Power storage device and power storage unit

Abstract

The invention relates to a power storage device and a power storage unit. According to the present disclosure, it is possible to improve the loading efficiency of the power storage device in the electrical product. A power storage device disclosed herein includes an electrode body, a case, an insulating material, and a current collector. The current collector is disposed so as to close the terminal mounting hole with an insulating material interposed therebetween, and is joined to the insulating material, the current collector having a terminal part that is exposed to the outside of the housing through the terminal mounting hole and that can be electrically connected to an external member. Moreover, the terminal part is located at a position closer to the inner side than the outer surface of the housing, and the terminal mounting hole is sealed by the insulating material and the current collector. According to this configuration, the formation of a conductive path to the outside of the case and the sealing of the inside of the case can be achieved even if an electrode terminal protruding to the outside of the case is not provided, and thus the loading efficiency in an electrical product can be improved.

Description

Technical Field

[0001] The present disclosure relates to an electric storage device and an electric storage unit. Background Art

[0002] Power storage devices such as lithium-ion secondary batteries are used as power sources for various electrical products. An example of such a power storage device (sealed battery) is disclosed in Patent Document 1 (Japanese Patent Publication No. 2021-86813). The power storage device described in Patent Document 1 includes: a shell member having a terminal mounting hole; an electrode body, the electrode body being accommodated inside the shell member; a collector terminal; and an insulating material. In addition, the collector terminal includes: an electrode body connection portion, the electrode body connection portion is arranged inside the shell member and connected to the electrode body; an external connection portion, the external connection portion is arranged outside the shell member; and a shaft portion, the shaft portion is located between the electrode body connection portion and the external connection portion and is inserted through the terminal mounting hole. In addition, at least one of the electrode body connection portion and the external connection portion is configured to be sized to be inserted through the terminal mounting hole. In addition, the insulating material is integrally formed with the shell member and the collector terminal in a manner that fills the terminal mounting hole and the collector terminal. The power storage device described in Patent Document 1 can more easily take out the electrode to the outside.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-86813 Summary of the invention

[0006] Problems to be solved by the invention

[0007] As described in Patent Document 1, in a general power storage device, a part of the collector terminal (external connection portion) protrudes outside the housing. On the other hand, the loading space of the power storage device in the electrical product is limited. Therefore, the external connection portion protruding outside the housing becomes a major factor that reduces the loading efficiency of the power storage device in the electrical product.

[0008] Means for solving problems

[0009] In order to solve the above-mentioned problems, an electric storage device having the following structure is provided.

[0010] The power storage device disclosed herein comprises: an electrode body; a shell, the shell accommodating the electrode body and having a terminal mounting hole; an insulating material, the insulating material continuously covers the peripheral wall of the terminal mounting hole and the peripheral edge of the terminal mounting hole in the circumferential direction, and is bonded to the peripheral edge of the terminal mounting hole; and a collector, the collector is electrically connected to the electrode body inside the shell. In addition, the collector is arranged in a manner to block the terminal mounting hole via the insulating material and is bonded to the insulating material. In addition, the collector has a terminal portion, the terminal portion is exposed to the outside of the shell through the terminal mounting hole, and can be electrically connected to an external member. In addition, in the power storage device disclosed herein, the terminal portion is located at a position closer to the inside than the outer surface of the shell, and the terminal mounting hole is sealed by the insulating material and the collector.

[0011] In the power storage device of the above structure, a part of the collector (terminal portion) housed in the shell is exposed to the outside of the shell through the terminal mounting hole. The upper surface of the terminal portion is located at a position closer to the inside than the outer surface of the shell. In addition, the terminal mounting hole of the shell is sealed by an insulating material and the terminal portion. According to this structure, even if an electrode terminal (external connecting member) protruding to the outside of the shell is not provided, it is possible to form a conductive path to the outside of the shell and to seal the inside of the shell. Therefore, the power storage device disclosed herein can contribute to improving the loading efficiency in electrical products. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a perspective view schematically showing the power storage device according to the first embodiment.

[0013] Figure 2 This is an enlarged cross-sectional view schematically showing the structure of the vicinity of the terminal mounting hole of the electric storage device according to the first embodiment.

[0014] Figure 3 It is a description of the production Figure 2 An enlarged cross-sectional view of the step of insulating material in FIG.

[0015] Figure 4 It is a perspective view schematically showing the power storage unit according to the first embodiment.

[0016] Figure 5 It is schematically shown Figure 4 An enlarged cross-sectional view of the connection structure of the power storage unit shown.

[0017] Figure 6 It is an enlarged cross-sectional view schematically showing the structure of the vicinity of the terminal mounting hole of the electric storage device according to the second embodiment.

[0018] Figure 7 It is an enlarged cross-sectional view schematically showing the structure of the vicinity of the terminal mounting hole of the electric storage device according to the third embodiment.

[0019] Figure 8 It is an enlarged cross-sectional view schematically showing the structure of the vicinity of the terminal mounting hole of the electric storage device according to the fourth embodiment.

[0020] Fig. 9 This is a cross-sectional view showing an example of a bus bar that can be used in the fourth embodiment.

[0021] Description of Reference Numerals

[0022] 1. Power storage equipment

[0023] 10 Electrode body

[0024] 12 Connect the tabs

[0025] 20 Shell

[0026] 22 Shell body

[0027] 24 Sealing plate

[0028] 25 Terminal mounting holes

[0029] 30 Insulation Materials

[0030] 32 External insulation

[0031] 34 Internal insulation

[0032] 36 Insulation part in hole

[0033] 38 Opening

[0034] 40 Current Collector

[0035] 42 Joint

[0036] 44 Terminal

[0037] 46 Internal current collecting part

[0038] 100 Storage Unit

[0039] 110 Busbar

[0040] 112 Connection protrusion

[0041] 120 End plate

[0042] 130 Restraining beam parts

[0043] 150 Buffering member DETAILED DESCRIPTION

[0044] Hereinafter, an implementation mode of the technology disclosed herein will be described with reference to the accompanying drawings. In addition, matters required for the implementation of the technology disclosed herein (for example, the detailed structure of the electrode body, etc.) other than matters specifically mentioned in this specification can be grasped as design matters for those skilled in the art based on the prior art in this field. The technology disclosed herein can be implemented based on the contents disclosed in this specification and the technical common sense in this field. In addition, in this specification, the expression "A to B" indicating a range includes the meaning of greater than A and less than B, and includes the meaning of "greater than A" and "less than B".

[0045] It should be noted that the term "electrical storage device" in this specification is a concept that includes a device that generates a charge-discharge reaction by the movement of charge carriers between a pair of electrodes (a positive electrode and a negative electrode). That is, the electrical storage device in the technology disclosed herein includes capacitors such as lithium ion capacitors and electric double layer capacitors in addition to secondary batteries such as lithium ion secondary batteries, nickel metal hydride batteries, and nickel cadmium batteries.

[0046] <First Embodiment>

[0047] 1. Structure of power storage equipment

[0048] Below, refer to Figure 1~Figure 3 , an embodiment of the power storage device disclosed herein is described. Figure 1 It is a perspective view schematically showing the power storage device according to the first embodiment. Figure 2 This is an enlarged cross-sectional view schematically showing the structure of the vicinity of the terminal mounting hole of the electric storage device according to the first embodiment. Figure 3 It is a description of the production Figure 2 An enlarged cross-sectional view of the step of insulating material in the drawing. It should be noted that the reference numerals L, R, F, Rr, U, and D in the drawings represent left, right, front, rear, top, and bottom, respectively. In addition, the reference numerals X, Y, and Z in the drawings represent the width direction, depth direction, and height direction of the power storage device, respectively. However, these directions are merely determined for the convenience of explanation and do not limit the setting method of the power storage device disclosed herein.

[0049] like Figure 1 and Figure 2As shown, the electric storage device 1 of the present embodiment includes: an electrode body 10; a case 20 that accommodates the electrode body 10 and has a terminal mounting hole 25; an insulating material 30 that continuously covers the peripheral wall 25a of the terminal mounting hole 25 and the peripheral edge portions 20a1 and 20b1 of the terminal mounting hole 25 in the circumferential direction and is bonded to the peripheral edge portions 20a1 and 20b1 of the terminal mounting hole 25; and a current collector 40 that is electrically connected to the electrode body 10 inside the case 20. The current collector 40 is arranged so as to block the terminal mounting hole 25 via the insulating material 30 and is bonded to the insulating material 30. In addition, the current collector 40 has a terminal portion 44 that is exposed to the outside of the case 20 through the terminal mounting hole 25 and can be electrically connected to an external member. Furthermore, in the power storage device 1 of the present embodiment, the terminal portion 44 is located at a position inside the outer surface 20a of the housing 20, and the terminal mounting hole 25 is sealed by the insulating material 30 and the current collector 40. According to this structure, even if the electrode terminal (external connection member) protruding outside the housing is not provided, it is possible to form a conductive path to the outside of the housing 20 and to seal the inside of the housing 20. As a result, it is possible to contribute to the improvement of the loading efficiency in the electrical product. The power storage device 1 of the present embodiment is described in detail below.

[0050] (1) Electrode body 10

[0051] The electrode body 10 is a power generation element of the power storage device 1. The power storage device 1 of the present embodiment includes one electrode body 10. However, the number of electrode bodies is not particularly limited and may be multiple. In addition, although detailed illustrations are omitted, the electrode body 10 includes a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate includes a positive electrode core body as a conductive metal foil (aluminum foil, etc.) and a positive electrode active material layer given to the surface of the positive electrode core body. On the other hand, the negative electrode plate includes a negative electrode core body as a conductive metal foil (copper foil, etc.) and a negative electrode active material layer given to the surface of the negative electrode core body. In addition, the separator is an insulating sheet between the positive electrode plate and the negative electrode plate. In addition, the raw materials of each component (positive electrode plate, negative electrode plate, separator, etc.) constituting the electrode body 10 can use materials that can be used in general power storage devices without particular restrictions, and are not limited to the technology disclosed herein, so detailed descriptions are omitted.

[0052] In addition, the specific structure of the electrode body 10 is not particularly limited. For example, the electrode body 10 can be a wound electrode body formed by winding a stack including a positive electrode plate, a negative electrode plate and a separator. In addition, the electrode body 10 can also be a stacked electrode body formed by stacking multiple pieces of each of the positive electrode plate, the negative electrode plate and the separator. However, no matter which structure is adopted, connecting tabs 12 are formed on both side edges of the electrode body 10 in the width direction X. The connecting tab 12 on one side is a positive electrode tab electrically connected to the positive electrode plate. The positive electrode tab is formed, for example, by bundling positive electrode cores that are not coated with a positive electrode active material layer. In addition, the connecting tab 12 on the other side is a negative electrode tab electrically connected to the negative electrode plate. The negative electrode tab is formed by bundling negative electrode cores that are not coated with a negative electrode active material layer. These connecting tabs 12 are electrically connected to the collector 40, and the details will be described later.

[0053] (2) Housing 20

[0054] The housing 20 is a container that contains the electrode body 10 and has a terminal mounting hole 25. Specifically, the housing 20 is a flat box-shaped container having an internal space. The electrode body 10 is contained in the internal space of the housing 20. In addition, although not shown in the figure, an electrolyte is also contained in the housing 20. The electrolyte can be used without particular limitation and can be used in general power storage devices, and the technology disclosed herein is not limited, so a detailed description is omitted.

[0055] In addition, the housing 20 in this embodiment includes a housing body 22 and a sealing plate 24. The housing body 22 is a box-shaped body with an upper surface opening. Figure 1 As shown, the shell body 22 has a bottom 22b which is a long rectangular plate-like member, a pair of first side walls 22c extending upward D from the long sides of the bottom 22b (sides along the width direction X), and a pair of second side walls 22d extending upward D from the short sides of the bottom 22b (sides along the depth direction Y). In addition, an upper surface opening surrounded by the upper ends of the first side wall 22c and the second side wall 22d is formed on the upper surface of the shell body 22. On the other hand, the sealing plate 24 is a rectangular plate-like member that blocks the upper surface opening of the shell body 22. Specifically, as Figure 2 As shown, the sealing plate 24 is embedded in the upper surface opening of the housing body 22. In addition, the boundary between the housing body 22 and the sealing plate 24 is joined by laser welding or the like. In addition, the housing 20 (housing body 22 and sealing plate 24) is preferably a metal member having a certain strength or more. As an example of the raw material of the housing 20, metal materials such as aluminum and aluminum alloy can be cited.

[0056] In addition, as described above, the housing 20 is provided with a terminal mounting hole 25. The terminal mounting hole 25 is a through hole that penetrates the housing 20. The terminal mounting hole 25 is an opening for forming a conductive path from the electrode body 10 inside the housing 20 to the outside of the housing 20. Figure 1 As shown, the terminal mounting hole 25 in the present embodiment is a circular opening when viewed from above. However, the planar shape of the terminal mounting hole is not particularly limited and may be square. In addition, in the power storage device 1 of the present embodiment, two terminal mounting holes 25 are formed in the sealing plate 24 of the housing 20. Specifically, the terminal mounting holes 25 are respectively formed at the two end portions in the width direction X of the sealing plate 24. In addition, the terminal mounting hole 25 on one side becomes a positive terminal mounting hole 25P that forms a conductive path with the positive electrode of the electrode body 10. In addition, the terminal mounting hole 25 on the other side becomes a negative terminal mounting hole 25N that forms a conductive path with the negative electrode of the electrode body 10. Below, the structure around the negative terminal mounting hole 25N is described as an example.

[0057] (3) Insulation material 30

[0058] The insulating material 30 continuously covers the peripheral wall 25a of the terminal mounting hole 25 and the peripheral edge portions 20a1, 20b1 of the terminal mounting hole 25 in the circumferential direction, and is bonded to the peripheral edge portions 20a1, 20b1 of the terminal mounting hole 25. The insulating material 30 is a member for preventing conduction to the housing 20. Specifically, a collector 40 that forms a conductive path from the electrode body 10 to the outside of the housing 20 is installed inside the housing 20. In addition, an external member ( Figure 4 The insulating material 30 is interposed between these conductive members and the housing 20 to prevent conduction to the housing 20. In addition, the insulating material 30 is made of an insulating resin such as a polypropylene resin, a polyphenylene sulfide resin, a polyamide resin, a polyacetal resin, or a polyimide resin. In addition, the insulating material 30 has an opening 38 that passes through the insulating material 30. The insulating material 30 is formed in such a manner that the opening 38 overlaps with the terminal mounting hole 25. That is, the insulating material 30 is arranged in such a manner that the terminal mounting hole 25 of the housing 20 is not blocked.

[0059] In addition, the insulating material 30 in this embodiment is manufactured by insert molding. In the insert molding, first, Figure 3As shown, the current collector 40 and the mold M are installed on the sealing plate 24. At this time, the positional relationship of each component is adjusted so as to produce a cavity S of a shape corresponding to the predetermined insulating material 30. Next, the resin material is filled into the interior of the cavity S through the injection hole M1 of the mold M. Then, by curing the resin material, the insulating material 30 of a shape corresponding to the cavity S is produced. When the insulating material 30 is produced by insert molding in this way, the sealing plate 24 and the current collector 40 are integrated via the insulating material 30. As a result, the insulating material 30 continuously covers the peripheral wall 25a of the terminal mounting hole 25 and the peripheral edge portions 20a1, 20b1 of the terminal mounting hole 25 in the circumferential direction, and is joined to the peripheral edge portions 20a1, 20b1 of the terminal mounting hole 25. In addition, the insulating material 30 after insert molding has an external insulating portion 32, an internal insulating portion 34, and an in-hole insulating portion 36. The specific shapes of each part are described below.

[0060] The insulating material 30 includes an external insulating portion 32 joined to the peripheral portion 20a1 of the terminal mounting hole 25 in the outer surface 20a of the housing 20. The external insulating portion 32 is a member that prevents conduction between an external member (bus bar 110, etc.) and the housing 20. Specifically, the external insulating portion 32 is a plate-shaped portion arranged along the outer surface 20a of the housing 20 (the upper surface 24a of the sealing plate 24). In addition, the lower surface 32a of the external insulating portion 32 is joined to the outer surface 20a of the housing 20 by insert molding. Figure 4 As shown, by providing the external insulating portion 32, it is possible to prevent the external member (bus bar 110) from contacting the housing 20 (sealing plate 24) when the external member (bus bar 110) is connected to the power storage device 1. In addition, the thickness of the external insulating portion 32 is preferably 0.5 mm or more, more preferably 1.0 mm or more, and particularly preferably 2.0 mm or more. Thus, conduction between the external member and the housing 20 can be more appropriately prevented. On the other hand, the thickness of the external insulating portion 32 is preferably 4.0 mm or less, more preferably 3.0 mm or less. Thus, the height dimension of the power storage device 1 can be further reduced, and thus the loading efficiency of the power storage device in the electrical product can be further improved.

[0061] In addition, the insulating material 30 is provided with an internal insulating portion 34 joined to the peripheral portion 20b1 of the terminal mounting hole 25 in the inner surface 20b of the housing 20. The internal insulating portion 34 is a member that prevents conduction between the collector 40 and the housing 20 described later. Specifically, the internal insulating portion 34 is a plate-shaped portion between the inner surface 20b of the housing 20 (the lower surface 24b of the sealing plate 24) and the joint 42 of the collector 40. In addition, the upper surface 34a of the internal insulating portion 34 is joined to the inner surface 20b of the housing 20 by insert molding. In addition, the thickness of the internal insulating portion 34 is preferably 0.1 mm or more, more preferably 0.3 mm or more, and particularly preferably 0.5 mm or more. Thus, conduction between the collector 40 and the sealing plate 24 can be more appropriately prevented. On the other hand, the thickness of the internal insulating portion 34 is preferably 2.0 mm or less, and more preferably 1.0 mm or less. This increases the space for accommodating the electrode assembly 10 in the case 20 , thereby contributing to improving the performance of the electrical storage device 1 .

[0062] Furthermore, the insulating material 30 includes an in-hole insulating portion 36 joined to the peripheral wall 25a of the terminal mounting hole 25. In the power storage device 1 of the present embodiment, the collector 40 is connected to the bus bar 110 inside the terminal mounting hole 25, and the details will be described later. The in-hole insulating portion 36 prevents these conductive members from directly contacting the housing 20 (sealing plate 24). Specifically, the in-hole insulating portion 36 is a cylindrical portion extending along the height direction Z. The in-hole insulating portion 36 is arranged inside the terminal mounting hole 25 of the housing 20. Furthermore, the outer periphery 36a of the in-hole insulating portion 36 is joined to the peripheral wall 25a of the terminal mounting hole 25. In addition, in the insulating material 30 of the present embodiment, the external insulating portion 32 and the internal insulating portion 34 are continuous via the in-hole insulating portion 36. In other words, the external insulating portion 32, the internal insulating portion 34 and the in-hole insulating portion 36 are integrally formed. In addition, the thickness of the in-hole insulating portion 36 is preferably 0.5 mm or more, more preferably 1.0 mm or more, and particularly preferably 2.0 mm or more. Thus, the in-hole insulating portion 36 can be prevented from being damaged by friction and heat when the collector 40 is connected to the bus bar 110. On the other hand, the thickness of the in-hole insulating portion 36 is preferably 4.0 mm or less, more preferably 3.0 mm or less. Thus, the size of the terminal mounting hole 25 can be fully ensured, so that the connection between the collector 40 and the bus bar 110 becomes easy.

[0063] In addition, the insulating material 30 in the present embodiment has a protrusion 34c protruding from a part of the internal insulating part 34 (the inner part in the width direction X) toward the lower side D. Thus, the up and down movement of the electrode body 10 in the shell 20 can be restricted. As a result, the contact between the electrode body 10 and the sealing plate 24, the damage of the connecting tab 12, etc. can be prevented. In addition, the thickness (protrusion amount) of the protrusion 34c is preferably greater than 2.0 mm, and more preferably greater than 3.0 mm. Thus, the up and down movement of the electrode body 10 can be more appropriately restricted. On the other hand, the thickness of the protrusion 34c is preferably less than 5.0 mm, and more preferably less than 4.0 mm. Thus, the accommodation space of the electrode body 10 in the shell 20 can be fully ensured.

[0064] In addition, in the present embodiment, a roughened surface is formed on the surface of the metal component (sealing plate 24, collector 40) in contact with the insulating material 30 by roughening. Specifically, the portion subjected to roughening is the peripheral portion 20a1 of the terminal mounting hole 25 in the outer surface 20a of the housing 20, the peripheral portion 20b1 of the terminal mounting hole 25 in the inner surface 20b of the housing 20, the peripheral wall 25a of the terminal mounting hole 25, and the surface of the collector 40 joined to the insulating material 30 (the upper surface 42a of the joint 42). Thus, when insert molding is implemented, the resin material enters the concave and convex surfaces of each metal component. As a result, an anchoring effect is generated, so that the insulating material 30 can be more firmly joined to the metal component. In addition, the roughened surface can be formed on at least one of the above-mentioned surfaces. In this case, the joining strength between the insulating material 30 and the metal component can also be appropriately improved. In addition, the roughening process is not limited to the technology disclosed herein. That is, even when the roughening process is not performed, the insulating material 30 and the metal member can be fully integrated by insert molding.

[0065] (4) Current collector 40

[0066] The collector 40 is a conductive member electrically connected to the electrode body 10 inside the shell 20. Specifically, the collector 40 has an internal collector portion 46 extending along the height direction Z. The internal collector portion 46 is a plate-shaped portion connected to the connecting tab 12 of the electrode body 10. In addition, the internal collector portion 46 is preferably composed of the same type of metal material as the connecting tab 12 as the connection object. For example, as described above, the negative electrode tab is composed of a negative electrode core as a copper foil. In this case, the internal collector portion 46 is preferably composed of a copper-based material (copper, copper alloy, etc.). As a result, the collector 40 can be firmly connected to the electrode body 10 with low resistance.

[0067] In addition, the current collector 40 in this embodiment is arranged in a manner of blocking the terminal mounting hole 25 via the insulating material 30 and is bonded to the insulating material 30. In addition, the current collector 40 has a terminal portion 44. The terminal portion 44 is exposed to the outside of the housing 20 through the terminal mounting hole 25 and can be electrically connected to an external member. The current collector of this structure is described in detail below.

[0068] First, the collector 40 is provided with a joint portion 42 as a plate-shaped member joined to the insulating material 30. The joint portion 42 is joined to the lower surface 34b of the internal insulating portion 34 in a manner that blocks the terminal mounting hole 25 inside the housing 20. More specifically, the joint portion 42 is formed by bending the upper end of the internal collector 46 so as to face the sealing plate 24. Thus, the joint portion 42 faces the inner surface 20b of the housing 20 across the internal insulating portion 34. In addition, the upper surface 42a of the joint portion 42 is joined to the lower surface 34b of the internal insulating portion 34 by insert molding. As a result, the lower end of the terminal mounting hole 25 is blocked by the joint portion 42.

[0069] The terminal portion 44 is exposed to the outside of the housing 20 through the terminal mounting hole 25. Thus, an external member such as a bus bar can be electrically connected to the collector 40. Specifically, Figure 2 As shown in FIG. 1 , in this embodiment, the upper end of the terminal mounting hole 25 is open. As a result, a portion of the current collector 40 (the terminal portion 44) is exposed to the outside of the housing 20. Thus, a portion of the external member (the connecting protrusion 112 of the bus bar 110) can be inserted from the outside of the housing 20 into the terminal mounting hole 25 (see FIG. 1 ). Figure 4 ). As a result, the current collector 40 can be electrically connected to the external member.

[0070] Furthermore, the terminal portion 44 of the power storage device 1 of the present embodiment is located inside the outer surface 20a of the case 20. In other words, Figure 2 As shown, the upper surface 44a of the terminal portion 44 is arranged at a position D side below the outer contour line L1 along the outer surface 20a of the housing 20. Thus, a part of the collector 40 can be prevented from protruding outside the housing 20. In addition, in the power storage device 1 of the present embodiment, the terminal mounting hole 25 is sealed by the insulating material 30 and the collector 40 (the junction 42 and the terminal portion 44). Thus, the outflow of the electrolyte, the intrusion of foreign matter, etc. can be prevented. As described above, according to the power storage device 1 of the present embodiment, even if an external connection portion is not provided, it is possible to form a conductive path to the outside of the housing 20 and to seal the inside of the housing 20. That is, according to the present embodiment, the conductive member protruding outside the housing 20 can be eliminated, so that the height dimension of the power storage device 1 can be reduced. As a result, the loading efficiency of the power storage device 1 in the electrical product can be improved.

[0071] In addition, the terminal portion 44 in the present embodiment is a convex terminal portion inserted into the terminal mounting hole 25 from the inner side of the housing 20. As a result, the position of the upper surface 44a of the terminal portion 44 in the terminal mounting hole 25 rises, so that the connection between the terminal portion 44 and the external member becomes easy. In addition, when the convex terminal portion 44 is inserted into the terminal mounting hole 25, the movement of the collector 40 in the horizontal direction (width direction X and depth direction Y) is restricted. As a result, the peeling of the bonding interface between the bonding portion 42 and the internal insulating portion 34 can also be suppressed. In addition, as the position of the upper surface 44a of the terminal portion 44 in the terminal mounting hole 25 becomes higher, there is a tendency that the connection between the terminal portion 44 and the external member becomes easier. From this point of view, the distance H1 from the outer surface 20a of the housing 20 to the upper surface 44a of the terminal portion 44 is preferably 2.0 mm or less, more preferably 1.0 mm or less, and further preferably 0.5 mm or less. In addition, the upper surface 44a of the terminal portion 44 may be substantially the same height as the outer surface 20a of the housing 20 (ie, the distance H1 is 0 mm). In this case, the connection between the terminal portion 44 and the external member becomes easier.

[0072] In addition, as mentioned above, Figure 2 The current collector 40 shown in the figure has a joint portion 42 as a plate-shaped member joined to the insulating material 30. In this case, Figure 2 The convex terminal portion 44 shown is a columnar member joined to the upper surface 42a of the joint portion 42. As a result, the thickness of the terminal portion 44 can be sufficiently ensured. As a result, a preferred welding depth can be ensured when the terminal portion 44 is connected to an external member by laser welding or the like. In addition, when such a structure is adopted, the raw material of the terminal portion 44 can be freely selected without being affected by the raw materials of other parts (joint portion 42, internal collector portion 46).

[0073] For example, Figure 2As shown, as the terminal portion 44, a clad material having a first layer 47 and a second layer 45 can be used. The first layer 47 of the terminal portion 44 is a layer that is bonded to the upper surface 42a of the bonding portion 42 and is composed of the same type of metal as the bonding portion 42. Thus, the terminal portion 44 can be firmly bonded to the bonding portion 42. On the other hand, the second layer 45 is a layer that is exposed to the outside of the housing 20 through the terminal mounting hole 25 and is composed of a metal different from the first layer 47. Thus, a metal that is easily connected to an external member can be arranged on the upper surface 44a of the terminal portion 44. For example, in the collector 40 on the negative electrode side, copper-based materials are used for the internal collector 46 and the bonding portion 42 in consideration of the connectivity with the negative electrode tab. On the other hand, in the construction of the storage cell 100 described later, aluminum-based materials are used for the external member (bus bar 110) in consideration of the connectivity with the bonding portion of the collector on the positive electrode side. In this case, the first layer 47 of the terminal portion 44 can be made of copper, and the second layer 45 can be made of aluminum. This allows a copper joint interface to be formed between the terminal portion 44 and the joint portion 42, and an aluminum joint interface to be formed between the terminal portion 44 and the bus bar 110. As a result, a conductive path from the electrode body 10 to the bus bar 110 can be formed firmly and with low resistance.

[0074] 2. Structure of the power storage unit

[0075] Next, the electric storage unit 100 constructed using the electric storage device 1 having the above-described structure will be described. Figure 4 It is a perspective view schematically showing the power storage unit in the first embodiment. Figure 5 It is schematically shown Figure 4 An enlarged cross-sectional view of the connection structure of the power storage unit shown.

[0076] Figure 4 The illustrated power storage unit 100 includes a plurality of power storage devices 1. Specifically, in the power storage unit 100, the plurality of power storage devices 1 are arranged along the depth direction Y in a manner that the first side walls 22c of the housing 20 face each other. In addition, the number of power storage devices 1 included in the power storage unit 100 is not particularly limited and may be appropriately changed according to the purpose of the power storage unit 100 (required power, specifications, etc. of the electrical product to be used). In addition, in the power storage unit 100 of the present embodiment, it is not necessary for all of the plurality of power storage devices 1 to have the above-mentioned structure. For example, when the power storage unit is mounted on an electrical product, sometimes only a portion of the plurality of power storage devices interferes with other components, and therefore sometimes the height dimension of the entire power storage unit has to be reduced. In such a case, the above-mentioned structure may be adopted only in the power storage device that interferes with other components. Thus, the loading efficiency of the power storage device in the electrical product can be improved.

[0077] In addition, a pair of end plates 120 are arranged on both outer sides of the arrangement direction (depth direction Y) of the storage battery unit 100. The pair of end plates 120 are bridged by a restraining beam member 130. Thus, restraining pressure along the arrangement direction can be applied to each storage battery device 1. In addition, a resin buffer member 150 is arranged between each arranged storage battery device 1. Thus, the restraining pressure applied to the storage battery device 1 can be uniformed.

[0078] Furthermore, the power storage unit 100 includes a plurality of bus bars 110 for electrically connecting the plurality of power storage devices 1. The bus bars 110 are connected to the terminal portions 44 of the respective power storage devices 1. Specifically, Figure 4 In the illustrated storage unit 100, a plurality of storage devices 1 are arranged so that the positive terminal mounting hole 25P of one storage device 1 is adjacent to the negative terminal mounting hole 25N of the other storage device 1. A bus bar 110 is connected to the terminal portion 44 existing in each of the adjacent pair of terminal mounting holes 25. The bus bar 110 is made of the same type of metal material (e.g., aluminum) as the terminal portion 44 on the positive electrode side.

[0079] In addition, if Figure 5 As shown, the bus bar 110 in this embodiment has a connection protrusion 112 that is inserted into the terminal mounting hole 25 from the outside of the housing 20 and connected to the terminal portion 44 of the collector 40. Thus, even if the terminal portion 44 is arranged on the inner side (lower side D) than the outer surface 20a of the housing 20, the terminal portion 44 can be easily connected to the bus bar 110. Specifically, the connection protrusion 112 is a portion of the bus bar 110 that is bent in a manner protruding toward the lower side D. And, the connection protrusion 112 of the bus bar 110 is inserted into the terminal mounting hole 25 from the upper side U in the height direction Z. Thus, the connection protrusion 112 is in contact with the upper surface 44a of the terminal portion 44. In this state, the connection protrusion 112 and the terminal portion 44 are laser welded. Thus, a welded portion spanning the connection protrusion 112 and the terminal portion 44 is formed, so that the terminal portion 44 is electrically connected to the bus bar 110.

[0080] In addition, the technology disclosed herein does not limit the external member connected to the power storage device to the bus bar 110 of the above structure. For example, an electric wire or the like may be used as an external member. These external members can also be easily inserted into the terminal mounting hole, so they can be appropriately connected to the collector (terminal portion) arranged at a position inside the outer surface of the housing.

[0081] Above, one embodiment of the technology disclosed herein is described. However, the technology disclosed herein is not limited to the above embodiment. Below, other embodiments of the technology disclosed herein are described. It should be noted that, Figure 6It is an enlarged cross-sectional view schematically showing the structure of the vicinity of the terminal mounting hole of the electric storage device according to the second embodiment. Figure 7 It is an enlarged cross-sectional view schematically showing the structure of the vicinity of the terminal mounting hole of the electric storage device according to the third embodiment. Figure 8 It is an enlarged cross-sectional view schematically showing the structure of the vicinity of the terminal mounting hole of the electric storage device according to the fourth embodiment. Fig. 9 This is a cross-sectional view showing an example of a bus bar that can be used in the fourth embodiment.

[0082] <Second Embodiment>

[0083] like Figure 2 As shown in FIG. 1 , the terminal portion 44 in the first embodiment is a columnar cladding material having a first layer 47 and a second layer 45. However, the terminal portion in the technology disclosed herein is not limited to a columnar cladding material. For example, the terminal portion 44 may also be a columnar member made of a single metal material (see FIG. 1 ). Figure 6 Even when this structure is adopted, the loading efficiency of the power storage device 1 can be improved as long as the upper surface 44 a of the terminal portion 44 is arranged inward (downward D) relative to the outer surface 20 a of the case 20 .

[0084] In addition, the terminal portion 44 made of a single metal material can be particularly preferably used when the joint portion 42 and the external member (bus bar) are made of the same material. For example, in the collector 40 on the positive electrode side, considering the connectivity with the positive electrode tab (aluminum foil), the internal collector portion 46 and the joint portion 42 are made of aluminum-based materials. On the other hand, as described above, the bus bar 110 when constructing the storage cell 100 is also made of aluminum-based materials (see Figure 4 In the case of this structure, even if the cladding material is not used for the terminal portion 44, the conductive path from the electrode body 10 to the bus bar 110 can be constructed with an aluminum-based material, so a strong and low-resistance conductive path can be formed.

[0085] <Third Embodiment>

[0086] In the first and second embodiments, the columnar terminal portion 44 is joined to the upper surface 42a of the joining portion 42 (see Figure 2 and Figure 6 However, the convex terminal portion 44 is not limited to this structure. For example, when the joint portion 42 is a plate-shaped member, the convex terminal portion 44 can also be formed by bending the joint portion 42 (see Figure 7). The convex terminal portion 44 can be formed by stamping the plate-shaped joint portion 42. When the terminal portion 44 of this structure is inserted into the terminal mounting hole 25, the connection between the terminal portion 44 and the external member becomes easy, and the movement of the collector 40 in the horizontal direction can be restricted. In addition, according to this embodiment, the number of components of the collector 40 can be reduced, which can help reduce material costs.

[0087] <Fourth Embodiment>

[0088] In the first to third embodiments, the convex terminal portion 44 is inserted into the terminal mounting hole 25. However, the current collector in the technology disclosed herein may not have a convex terminal portion. Figure 8 As shown, the joint portion 42 and the terminal portion 44 may also constitute a continuous flat surface. Even in the case of adopting such a structure, the terminal mounting hole 25 can be sealed by the insulating material 30 and the terminal portion 44. Moreover, even in the case of adopting this structure, the terminal portion 44 is exposed to the outside of the housing 20 through the terminal mounting hole 25, so that the external member can be electrically connected to the collector 40. Moreover, in this case, the terminal portion 44 is also arranged at a position closer to the inside (lower D) than the outer surface 20a of the housing 20, so that the loading efficiency of the storage device in the electrical product can be improved.

[0089] In addition, when the fourth embodiment is adopted, the protrusion amount of the connection protrusion of the bus bar can be increased. Thus, the bus bar and the terminal portion 44 can be properly connected. Fig. 9 As shown in FIG. 1 , the connection protrusion 112 of the bus bar 110 may be formed of a clad material. In this case, the connection protrusion 112 includes an upper layer 112a that is joined to the main body 114 of the bus bar 110 and is formed of the same type of metal as the main body 114, and a lower layer 112b that is arranged below the upper layer 112a and is formed of the same type of metal as the terminal portion 44 of the power storage device 1. Thus, even when the terminal portion 44 is not a convex member, a strong and low-resistance conductive path can be easily formed.

[0090] The above describes the technology disclosed herein in detail. However, these are only examples and do not limit the claims. The technology described in the claims includes technologies obtained by various deformations and changes to the specific examples illustrated above. That is, the technology disclosed herein includes the methods described in the following items 1 to 8.

[0091] [Project 1]

[0092] An electric storage device comprising:

[0093] Electrode body;

[0094] a shell, the shell accommodating the electrode body and having a terminal mounting hole;

[0095] an insulating material that continuously covers a peripheral wall of the terminal mounting hole and a peripheral edge of the terminal mounting hole in a circumferential direction and is bonded to the peripheral edge of the terminal mounting hole; and

[0096] a current collector electrically connected to the electrode body inside the casing,

[0097] The current collector is arranged via the insulating material so as to block the terminal mounting hole.

[0098] The current collector is bonded to the insulating material,

[0099] The current collector has a terminal portion, the terminal portion is exposed to the outside of the case through the terminal mounting hole and can be electrically connected to an external member.

[0100] The terminal portion is located inside the outer surface of the case, and the terminal mounting hole is sealed by the insulating material and the current collector.

[0101] [Project 2]

[0102] The power storage device according to item 1,

[0103] The terminal portion is a convex terminal portion that is inserted into the terminal mounting hole from the inner side of the housing.

[0104] [Item 3]

[0105] The power storage device according to item 2,

[0106] The current collector includes a joining portion as a plate-shaped member joined to the insulating material,

[0107] The convex terminal portion is a portion where the joining portion is bent.

[0108] [Item 4]

[0109] The power storage device according to item 2,

[0110] The current collector includes a joining portion as a plate-shaped member joined to the insulating material,

[0111] The convex terminal portion is a columnar member joined to the upper surface of the joining portion.

[0112] [Item 5]

[0113] The power storage device according to item 4,

[0114] The columnar terminal portion comprises:

[0115] a first layer bonded to the upper surface of the bonding portion and made of the same type of metal as the bonding portion; and

[0116] The second layer is exposed to the outside of the housing through the terminal mounting hole and is made of a metal different from that of the first layer.

[0117] [Item 6]

[0118] The electrical storage device according to any one of items 1 to 5,

[0119] The electrical storage device also has a roughened surface, which is arranged at least one of the peripheral portion of the terminal mounting hole in the outer surface of the shell, the peripheral portion of the terminal mounting hole in the inner surface of the shell, the peripheral wall of the terminal mounting hole, and the surface of the collector joined to the insulating material.

[0120] [Item 7]

[0121] A power storage unit comprising:

[0122] a plurality of electrical storage devices; and

[0123] a plurality of bus bars electrically connecting the plurality of power storage devices;

[0124] At least one of the plurality of electrical storage devices is the electrical storage device according to any one of items 1 to 6, and the bus bar is joined to the terminal portion of the electrical storage device.

[0125] [Item 8]

[0126] The power storage unit according to item 7,

[0127] The bus bar includes a connecting protrusion that is inserted into the terminal mounting hole from the outside of the case and connected to the terminal portion of the current collector.

Claims

1. An electric storage device, wherein: The power storage device comprises: Electrode body; a shell, the shell accommodating the electrode body and having a terminal mounting hole; an insulating material, the insulating material continuously covering the peripheral wall of the terminal mounting hole and the peripheral edge of the terminal mounting hole in the circumferential direction and being joined to the peripheral edge of the terminal mounting hole; as well as a current collector electrically connected to the electrode body inside the casing, The current collector is arranged via the insulating material so as to block the terminal mounting hole. The current collector is bonded to the insulating material, The current collector has a terminal portion, the terminal portion is exposed to the outside of the case through the terminal mounting hole and can be electrically connected to an external member. The terminal portion is located inside the outer surface of the case, and the terminal mounting hole is sealed by the insulating material and the current collector.

2. The power storage device according to claim 1, wherein The terminal portion is a convex terminal portion that is inserted into the terminal mounting hole from the inner side of the housing.

3. The power storage device according to claim 2, wherein: The current collector includes a joining portion as a plate-shaped member joined to the insulating material, The convex terminal portion is a portion where the joining portion is bent.

4. The power storage device according to claim 2, wherein: The current collector includes a joining portion as a plate-shaped member joined to the insulating material, The convex terminal portion is a columnar member joined to the upper surface of the joining portion.

5. The power storage device according to claim 4, wherein: The columnar terminal portion comprises: a first layer bonded to the upper surface of the bonding portion and made of the same type of metal as the bonding portion; and The second layer is exposed to the outside of the housing through the terminal mounting hole and is made of a metal different from that of the first layer.

6. The power storage device according to any one of claims 1 to 5, wherein: The electrical storage device also has a roughened surface, which is arranged at least one of the peripheral portion of the terminal mounting hole in the outer surface of the shell, the peripheral portion of the terminal mounting hole in the inner surface of the shell, the peripheral wall of the terminal mounting hole, and the surface of the collector joined to the insulating material.

7. A power storage unit, wherein: The power storage unit comprises: a plurality of electrical storage devices; and a plurality of bus bars electrically connecting the plurality of power storage devices; At least one of the plurality of power storage devices is the power storage device according to claim 1, and the bus bar is joined to the terminal portion of the power storage device.

8. The power storage unit according to claim 7, wherein: The bus bar includes a connecting protrusion that is inserted into the terminal mounting hole from the outside of the case and connected to the terminal portion of the current collector.

Images