In addition, when there is no need to distinguish the polarity of the output terminal 18, the positive terminal 18a and the negative terminal 18b are collectively referred to as the output terminal 18. The outer can 10 and the sealing plate 16 are conductive bodies, for example, made of metals such as aluminum, iron, and stainless steel. The sealing plate 16 and the outer can 10 are joined, for example, by laser. Therefore, the power storage device 2 has a joint 20 of the outer can 10 and the sealing plate 16. As an example, the joint 20 is provided in the entire periphery of the sealing plate 16. In addition, in addition to laser, the sealing plate 16 and the outer can 10 can also be joined by friction stir welding or brazing.

[0090] In the description of this embodiment, for convenience, the surface on the side where the sealing plate 16 is provided is regarded as the upper surface of the power storage device 2. In addition, the bottom surface 10a of the outer can 10 is regarded as the bottom surface of the power storage device 2, the long side surface 10b of the outer can 10 is regarded as the long side surface of the power storage device 2, and the short side surface of the outer can 10 is regarded as the short side surface of the power storage device 2. In addition, in the power storage module 1, the surface on the upper surface side of the power storage device 2 is regarded as the upper surface of the power storage module 1, the surface on the bottom surface side of the power storage device 2 is regarded as the bottom surface of the power storage module 1, and the surface on the short side surface side of the power storage device 2 is regarded as the side surface of the power storage module 1. In addition, the upper surface side of the power storage module 1 is regarded as the upper side in the vertical direction, and the bottom surface side of the power storage module 1 is regarded as the lower side in the vertical direction. These directions and positions are defined for convenience. Therefore, for example, in the present invention, the portion defined as the upper surface does not necessarily mean that it is located above the portion defined as the bottom surface. Therefore, the sealing plate 16 is not limited to be located above the bottom surface 10 a of the exterior can 10 .

[0091] A safety valve 22 is provided between a pair of output terminals 18 on the sealing plate 16. The safety valve 22 is configured to open when the internal pressure of the outer tank 10 rises to a predetermined value or more, and to release the gas inside the outer tank 10. The safety valve 22 of each power storage device 2 is connected to a gas conduit (not shown), and the gas inside the power storage device 2 is discharged from the safety valve 22 to the gas conduit. The safety valve 22 is configured, for example, by a thin-walled portion having a thickness thinner than other portions provided on a portion of the sealing plate 16 and a linear groove formed on the surface of the thin-walled portion. In this configuration, if the internal pressure of the outer tank 10 rises, the thin-walled portion is ruptured starting from the groove, and the safety valve 22 is opened.

[0092] A plurality of power storage devices 2 are arranged side by side at a predetermined interval so that the long sides 10b of adjacent power storage devices 2 are opposite to each other to form an assembly. In the present embodiment, the direction in which the plurality of power storage devices 2 are arranged is set as the first direction X. In addition, the direction in which the sealing plate 16 extends is set as the second direction Y, and the direction in which the sealing plate 16 and the bottom surface 10a are arranged is set as the third direction Z. In addition, the output terminals 18 of each power storage device 2 are arranged in a manner facing the same direction as each other. In the present embodiment, for convenience, the output terminals 18 of each power storage device 2 are arranged in a manner facing upward in the vertical direction. In addition, the output terminals 18 of each power storage device 2 may also be arranged in a manner facing different directions.

[0093] Two adjacent power storage devices 2 are stacked in such a manner that the positive terminal 18a of one power storage device 2 is adjacent to the negative terminal 18b of the other power storage device 2. The positive terminal 18a and the negative terminal 18b are connected in series via a bus bar (not shown). In addition, the output terminals 18 of the same polarity in a plurality of adjacent power storage devices 2 may be connected in parallel via a bus bar to form a power storage device block, and the power storage device blocks may be connected in series.

[0094] The partition 4 is also called an insulating spacer, and is disposed between two adjacent power storage devices 2 to electrically insulate the two power storage devices 2. The partition 4 of this embodiment includes a frame 24 and a heat conduction suppressing portion 26. The frame 24 is made of, for example, an insulating resin. Examples of the resin constituting the frame 24 include thermoplastic resins such as polypropylene (PP), polybutylene terephthalate (PBT), polycarbonate (PC), and Noyl (registered trademark) resin (modified PPE).

[0095] The frame 24 has a locking portion 27 interposed between the long side surfaces 10b of the two adjacent power storage devices 2. The existence of the locking portion 27 insulates the two adjacent power storage devices 2. The frame 24 is a polygonal ring (a quadrangular ring in the present embodiment) corresponding to the shape of the long side surface 10b, and the inner side of the frame or ring corresponds to the center side of the power storage module 1 in the YZ plane, and the outer side of the frame or ring corresponds to the outer side of the power storage module 1 in the YZ plane. The YZ plane is a plane extending along the second direction Y and the third direction Z.

[0096] In addition, the frame portion 24 has a wall portion 28. The wall portion 28 is connected to the outer peripheral surface of the locking portion 27 and extends in the first direction X, covering the upper surface, short side surface and bottom surface of the power storage device 2. As a result, the creepage distance between adjacent power storage devices 2 or between the power storage device 2 and the end plate 6 can be ensured. In addition, the position of the power storage device 2 in the second direction Y and the third direction Z can be restricted. In addition, each power storage device 2 can be electrically insulated from the restraining member 8. In the present embodiment, the locking portion 27 and the wall portion 28 are integrally formed.

[0097] A cutout 30 is provided at a position of the wall portion 28 corresponding to the output terminal 18 so as to expose the output terminal 18. In addition, a pair of protruding wall portions 32 are provided on the wall portion 28 so as to protrude in the third direction Z in which the sealing plate 16 and the bottom surface 10a are arranged. The pair of protruding wall portions 32 are arranged in the second direction Y in which the sealing plate 16 extends, in other words, in the second direction Y in which the two output terminals 18 are arranged, so as to sandwich the cutout 30.

[0098] In addition, an opening portion 34 is provided at a position of the wall portion 28 corresponding to the safety valve 22 so as to expose the safety valve 22. A tubular conduit portion 36 is provided around the opening portion 34 so as to protrude from the wall portion 28 in the third direction Z. The conduit portion 36 surrounds the entire circumference of the opening portion 34. The conduit portion 36 connects the safety valve 22 and a gas conduit (not shown). In addition, a cutout portion 38 is provided at a position of the wall portion 28 corresponding to the bottom surface 10a of the outer tank 10 so as to expose a portion of the bottom surface 10a. As an example, the cooling plate is thermally connected to the bottom surface 10a of the power storage device 2.

[0099] The heat conduction suppression portion 26 is interposed between the long side surfaces 10b of two adjacent power storage devices 2, and suppresses heat conduction between the two power storage devices 2. Thus, even if the temperature of any power storage device 2 rises excessively during use of the power storage module 1, the heat can be suppressed from being transferred to the adjacent power storage device 2. Therefore, the chain reaction of overheating (chain reaction of thermal runaway) can be suppressed. In addition, the heat conduction suppression portion 26 has insulating properties. The heat conduction suppression portion 26 is plate-shaped or sheet-shaped, and is composed of a heat insulating material and a laminate film as an example. The thickness of the heat conduction suppression portion 26 is, for example, 1 to 2 mm.

[0100] The thermal insulation material is in sheet form and has a structure in which a porous material such as silica dry gel is carried between fibers of a fiber sheet composed of non-woven fabric or the like. Silica dry gel has a nano-sized void structure that restricts the movement of air molecules and has a low thermal conductivity. The thermal conductivity of the thermal insulation material is about 0.018~0.024W / m·K. The thermal insulation material is particularly useful as a thermal insulation material used in a narrow space. The thermal conductivity of the thermal insulation material is lower than the thermal conductivity of air. Therefore, by providing a thermal conduction suppression portion 26, the heat conduction between the two adjacent power storage devices 2 can be further suppressed compared to the case where only an air layer exists between the two adjacent power storage devices 2. In addition, the thermal conductivity of the thermal conduction suppression portion 26 is lower than that of the frame portion 24.

[0101] In addition, the silica dry gel has a high structural stability against external pressure. Therefore, the thermal insulation performance of the thermal insulation material can be stably maintained. Therefore, the power storage module 1 can further stably suppress the heat conduction between the power storage devices 2 by including the heat conduction suppression unit 26. Furthermore, the thermal conductivity of the thermal insulation material is lower than that of the air, so the same degree of thermal insulation effect can be obtained with a thinner layer thickness than the air layer. As a result, the size of the power storage module 1 can be suppressed.

[0102] The laminate film is a member for wrapping the entire heat insulating material and protecting it. The laminate film can prevent the porous material in the heat insulating material from falling off from the fiber sheet. In addition, by covering the heat insulating material with the laminate film, the heat conduction suppressing portion 26 can be easily embedded in the frame portion 24 when assembling the power storage module 1. The laminate film is made of, for example, polyethylene terephthalate (PET) or the like.

[0103] The heat resistance of the heat conduction suppressing portion 26 is higher than that of the frame 24. More specifically, the heat resistance of the heat insulating material is higher than that of the frame 24. More specifically, the fiber sheet contains fibers having a higher melting point than that of the frame 24, or the porous material is composed of a substance having a higher melting point than that of the frame 24, or both. For example, the melting point of the heat insulating material is above 300°C. Specifically, the melting point of the fiber sheet and / or the porous material constituting the heat insulating material is above 300°C. In particular, it is preferred that the melting point of the fibers constituting the fiber sheet is above 300°C. Thus, even when the heat insulating material is exposed to high temperature, the fiber sheet can maintain a state of being loaded with the porous material.

[0104] Since the heat resistance of heat conduction suppressing portion 26 is higher than that of frame portion 24, heat conduction suppressing portion 26 can remain even when frame portion 24 melts due to heat generated by power storage device 2. Therefore, even when frame portion 24 melts, insulation between power storage devices 2 can be maintained by heat conduction suppressing portion 26. In addition, the state in which heat conduction between adjacent power storage devices 2 is suppressed can be maintained for a long time.

[0105] The plurality of power storage devices 2 and the plurality of partitions 4 arranged in parallel are clamped in the first direction X by a pair of end plates 6. As an example, a partition without a heat conduction suppressing portion 26 is arranged between the pair of end plates 6 and the power storage devices 2 located at both ends in the first direction X. In this way, the power storage device 2 and the end plates 6 can be electrically insulated, and interference with heat dissipation of the power storage device 2 through the end plates 6 can be avoided. In addition, the partition preferably has a separation area 48 described later. The end plate 6 is made of, for example, a metal plate. On the surface of the end plate 6 opposite to the long side surface 10b of the outer can 10, a threaded hole (not shown) for screwing the screw 40 is provided.

[0106] A pair of restraining members 8, also called connecting strips, are long strip-shaped members with the first direction X as the length direction. The pair of restraining members 8 are arranged in a manner opposite to each other above the second direction Y in which the pair of output terminals 18 are arranged. There are a plurality of storage devices 2, a plurality of partitions 4, and a pair of end plates 6 between the pair of restraining members 8. Each restraining member 8 has a rectangular plane portion 8a extending parallel to the short side of the storage device 2 and four shelter portions 8b protruding from each end edge of the plane portion 8a toward the storage device 2. Two shelter portions 8b facing each other in the first direction X are provided with through holes (not shown) for inserting screws 40.

[0107] In a state where a plurality of power storage devices 2 and a plurality of partitions 4 are alternately arranged and clamped by a pair of end plates 6 in the first direction X, they are clamped by a pair of restraining members 8 in the second direction Y. Each restraining member 8 is positioned in such a way that the through hole of the shelter 8b overlaps with the threaded hole of the end plate 6. In addition, the screw 40 is inserted through the through hole and screwed into the threaded hole. In this way, the plurality of power storage devices 2 are restrained by the engagement of a pair of restraining members 8 with a pair of end plates 6. The plurality of power storage devices 2 and the plurality of partitions 4 are fastened by the restraining members 8 in a state where a predetermined pressure is applied along the first direction X.

[0108] The plurality of power storage devices 2 are fastened in the first direction X by the constrained member 8, thereby being positioned in the first direction X. In addition, the upper surface and the bottom surface of the plurality of power storage devices 2 are in contact with two shelters 8b arranged on the upper surface and the bottom surface and facing each other in the third direction Z via the wall portion 28 of the partition plate 4. Thus, the plurality of power storage devices 2 are positioned in the third direction Z. As an example, after these positionings are completed, a bus bar is mounted on the output terminal 18 of each power storage device 2, and the output terminals 18 of the plurality of power storage devices 2 are electrically connected to each other. For example, the bus bar is fixed to the output terminal 18 by welding.

[0109] The upper surfaces of the plurality of power storage devices 2 are covered by a cover member (not shown). The cover member is supported by the protruding wall portion 32. The cover member prevents condensation water, dust, etc. from contacting the output terminal 18, bus bar, safety valve 22, etc. of the power storage device 2. The cover member is made of, for example, an insulating resin.

[0110] Fig.11 It is a three-dimensional diagram of the partition. Fig.12 It is a perspective view showing a part of the partition in an enlarged manner. Fig.13 This is a cross-sectional view of a portion of the power storage module. Fig.14 It is a cross-sectional view showing a part of the upper portion of the power storage module in an enlarged manner. Fig.15 FIG. 2 is a cross-sectional view showing a part of the lower portion of the power storage module in an enlarged manner. Fig.11 and Fig.12The heat conduction suppressing portion 26 is omitted from the illustration. The plurality of power storage devices 2 included in the power storage module 1 include a first power storage device 2a and a second power storage device 2b that are adjacent to each other. Figure 13~Figure 15 In the figure, as a part of the power storage module 1, the first power storage device 2a and the second power storage device 2b and the separator 4 arranged therebetween are shown. Hereinafter, when it is not necessary to distinguish between the first power storage device 2a and the second power storage device 2b, they are collectively referred to as the power storage device 2. Figures 13-15 , the internal structure of each power storage device 2 is schematically illustrated.

[0111] The partition 4 is arranged between the first power storage device 2a and the second power storage device 2b arranged along the first direction X, and insulates the two power storage devices 2. In addition, as described above, the partition 4 has the frame portion 24 and the heat conduction suppression portion 26. The locking portion 27 of the frame portion 24 is interposed between the first power storage device 2a and the second power storage device 2b, and has a hole 42 extending between the two power storage devices 2. In addition, when viewed from the first direction X in which the power storage devices 2 are arranged, the frame portion 24 extends along the peripheral portion of the outer can 10. Therefore, the hole 42 overlaps with the central portion of the outer can 10 when viewed from the first direction X. In other words, the hole 42 is a through hole that penetrates the partition 4 along the first direction X.

[0112] The heat conduction inhibiting portion 26 is arranged so as to block the hole 42. The locking portion 27 of the frame portion 24 has a predetermined thickness in the first direction X, and has a groove portion 44 on the inner peripheral surface facing the hole 42 side of the frame portion 24. The groove portion 44 extends over the entire circumference of the hole 42. The heat conduction inhibiting portion 26 is supported by the frame portion 24 by fitting the peripheral portion into the groove portion 44. In addition, the groove portion 44 may not extend over the entire circumference of the hole 42. For example, the groove portion 44 may be formed only at both ends of the heat conduction inhibiting portion 26 to hold the both ends of the heat conduction inhibiting portion 26.

[0113] The frame portion 24 of the present embodiment has a locking portion 27 as a structure for locking the heat conduction suppressing portion 26. The locking portion 27 has a first portion 27a, a second portion 27b, and a third portion 27c. In addition, the groove portion 44 is divided and formed by the first portion 27a, the second portion 27b, and the third portion 27c. Specifically, the first portion 27a to the third portion 27c are frame-shaped, and the second portion 27b, the first portion 27a, and the third portion 27c are arranged in this order in the first direction X. That is, the first portion 27a is clamped by the second portion 27b and the third portion 27c in the first direction X.

[0114] In addition, the second portion 27b is arranged between the first portion 27a and the first power storage device 2a, and the third portion 27c is arranged between the first portion 27a and the second power storage device 2b. In the present embodiment, the first portion 27a, the second portion 27b and the third portion 27c are integrally formed. In addition, the outer peripheral surfaces of the first portion 27a to the third portion 27c are respectively connected to the inner peripheral surface of the wall surface 28. Regarding the protruding height of each stopper from the inner peripheral surface of the wall portion 28, the second portion 27b and the third portion 27c are larger than the first portion 27a.

[0115] Therefore, the bottom surface of the groove 44 is formed by the inner peripheral surface 54 of the first portion 27a. In addition, one side surface of the groove 44 is formed by a region of the side surface 56 of the second portion 27b facing the second power storage device 2b that protrudes toward the inner side of the frame 24 more than the inner peripheral surface 54. In addition, the other side surface of the groove 44 is formed by a region of the side surface 58 of the third portion 27c facing the first power storage device 2a that protrudes toward the inner side of the frame 24 more than the inner peripheral surface 54. In addition, the protruding height of the first portion 27a may be 0. That is, the first portion 27a may be formed by a region of the inner peripheral surface of the wall portion 28 that is sandwiched between the second portion 27b and the third portion 27c.

[0116] The first portion 27a contacts the surface 26a of the heat conduction suppression portion 26 that faces the direction intersecting the first direction X. The surface 26a is the surface of the heat conduction suppression portion 26 that faces the outside of the frame portion 24, or the surface of the heat conduction suppression portion 26 that extends along the first direction X. In addition, the second portion 27b is interposed between the heat conduction suppression portion 26 and the first power storage device 2a. That is, the second portion 27b is sandwiched between the peripheral portion of the heat conduction suppression portion 26 and the peripheral portion of the outer can 10 of the first power storage device 2a. In addition, the third portion 27c is interposed between the heat conduction suppression portion 26 and the second power storage device 2b. That is, the third portion 27c is sandwiched between the peripheral portion of the heat conduction suppression portion 26 and the peripheral portion of the outer can 10 of the second power storage device 2b.

[0117] In this way, by the presence of the second portion 27b and the third portion 27c between the peripheral portion of the heat conduction suppressing portion 26 and the peripheral portion of the outer can 10 of each adjacent power storage device 2, a gap 52 is formed between the central portion of the heat conduction suppressing portion 26 and the central portion of each outer can 10. By providing the gap 52, at least in the initial stage of expansion of each outer can 10, the central portion of each outer can 10 expands without touching the heat conduction suppressing portion 26. That is, the gap 52 functions as a space that allows a predetermined amount of expansion of each outer can 10. As a result, the amount of compression of the heat conduction suppressing portion 26 in the first direction X caused by the expansion of each outer can 10 can be reduced. As a result, the reduction in the heat insulation performance of the heat conduction suppressing portion 26 can be suppressed. In addition, the load applied to the end plate 6 or the restraining member 8 by the expanded portion of the outer can 10 pressing the end plate 6 or the restraining member 8 can also be reduced.

[0118] An elastic body (not shown) may be present between the heat conduction suppression portion 26 and the power storage device 2 adjacent to the heat conduction suppression portion 26 instead of the gap 52. The elastic body is, for example, a member having a lower elastic modulus than the heat conduction suppression portion 26. In this case, when the power storage device 2 expands, the elastic body is compressed in priority to the heat conduction suppression portion 26. Thus, it is possible to suppress the heat conduction suppression portion 26 from being excessively compressed and plastically deformed due to the expanding power storage device 2. In the case where the heat conduction suppression portion 26 is interposed between two power storage devices 2, the elastic body may be arranged in a manner that sandwiches the sheet-like heat conduction suppression portion 26. In addition, the elastic body may be interposed not only between the heat conduction suppression portion 26 and the power storage device 2, but also between the abutting area of ​​the partition 4 and the power storage device 2.

[0119] In addition, the locking portion 27 of the present embodiment has both the second portion 27b and the third portion 27c, but as in the later-described Modification 1, the locking portion 27 may have only the second portion 27b. Since the locking portion 27 has the second portion 27b, at least the gap 52 can be provided between the heat conduction suppressing portion 26 and the outer can 10 of the first power storage device 2a. Thus, the expansion of the outer can 10 of the first power storage device 2a can be allowed through the gap 52. In addition, if the outer can 10 of the second power storage device 2b expands, the heat conduction suppressing portion 26 is pressed toward the first power storage device 2a, and the heat conduction suppressing portion 26 can be displaced toward the first power storage device 2a in the gap 52. Therefore, even in the case where the frame portion 24 does not have the third portion 27c, the amount of compression of the heat conduction suppressing portion 26 due to the expansion of each outer can 10 can be reduced.

[0120] As a method of providing the heat conduction suppressing portion 26 on the frame 24, in other words, as a method of assembling the partition 4, the following method is exemplified. For example, the frame 24 is divided into a plurality of (for example, two) parts in the second direction Y or the third direction Z. Then, the divided parts are arranged with the heat conduction suppressing portion 26 interposed therebetween, and after the end of the heat conduction suppressing portion 26 is aligned with the groove 44 of each part, the parts are brought close to each other. After the parts touch each other, they are fixed, for example, by bonding. Thus, the peripheral edge of the heat conduction suppressing portion 26 is inserted into the groove 44 and supported by the frame 24. Alternatively, a slit for inserting the heat conduction suppressing portion 26 into the hole 42 may be provided on the frame 24, and the heat conduction suppressing portion 26 may be inserted into the frame 24 through the slit. In addition, the frame 24 may be divided in the first direction X, and the partition 4 may be assembled by sandwiching the heat conduction suppressing portion 26 between the parts in the first direction X. Alternatively, the partition plate 4 may be formed by integrally molding the frame portion 24 and the heat conduction suppressing portion 26 .

[0121] In addition, the partition plate 4 has a contact area 46 and a separation area 48. In the present embodiment, the contact area 46 and the separation area 48 are arranged on the frame portion 24. More specifically, the contact area 46 and the separation area 48 are arranged on the side of the second portion 27b facing the first power storage device 2a and the side of the third portion 27c facing the second power storage device 2b. The contact area 46 contacts the surface of each outer tank 10 facing the first direction X, that is, the long side 10b. As a result, each power storage device 2 is positioned in the first direction X. In addition, the expansion of the outer tank 10 is squeezed. The contact area 46 of the present embodiment contacts three edges of the long side 10b, namely, the edge adjacent to the bottom surface 10a and the edge adjacent to a pair of short sides. Therefore, when viewed from the first direction X, the contact area 46 is roughly U-shaped.

[0122] The separation region 48 has a shape that is recessed in a direction away from the outer can 10 compared to the contact region 46. Furthermore, the separation region 48 is arranged so as to overlap with the joint portion 20 when viewed from the first direction X. The long side surface 10b of the present embodiment is rectangular, the contact region 46 overlaps with three of the four end sides of the long side surface 10b facing the first direction X, and the separation region 48 overlaps with the remaining end side of the four end sides.

[0123] A gap 50 is provided between the separation area 48 of the frame 24 and the long side surface 10b of the outer can 10. Since the frame 24 has the separation area 48, it is possible to prevent the joint 20 from being pressed by the frame 24 when the storage battery module 1 is assembled. As a result, it is possible to reduce the load applied to the joint 20 due to the pressure from the partition 4 when the storage battery module 1 is assembled. In addition, the separation area 48 may be provided so as to extend intermittently in the second direction Y or the third direction Z.

[0124] In addition, at the initial stage of expansion of the outer can 10, the region near the joint 20 in the outer can 10 expands without being pressed by the frame 24. When the outer can 10 expands by a predetermined amount, the outer can 10 abuts against the separation region 48, and further expansion of the outer can 10 is suppressed. Thus, excessive deformation of the joint 20 is suppressed. As a result, the load applied to the joint 20 due to the deformation can be reduced.

[0125] In addition, the separation area 48 of the present embodiment extends over the entirety of the locking portion 27 in the second direction Y in which the sealing plate 16 extends. That is, both ends of the separation area 48 in the second direction Y are in contact with the wall portion 28 extending parallel to the short side surface of the power storage device 2. Therefore, when viewed from the first direction X, the separation area 48 overlaps the entirety of the joint portion 20 in the second direction Y in which the sealing plate 16 extends. Thus, the load applied to the joint portion 20 can be reliably reduced. In addition, both ends of the separation area 48 in the second direction Y can also be connected to the portion of the abutment area 46 extending in the third direction Z. In this case, the mechanical strength of the frame portion 24 is improved, and the reliability related to the retention of the power storage device 2 is improved.

[0126] In addition, the separation area 48 overlaps with the entirety of the joint 20 in the thickness direction of the sealing plate 16, that is, the third direction Z. In other words, the separation area 48 extends from the surface of the sealing plate 16 facing the outside of the power storage device 2 to the surface facing the internal space side of the power storage device 2. As a result, the load applied to the joint 20 can be further reliably reduced. Furthermore, the separation area 48 protrudes from the sealing plate 16 toward the side of the surface of the outer can 10 opposite to the sealing plate 16, that is, the bottom surface 10a side. That is, the separation area 48 extends further toward the bottom surface 10a side than the surface of the sealing plate 16 facing the internal space side of the power storage device 2. As a result, the load applied to the joint 20 can also be further reliably reduced.

[0127] Furthermore, in the present embodiment, the portion of the frame 24 extending along the joint 20, that is, the portion where the separation region 48 is arranged, is arranged outside the electrode body 14 when viewed from the first direction X. The expansion of the outer can 10 is mainly caused by the expansion of the electrode body 14. Therefore, by arranging this portion of the frame 24 outside the electrode body 14, the separation region 48 does not overlap with the electrode body 14, and the load applied to the joint 20 can be further reliably reduced.

[0128] As described above, the power storage module 1 of the present embodiment includes: the first power storage device 2a and the second power storage device 2b arranged in the first direction X; and the partition 4 arranged between the first power storage device 2a and the second power storage device 2b to insulate the two power storage devices 2. The partition 4 includes a frame portion 24 and a heat conduction suppressing portion 26. The frame portion 24 is interposed between the first power storage device 2a and the second power storage device 2b, and includes a hole 42 extending between the two power storage devices 2 and a stopper portion 27 of the heat conduction suppressing portion 26. The heat conduction suppressing portion 26 is arranged so as to block the hole 42 and is supported by the frame portion 24. The stopper portion 27 includes a first portion 27a that abuts against a surface 26a of the heat conduction suppressing portion 26 that faces a direction intersecting the first direction X; and a second portion 27b interposed between the heat conduction suppressing portion 26 and the first power storage device 2a.

[0129] By interposing the second portion 27b between the heat conduction suppressing portion 26 and the first power storage device 2a, a gap 52 can be formed between the heat conduction suppressing portion 26 and the first power storage device 2a. More specifically, the second portion 27b is inserted between the peripheral portion of the heat conduction suppressing portion 26 and the peripheral portion of the first power storage device 2a. Therefore, the gap 52 can be more reliably formed between the central portion of the heat conduction suppressing portion 26 and the central portion of the first power storage device 2a.

[0130] Thus, it is possible to suppress the heat conduction suppression portion 26 from being compressed in the first direction X due to the expansion of the first power storage device 2a and / or the second power storage device 2b adjacent to the partition plate 4. As a result, it is possible to reduce the change in thickness of the heat conduction suppression portion 26 in the first direction X, thereby suppressing the reduction in the heat insulation performance of the heat conduction suppression portion 26. Thus, according to the present embodiment, it is possible to suppress the reduction in the reliability of the power storage module 1. In addition, it is possible to achieve a high capacity of the power storage module 1 while maintaining the reliability of the power storage module 1.

[0131] In addition, by providing the gap 52 to allow a predetermined amount of expansion of the power storage device 2, the load applied to the end plate 6 or the restraining member 8 can be reduced. As a countermeasure to the increase in the amount of expansion of the power storage device 2, it is possible to avoid increasing the strength of the end plate 6 or the restraining member 8. As a result, it is possible to suppress an increase in the cost of the power storage module 1 and a decrease in the processability of the end plate 6 or the restraining member 8. The size of the gap 52 in the first direction X can be equal to or larger than the size of the gap 50 in the first direction X. With this configuration, it is possible to provide the separation area 48 and ensure a space for the expansion of the outer can 10.

[0132] In addition, the locking portion 27 of the present embodiment has a third portion 27c interposed between the heat conduction suppression portion 26 and the second power storage device 2b. Thus, a gap 52 can be formed not only between the heat conduction suppression portion 26 and the first power storage device 2a, but also between the heat conduction suppression portion 26 and the second power storage device 2b. More specifically, the third portion 27c is inserted between the peripheral portion of the heat conduction suppression portion 26 and the peripheral portion of the second power storage device 2b. Therefore, the gap 52 can be further reliably formed between the central portion of the heat conduction suppression portion 26 and the central portion of the second power storage device 2b. Thus, the compression of the heat conduction suppression portion 26 caused by the expansion of the first power storage device 2a and / or the second power storage device 2b can be further suppressed. As a result, the reduction in the reliability of the power storage module 1 can be further suppressed.

[0133] In addition, the power storage device 2 of the present embodiment includes: an outer can 10 having an opening 12; a sealing plate 16 that blocks the opening 12; and a joint 20 between the outer can 10 and the sealing plate 16. Furthermore, the frame portion 24 includes: a contact region 46 that contacts the surface of the outer can 10 that faces the first direction X; and a separation region 48 that overlaps with the joint 20 and is recessed in a direction away from the outer can 10 relative to the contact region 46 when viewed from the first direction X.

[0134] Since the separator 4 has the separation area 48, when the plurality of electricity storage devices 2 and the plurality of separators 4 are compressed in the first direction X and constrained by the constraining member 8 during assembly of the electricity storage module 1, the load applied to the joint 20 can be reduced. In addition, the load repeatedly applied to the joint 20 when the outer can 10 expands can be reduced.

[0135] In addition, when the outer can 10 expands to a predetermined size, the outer can 10 abuts against the separation area 48, and further expansion of the outer can 10 is suppressed. As a result, excessive deformation of the joint 20 can be suppressed, and the load applied to the joint 20 due to the deformation can be reduced. As a result, according to the power storage module 1 of this embodiment, the possibility of damage to the joint 20 between the outer can 10 and the sealing plate 16 can be reduced, so the reliability of the power storage device 2 and the power storage module 1 can be improved.

[0136] In addition, when viewed from the first direction X, the separation region 48 overlaps the entirety of the joint portion 20 in the second direction Y in which the sealing plate 16 extends. In addition, the separation region 48 overlaps the entirety of the joint portion 20 in the thickness direction of the sealing plate 16. Furthermore, the separation region 48 protrudes toward the bottom surface 10a side of the outer can 10 from the sealing plate 16. Thus, the load applied to the joint portion 20 when the outer can 10 expands or when the power storage device 2 is fastened by the restraining member 8 can be further reliably reduced.

[0137] (Implementation method 4)

[0138] Embodiment 4 has the same configuration as Embodiment 3 except for the shape of the frame 24. Hereinafter, this embodiment will be described with a focus on the configuration different from Embodiment 3, and the common configuration will be briefly described or omitted. Fig.16 FIG. 2 is a cross-sectional view showing an enlarged portion of a lower portion of a power storage module according to Embodiment 4. Fig.16 , the internal structure of the power storage device 2 is schematically illustrated.

[0139] The partition plate 4 included in the power storage module 1 of the present embodiment has a frame portion 24 and a heat conduction suppressing portion 26, similarly to the third embodiment. The frame portion 24 is interposed between the first power storage device 2a and the second power storage device 2b, and has a hole 42 extending between the two power storage devices 2 and a stopper portion 27 of the heat conduction suppressing portion 26. The stopper portion 27 has a first portion 27a, a second portion 27b, and a third portion 27c. The heat conduction suppressing portion 26 is arranged to block the hole 42 and is supported by the frame portion 24. The first portion 27a is in contact with a surface 26a of the heat conduction suppressing portion 26 that faces a direction intersecting the first direction X. The second portion 27b is interposed between the heat conduction suppressing portion 26 and the first power storage device 2a. The third portion 27c is interposed between the heat conduction suppressing portion 26 and the second power storage device 2b.

[0140] In addition, the second portion 27b of the present embodiment has a first inclined surface 60 on the side opposite to the heat conduction suppressing portion 26, that is, on the side surface 56 of the second portion 27b facing the second power storage device 2b. The first inclined surface 60 is inclined so as to be away from the heat conduction suppressing portion 26 as it moves from the outside of the frame portion 24 toward the inside. The first inclined surface 60 is arranged at the end of the second portion 27b on the hole 42 side. Therefore, the second portion 27b has a tapered portion in which the thickness (the size in the first direction X) becomes thinner from the outside of the power storage module 1 toward the center.

[0141] The expansion amount of the central portion of the power storage device 2 is greater than that of the peripheral portion. Therefore, when the heat conduction suppression portion 26 is pressed toward the first power storage device 2a due to the expansion of the second power storage device 2b, the heat conduction suppression portion 26 is pressed against the corner of the second portion 27b, and the heat conduction suppression portion 26 may be damaged. In contrast, by providing the first inclined surface 60, the damage of the heat conduction suppression portion 26 can be suppressed. As a result, the reliability of the power storage module 1 can be further improved.

[0142] In addition, the third portion 27c of the present embodiment has a third inclined surface 62 on the side opposite to the heat conduction suppressing portion 26, that is, on the side surface 58 of the third portion 27c facing the first power storage device 2a. The third inclined surface 62 is inclined so as to be away from the heat conduction suppressing portion 26 as it moves from the outside of the frame portion 24 toward the inside. The third inclined surface 62 is arranged at the end of the third portion 27c on the hole 42 side. Therefore, the third portion 27c has a tapered portion whose thickness decreases from the outside to the center of the power storage module 1. By providing the third inclined surface 62, it is possible to prevent the heat conduction suppressing portion 26 from being pressed against the corner of the third portion 27c due to the expansion of the first power storage device 2a and being damaged. As a result, the reliability of the power storage module 1 can be further improved.

[0143] (Implementation method 5)

[0144] Embodiment 5 has the same configuration as Embodiment 3 except for the shape of the frame 24. Hereinafter, this embodiment will be described mainly focusing on the configuration different from Embodiment 3, and the common configuration will be briefly described or omitted. Fig.17 FIG. 2 is a cross-sectional view showing an enlarged portion of a lower portion of a power storage module according to Embodiment 5. Fig.17 , the internal structure of the power storage device 2 is schematically illustrated.

[0145] The partition plate 4 included in the power storage module 1 of the present embodiment has a frame portion 24 and a heat conduction suppressing portion 26, similarly to the third embodiment. The frame portion 24 is interposed between the first power storage device 2a and the second power storage device 2b, and has a hole 42 extending between the two power storage devices 2 and a stopper portion 27 of the heat conduction suppressing portion 26. The stopper portion 27 has a first portion 27a, a second portion 27b, and a third portion 27c. The heat conduction suppressing portion 26 is arranged to block the hole 42 and is supported by the frame portion 24. The first portion 27a is in contact with a surface 26a of the heat conduction suppressing portion 26 that faces a direction intersecting the first direction X. The second portion 27b is interposed between the heat conduction suppressing portion 26 and the first power storage device 2a. The third portion 27c is interposed between the heat conduction suppressing portion 26 and the second power storage device 2b.

[0146] In addition, the second portion 27b of the present embodiment has a second inclined surface 64 on the side opposite to the first power storage device 2a, that is, on the side surface of the second portion 27b facing the first power storage device 2a. The second inclined surface 64 is inclined so as to be away from the first power storage device 2a as it moves from the outside of the frame 24 toward the inside. The second inclined surface 64 is arranged at the end of the second portion 27b on the hole 42 side. Therefore, the second portion 27b has a tapered portion whose thickness becomes thinner from the outside of the power storage module 1 toward the center.

[0147] By providing the second inclined surface 64 on the second portion 27b, it is possible to prevent the outer can 10 of the first power storage device 2a from being pressed against the corner of the second portion 27b due to the expansion of the first power storage device 2a. This can reduce the possibility of damage such as dents on the outer can 10 or the insulating tape covering the outer surface of the outer can 10. Therefore, the reliability of the power storage module 1 can be further improved.

[0148] In addition, the third portion 27c of the present embodiment has a fourth inclined surface 66 on the side opposite to the second power storage device 2b, that is, on the side surface of the third portion 27c facing the second power storage device 2b. The fourth inclined surface 66 is inclined so as to be away from the second power storage device 2b as it moves from the outside of the frame 24 toward the inside. The fourth inclined surface 66 is arranged at the end of the third portion 27c on the hole 42 side. Therefore, the third portion 27c has a tapered portion whose thickness becomes thinner from the outside of the power storage module 1 toward the center.

[0149] By providing the fourth inclined surface 66 on the third portion 27c, it is possible to prevent the outer can 10 of the second power storage device 2b from being pressed against the corner of the third portion 27c due to the expansion of the second power storage device 2b. This can reduce the possibility of damage such as dents on the outer can 10 or the insulating tape covering the outer surface of the outer can 10. Therefore, the reliability of the power storage module 1 can be further improved.

[0150] The above describes the embodiments of the present invention in detail. The above embodiments are only specific examples of the implementation of the present invention. The contents of the embodiments do not limit the technical scope of the present invention. Various design changes such as changes, additions, and deletions of constituent elements can be made without departing from the scope of the idea of ​​the invention defined by the scope of the claims. The new embodiment with the design changes has the respective effects of the combined embodiments and the deformations. In the above embodiments, the contents that can be subjected to such design changes are emphasized with marks such as "in this embodiment" and "in this embodiment", but the contents without such marks also allow design changes. Any combination of the above constituent elements is also valid as a mode of the present invention. The hatched lines marked on the cross-section of the accompanying drawings do not limit the material of the objects marked with hatched lines.

[0151] In the power storage module 1 of embodiments 1 and 2, the partition 4 may not include the heat conduction suppression portion 26. That is, the partition 4 may be only the frame portion 24. In addition, the partition 4 may include a flat plate portion without the hole 42 instead of the frame portion 24. In this case, the separation region 48 is arranged in the region of the flat plate portion that overlaps with the joint portion 20 as viewed from the first direction X. In addition, the abutment region 46 may be formed by all regions of the flat plate portion except the separation region 48, but it is preferred that the abutment region 46 be formed only by the region that overlaps with the peripheral portion of the long side surface 10b as viewed from the first direction X. That is, it is preferred to form a gap 52 in the region that overlaps with the electrode body 14 as viewed from the first direction X. In addition, the partition 4 may not include the wall portion 28.

[0152] The number of the power storage devices 2 included in the power storage module 1 is not particularly limited. The structure of each part of the power storage module 1 including the shape of the wall portion 28 of the partition 4 and the fastening structure of the end plate 6 and the restraining member 8 is not particularly limited. The power storage module 1 may also include a busbar plate. The busbar plate is a plate-shaped member that is arranged to face the upper surfaces of the plurality of power storage devices 2 and covers the upper surfaces. The shape of the opening 12 of the outer can 10 may also be a quadrilateral such as a square, or a polygon other than a quadrilateral.

[0153] The power storage modules 1 of the third to fifth embodiments may include the following Modification 1.

[0154] (Variant 1)

[0155] Fig.18 FIG. 2 is a cross-sectional view showing an enlarged portion of the lower portion of the power storage module according to Modification 1. Fig.18 , the internal structure of the power storage device 2 is schematically shown. The locking portion 27 of the modification 1 has the first portion 27a and the second portion 27b, and does not have the third portion 27c. Even when the third portion 27c is not provided, the gap 52 can be provided between the heat conduction suppressing portion 26 and the first power storage device 2a, so as described in the third embodiment, the compression amount of the heat conduction suppressing portion 26 caused by the expansion of each outer can 10 can be reduced.

[0156] In addition, Fig.18 The middle figure shows the second portion 27b having the first inclined surface 60 (equivalent to the structure in which the third portion 27c is omitted in the fourth embodiment), but the present invention is not particularly limited to this structure. The second portion 27b may also have the second inclined surface 64 (equivalent to the structure in which the third portion 27c is omitted in the fifth embodiment), or may not have the first inclined surface 60 and the second inclined surface 64 (equivalent to the structure in which the third portion 27c is omitted in the third embodiment).

[0157] (other)

[0158] The second part 27b may also include the first inclined surface 60 and the second inclined surface 64. Similarly, the third part 27c may also include the third inclined surface 62 and the fourth inclined surface 66. In addition, the first inclined surface 60 to the fourth inclined surface 66 may be arbitrarily combined. The second part 27b and / or the third part 27c may not be provided on the entire circumference of the frame portion 24. That is, the second part 27b and / or the third part 27c may also be provided intermittently around the hole 42. Similarly, the first inclined surface 60 to the fourth inclined surface 66 may also be provided intermittently around the hole 42. In addition, the first part 27a to the third part 27c may not be integrated, but may be separated from each other by a predetermined distance.

[0159] In embodiments 3 to 5 and modification 1, the first power storage device 2a and the second power storage device 2b are any two power storage devices 2 among the plurality of power storage devices 2. In addition, it is preferred that all separators 4 included in the power storage module 1 have the structure described in each embodiment or modification 1, but at least one separator 4 may have this structure.

[0160] The number of the power storage devices 2 included in the power storage module 1 is not particularly limited. The structure of each part of the power storage module 1 including the shape of the wall portion 28 of the partition 4 and the fastening structure of the end plate 6 and the restraining member 8 is not particularly limited. The power storage module 1 may also include a busbar plate. The busbar plate is a plate-shaped member that is arranged to face the upper surfaces of the plurality of power storage devices 2 and covers the upper surfaces. The shape of the opening 12 of the outer can 10 may also be a quadrilateral such as a square, or a polygon other than a quadrilateral.

[0161] [Industrial Applicability]

[0162] The present invention can be used in a power storage module.

[0163] [Explanation of Reference Numerals]

[0164] 1 Power storage module, 2 Power storage device, 2a First power storage device, 2b Second power storage device, 4 Partition, 10 External can, 12 Opening, 16 Sealing plate, 20 Joining portion, 24 Frame portion, 26 Heat conduction suppressing portion, 27 Stopping portion, 27a First portion, 27b Second portion, 27c Third portion, 42 Hole, 46 Contact region, 48 Separation region, 48a Inclined surface, 60 First inclined surface, 62 Third inclined surface, 64 Second inclined surface, 66 Fourth inclined surface.

Claims

1. A power storage module, characterized in that: include: a first power storage device and a second power storage device arranged along a first direction, and a separator disposed between the first power storage device and the second power storage device to insulate the two power storage devices; The partition has a frame portion and a heat conduction inhibiting portion; The frame portion has: a hole interposed between the first power storage device and the second power storage device and extending between the two power storage devices; and a locking portion of the heat conduction suppressing portion; The heat conduction suppressing portion is arranged in a manner of blocking the hole and is supported by the frame portion; The locking portion includes a first portion that contacts a surface of the heat conduction suppressing portion that faces a direction intersecting the first direction, and a second portion that is interposed between the heat conduction suppressing portion and the first power storage device.

2. The power storage module according to claim 1, wherein: The second portion has a first inclined surface on a side facing the heat conduction inhibiting portion, the first inclined surface being inclined so as to become more distant from the heat conduction inhibiting portion as it moves from the outside of the frame portion toward the inside.

3. The power storage module according to claim 1 or 2, wherein: The second portion has a second inclined surface on a side facing the first power storage device, the second inclined surface being inclined so as to become farther away from the first power storage device as it moves from the outside toward the inside of the frame portion.

4. The power storage module according to any one of claims 1 to 3, wherein: The locking portion includes a third portion interposed between the heat conduction suppressing portion and the second power storage device.

5. The power storage module according to claim 4, wherein: The third portion has a third inclined surface on a side facing the heat conduction inhibiting portion, the third inclined surface being inclined so as to be separated from the heat conduction inhibiting portion as it moves from the outside of the frame portion toward the inside.

6. The power storage module according to claim 4 or 5, wherein: The third portion has a fourth inclined surface on a side facing the second power storage device, the fourth inclined surface being inclined so as to be away from the second power storage device as it moves from the outside toward the inside of the frame portion.

7. The power storage module according to any one of claims 1 to 6, wherein: Each power storage device comprises: an outer can having an opening, a sealing plate for sealing the opening, and a joint between the outer can and the sealing plate. The frame portion includes a contact region that contacts the surface of the outer can facing the first direction, and a separation region that overlaps the joining portion when viewed from the first direction and is recessed in a direction away from the outer can than the contact region.

8. The power storage module according to claim 7, wherein: The separation region overlaps the entirety of the joining portion in a second direction in which the sealing plate extends when viewed from the first direction.

9. The power storage module according to claim 7 or 8, wherein: The separation region overlaps the entirety of the joint portion in the thickness direction of the sealing plate.

10. The power storage module according to any one of claims 7 to 9, wherein: The separation region protrudes further than the sealing plate toward a surface of the outer can that faces the sealing plate.

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