Energy Storage Module

Abstract

An electrical storage module comprising a plurality of electrical storage devices and a first current collector holding the plurality of electrical storage devices. The electrical storage devices each include: a case having an opening; an electrode assembly housed in the case and comprising a first electrode and a second electrode; and a seal assembly sealing the opening. The case includes a tube portion having an opening in one end thereof, and a bottom portion closing the other end of the tube portion. The case is electrically connected to the first electrode. The first current collector has a plurality of first through-holes respectively housing and positioning the plurality of electrical storage devices, the first through-holes having peripheral portions being electrically connected to the case. In this way, it is possible to increase the energy density of the electrical storage module.

Description

[Technical field]

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

[0002] Electricity storage modules are widely used as driving sources for vehicles, electronic devices, etc. Conventional electricity storage modules generally include a holder made of resin, metal, or the like to fix or hold a plurality of electricity storage devices. As an example of an electricity storage module, Patent Document 1 teaches a battery block including a plurality of cylindrical batteries (electricity storage devices) held in a holding section (holder) such that a positive electrode is arranged on one side and a negative electrode is arranged on the other side, a positive electrode lead section arranged on the positive electrode side of the plurality of batteries and fixed to one end (first holding section) of the holding section, and a negative electrode lead section arranged on the negative electrode side of the plurality of batteries and fixed to the other end (second holding section) of the holding section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6286679 Summary of the Invention [Problem to be solved by the invention]

[0004] From the viewpoint of the driving efficiency and convenience of a device in which the power storage module is mounted, it is desirable to reduce the weight of the power storage module. Therefore, an object of the present disclosure is to provide a power storage module that can be made lighter. [Means for solving the problem]

[0005] One aspect of the present disclosure relates to an energy storage module comprising: a plurality of energy storage devices; and a first current collector that holds the plurality of energy storage devices, wherein the energy storage devices include a case having an opening, an electrode body including a first electrode and a second electrode housed in the case, and a sealing member that seals the opening, wherein the case has a cylindrical portion having the opening at one end and a bottom that closes the other end of the cylindrical portion, the case being electrically connected to the first electrode, and the first current collector having a plurality of first through holes that house and position each of the plurality of energy storage devices, and a peripheral portion of the first through hole being electrically connected to the case. Effect of the Invention

[0006] According to the present disclosure, the current collector also functions as a holder, so that the current collector holds the electricity storage device. This eliminates the need to use a holder, and reduces the number of parts in the electricity storage module, making it possible to reduce the weight of the electricity storage module.

[0007] The novel features of the present invention are set forth in the appended claims, but the present invention, both in terms of structure and content, together with other objects and features of the present application, will be better understood from the following detailed description taken in conjunction with the drawings. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of an electricity storage module according to a first embodiment of the present disclosure. [Diagram 2] FIG. 2 is an exploded perspective view of the electricity storage module of FIG. [Diagram 3] 1A is a plan view, FIG. 1B is a side view, and FIG. [Figure 4] FIG. 2 is a perspective view showing a plurality of electricity storage devices (a) before being held by a first current collector, and a perspective view showing a plurality of electricity storage devices (b) after being held by a first current collector. [Diagram 5] FIG. 4 is a perspective view of a second current collector. [Figure 6] 1A is a plan view, FIG. 1B is a side view, and FIG. [Figure 7]1 is a cross-sectional view illustrating a structure of an example of an electricity storage device. [Figure 8] 4 is a cross-sectional view of a main part of an electricity storage device inserted into a first current collector. FIG. [Figure 9] 9 is an enlarged view of a main portion of FIG. 8, showing a welded portion between the first current collector and the opening edge of the case. FIG. [Figure 10] FIG. 11 is a perspective view of an energy storage module according to another embodiment of the present disclosure. [Figure 11] FIG. 11 is a perspective view of an electricity storage module according to a second embodiment of the present disclosure. [Figure 12] FIG. 12 is an exploded perspective view of the electricity storage module of FIG. [Figure 13] 1A is a plan view, FIG. 1B is a side view, and FIG. [Figure 14] FIG. 2 is a perspective view showing a plurality of electricity storage devices (a) before being held by a first current collector, and a perspective view showing a plurality of electricity storage devices (b) after being held by a first current collector. [Figure 15] FIG. 4 is a perspective view of a second current collector. [Figure 16] 1A is a plan view, FIG. 1B is a side view, and FIG. [Figure 17] 1 is a cross-sectional view illustrating a structure of an example of an electricity storage device. [Figure 18] 4 is a cross-sectional view of a main part of an electricity storage device inserted into a first current collector. FIG. [Figure 19] 19 is an enlarged view of a main portion of FIG. 18, showing a welded portion between the first current collector and the opening edge of the case. FIG. [Figure 20] FIG. 11 is a perspective view of an energy storage module according to another embodiment of the present disclosure. [Figure 21] FIG. 11 is a perspective view of an electricity storage module according to a third embodiment of the present disclosure. [Figure 22] FIG. 22 is an exploded perspective view of the electricity storage module of FIG. 21. [Figure 23] 1A is a plan view, FIG. 1B is a side view, and FIG. [Figure 24] FIG. 2 is a perspective view showing a plurality of electricity storage devices (a) before being held by a first current collector, and a perspective view showing a plurality of electricity storage devices (b) after being held by a first current collector. [Diagram 25]FIG. 4 is a perspective view of a second current collector. [Figure 26] 1A is a plan view, FIG. 1B is a side view, and FIG. [Figure 27] 1 is a cross-sectional view illustrating a structure of an example of an electricity storage device. [Figure 28] 4 is a cross-sectional view of a main part of an electricity storage device inserted into a first current collector. FIG. [Figure 29A] 29 is an enlarged view of a main portion of FIG. 28, showing a welded portion between the first current collector and the opening edge of the case. FIG. [Figure 29B] FIG. 29B shows a variation of the embodiment of FIG. 29A. [Diagram 30] FIG. 11 is a perspective view of an energy storage module according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] First Embodiment A first embodiment of the present disclosure will be described. The power storage module according to this embodiment includes a plurality of power storage devices and a first current collector that holds the plurality of power storage devices. Since the plurality of power storage devices are held and integrated by the first current collector, a holder for holding the plurality of power storage devices is not essential, and the holder can be significantly reduced in size or omitted. Thus, the energy density per weight of the power storage module is significantly improved. As a result, for example, it becomes easy to extend the driving range of a vehicle or the like that is equipped with the power storage module. The plurality of power storage devices may be held by the first current collector and fixed to the first current collector.

[0010] However, the power storage module may also include a holder for fixing or holding the multiple power storage devices. For example, the power storage module may further include a holder having multiple housing parts for housing and positioning the bottoms of the multiple power storage devices. This configuration further increases resistance to external forces such as vibration. Also, a heat absorbing agent or a heat dissipating member may be interposed between a pair of adjacent power storage devices.

[0011] The electricity storage device includes a case having an opening, an electrode body including a first electrode and a second electrode housed in the case, and a sealing member that seals the opening. The shape of the case may be, for example, cylindrical, but is not particularly limited. The electrode body is, for example, configured by winding the first electrode and the second electrode with a separator interposed therebetween. When the electricity storage device is a battery, one of the first electrode and the second electrode is a positive electrode, and the other is a negative electrode.

[0012] The case has a cylindrical portion, a flange portion extending in a direction away from an opening provided at one end of the cylindrical portion, and a bottom portion closing the other end of the cylindrical portion. The case is electrically connected to the first electrode.

[0013] The first current collector has a plurality of first through holes that accommodate and position each of the plurality of electricity storage devices. That is, the arrangement of the plurality of electricity storage devices is determined by the arrangement of the first through holes. In this case, the configuration of the electricity storage module or the number of electricity storage devices connected in parallel can be easily changed simply by changing the arrangement (layout) of the first through holes in the first current collector. Here, the peripheral portion of the first through hole is electrically connected to the flange portion.

[0014] The multiple power storage devices may be arranged side by side such that the axial directions of the electrode bodies are oriented in the same direction and the openings of the cases are located on the same side. More specifically, the multiple power storage devices may be arranged such that the axial directions of the electrode bodies are generally parallel, one and the other end faces of the electrode bodies are located in generally the same plane, and the side faces of the cylindrical parts of the cases are adjacent to each other.

[0015] The plurality of electric storage devices may be held in any manner relative to the first current collector. For example, the electric storage devices may be fixed to the first current collector by joining the periphery of the first through hole to a flange of the case. By joining the flange to the periphery of the first through hole, the flange can be expanded to ensure a region in which the first current collector and the case can be connected. Furthermore, the periphery of the first through hole and the flange can be at least partially joined by welding. By joining by welding, the case and the first current collector can be firmly fixed. In addition, the connection resistance between the case and the first current collector can be reduced.

[0016] The periphery of the first through hole may extend toward the bottom of the case of the electric storage device and may have a wall portion that abuts against the tubular portion of the case or biases the tubular portion. Such a wall portion may be, for example, a ring-shaped wall portion surrounding the tubular portion. Also, the wall portion may be a tongue-shaped portion intermittently formed in the circumferential direction of the tubular portion, or a portion of the ring-shaped wall portion may be cut out. Also, the wall portion may be formed by connecting a separate member to the periphery of the first through hole. This allows the electric storage device to be held by the first current collector more stably.

[0017] The energy storage module may further include a second current collector electrically connected to the second electrode of the electrode assembly. In this case, a flange portion may be disposed between the first current collector and the second current collector. More specifically, the first current collector and the second current collector may be disposed overlapping each other so as to sandwich the flange portion. This makes it possible to more firmly fix the flange portion to both the first current collector and the second current collector. The outer shapes of the planar shapes of the first current collector and the second current collector may generally correspond to each other.

[0018] An insulating member may be interposed between the first current collector and the second current collector. In this case, the first surface of the insulating member may be in contact with the second current collector, and the second surface located on the opposite side of the first surface may be in contact with the flange portion or the plugging member. By arranging the first and second current collectors with the flange portion in between, both the first and second current collectors can be arranged on one end side of the electricity storage device (specifically, the side having the plugging member), and therefore it is not necessary to provide a current collecting structure on the other end side of the electricity storage device (specifically, the bottom side). This makes it possible to reduce the space required by the electricity storage device in the axial direction, which is advantageous for improving the volumetric energy density of the electricity storage module.

[0019] The structure of the sealing member is not particularly limited, and may include, for example, a sealing plate, an annular cap surrounding the sealing plate, and a gasket for insulating the sealing plate from the cap. When a sealing member having such a structure is used, the flange portion and the cap can be electrically connected, and the sealing plate and the second electrode of the electrode body can be electrically connected.

[0020] The second current collector may have a second through hole in a region facing the sealing plate, and may have a tongue-shaped lead extending inward from a peripheral portion of the second through hole. The second current collector is electrically connected to the sealing plate by electrically connecting the tongue-shaped lead to the sealing plate.

[0021] The type of the power storage device is not particularly limited, and examples thereof include a primary battery, a secondary battery, a lithium ion capacitor, an electric double layer capacitor, a solid electrolytic capacitor, etc. Among them, a non-aqueous electrolyte secondary battery (including an all-solid-state battery) such as a lithium ion secondary battery having a high energy density can be preferably used.

[0022] Hereinafter, the electricity storage module according to the first embodiment of the present invention will be described in detail with reference to the drawings, however, the present invention is not limited to the following.

[0023] Fig. 1 is a perspective view of an electric storage module according to an embodiment of the present disclosure. Fig. 2 is an exploded perspective view of the electric storage module of Fig. 1. The electric storage module 10 includes a plurality of electric storage devices 200, each of which is cylindrical, a first current collector 300 that holds the plurality of electric storage devices 200, and a second current collector 400. The first current collector 300 also serves to integrate the plurality of electric storage devices 200. The plurality of electric storage devices 200 are arranged side by side such that the axial directions of the respective electrode bodies face in the same direction and the openings of the cases are disposed on the same side.

[0024] FIG. 3 is a plan view (a), a side view (b), and a bottom view (c) of the first current collector. FIG. 4 is a perspective view showing a plurality of power storage devices (a) before being held by the first current collector, and a plurality of power storage devices (b) held by the first current collector. The first current collector 300 has a plurality of first through holes 301 through which the plurality of power storage devices 200 are inserted and positioned. The arrangement of the plurality of power storage devices 200 is easily determined by the arrangement of the first through holes 301. Each power storage device 200 is inserted into the first through hole 301 from the bottom side and positioned. The illustrated example is an example in which 12 power storage devices are arranged in a honeycomb shape (staggered) so as to be close to closest packing, but the arrangement, number, etc. of the power storage devices are not particularly limited. The first current collector 300 can be obtained by processing a metal plate by punching, pressing, or the like.

[0025] Fig. 5 is a perspective view of the second current collector, and Fig. 6 is a plan view (a), a side view (b) and a bottom view (c) of the second current collector. The second current collector 400 is a plate-like member having second through-holes 401 at positions corresponding to the positions of the multiple electricity storage devices 200. The second current collector 400 can be obtained by processing a metal plate by punching, pressing or the like.

[0026] 7 is a cross-sectional view showing the structure of an example of an electricity storage device 200. The electricity storage device 200 includes a cylindrical case 210 having an opening 201, an electrode body 220 including a first electrode and a second electrode housed in the case 210, and a sealing member 230 that seals the opening 201.

[0027] Case 210 has a cylindrical portion 211, a flange portion 212 extending in a direction away from opening 201 provided at one end of cylindrical portion 211, and a bottom portion 213 closing the other end of cylindrical portion 211. Flange portion 212 is an annular portion having an outer diameter larger than the outer diameter of cylindrical portion 211, and extends from one end of cylindrical portion 211 of case 210 toward the radial outside of opening 201 approximately perpendicular to the axial direction.

[0028] The sealing member 230 has a sealing plate 231, an annular cap (outer ring) 232 surrounding the sealing plate 231, and a gasket 233 that provides insulation between the sealing plate 231 and the cap 232. The flange portion 212 and the cap 232 are electrically connected. Specifically, the flange portion 212 and the peripheral portion of the cap 232 are joined by welding around the entire circumference of the opening 201, thereby electrically connecting the two. This maintains the airtightness of the inside of the can case 210.

[0029] An internal insulating plate 240 is disposed between the electrode body 220 and the sealing member 230, and prevents contact between the electrode body 220 and the sealing member 230. A predetermined lead hole 241 is provided in the internal insulating plate 240. A lead 222 extending from a second electrode constituting the electrode body 220 passes through the lead hole 241 and is connected to the inner surface (inner surface) of the case of the sealing plate 231. Thus, the sealing plate 231 has the same polarity as the second electrode. On the other hand, the first electrode constituting the electrode body 220 is electrically connected to the case 210. Thus, the case 210 has the same polarity as the first electrode.

[0030] FIG. 8 is a cross-sectional view of a main part of the electricity storage device 200 held by the first current collector 300. FIG. 9 is an enlarged view of a main part of FIG. 8, showing a welding portion between the first current collector 300 and the flange portion 212 of the case 210. When the flange portion 212 and the first through hole 301 are viewed from the axial direction of the case 210, the diameter of the flange portion 212 is larger than the diameter of the first through hole 301. Thus, the flange portion 212 and the peripheral portion 302 of the first through hole 301 overlap over the entire circumference of the flange portion 212. The portion where the flange portion 212 and the peripheral portion 302 of the first through hole 301 overlap and directly contact each other can be joined by welding. As a result, the plurality of electricity storage devices 200 are firmly fixed to the first current collector 300 and integrated. The welding method is not particularly limited, but for example, laser welding is convenient.

[0031] 9 shows an example of a welding spot WP when welding flange portion 212 and peripheral portion 302 of first through hole 301 with a laser from the flange portion 212 side. Flange portion 212 and peripheral portion 302 of first through hole 301 may be at least partially welded.

[0032] In the radial direction of the cylindrical portion 211, the welding location WP between the flange portion 212 and the peripheral edge portion 302 may be formed outside the flange portion 212 compared to the welding location (hereinafter referred to as welding location WPS) between the flange portion 212 and the cap 232. Due to such a positional relationship of the welding locations, when joining the flange portion 212 and the cap 232 to fabricate the power storage device 200 and then joining the power storage device 200 and the first current collector 300, compared with the configuration where the welding location WP is formed inside the flange portion from the welding location WPS, the workability and reliability of fabricating the power storage module are improved. This is because when attempting to form the welding location WP, in the region of the flange portion 212 sandwiched between the cap 232 and the first current collector 300, it is necessary to weld three members simultaneously. In this welding, more energy is required for welding compared to the method of simply welding the two members of the flange portion 212 and the first current collector 300. Also, it is necessary to maintain the airtightness of the power storage device 200 by the welding location WP. Therefore, welding with higher precision is required. On the other hand, as shown in FIG. 9, when the flange portion 212 extends outward from the cap 232 and the welding location WP is formed outside the flange portion from the welding location WPS, welding of the two members by the flange portion 212 and the first current collector 300 can be performed.

[0033] In addition, when the flange portion 212 and the first current collector 300 are welded together, and then the flange portion 212 and the cap 232 are welded together to produce the electricity storage device 200, a configuration in which the welded portion WP is located outside the flange portion 212 relative to the welded portion WPS enhances the reliability of the electricity storage module compared to a configuration in which the welded portion WP is located inside the welded portion WPS. In a configuration in which the welded portion WP is located inside the welded portion WPS, when the welded portion WPS is formed after the welded portion WP is formed, the cap 232 abuts against the welded mark of the welded portion WP formed earlier. The welded mark is likely to be less flat than the unwelded portion, so that the positioning tolerance when the cap 232 is placed on the flange portion 212 is likely to be large. If the exposed surface of the melting mark is raised, there is a risk of a gap being formed between the cap 232 and the unwelded portion of the flange portion 212. It is more difficult to form the welded portion WPS in a state in which this gap exists compared to a state in which there is no gap. In contrast, by having the flange portion 212 extend outward from the cap 232 and the welded spots WP be located outside the welded spots WPS, the possibility of the welded spots WP and the cap 232 coming into contact when the welded spots WPS are formed can be reduced.

[0034] Furthermore, by forming a recess (or step) extending from peripheral portion 302 of first current collector 300 and forming welding points WP with flange portion 212 housed in this recess, the height of the electricity storage module can be further reduced. Furthermore, the welding points WP are not limited to the above positions, and may be formed between the peripheral edge of flange portion 212 and the upper surface of first current collector 300.

[0035] A ring-shaped wall portion 303 is formed extending from a peripheral portion 302 of the first through-hole 301 of the first current collector 300 toward the bottom portion 213 of the case 210 of the electricity storage device 200. The ring-shaped wall portion 303 is disposed so as to abut against the entire circumference of the tube portion 211 in the vicinity of the flange portion 212. The ring-shaped wall portion 303 facilitates more accurate positioning of the electricity storage device 200 and also plays a role in limiting movement of the electricity storage device 200 due to vibration or the like.

[0036] The second current collector 400 is disposed overlapping the first current collector 300 so as to sandwich the flange portion 212. More specifically, the first current collector 300 and the second current collector 400 are disposed overlapping so as to sandwich the peripheral portion of the cap 232 together with the flange portion 212. That is, both the first current collector 300 and the second current collector 400 are disposed on the side of the sealing member 230 of the electricity storage device 200. Therefore, since there is no need to provide a current collecting structure on the bottom 213 side of the electricity storage device 200, the space required by the electricity storage device 200 in the axial direction can be reduced.

[0037] The second through hole 401 of the second current collector 400 is located directly above the sealing member 230 of each of the multiple electricity storage devices 200. The second through hole 401 plays a role of guiding gas released from the electricity storage device 200 in the event of an abnormality, for example, to a predetermined duct. A tongue-shaped lead 410 is led out from the periphery of the second through hole 401 toward the inside of the second through hole. The tongue-shaped lead 410 is electrically connected to the surface (outer surface) of the sealing plate 231 on the outer side of the case. Therefore, the second current collector 400 has the same polarity as the sealing plate 231 and the second electrode.

[0038] An insulating member 500 is interposed between the first current collector 300 and the second current collector 400. The insulating member 500 is a plate-like member having a first surface 502 and a second surface 503 located on the opposite side of the first surface 502. The insulating member 500 has third through holes 501 at positions corresponding to the plugging members 230 of the multiple electricity storage devices 200. The first surface 502 of the insulating member 500 abuts against the second current collector 400. Meanwhile, the second surface 503 abuts against the cap 232 of the plugging member 230. With this configuration, the cap 232 and the flange portion 212 can be sandwiched between the insulating member 500 and the first current collector 300. Therefore, the electricity storage device 200 can be held more firmly. At this time, the insulating member 500 and the first current collector 300 may be fastened with a screw or the like. 9, the insulating member 500 may abut against the extended portion. This enables the electricity storage device 200 to be held more firmly. Furthermore, the insulating member 500 abuts or connects with the first current collector 300, thereby fixing the first current collector 300 and the insulating member 500. Similar to the second through hole, the third through hole 501 plays a role of guiding gas released from the electricity storage device 200 in the event of an abnormality to a specified duct.

[0039] 10 is a perspective view of an energy storage module according to another embodiment of the present disclosure. The energy storage module 10A has a similar structure to the energy storage module 10 already described, except that the energy storage module 10A includes a holder 600 having a plurality of housing portions 601 that house and position the bottoms 213 of the plurality of energy storage devices 200.

[0040] By fixing the flange portion 212 located at one end of the energy storage device 200 to the first collector 300 and holding or fixing the bottom portion 213 located at the other end of the energy storage device 200 with a holder, it is possible to form an energy storage module 10A in which multiple energy storage devices 200 are more firmly integrated.

[0041] Since one end side of the multiple electricity storage devices 200 is fixed by the first current collector 300, the depth of the storage portion 601 of the holder 600 that holds or fixes the bottoms 213 of the electricity storage devices 200 may be shallow. For example, when the axial height of the electricity storage devices 200 (the distance from one end to the other end) is H, the depth of the storage portion of the holder may be 20% or less of H. The bottom surface of the holder 600 may be flush with the bottom surface of the storage portion as a whole, but in order to reduce weight, the holder 600 may be recessed except for the portion where the recess (storage portion) that stores each electricity storage device 200 is formed.

[0042] Second Embodiment A second embodiment of the present disclosure will be described. The power storage module according to this embodiment includes a plurality of power storage devices and a first current collector that holds the plurality of power storage devices. Since the plurality of power storage devices are held and integrated by the first current collector, a holder for holding the plurality of power storage devices is not essential, and the holder can be significantly reduced in size or omitted. This significantly improves the energy density per weight of the power storage module. As a result, for example, it becomes easier to extend the driving range of a vehicle or the like that is equipped with the power storage module. The plurality of power storage devices may be held by the first current collector and fixed to the first current collector.

[0043] However, the power storage module may also include a holder for fixing or holding the multiple power storage devices. For example, the power storage module may further include a holder having multiple housing parts for housing and positioning the bottoms of the multiple power storage devices. This configuration further increases resistance to external forces such as vibration. Also, a heat absorbing agent or a heat dissipating member may be interposed between a pair of adjacent power storage devices.

[0044] The electricity storage device includes a case having an opening, an electrode body including a first electrode and a second electrode housed in the case, and a sealing member that seals the opening. The case has a cylindrical shape, for example. The electrode body is formed, for example, by winding the first electrode and the second electrode with a separator interposed therebetween. When the electricity storage device is a battery, one of the first electrode and the second electrode is a positive electrode, and the other is a negative electrode.

[0045] The case has a cylindrical portion, an expanded portion that is continuous with one end of the cylindrical portion and has an open end corresponding to the opening, a bottom portion that closes the other end of the cylindrical portion, and an annular groove portion that is recessed radially inwardly of the cylindrical portion and is provided between the cylindrical portion and the expanded portion. The case is electrically connected to the first electrode. The maximum outer diameter D1 of the expanded portion is larger than the outer diameter D2 of the cylindrical portion. If the outer diameter of the cylindrical portion is not strictly circular, the maximum outer diameter of the cylindrical portion may be set to D2. The expanded portion protrudes from the outer periphery of the cylindrical portion when viewed from the bottom side in the axial direction of the case.

[0046] The enlarged diameter portion compresses the sealing material, for example, by compressing the sealing material together with the groove portion to form a crimped sealing structure.

[0047] The enlarged diameter portion may be bent to form a first portion disposed on the outer surface of the peripheral portion (hereinafter also referred to as "peripheral portion X") of the sealing member, and a second portion disposed on the side surface of the peripheral portion X. In this case, the first portion and the groove compress the peripheral portion X of the sealing member in the direction in which its outer surface and inner surface face (or the axial direction of the case). In other words, the side surface of the peripheral portion X is a surface that connects the outer surface and inner surface of the sealing member in the peripheral portion X.

[0048] The first current collector has a plurality of first through-holes that accommodate and position each of the plurality of power storage devices. That is, the arrangement of the plurality of power storage devices is determined by the arrangement of the first through-holes. In this case, by simply changing the arrangement (layout) of the first through-holes in the first current collector, the configuration of the power storage module or the number of power storage devices connected in parallel can be easily changed. The first current collector is electrically connected to at least one of the diameter-expanded portion and the groove portion. Thereby, the first current collector is electrically connected to the case and further electrically connected to the first electrode. The first current collector is, for example, a plate having conductivity.

[0049] Here, the peripheral portion surrounding the first through-hole of the first current collector (hereinafter, also referred to as "peripheral portion Y") is arranged on the inner surface of the groove portion so as to overlap the surface on the diameter-expanded portion side. Here, the surface on the diameter-expanded portion side on the inner surface of the groove portion means a surface extending from the location having the minimum diameter (the deepest portion of the groove portion) to the diameter-expanded portion on the inner surface of the groove portion. With this configuration, it becomes possible for the case to come into contact with the first current collector in a state where the case is inserted into the first through-hole. By this contact, displacement between the power storage device and the first current collector can be suppressed. Also, the maximum outer diameter of the cylindrical portion is larger than the minimum outer diameter of the groove portion, and the peripheral portion Y of the first current collector does not have to overlap the surface on the cylindrical portion side of the inner surface of the groove portion. Here, the surface on the cylindrical portion side on the inner surface of the groove portion means a surface extending from the location having the minimum diameter to the cylindrical portion on the inner surface of the groove portion. With this configuration, it is possible to suppress the peripheral portion Y of the first current collector from interfering with the cylindrical portion when inserting the power storage device into the first through-hole. The peripheral portion Y of the first current collector may have, for example, a holding portion suitable for receiving the inner surface of the groove portion. The holding portion supports the diameter-expanded portion by receiving the inner surface of the groove portion.

[0050] The holding portion may have a first wall portion that extends toward the bottom of the case and faces the second portion, and an inner flange portion that is continuous with the first wall portion and supports the surface on the enlarged-diameter portion side on the inner surface of the groove portion. The second portion and the first wall portion of the first current collector may be brought into contact with each other. At this time, the first wall portion suppresses the movement of the enlarged-diameter portion in a direction perpendicular to the axial direction of the case. The inner flange portion suppresses the movement of the enlarged-diameter portion in the axial direction of the case. Thereby, the rocking of the case is suppressed, and the power storage device is positioned more stably. Note that the holding portion is a concave portion or a stepped portion formed in the first current collector such that the surface on the sealing member side is recessed, and it can be said that at least a part of the enlarged-diameter portion is accommodated in this concave portion or stepped portion.

[0051] The holding portion may further have a second wall portion that is continuous with the inner flange portion, extends toward the bottom of the case, and faces the cylindrical portion. The cylindrical portion and the second wall portion may be brought into contact with each other to give the second wall portion a function of pressing the cylindrical portion. Such a second wall portion more strictly suppresses the movement of the enlarged-diameter portion in a direction perpendicular to the axial direction of the case (the radial direction of the cylindrical portion). For example, it is possible to regulate the inclination of the power storage device with respect to the first current collector. Thereby, the rocking of the case is further suppressed, and the power storage device is firmly fixed in a predetermined position.

[0052] The holding portion, or the first wall portion, or the connecting body of the first wall portion and the second wall portion may be, for example, a ring-shaped wall portion surrounding the enlarged-diameter portion and / or the cylindrical portion. Also, a tongue piece shape intermittently formed in the circumferential direction of the enlarged-diameter portion, or a shape in which a part of the ring-shaped wall portion is cut out may be used. Further, a separate member may be connected to the peripheral edge portion Y of the first through hole to form the holding portion.

[0053] The plurality of power storage devices may be held in any manner with respect to the first current collector. For example, the first portion of the enlarged-diameter portion and the surface (particularly the outer surface) of the first current collector may be flush. Such a structure improves the storability of the second current collector, the insulating member, and the like. However, the outer surface of the first portion and the outer surface of the first current collector do not necessarily have exactly the same height in the axial direction of the case, and there may be a deviation of within 2 mm from each other.

[0054] The electric storage device may be more firmly fixed to the first current collector by joining the peripheral portion Y of the first current collector to the expanded portion. When the first portion of the expanded portion and the surface of the first current collector are flush with each other, the bent portion at the boundary between the first portion and the second portion may be welded to the peripheral portion Y of the first current collector (or a portion adjacent to the first portion of the holding portion). This makes it possible to more firmly fix the electric storage device to the first current collector. In this case, the welded area in the peripheral portion Y may be the entire circumference of the peripheral portion Y (or the bent portion), or may be formed by dotting some areas along the circumferential direction of the peripheral portion Y. If the welded area is the entire circumference, the connection resistance between the case and the first current collector can be reduced. In addition, the unity between the electric storage device and the first current collector can be improved. In addition, when the welding is done in a dotted manner, even if a force that causes a minute displacement acts on the electric storage device or the first current collector, the stress in the joint between the inner flange portion and the bent portion is smaller than when the welding is done to the entire circumference of the peripheral portion Y. This makes it possible to reduce distortion of the entire electricity storage module. In the electricity storage module of the present disclosure, the peripheral edge portion Y of the first current collector and the surface of the inner surface of the groove on the expanded diameter portion side may be joined together.

[0055] The multiple power storage devices may be arranged side by side such that the axial directions of the electrode bodies are oriented in the same direction and the openings of the cases are located on the same side. More specifically, the multiple power storage devices may be arranged such that the axial directions of the electrode bodies are generally parallel, one and the other end faces of the electrode bodies are located in generally the same plane, and the side faces of the cylindrical parts of the cases are adjacent to each other.

[0056] The energy storage module may further include a second current collector electrically connected to the second electrode of the electrode assembly. The first current collector and the second current collector may have substantially the same outer shape in plan view, and one of the first current collector and the second current collector may be larger than the other current collector.

[0057] An insulating member may be interposed between the first current collector and the second current collector. In this case, a first surface of the insulating member may be in contact with the second current collector, and a second surface located on the opposite side of the first surface may be in contact with the first current collector. By arranging the first and second current collectors with the insulating member sandwiched therebetween, both the first and second current collectors can be arranged on one end side of the electricity storage device (specifically, the side having the sealing member), and therefore it becomes unnecessary to provide a current collecting structure on the other end side of the electricity storage device (specifically, the bottom side). Therefore, it is possible to reduce the space required for the electricity storage device in the axial direction, which is advantageous for improving the volumetric energy density of the electricity storage module. In addition, it is possible to easily prevent the positions of the first and second current collectors from shifting. Furthermore, by using a material with high rigidity for the insulating member, the mechanical strength of the current collecting member including the first and second current collectors is increased.

[0058] The structure of the sealing member is not particularly limited, but may include, for example, a sealing plate and a gasket that provides insulation between the sealing plate and the enlarged diameter portion. When a sealing member having such a structure is used, the sealing plate and the second electrode of the electrode assembly can be electrically connected.

[0059] The second current collector may have a second through hole in a region facing the sealing plate, and may have a tongue-shaped lead extending inward from a peripheral portion surrounding the second through hole of the second current collector into the second through hole. The second current collector is electrically connected to the sealing plate by electrically connecting the tongue-shaped lead to the sealing plate.

[0060] The type of the power storage device is not particularly limited, and examples thereof include a primary battery, a secondary battery, a lithium ion capacitor, an electric double layer capacitor, a solid electrolytic capacitor, etc. Among them, a non-aqueous electrolyte secondary battery (including an all-solid-state battery) such as a lithium ion secondary battery having a high energy density can be preferably used.

[0061] Hereinafter, the electricity storage module according to the second embodiment of the present invention will be specifically described with reference to the drawings, however, the present invention is not limited to the following.

[0062] Fig. 11 is a perspective view of an electric storage module according to an embodiment of the present disclosure. Fig. 12 is an exploded perspective view of the electric storage module of Fig. 11. The electric storage module 1010 includes a plurality of electric storage devices 1200 each having a cylindrical shape, a first current collector 1300 that holds the plurality of electric storage devices 1200, and a second current collector 1400. The first current collector 1300 also serves to integrate the plurality of electric storage devices 1200. The plurality of electric storage devices 1200 are arranged side by side such that the axial directions of the respective electrode bodies face in the same direction and the openings of the cases are disposed on the same side.

[0063] FIG. 13 is a plan view (a), a side view (b), and a bottom view (c) of the first current collector. FIG. 14 is a perspective view showing a plurality of power storage devices (a) before being held by the first current collector, and a plurality of power storage devices (b) held by the first current collector. The first current collector 1300 has a plurality of first through holes 1301 through which the plurality of power storage devices 1200 are inserted and positioned. The arrangement of the plurality of power storage devices 1200 is easily determined by the arrangement of the first through holes 1301. Each power storage device 1200 is inserted into the first through hole 1301 from the bottom side and positioned. The illustrated example is an example in which 12 power storage devices are arranged in a honeycomb shape (staggered) so as to be close to closest packing, but the arrangement, number, etc. of the power storage devices are not particularly limited. The first current collector 1300 can be obtained by processing a metal plate by punching, pressing, or the like.

[0064] Fig. 15 is a perspective view of the second current collector, and Fig. 16 is a plan view (a), a side view (b), and a bottom view (c) of the second current collector. The second current collector 1400 is a plate-like member having second through-holes 1401 at positions corresponding to the positions of the multiple electricity storage devices 1200. The second current collector 1400 can be obtained by processing a metal plate by punching, pressing, or the like.

[0065] The second current collector 1400 is disposed overlapping the first current collector 1300. Specifically, both the first current collector 1300 and the second current collector 1400 are disposed on the side of the sealing member of the power storage device 1200. Therefore, since it is not necessary to provide a current collecting structure on the bottom side of the power storage device 1200, the space required by the power storage device 1200 in the axial direction can be reduced.

[0066] FIG. 17 is a cross-sectional view showing the structure of an example of the power storage device 1200. The power storage device 1200 includes a cylindrical case 1210 having an opening 1201, an electrode body 1220 including a first electrode and a second electrode accommodated in the case 1210, and a sealing member 1230 that seals the opening 1201.

[0067] The case 1210 has a cylindrical tube portion 1211, a diameter-expanded portion 1212 that is continuous with one end of the tube portion 1211 and has an opening end portion 1212T corresponding to the opening 1201, a bottom portion 1213 that closes the other end of the tube portion 1211, and an annular groove portion 1214 that is recessed inward in the radial direction of the tube portion 1211 provided between the tube portion and the diameter-expanded portion. The diameter-expanded portion 1212 is an annular portion having an outer diameter D1 larger than the outer diameter D2 of the tube portion 1211.

[0068] The sealing member 1230 has a sealing plate 1231 and a gasket 1232 that insulates between the sealing plate 1231 and the diameter-expanded portion 1212. Note that the sealing plate 1231 may include a valve body having a circular outer shape, a metal plate disposed on the inner side of the battery with respect to the valve body and connected to the central portion of the valve body, and an annular insulating member interposed between the outer peripheral portions of the valve body and the metal plate. At this time, the valve body has an inclined region in which the thickness continuously decreases along the radial direction from the inner peripheral side to the outer peripheral side. The metal plate may have at least a part formed in a thin wall and may have a vent hole (not shown). When the internal pressure of the battery abnormally rises, the valve body is pulled outward by the gas pressure from the vent hole to the metal plate connected to the central portion of the valve body, and when the internal pressure of the battery reaches a predetermined value, the thin wall portion of the metal plate breaks and the current path between the valve body and the metal plate is interrupted.

[0069] The enlarged diameter portion 1212 is bent to form a first portion 1212a disposed on the outer surface of the peripheral portion X of the sealing member 1230 (the gasket 1232 disposed on the peripheral portion X), and a second portion 1212b disposed on the side surface of the peripheral portion X of the sealing member 1230. The first portion 1212a, together with the groove portion 1214, compresses the gasket 1232 disposed on the peripheral portion X of the sealing member 1230 in the direction in which the outer surface and inner surface of the sealing member face each other. This maintains the airtightness of the inside of the case 1210.

[0070] An internal insulating plate 1240 is disposed between the electrode body 1220 and the sealing member 1230, and the internal insulating plate 1240 prevents contact between the electrode body 1220 and the sealing member 1230. A predetermined lead hole 1241 is provided in the internal insulating plate 1240. A lead 1222 extending from a second electrode constituting the electrode body 1220 passes through the lead hole 1241 and is electrically connected to the inner surface of the sealing plate 1231. Thus, the sealing plate 1231 has the same polarity as the second electrode. On the other hand, a first electrode constituting the electrode body 1220 is electrically connected to the case 1210. Thus, the case 1210 has the same polarity as the first electrode.

[0071] Fig. 18 is a cross-sectional view of a main part of an electricity storage device 1200 held by a first current collector 1300. Fig. 19 is an enlarged view of a main part of Fig. 18, showing a welding point between a peripheral part 1302 (peripheral part Y) surrounding a first through-hole 1301 of the first current collector 1300 and an enlarged diameter part 1212 of the case 1210.

[0072] The holding portion 1310 of the peripheral portion Y has a first wall portion 1311 extending toward the bottom portion 1213 of the case 1210 and facing the second portion 1212b, an inner flange portion 1312 continuing with the first wall portion 1311, and a second wall portion 1313 continuing with the inner flange portion 1312. The inner flange portion 1312 supports the surface of the groove portion 1214 on the side of the enlarged diameter portion 1212. The second wall portion 1313 extends further toward the bottom portion 1213 of the case 1210 and faces the tube portion 1211. The first wall portion 1311 is in contact with at least a portion of the second portion 1212b to suppress movement of the enlarged diameter portion 1212 in a direction perpendicular to the axial direction of the case 1210. Furthermore, inner flange portion 1312 suppresses movement of expanded diameter portion 1212 in the axial direction of case 1210. Second wall portion 1313 is in at least partial contact with tubular portion 1211, suppressing movement of tubular portion 1211 in a direction perpendicular to the axial direction of case 1210. With this configuration, the electricity storage device can be held more firmly while suppressing the shapes of insulating member 1500 and second current collector, which will be described later, from becoming complicated.

[0073] The second through hole 1401 of the second current collector 1400 is located directly above the sealing member 1230 of each of the multiple electricity storage devices 1200. The second through hole 1401 plays a role of guiding gas released from the electricity storage device 1200 in the event of an abnormality, for example, to a predetermined duct. A tongue-shaped lead 1410 is led out from the periphery of the second through hole 1401 toward the inside of the second through hole. The tongue-shaped lead 1410 is electrically connected to the outer surface of the sealing plate 1231. Therefore, the second current collector 1400 has the same polarity as the sealing plate 1231 and the second electrode.

[0074] FIG. 19 shows an example of a welding point WP when the enlarged diameter portion 1212 and the peripheral portion Y of the first current collector 1300 are welded by a laser from the side of the enlarged diameter portion 1212. When the enlarged diameter portion 1212 and the first through hole 1301 are viewed from the axial direction of the case 1210, the diameter of the enlarged diameter portion 1212 is larger than the inner diameter of the inner flange portion 1312. Therefore, the enlarged diameter portion 1212 and the holding portion 1310 of the first current collector 1300 have an overlapping region. In addition, the first portion 1212a and the main surface of the first current collector 1300 are substantially flush with each other. The portion where the enlarged diameter portion 1212 and the peripheral portion Y (holding portion 1310) are adjacent to each other are joined by welding. As a result, the multiple electricity storage devices 1200 are firmly fixed to the first current collector 1300 and integrated. The enlarged diameter portion 1212 and the peripheral edge portion Y (the holding portion 1310) may be at least partially welded together.

[0075] The welding points WP are not limited to the above positions, and for example, the inner flange portion 1312 of the holding portion 1310 and the surface of the groove portion 1214 on the enlarged diameter portion side may be welded together.

[0076] As shown in FIG. 12 and the like, an insulating member 1500 is interposed between the first current collector 1300 and the second current collector 1400. The insulating member 1500 is a plate-like member having a first surface 1502 and a second surface 1503 located on the opposite side of the first surface 1502. The insulating member 1500 has third through holes 1501 at positions corresponding to the sealing members 1230 of the multiple electricity storage devices 1200. The first surface 1502 of the insulating member 1500 abuts against the second current collector 1400. Meanwhile, the second surface 1503 abuts against the first current collector 1300 and the first portion 1212a of the enlarged diameter portion 1212. With this configuration, the insulating member 1500, the first current collector 1300, and the second current collector 1400 can be stacked with almost no gaps. Therefore, the electricity storage device 1200 can be held more firmly. Furthermore, the insulating member 1500 abuts or connects with the first current collector 1300, thereby fixing the first current collector 1300 and the insulating member 1500. At this time, the insulating member 1500 and the first current collector 1300 may be fastened with a screw or the like. The third through hole 1501, like the second through hole, plays a role in guiding gas released from the electricity storage device 1200 in the event of an abnormality to a specified duct.

[0077] 20 is a perspective view of an energy storage module according to another embodiment of the present disclosure. The energy storage module 1010A has a structure similar to that of the energy storage module 1010 already described, except that the energy storage module 1010A includes a holder 1600 having a plurality of receiving portions 1601 that receive and position the bottoms 1213 of the plurality of energy storage devices 1200.

[0078] By fixing the expanded diameter portion 1212 located at one end of the energy storage device 1200 with a first collector 1300 and holding or fixing the bottom portion 1213 located at the other end of the energy storage device 1200 with a holder, a storage module 1010A can be constructed in which multiple energy storage devices 1200 are more firmly integrated.

[0079] Since one end side of the multiple electricity storage devices 1200 is fixed by the first current collector 1300, the depth of the storage portion 1601 of the holder 1600 that holds or fixes the bottoms 1213 of the electricity storage devices 1200 may be shallow. For example, when the axial height of the electricity storage devices 1200 (the distance from one end to the other end) is H, the depth of the storage portion of the holder may be 20% or less of H. The bottom surface of the holder 1600 may be flush with the bottom surface of the storage portion as a whole, but may be recessed in areas other than where the recesses (storage portions) that store the electricity storage devices 1200 are formed, in order to reduce weight.

[0080] Third Embodiment A third embodiment of the present disclosure will be described. The power storage module according to this embodiment includes a plurality of power storage devices and a first current collector that holds the plurality of power storage devices. Since the plurality of power storage devices are held and integrated by the first current collector, a holder for holding the plurality of power storage devices is not essential, and the holder can be significantly reduced in size or omitted. This significantly improves the energy density per weight of the power storage module. As a result, for example, it becomes easier to extend the driving range of a vehicle or the like that is equipped with the power storage module. The plurality of power storage devices may be held by the first current collector and fixed to the first current collector.

[0081] However, the power storage module may also include a holder for fixing or holding the multiple power storage devices. For example, the power storage module may further include a holder having multiple housing parts for housing and positioning the bottoms of the multiple power storage devices. This configuration further increases resistance to external forces such as vibration. Also, a heat absorbing agent or a heat dissipating member may be interposed between a pair of adjacent power storage devices.

[0082] The electricity storage device includes a case having an opening, an electrode body including a first electrode and a second electrode housed in the case, and a sealing member that seals the opening. The case has a cylindrical shape, for example. The electrode body is formed, for example, by winding the first electrode and the second electrode with a separator interposed therebetween. When the electricity storage device is a battery, one of the first electrode and the second electrode is a positive electrode, and the other is a negative electrode.

[0083] The case has a cylindrical portion, a reduced diameter portion that is continuous with one end of the cylindrical portion and has an opening end corresponding to the opening, a bottom portion that closes the other end of the cylindrical portion, and an annular groove portion that is recessed inward in the radial direction of the cylindrical portion and is provided between the cylindrical portion and the reduced diameter portion. The case is electrically connected to the first electrode. The maximum outer diameter D3 of the reduced diameter portion is smaller than the outer diameter D4 of the cylindrical portion, and the minimum outer diameter D5 of the groove portion is smaller than the maximum outer diameter D3 of the reduced diameter portion. If the outer diameter of the cylindrical portion is not strictly circular, the maximum outer diameter of the cylindrical portion may be set to D4. The cylindrical portion protrudes from the outer periphery of the reduced diameter portion when viewed from the sealing member side in the axial direction of the case.

[0084] The reduced diameter portion compresses the sealing material. For example, the reduced diameter portion, together with the groove portion, compresses the peripheral portion of the sealing material (hereinafter also referred to as "peripheral portion X") in the axial direction of the case to form a crimped sealing structure.

[0085] The reduced diameter portion may be bent to form a first portion disposed on the outer surface of the peripheral portion X of the sealing member and a second portion disposed on the side surface of the peripheral portion X. In this case, the first portion and the groove compress the sealing member (particularly the peripheral portion X) in the direction in which the outer surface and the inner surface face each other. In other words, the side surface of the peripheral portion X is a surface that connects the outer surface and the inner surface of the sealing member.

[0086] The first current collector has a plurality of first through holes that accommodate and position each of the plurality of power storage devices. That is, the arrangement of the plurality of power storage devices is determined by the arrangement of the first through holes. In this case, the configuration of the power storage module or the number of power storage devices connected in parallel can be easily changed simply by changing the arrangement (layout) of the first through holes in the first current collector. The first current collector is electrically connected to at least one of the groove portion and the reduced diameter portion. As a result, the first current collector is electrically connected to the case and further to the first electrode. The first current collector is, for example, a plate having electrical conductivity.

[0087] Here, the first current collector is arranged so as to overlap the surface of the cylindrical portion on the inner surface of the groove. For example, a peripheral portion (hereinafter also referred to as "peripheral portion Y") surrounding the first through hole of the first current collector is arranged so as to overlap the surface of the cylindrical portion on the inner surface of the groove. Here, the surface of the cylindrical portion on the inner surface of the groove means a surface extending from a place of minimum diameter (deepest place of the groove) to the cylindrical portion on the inner surface of the groove. With this configuration, it is possible to abut against the first current collector when the case is inserted into the first through hole. This abutment can suppress misalignment between the electricity storage device and the first current collector. In addition, the first current collector does not need to overlap the surface of the inner surface of the groove on the narrowed diameter portion side. Here, the surface of the inner surface of the groove on the narrowed diameter portion side means a surface extending from a place of minimum diameter on the inner surface of the groove to the narrowed diameter portion. With this configuration, it is possible to suppress interference of the peripheral portion Y of the first current collector with the narrowed diameter portion when inserting the electricity storage device into the first through hole. The peripheral portion Y may have a holding portion that receives a bent portion at the boundary between the tube portion and the groove portion. When the holding portion receives and supports such a bent portion, it becomes easier to position and fix the electricity storage device.

[0088] The retaining portion may have an inner flange portion that abuts against a bent portion at the boundary between the tube portion and the groove portion. The inner flange portion may be annular, may have a shape with a portion of the ring removed, or may have a shape like a plurality of engagement pieces as a whole. The shape of the inner flange portion is not particularly limited, but may have a shape that rises toward the opening side of the case and extends toward the inside in the radial direction of the first through hole. Note that the retaining portion is a recess or step portion formed in the first current collector so that the surface on the bottom side of the case is recessed, and it can be said that at least a portion of the tube portion is accommodated in this recess or step portion.

[0089] The groove portion has an upper ring portion continuous with the second portion of the reduced diameter portion, a lower ring portion continuous with the cylindrical portion, and a groove bottom portion connecting the upper ring portion and the lower ring portion. When viewed from the axial direction of the case, a portion of the lower ring portion is shielded by the upper ring portion (reduced diameter portion), and the remaining portion protrudes from the upper ring portion toward the radial outside of the case. The inner flange portion extends so as to cover at least a portion of an area of ​​the lower ring portion that is not shielded by the upper ring portion (reduced diameter portion). The inner flange portion suppresses axial movement of the case of the electricity storage device.

[0090] The inner flange may cover an end of the cylindrical portion on the outer surface of the bent portion at the boundary between the cylindrical portion and the groove. This makes it easier to position and fix the electric storage device. For example, the end of the cylindrical portion is restricted by the inner flange, which makes it easier to suppress shaking of the electric storage device.

[0091] The retaining portion may have a first wall portion extending toward the bottom of the case and facing the second portion, and the inner flange portion may be provided continuous with the first wall portion. By providing the first wall portion, the mechanical strength of the first current collector is improved, thereby improving the structural strength of the entire energy storage module.

[0092] The holding portion may have a first wall portion extending toward the bottom of the case and facing the second portion and the tube portion, and a second wall portion continuing from the first wall portion and extending on the opposite side of the first wall portion and facing the tube portion, and the inner flange portion may be provided continuously with the second wall portion. In this case, the tube portion may be in contact with the second wall portion. As a result, a larger portion of the tube portion is restricted by the second wall portion, and the second wall portion may have a function of pressing the tube portion. Such a second wall portion more strictly suppresses the movement of the electric storage device in a direction perpendicular to the axial direction of the case. As a result, the rocking of the case is further suppressed, and the electric storage device is firmly fixed at a predetermined position. In addition, by providing the second wall portion, the mechanical strength of the first current collector is further improved. In addition, even if the second wall portion does not have a function of pressing the tube portion, it can restrict the electric storage device from tilting with respect to the first current collector just by being provided facing the outer circumferential surface of the tube portion.

[0093] The holding portion, the first wall portion, or the connection body between the first wall portion and the second wall portion may be, for example, a ring-shaped wall portion surrounding the reduced diameter portion and / or the cylindrical portion. Also, it may be a tongue-shaped portion intermittently formed in the circumferential direction of the reduced diameter portion, or a shape in which a part of the ring-shaped wall portion is cut out. Also, the holding portion may be formed by connecting a separate member to the periphery of the first through hole.

[0094] The multiple electricity storage devices may be held in any manner relative to the first current collector, but when a first wall portion is provided, it is possible to make the first portion of the reduced diameter portion and the main surface of the first current collector flush with each other by controlling the height of the first wall portion. Such a structure improves the storability of the insulating member and the second current collector described below. As a result, the compactness of the entire electricity storage module is increased and the structural strength is improved. However, it is not necessary for the outer surface of the first portion and the outer surface of the first current collector to be at exactly the same height in the axial direction of the case.

[0095] The electric storage device may be more firmly fixed to the first current collector by joining the peripheral portion Y of the first current collector to the case. For example, the bent portion at the boundary between the tube portion and the groove portion and the inner flange portion may be welded. This makes it possible to more firmly fix the electric storage device to the first current collector. When the inner flange portion is provided around the entire circumference of the peripheral portion Y, the bent portion at the boundary between the tube portion and the groove portion and the inner flange portion may be welded around the entire circumference of the bent portion or at intervals in the circumferential direction. By welding around the entire circumference, it is possible to improve the unity between the electric storage device and the first current collector. In addition, it is possible to reduce the connection resistance between the case and the first current collector. Furthermore, by welding at intervals, even if a force that causes a minute displacement acts on the electric storage device or the first current collector, the stress at the joint between the inner flange portion and the bent portion is smaller than when welding is performed around the entire circumference of the peripheral portion Y. This makes it possible to reduce the distortion of the entire electric storage module.

[0096] The multiple power storage devices may be arranged side by side such that the axial directions of the electrode bodies are oriented in the same direction and the openings of the cases are located on the same side. More specifically, the multiple power storage devices may be arranged such that the axial directions of the electrode bodies are generally parallel, one and the other end faces of the electrode bodies are located in generally the same plane, and the side faces of the cylindrical parts of the cases are adjacent to each other.

[0097] The energy storage module may further include a second current collector electrically connected to the second electrode of the electrode assembly. The first current collector and the second current collector may have substantially corresponding planar external shapes, and one of the first current collector and the second current collector may be larger than the other current collector.

[0098] An insulating member may be interposed between the first current collector and the second current collector. In this case, a first surface of the insulating member may be in contact with the second current collector, and a second surface located on the opposite side of the first surface may be in contact with the first current collector. By arranging the first and second current collectors with the insulating member sandwiched therebetween, both the first and second current collectors can be arranged on one end side of the electricity storage device (specifically, the side having the sealing member), and therefore it becomes unnecessary to provide a current collecting structure on the other end side of the electricity storage device (specifically, the bottom side). Therefore, it is possible to reduce the space required for the electricity storage device in the axial direction, which is advantageous for improving the volumetric energy density of the electricity storage module. In addition, it is possible to easily prevent the positions of the first and second current collectors from shifting. Furthermore, by using a material with high rigidity for the insulating member, the mechanical strength of the current collecting member including the first and second current collectors is increased.

[0099] The structure of the sealing member is not particularly limited, but may include, for example, a conductive sealing plate and a gasket that provides insulation between the sealing plate and the reduced diameter portion. When a sealing member having such a structure is used, the sealing plate and the second electrode of the electrode body can be electrically connected.

[0100] The second current collector may have a second through hole in a region facing the sealing plate, and may have a tongue-shaped lead extending inward from a peripheral portion surrounding the second through hole of the second current collector into the second through hole. The second current collector is electrically connected to the sealing plate by electrically connecting the tongue-shaped lead to the sealing plate.

[0101] The type of the power storage device is not particularly limited, and examples thereof include a primary battery, a secondary battery, a lithium ion capacitor, an electric double layer capacitor, a solid electrolytic capacitor, etc. Among them, a non-aqueous electrolyte secondary battery (including an all-solid-state battery) such as a lithium ion secondary battery having a high energy density can be preferably used.

[0102] Hereinafter, a power storage module according to an embodiment of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following.

[0103] Fig. 21 is a perspective view of an electric storage module according to an embodiment of the present disclosure. Fig. 22 is an exploded perspective view of the electric storage module of Fig. 21. The electric storage module 2010 includes a plurality of electric storage devices 2200, each of which is cylindrical, a first current collector 2300 that holds the plurality of electric storage devices 2200, and a second current collector 2400. The first current collector 2300 also serves to integrate the plurality of electric storage devices 2200. The plurality of electric storage devices 2200 are arranged side by side such that the axial directions of the respective electrode bodies face in the same direction and the openings of the cases are disposed on the same side.

[0104] FIG. 23 is a plan view (a), a side view (b), and a bottom view (c) of the first current collector. FIG. 24 is a perspective view showing a plurality of power storage devices (a) before being held by the first current collector, and a plurality of power storage devices (b) held by the first current collector. The first current collector 2300 has a plurality of first through holes 2301 through which the plurality of power storage devices 2200 are inserted and positioned. The arrangement of the plurality of power storage devices 2200 is easily determined by the arrangement of the first through holes 2301. Each power storage device 2200 is inserted into the first through hole 2301 from the bottom side and positioned. The illustrated example is an example in which 12 power storage devices are arranged in a honeycomb shape (staggered) so as to be close to closest packing, but the arrangement, number, and the like of the power storage devices are not particularly limited. The first current collector 2300 can be obtained by processing a metal plate by punching, pressing, or the like.

[0105] Fig. 25 is a perspective view of the second current collector, and Fig. 26 is a plan view (a), a side view (b), and a bottom view (c) of the second current collector. The second current collector 2400 is a plate-like member having second through-holes 2401 at positions corresponding to the positions of the multiple electricity storage devices 2200. The second current collector 2400 can be obtained by processing a metal plate by punching, pressing, or the like.

[0106] The second current collector 2400 is disposed so as to overlap the first current collector 2300. Specifically, both the first current collector 2300 and the second current collector 2400 are disposed on the side of the sealing member 2230 of the electricity storage device 2200. Therefore, there is no need to provide a current collection structure on the bottom 2213 side of the electricity storage device 2200, and therefore the space required by the electricity storage device 2200 in the axial direction can be reduced.

[0107] 27 is a cross-sectional view showing the structure of an example of an electricity storage device 2200. The electricity storage device 2200 includes a cylindrical case 2210 having an opening 2201, an electrode body 2220 including a first electrode and a second electrode housed in the case 2210, and a sealing member 2230 that seals the opening 2201.

[0108] The case 2210 has a cylindrical tube portion 2211, a reduced diameter portion 2212 that is continuous with one end of the tube portion 2211 and has an open end 2212T that corresponds to the opening 2201, a bottom portion 2213 that closes the other end of the tube portion 2211, and an annular groove portion 2214 that is recessed radially inward of the tube portion 2211 and is provided between the tube portion 2211 and the reduced diameter portion 2212. The reduced diameter portion 2212 is an annular portion that has a maximum outer diameter D3 that is smaller than an outer diameter D4 of the cylindrical tube portion 2211.

[0109] The reduced diameter portion 2212 is bent to form a first portion 2212a disposed on the outer surface of the peripheral portion X of the sealing member 2230 (the gasket 2232 disposed on the peripheral portion X), and a second portion 2212b disposed on the side surface of the peripheral portion X of the sealing member 2230. The first portion 2212a, together with the groove portion 2214, compresses the gasket 2232 disposed on the peripheral portion X of the sealing member 2230 in the direction in which the outer surface and inner surface of the sealing member face each other. This maintains the airtightness of the inside of the case 2210.

[0110] The groove portion 2214 has an upper ring portion 2214a continuing with the second portion 2212b of the reduced diameter portion 2212, a lower ring portion 2214b continuing with the cylindrical portion 2211, and a groove bottom portion 2214c connecting the upper ring portion 2214a and the lower ring portion 2214b. When viewed in the axial direction of the case 2210, a part of the lower ring portion 2214b protrudes from the outer periphery of the reduced diameter portion 2212 together with the cylindrical portion 2211.

[0111] The sealing member 2230 has a sealing plate 2231 and a gasket 2232 that insulates between the sealing plate 2231 and the reduced diameter portion 2212. The sealing plate 2231 may include a valve body having a circular outer shape, a metal plate that is disposed on the inner side of the battery from the valve body and connected to the center of the valve body, and an annular insulating member that is interposed between the outer periphery of the valve body and the metal plate. The valve body has an inclined region in which the thickness continuously decreases along the radial direction from the inner periphery side to the outer periphery side. At least a part of the metal plate is formed to be thin-walled and may have an air hole (not shown). When the internal pressure of the battery increases abnormally, the valve body receives gas pressure from the air hole and pulls the metal plate connected to the center of the valve body outward, and when the internal pressure of the battery reaches a predetermined value, the thin-walled part of the metal plate breaks and the current path between the valve body and the metal plate is interrupted.

[0112] An internal insulating plate 2240 is disposed between the electrode body 2220 and the sealing member 2230, and the internal insulating plate 2240 prevents contact between the electrode body 2220 and the sealing member 2230. A predetermined lead hole 2241 is provided in the internal insulating plate 2240. A lead 2222 extending from a second electrode constituting the electrode body 2220 passes through the lead hole 2241 and is electrically connected to the inner surface of the sealing plate 2231. Thus, the sealing plate 2231 has the same polarity as the second electrode. On the other hand, a first electrode constituting the electrode body 2220 is electrically connected to the case 2210. Thus, the case 2210 has the same polarity as the first electrode.

[0113] Fig. 28 is a cross-sectional view of a main part of electricity storage device 2200 held by first current collector 2300. Fig. 29A is an enlarged view of a main part of Fig. 28, showing a welding location between peripheral part 2302 (peripheral part Y) surrounding first through-hole 2301 of first current collector 2300 and a bent part at the boundary between tube part 2211 and groove part 2214 of case 2210 (hereinafter also referred to as bent part C of the case).

[0114] The holding portion 2310 of the peripheral portion Y has an inner flange portion 2311 that abuts against the bent portion C at the boundary between the tube portion 2211 and the groove portion 2214. The inner flange portion 2311 is shaped like a ring with a part of it removed, and is shaped like four engagement pieces. The inner flange portion 2311 rises from the main surface of the first current collector 2300 toward the opening side of the case and extends toward the inside in the radial direction of the first through hole 2301. However, when viewed from the axial direction of the case 2210, the inner flange portion 2311 covers only the area that is not shielded by the upper ring portion 2214a of the lower ring portion 2214b. The inner flange portion 2311 also covers the end of the outer surface of the bent portion C on the boundary side of the tube portion 2211.

[0115] The second through hole 2401 of the second current collector 2400 is located directly above the sealing member 2230 of each of the multiple electricity storage devices 2200. The second through hole 2401 plays a role of guiding gas released from the electricity storage device 2200 in the event of an abnormality, for example, to a predetermined duct. A tongue-shaped lead 2410 is led out from the periphery of the second through hole 2401 toward the inside of the second through hole. The tongue-shaped lead 2410 is electrically connected to the outer surface of the sealing plate 2231. Therefore, the second current collector 2400 has the same polarity as the sealing plate 2231 and the second electrode.

[0116] FIG. 29A shows an example of a welding point WP when the inner flange portion 2311 and the bent portion C of the case are welded by a laser from the side of the reduced diameter portion 2212. When the reduced diameter portion 2212 and the first through hole 2301 are viewed from the axial direction of the case 2210, the diameter of the reduced diameter portion 2212 is smaller than the inner diameter of the holding portion 2310. On the other hand, the outer diameter of the tubular portion 2211 is larger than the inner diameter of the holding portion 2310. By passing the reduced diameter portion 2212 through the first through hole 2301 of the first current collector 2300, the inner flange portion 2311 of the holding portion 2310 provided on the peripheral portion Y is placed so as to overlap with the bent portion C of the case. At least a part of the portion where the holding portion 2310 and the bent portion C of the case are overlapped and directly contacted can be joined by welding. As a result, the multiple electricity storage devices 2200 are firmly fixed and integrated by the first current collector 2300. The welding method is not particularly limited, but for example, laser welding is convenient.

[0117] It is sufficient that the inner flange portion 2311 and the bent portion C of the case are at least partially welded. Although welding may be performed at a plurality of welding points along the portion where the inner flange portion 2311 and the bent portion C overlap and directly contact each other, welding may be performed around the entire circumference of the portion where the inner flange portion 2311 and the bent portion C overlap and directly contact each other. The welding points WP are not limited to the above positions.

[0118] 29B is a diagram showing a modified example of the embodiment of FIG. 29A. The main surface of the first current collector 2300 is designed to be flush with the first portion 2212a of the reduced diameter portion 2212. That is, the holding portion 2310 of the first current collector 2300 has a first wall portion 2312 that extends toward the bottom portion 2213 of the case 2210 and faces the second portion 2212b of the reduced diameter portion 2212 and the cylindrical portion 2211, and a second wall portion 2313 that is continuous with the first wall portion 2312, extends to the opposite side of the first wall portion 2312, and faces the cylindrical portion 2211, and the inner flange portion 2311 is provided continuous with the second wall portion 2313. In addition, the cylindrical portion 2211 contacts the second wall portion 2313, and most of the cylindrical portion 2211 is restricted by the second wall portion 2313. Therefore, movement of the power storage device 2200 in a direction perpendicular to the axial direction of the case 2210 is strictly suppressed. Moreover, the first wall portion 2312 and the second wall portion 2313 increase the mechanical strength of the first current collector 2300. Moreover, it is possible to suppress the configuration of the insulating member 2500 and the second current collector 2400 described later from becoming complicated. Note that the portion connecting the first wall portion 2312 and the second wall portion 2313 may be flat as shown in FIG. 9B, or may be curved and formed into a U-shape including the first wall portion 2312 and the second wall portion 2313.

[0119] As shown in FIG. 22 and the like, an insulating member 2500 is interposed between the first current collector 2300 and the second current collector 2400. The insulating member 2500 is a plate-like member having a first surface 2502 and a second surface 2503 located on the opposite side of the first surface 2502. The insulating member 2500 has third through holes 2501 at positions corresponding to the sealing members 2230 of the multiple electricity storage devices 2200. The first surface 2502 of the insulating member 2500 abuts against the second current collector 2400. Meanwhile, the second surface 2503 abuts against a region of the first current collector 2300 excluding the holding portion 2310 and the first portion 2212a of the reduced diameter portion 2212. With this configuration, the insulating member 2500, the first current collector 2300, and the second current collector 2400 can be stacked with almost no gaps. Therefore, the compactness of the entire power storage module is improved and the power storage device 2200 can be held more firmly. In addition, the insulating member 2500 abuts or connects with the first current collector 2300, thereby fixing the first current collector 2300 and the insulating member 2500. At this time, the insulating member 2500 and the first current collector 2300 may be fastened with a screw or the like. The third through hole 2501, like the second through hole, plays a role of guiding gas released from the power storage device 2200 in the event of an abnormality to a predetermined duct. Note that, although a gap is formed between the insulating member 2500 and the first current collector 2300 in FIG. 9A, the insulating member 2500 and the first current collector 2300 may be laminated to fill the gap.

[0120] 30 is a perspective view of an electric storage module according to another embodiment of the present disclosure. The electric storage module 2010A has a similar structure to the electric storage module 2010 already described, except that the electric storage module 2010A includes a holder 2600 having a plurality of receiving portions 2601 that receive and position the bottoms 2213 of the plurality of electric storage devices 2200.

[0121] By fixing the bent portion C of the case 2210 located at one end of the power storage device 2200 with a first collector 2300 and holding or fixing the bottom 2213 located at the other end of the power storage device 2200 with a holder, a power storage module 2010A can be constructed in which multiple power storage devices 2200 are more firmly integrated.

[0122] Since one end side of the multiple power storage devices 2200 is fixed by the first current collector 2300, the depth of the storage portion 2601 of the holder 2600 that holds or fixes the bottom portion 2213 of the power storage device 2200 may be shallow. For example, when the axial height of the power storage device 2200 (the distance from one end to the other end) is H, the depth of the storage portion of the holder may be 20% or less of H. The bottom surface of the holder 2600 may be flush with the bottom surface of the storage portion as a whole, but may be recessed in areas other than where the recesses (storage portions) that store the power storage devices 2200 are formed, in order to reduce weight.

[0123] Although a cylindrical electricity storage device has been described above as an example, the present disclosure can also be used for electricity storage devices of various shapes (for example, rectangular).

[0124] Although the present invention has been described with respect to the presently preferred embodiments, such disclosure should not be interpreted as limiting. Various variations and modifications will no doubt become apparent to those skilled in the art to which the present invention pertains upon reading the above disclosure. Accordingly, the appended claims should be interpreted to cover all variations and modifications without departing from the true spirit and scope of the present invention. [Industrial Applicability]

[0125] The power storage module according to the present disclosure can be used in various power storage devices, and is particularly suitable for use as a power source for vehicles such as hybrid automobiles and electric automobiles. [Explanation of symbols]

[0126] 10, 10A: Energy storage module 200: Energy storage device 201:Aperture 210: Case 211:Cylinder part 212: Flange part 213: Bottom 220: Electrode body 222: Lead 230: Sealing member 231: Sealing board 232: Cap (outer ring) 233: Gasket 240: Internal insulation plate 241: Lead hole 300: First current collector 301: First through hole 302: Periphery of the first through hole 303: Wall 400: Second current collector 401: Second through hole 410: Tongue-shaped reed 500: Insulating materials 501: Third through hole 502: First Side 503: The Second Side 600: Holder 601: Storage unit 1010, 1010A: Energy storage module 1200: Energy storage device 1201:Aperture 1210: Case 1211:Cylinder part 1212: Expanded diameter part 1212a: Part 1 1212b:Second part 1212T: Open end 1213: Bottom 1214: Annular groove 1220: Electrode body 1222: Lead 1230: Sealing member 1231: Sealing board 1232: Gasket 1240: Internal insulation plate 1241: Lead hole 1300: First current collector 1301: First through hole 1302: Periphery 1310: Holding part 1311:First wall part 1312: Inner flange 1313:Second wall part 1400: Second current collector 1401: Second through hole 1410: Tongue-shaped reed 1500: Insulating materials 1501: 3rd through hole 1502: First Side 1503: The second side 1600: Holder 1601: Storage unit 2010, 2010A: Energy storage module 2200:Electricity storage device 2201:Aperture 2210: Case 2211:Cylinder part 2212: Reduced diameter part 2212a: Part 1 2212b:Second part 2212T: Open end 2213: Bottom 2214: Groove 2214a: Upper ring part 2214b: Lower ring part 2214c: Groove bottom 2220: Electrode body 2222: Lead 2230: Sealing material 2231: Sealing board 2232: Gasket 2240: Internal insulation plate 2241: Lead hole 2300: First current collector 2301: First through hole 2302: Periphery of the first through hole 2310: Holding part 2311: Inner flange 2312: 1st wall part 2313:Second wall part 2400: Second current collector 2401: Second through hole 2410: Tongue-shaped reed 2500: Insulating materials 2501: 3rd through hole 2502: First Side 2503: Second Side 2600: Holder 2601: Containment unit

Claims

1. A plurality of power storage devices; a first current collector that holds the plurality of electricity storage devices; the power storage device includes a case having an opening, an electrode body including a first electrode and a second electrode housed in the case, and a sealing member that seals the opening; the case has a cylindrical portion having the opening at one end and a bottom portion closing the other end of the cylindrical portion, the case is electrically connected to the first electrode, the first current collector has a plurality of first through holes that accommodate and position the plurality of power storage devices, and a peripheral portion of the first through hole is electrically connected to the case; The case further includes a flange portion provided at one end of the cylindrical portion and extending in a direction away from the opening, The first current collector has a peripheral portion of the first through hole electrically connected to the flange portion. Energy storage module.

2. The peripheral portion of the first through hole and the flange portion are at least partially joined by welding. The energy storage module according to claim 1 .

3. the peripheral portion of the first through hole extends toward the bottom of the case of the power storage device and has a wall portion that abuts against the cylindrical portion of the case; The energy storage module according to claim 1 or 2.

4. Further comprising a second current collector electrically connected to the second electrode of the electrode assembly, The flange portion is disposed between the first current collector and the second current collector. The storage module according to any one of claims 1 to 3.

5. an insulating member is interposed between the first current collector and the second current collector; the insulating member abuts against the second current collector at a first surface and abuts against the flange portion or the sealing member at a second surface located opposite to the first surface; The power storage module according to claim 4 .

6. The sealing member is A sealing plate; an annular cap surrounding the sealing plate; a gasket for insulating the sealing plate from the cap; the cap and the flange portion are electrically connected, and the sealing plate and the second electrode of the electrode body are electrically connected. The energy storage module according to claim 4 or 5.

7. the second current collector has a second through hole in a region facing the sealing plate, and has a tongue-shaped lead extending inward from a peripheral portion of the second through hole into the second through hole, the tongue-shaped lead is electrically connected to the sealing plate; The power storage module according to claim 6 .

8. A plurality of power storage devices; a first current collector that holds the plurality of electricity storage devices; the power storage device includes a case having an opening, an electrode body including a first electrode and a second electrode housed in the case, and a sealing member that seals the opening; the case has a cylindrical portion having the opening at one end and a bottom portion closing the other end of the cylindrical portion, the case is electrically connected to the first electrode, the first current collector has a plurality of first through holes that accommodate and position the plurality of power storage devices, and a peripheral portion of the first through hole is electrically connected to the case; The case further includes an expanded diameter portion that is continuous with one end of the cylindrical portion and has an opening end that corresponds to the opening, and an annular groove portion that is recessed radially inwardly of the cylindrical portion and is provided between the cylindrical portion and the expanded diameter portion, The maximum outer diameter D1 of the expanded diameter portion is larger than the outer diameter D2 of the cylindrical portion, the enlarged diameter portion compresses the sealing member, the first current collector is electrically connected to at least one of the enlarged diameter portion and the groove portion, The peripheral portion surrounding the first through hole of the first current collector overlaps with a surface of the inner surface of the groove portion on the side of the expanded diameter portion. Energy storage module.

9. the peripheral portion surrounding the first through hole of the first current collector has a holding portion that receives an inner surface of the groove portion; The power storage module according to claim 8 .

10. the enlarged diameter portion is bent to form a first portion disposed on an outer surface of a peripheral portion of the sealing member and a second portion disposed on a side surface of the peripheral portion, the first portion and the groove portion compress the peripheral portion of the sealing member in a direction toward an outer surface and an inner surface of the sealing member; The power storage module according to claim 9 .

11. The holding portion of the first current collector has a first wall portion extending toward the bottom portion of the case and facing the second portion, and an inner flange portion continuing to the first wall portion and supporting a surface of the groove portion on the side of the enlarged diameter portion. The power storage module according to claim 10.

12. the holding portion of the first current collector further includes a second wall portion that is continuous with the inner flange portion, extends toward the bottom portion of the case, and faces the cylindrical portion; The energy storage module according to claim 11.

13. The first portion and a surface of the first current collector are flush with each other. The storage module according to any one of claims 10 to 12.

14. a bent portion at a boundary between the first portion and the second portion and the peripheral portion surrounding the first through hole of the first current collector are welded to each other around the entire periphery of the bent portion. The energy storage module according to claim 13.

15. a bent portion at a boundary between the first portion and the second portion and the peripheral portion surrounding the first through hole of the first current collector are welded at a plurality of welding points along a periphery of the bent portion; The energy storage module according to claim 13.

16. The sealing member is A sealing plate having electrical conductivity; a gasket for insulating the sealing plate from the enlarged diameter portion, The sealing plate and the second electrode of the electrode body are electrically connected to each other. The storage module according to any one of claims 8 to 15.

17. Further comprising a second current collector electrically connected to the second electrode of the electrode assembly, an insulating member is interposed between the first current collector and the second current collector, the insulating member abuts against the second current collector at a first surface and abuts against the first current collector at a second surface located opposite to the first surface; The energy storage module according to claim 16.

18. the second current collector has a second through hole in a region facing the sealing plate, and has a tongue-shaped lead extending inward from a peripheral portion of the second through hole into the second through hole, the tongue-shaped lead is electrically connected to the sealing plate; The energy storage module according to claim 17.

19. a maximum outer diameter of the cylindrical portion is greater than a minimum outer diameter of the groove portion; The energy storage module according to any one of claims 8 to 18, wherein the peripheral portion surrounding the first through hole of the first current collector does not overlap with a surface on the cylindrical portion side on an inner surface of the groove portion.

20. A plurality of power storage devices; a first current collector that holds the plurality of electricity storage devices; the power storage device includes a case having an opening, an electrode body including a first electrode and a second electrode housed in the case, and a sealing member that seals the opening; the case has a cylindrical portion having the opening at one end and a bottom portion closing the other end of the cylindrical portion, the case is electrically connected to the first electrode, the first current collector has a plurality of first through holes that accommodate and position the plurality of power storage devices, and a peripheral portion of the first through hole is electrically connected to the case; the case further includes a reduced diameter portion that is continuous with one end of the cylindrical portion and has an open end that corresponds to the opening, and an annular groove portion that is recessed radially inwardly of the cylindrical portion and is provided between the cylindrical portion and the reduced diameter portion, The maximum outer diameter D3 of the reduced diameter portion is smaller than the outer diameter D4 of the cylindrical portion, The minimum outer diameter D5 of the groove portion is smaller than the maximum outer diameter D3 of the reduced diameter portion, the reduced diameter portion compresses the sealing member, the first current collector is electrically connected to at least one of the groove portion and the reduced diameter portion, The first current collector overlaps with a surface of the groove portion on the cylindrical portion side at an inner surface of the groove portion. Energy storage module.

21. the reduced diameter portion is bent to form a first portion disposed on an outer surface of a peripheral portion of the sealing member and a second portion disposed on a side surface of the peripheral portion, the first portion and the groove portion compress the peripheral portion of the sealing member in a direction toward an outer surface and an inner surface of the sealing member; The energy storage module according to claim 20.

22. the peripheral portion surrounding the first through hole of the first current collector has a holding portion that receives a bent portion of the boundary between the cylindrical portion and the groove portion; The energy storage module according to claim 21.

23. The holding portion has an inner flange portion that abuts against the bent portion. The energy storage module according to claim 22.

24. the holding portion has a first wall portion extending toward the bottom portion of the case and facing the second portion, The inner flange portion is continuous with the first wall portion. The energy storage module according to claim 23.

25. the holding portion includes a first wall portion extending toward the bottom of the case and facing the second portion and the cylindrical portion; a second wall portion that is continuous with the first wall portion, extends on an opposite side to the first wall portion, and faces the cylindrical portion, The inner flange portion is continuous with the second wall portion. The energy storage module according to claim 23.

26. The bent portion and the inner flange portion are welded to each other. The storage module according to any one of claims 23 to 25.

27. The first portion and a surface of the first current collector are flush with each other. The storage module according to any one of claims 21 to 26.

28. The sealing member is A sealing plate having electrical conductivity; a gasket for insulating the sealing plate from the reduced diameter portion, The sealing plate and the second electrode of the electrode body are electrically connected to each other. The storage module according to any one of claims 20 to 27.

29. Further comprising a second current collector electrically connected to the second electrode of the electrode assembly, an insulating member is interposed between the first current collector and the second current collector, the insulating member abuts against the second current collector at a first surface and abuts against the first current collector at a second surface located opposite to the first surface; The energy storage module according to claim 28.

30. the second current collector has a second through hole in a region facing the sealing plate, and has a tongue-shaped lead extending inward from a peripheral portion of the second through hole into the second through hole, the tongue-shaped lead is electrically connected to the sealing plate; The energy storage module according to claim 29.

31. the first current collector does not overlap a surface of the inner surface of the groove portion on the side of the reduced diameter portion; The storage module according to any one of claims 20 to 30.

32. a holder having a plurality of receiving portions for receiving and positioning the bottom portions of the plurality of power storage devices; The storage module according to any one of claims 1 to 31.

Images