JP2016162590A - Power storage device and power storage module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device and a power storage module that can simplify the shape of a connection member and reduce the cost.SOLUTION: A secondary battery includes an electrode assembly 12, a metal case 14, a connecting member 38, an insulating member 29, and a bus bar bolt 34. A case 14 houses the electrode assembly 12, and has a lid member 16. The connecting member 38 is arranged on the upper surface 16a of the lid member 16, and electrically connected to the electrode assembly 12. The insulating member 29 is interposed between the lid member 16 and the connecting member 38 to insulate the lid member and the connection member from each other. A bus bar bolt 34 has non-conductivity, and are interposed between the case 14 and the connecting member 38 while penetrating through the insulating member 29. The bus bar 50 can be fastened to the connecting member 38 by tightening a nut 53 to the bus bar bolt 34.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power storage device and a power storage module.

  2. Description of the Related Art Conventionally, secondary batteries such as lithium ion secondary batteries are known as power storage devices mounted on vehicles and the like. A conventional example of a secondary battery will be described. FIG. 15 is a cross-sectional view showing the bus bar connecting portion of the secondary battery. As shown in FIG. 15, a metal connecting member 106 is disposed on a metal lid member 102 of the case 101 via a resin insulating member 104. The connecting member 106 has an upper step 107 and a lower step 108 which are formed by bending a band plate material into a Z-shape and have a stepped shape. An insertion hole 109 is formed in the upper stage 107. The insulating member 104 and the lower step portion 108 of the connecting member 106 are fastened to the lid member 102 by caulking the caulking terminal member 111 connected to a current collecting terminal member (not shown) provided in the power generation element in the case 101. Yes. Thereby, the connection member 106 is electrically connected to a power generation element (not shown) in the case 101. An anti-rotation portion 114 formed on the lower surface of the insulating member 104 is fitted in the anti-rotation groove 113 formed on the upper surface of the lid member 102. The metal bus bar bolt 116 has a head portion 117 and a screw shaft portion 118. The screw shaft portion 118 is inserted upward into the insertion hole 109 of the connection member 106. The head 117 is interposed between the insulating member 104 and the connecting member 106 and is fitted in a rotation preventing groove 120 formed on the upper surface of the insulating member 104. When connecting the bus bar 122 to the connecting member 106, the fitting hole 123 of the bus bar 122 is fitted to the screw shaft portion 118 of the bus bar bolt 116, and then the nut 125 is tightened to the screw shaft portion 118. Thereby, the bus bar 122 is fastened to the connection member 106. Such a configuration is described in Patent Document 1, for example.

JP, 2014-11073, A

  In the conventional example, the case 101 and the lid member 102 are made of metal. This is because a high-capacity power storage device such as a lithium ion secondary battery is required to have high heat dissipation, and when a non-aqueous electrolyte is used, corrosion resistance is required. Since the lid member is made of metal, and the bus bar bolt 116 is made of metal and has conductivity, it is necessary to interpose the insulating member 104 between the bus bar bolt 116 and the lid member 102 so as to insulate between the two. was there. As a result, the connecting member 106 has to be formed into a complicated shape that is bent in a Z-shape, which causes a problem of increasing costs. An object of the present invention is to provide a power storage device and a power storage module that can simplify the shape of a connection member and reduce the cost.

  The first invention includes a power storage element, a metal case that houses the power storage element, a connection member that is disposed on an outer surface of the case and is electrically connected to the power storage element, and the case and the connection member An insulating member that is interposed between and insulates between the two and the case and the connecting member, and is interposed in a state of penetrating the insulating member and at least a portion that contacts the case is non-conductive A to-be-fastened member having a non-conductive portion, and the bus bar can be fastened to the connecting member by fastening the fastening member to the to-be-fastened member. According to this structure, a to-be-fastened member can be arrange | positioned with respect to a case so that a nonelectroconductive part may contact. Thereby, it is not necessary to interpose the insulating member which insulates between both between a case and a to-be-fastened member. Therefore, the shape of the connecting member can be simplified, that is, flattened, and the cost can be reduced.

  In a second aspect based on the first aspect, one member of the fastened member and the fastening member is a bolt, and the other member is a nut. According to this configuration, the fastening member can be detachably fastened to the fastened member. For this reason, as needed, by removing the fastening member fastened to the fastened member, the bus bar can be disassembled, and maintenance such as repair and replacement of the power storage device can be performed.

In a third aspect based on the second aspect, the case is provided with a rotation preventing means for restricting the rotation of the fastened member around the axis.
According to this configuration, the rotation of the fastened member around the axis can be restricted by the rotation preventing means provided in the case.

  In a fourth aspect based on the first aspect, the member to be fastened includes a pedestal portion interposed between the case and the connection member, and a shaft portion inserted through an insertion hole formed in the connection member. A resin-made caulking member, and the fastening member is a caulking portion formed by caulking a shaft portion of the caulking member. According to this configuration, since it is not necessary to prevent the caulking member from rotating about the axis, it is possible to omit the rotation preventing means for preventing the caulking member from rotating.

  In a fifth aspect based on any one of the first to fourth aspects, the member to be fastened is integrated with the insulating member. According to this configuration, the number of parts can be reduced.

  In a sixth invention, the power storage device according to any one of claims 1 to 5 is a secondary battery.

  A seventh invention is a power storage module configured by connecting a plurality of power storage devices according to any one of the first to sixth inventions, wherein the connection is achieved by fastening the fastening member to a member to be fastened of the power storage device. A bus bar is fastened to the member.

1 is a perspective view showing a secondary battery according to Embodiment 1. FIG. It is sectional drawing which shows a secondary battery. It is sectional drawing which shows a bus-bar connection part. It is a top view which shows a bus-bar connection part. It is a top view which shows the rotation prevention groove | channel of a cover member. It is a top view which shows the fitting hole of an insulating member. It is a perspective view which shows an assembled battery. It is sectional drawing which shows the bus-bar connection part to which the bus-bar was connected. It is sectional drawing which shows the bus-bar connection part concerning Embodiment 2. FIG. It is sectional drawing which shows the bus-bar connection part concerning Embodiment 3. It is sectional drawing which shows the bus-bar connection part concerning Embodiment 4. It is sectional drawing which shows the bus-bar connection part concerning Embodiment 5. It is sectional drawing which shows the bus-bar connection part concerning Embodiment 6. It is sectional drawing which shows the bus-bar connection part concerning Embodiment 7. It is sectional drawing which shows the bus-bar connection part of the secondary battery concerning a prior art example.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[Embodiment 1] Embodiment 1 illustrates a secondary battery as a power storage device. In the present embodiment, the secondary battery is a wound lithium ion secondary battery. However, any other type of battery may be used as long as the power storage device uses a metal case. Although a lithium ion secondary battery can be used alone, it is generally used as an assembled battery as a power storage module by connecting a plurality of secondary batteries in series or in parallel. The secondary battery can be used for various applications. For example, the secondary battery is mounted on a vehicle and used as a power source for a traveling motor or a power source for other electrical devices. FIG. 1 is a perspective view showing a secondary battery, and FIG. 2 is a sectional view of the same.

  As shown in FIG. 2, the secondary battery 10 includes an electrode assembly 12 and a case 14 that houses the electrode assembly 12. The case 14 includes a case main body 15 formed in a rectangular box shape having an upper surface opened, and a lid member 16 that closes the upper surface of the case main body 15. The case main body 15 and the lid member 16 are made of metal (for example, made of stainless steel, aluminum, etc.). The lid member 16 is provided with a pair of left and right bus bar connecting portions 18. For convenience of explanation, the arrangement direction of the bus bar connecting portions 18 is the left-right direction, and the direction intersecting the direction (the front and back direction in FIG. 2) is the front-rear direction. The case 14 is flattened in the front-rear direction (see FIG. 1). The bus bar connection unit 18 will be described later.

  The electrode assembly 12 is a wound electrode body formed by winding a positive electrode, a negative electrode, and a separator. The electrode assembly 12 is wound so that a belt-like positive electrode, a negative electrode, and a separator are overlapped and folded at an upper edge and a lower edge. The electrode assembly 12 is connected to a pair of left and right conductive members 20 connected to the positive electrode or the negative electrode on the left and right sides thereof. One conductive member 20 is connected to the positive electrode, and the other conductive member 20 is connected to the negative electrode. Each conductive member 20 is a substantially U-shaped metal piece having a portion extending upward along the side wall of the case body 15 and a portion extending inward along the lid member 16 from the upper end thereof. One end thereof is connected to the positive electrode or the negative electrode as described above, and the head 23 of the rivet-type caulking terminal member 22 is formed at the other end. The caulking terminal member 22 is made of metal having conductivity. The caulking shaft portion 24 of the caulking terminal member 22 faces upward. The electrode assembly 12 corresponds to a “storage element” in the present specification.

  Next, the bus bar connection unit 18 will be described. Since the left and right bus bar connection portions 18 are provided symmetrically, only one (left side in FIG. 2) bus bar connection portion 18 will be described, and description of the other (also right side) bus bar connection portion 18 will be omitted. FIG. 3 is a cross-sectional view showing the bus bar connecting portion, and FIG. 4 is a plan view. As shown in FIG. 3, a through-hole 26 that penetrates in the plate thickness direction (vertical direction) is formed at the end of the lid member 16. A square-shaped detent groove 27 is formed on the upper surface 16a of the lid member 16 and is located closer to the center (right side in FIG. 3) than the through hole 26 (see FIG. 5).

  On the upper surface 16 a of the lid member 16, strip-shaped insulating members 29 are arranged in a stacked manner. The insulating member 29 is made of resin and has an insulating property. An insertion hole 30 penetrating in the thickness direction (vertical direction) is formed at one end portion (left end portion in FIG. 3) of the insulating member 29. The insertion hole 30 is arranged coaxially with the through hole 26 of the lid member 16. A fitting hole 31 penetrating in the thickness direction (vertical direction) is formed in the other end portion (right end portion in FIG. 3) of the insulating member 29 (see FIG. 6). The fitting hole 31 has a similar shape to the rotation prevention groove 27 (see FIG. 5) of the lid member 16 and is formed in a square shape that is slightly smaller than the rotation prevention groove 27. On the lower surface of the insulating member 29, a rectangular frame-like projection 32 is formed along the edge of the fitting hole 31. The frame-like protrusion 32 is fitted in the rotation stop groove 27 of the lid member 16 with almost no gap. The upper surface 16a of the lid member 16 corresponds to the “outer surface of the case” in this specification.

  A bus bar bolt 34 is disposed in the fitting hole 31 of the insulating member 29. The bus bar bolt 34 is made of, for example, resin and has non-conductivity. That is, the entire bus bar bolt 34 constitutes a nonconductive portion. The bus bar bolt 34 has a head portion 35 and a screw shaft portion 36. The head 35 is formed in a quadrangular prism shape. The head portion 35 is fitted in the fitting hole 31 of the insulating member 29 with almost no gap with the screw shaft portion 36 facing upward. Accordingly, the head portion 35 is fitted in the rotation stop groove 27 of the lid member 16 through the frame-shaped protrusion 32 of the insulating member 29 with almost no gap. The top surface (the lower surface in FIG. 3) of the head portion 35 is in surface contact with the bottom surface of the detent groove 27. The bus bar bolts 34 correspond to “fastened members” and “bolts” in this specification. Further, the anti-rotation groove 27 of the lid member 16 corresponds to “non-rotation means” in the present specification.

  On the upper surface of the insulating member 29, strip-like connection members 38 are arranged in a stacked manner. The connection member 38 is made of a conductive metal such as a copper alloy, steel, stainless steel, or the like. The connecting member 38 is formed in a flat plate shape without being bent. The connecting member 38 is formed with an outer shape that is slightly smaller than the outer shape of the insulating member 29. A first insertion hole 39 penetrating in the thickness direction (vertical direction) is formed at one end portion (right end portion in FIG. 3) of the connection member 38. A second insertion hole 40 penetrating in the thickness direction (vertical direction) is formed at the other end portion (left end portion in FIG. 3) of the connection member 38. The first insertion hole 39 is fitted to the screw shaft portion 36 of the bus bar bolt 34. The screw shaft portion 36 is exposed on the connection member 38 (see FIG. 4). The second insertion hole 40 is disposed coaxially with the through hole 26 of the lid member 16 and the insertion hole 30 of the insulating member 29. The insulating member 29 is interposed between the lid member 16 and the connecting member 38 and insulates both the members 16 and 38. Further, the head portion 35 of the bus bar bolt 34 is interposed between the lid member 16 and the connection member 38 so as to penetrate the insulating member 29.

  A gasket 42 is disposed on the lower surface of the lid member 16. The gasket 42 is made of resin and has an insulating property. The gasket 42 has a cylindrical tube portion 43. The cylindrical portion 43 is fitted in the through hole 26 of the lid member 16. An insertion hole 44 penetrating in the axial direction (vertical direction) is formed in the cylindrical portion 43.

  The caulking shaft portion 24 of the caulking terminal member 22 of the electrode assembly 12 extends from below the lid member 16 to the insertion hole 44 of the gasket 42, the insertion hole 30 of the insulating member 29, and the second insertion hole 40 of the connection member 38. It is inserted (see the two-dot chain line 24 in FIG. 3). The caulking shaft portion 24 of the caulking terminal member 22 is exposed and caulked on the connection member 38. By caulking, a flange-shaped caulking portion 45 having an outer shape larger than the outer diameter of the caulking shaft portion 24 is formed at the upper end portion of the caulking shaft portion 24 of the caulking terminal member 22. Further, the insulating member 29 and the connecting member 38 are fastened to the lid member 16 together with the gasket 42. Further, the conductive member 20 is electrically connected to the connection member 38 via the crimping terminal member 22. In this manner, the bus bar connection portion 18 is configured in which the insulating member 29, the bus bar bolt 34, and the connection member 38 are assembled to the lid member 16.

  After the electrode assembly 12 connected to the pair of bus bar connecting portions 18 of the lid member 16 is accommodated in the case body 15, the lid member 16 is attached to the case body 15. Thereafter, an electrolytic solution is injected from a liquid injection hole provided in the lid member 16 (not shown), and after the injection, the liquid injection port is sealed to constitute the secondary battery 10 (FIGS. 1 and FIG. 1). 2). The electrolytic solution is, for example, an organic solvent-based or non-aqueous electrolytic solution.

  FIG. 7 is a perspective view showing the assembled battery. As shown in FIG. 7, the assembled battery 47 is configured by arranging a plurality of (six in FIG. 7) secondary batteries 10 in a line in the front-rear direction. Adjacent secondary batteries 10 are arranged such that the poles of the bus bar connection portion 18 are in the opposite direction. Between adjacent bus bar connecting portions 18, a bus bar 50 is connected to connect the connecting members 38. In FIGS. 1 and 3, the bus bar 50 before assembly is indicated by a two-dot chain line 50, and the nut 53 is also indicated by a two-dot chain line 53.

  As shown in FIG. 1, the bus bar 50 is formed in a band plate shape. The bus bar 50 is made of metal (for example, made of copper or aluminum). At both ends of the bus bar 50, attachment holes 51 are formed penetrating in the plate thickness direction (vertical direction). Since the connection structures of the bus bars 50 to the adjacent bus bar connection portions 18 are the same, one connection structure will be described. FIG. 8 is a cross-sectional view showing the bus bar connecting portion to which the bus bar is connected.

  As shown in FIG. 8, when the bus bar 50 is connected to the bus bar connecting portion 18, the mounting hole 51 of the bus bar 50 is fitted into the screw shaft portion 36 of the bus bar bolt 34. Thereby, the screw shaft portion 36 of the bus bar bolt 34 is exposed from the bus bar 50. Next, a nut 53 is fastened to the screw shaft portion 36 of the bus bar bolt 34. In this way, the bus bar 50 is fastened to the connection member 38. The nut 53 is a hexagonal nut, for example, and has a screw hole 54 that is screwed into the screw shaft portion 36 of the bus bar bolt 34. The nut 53 is made of the same resin material as the bus bar bolt 34, for example. Further, in the assembled battery 47 (see FIG. 7), an external connection terminal connected to another device and connected to the connection member 38 of the bus bar connection portion 18 is also included in the “bus bar” in the present specification. The nut 53 corresponds to a “fastening member” in the present specification. Further, the bus bar bolt 34 and the nut 53 constitute a “fastening means” in this specification.

  According to the secondary battery 10 described above, the non-conductive bus bar bolt 34 can be disposed so as to contact the lid member 16 of the case 14. Thereby, it is not necessary to interpose the insulating member 29 which insulates between the cover member 16 and the bus bar bolt 34 between them. Therefore, unlike the conventional example (see FIG. 15), there is no need to bend the connecting member 38 into a Z shape. Therefore, the shape of the connection member 38 can be simplified, that is, flattened, and the cost can be reduced.

  Further, the nut 53 can be detachably fastened to the bus bar bolt 34. For this reason, the bus bar 50 can be disassembled by removing the nut 53 fastened to the bus bar bolt 34 as necessary, and maintenance such as repair and replacement of the secondary battery 10 can be performed.

  Further, the head 35 of the bus bar bolt 34 is fitted in the rotation preventing groove 27 of the lid member 16. The head 35 is engaged with the detent groove 27 via the frame-like protrusion 32 of the insulating member 29. Thereby, rotation of the bus bar bolt 34 around the axis can be restricted.

  More specifically, the conductive member 20 is connected to the connection member 38 and the bus bar bolt 34 by caulking the caulking terminal member 22 connected to the conductive member 20. For this reason, when the nut 53 is fastened to the bus bar bolt 34, if the bus bar bolt 34 is disengaged from a predetermined position, the connecting member 38 rotates with the caulking terminal member 22 as a fulcrum, and the conductive member 20 rotates with the caulking member. There is a possibility that the conductive member 20 contacts the inner wall of the case body. Regarding this problem, for example, Patent Document 1 also employs a detent structure. However, if the anti-rotation between the lid member and the insulating member and the anti-rotation between the insulating member and the bus bar bolt are arranged separately and stacked in the vertical direction, twisting occurs when a strong force is applied, The detent is easy to come off. In the structure of the present embodiment, when a strong force acts on the bus bar bolt 34, the force acts linearly on the inner wall of the detent groove 27 via the frame-shaped protrusion, so that the rotation of the bus bar bolt 34 is higher than before. This is effective in suppressing the rotation of the connecting member 38. Moreover, since the strength of the connection member 38 is increased by flattening the connection member 38, the deformation of the connection member 38 with respect to the rotational force when the nut 53 is tightened can be suppressed. Further, when the strength of the bus bar bolt 34 is insufficient, the screw shaft portion 36 may be increased in diameter.

  Further, since the head 35 of the bus bar bolt 34 is fitted, that is, engaged with the fitting hole 31 of the insulating member 29, the rotation of the bus bar bolt 34 around the axis can be restricted.

  Further, since the frame-shaped protrusion 32 of the insulating member 29 is fitted, that is, engaged with the rotation-preventing groove 27 of the lid member 16, the rotation of the insulating member 29 around the fulcrum of the crimping terminal member 22 can be restricted. it can. Note that the frame-like protrusion 32 of the insulating member 29 may be omitted, and the head portion 35 of the bus bar bolt 34 may be fitted (engaged) with the detent groove 27 of the lid member 16.

  Further, the assembled battery 47 in which the bus bar 50 is fastened to the connection member 38 can be provided by fastening the nut 53 to the bus bar bolt 34.

[Embodiment 2] Since the embodiment after this embodiment is a modification of Embodiment 1 (see FIG. 8), the changed portion will be described, and duplicate description will be omitted. FIG. 9 is a cross-sectional view showing the bus bar connecting portion. As shown in FIG. 9, an insulating portion (denoted by reference numeral 55) corresponding to the insulating member 29 in the first embodiment (see FIG. 8) is formed on the head portion 35 of the bus bar bolt 34 by integral molding. That is, since the insulating part 55 is integrated with the bus bar bolt 34, the number of parts can be reduced.

[Third Embodiment] In the third embodiment, the bus bar bolt 34 and the nut 53 of the first embodiment (see FIG. 8) are arranged in reverse. FIG. 10 is a cross-sectional view showing the bus bar connecting portion. As shown in FIG. 10, the nut (reference numeral 57) has a screw hole 58. The nut 57 is made of, for example, resin and has non-conductivity. That is, the whole nut 57 constitutes a nonconductive portion. The nut 57 is formed in a quadrangular prism shape. The nut 57 is fitted in the fitting hole 31 of the insulating member 29 with almost no gap. Along with this, the nut 57 is fitted into the anti-rotation groove 27 of the lid member 16 through the frame-shaped protrusion 32 of the insulating member 29 with almost no gap and is brought into contact with the bottom surface of the anti-rotation groove 27 in a surface contact manner. ing. The nut 57 is interposed between the lid member 16 and the connection member 38 so as to penetrate the insulating member 29. The first insertion hole 39 of the connection member 38 is disposed coaxially with the screw hole 58 of the nut 57. The nut 57 corresponds to a “fastened member” in the present specification.

  The bus bar bolt (reference numeral 60) corresponding to the nut 57 is, for example, a hexagon bolt, and has a head portion 61 and a screw shaft portion 62. The bus bar bolt 60 is formed of the same resin material as the nut 57, for example. The bus bar bolt 60 corresponds to “fastening member” and “bolt” in the present specification.

  When the bus bar 50 is connected to the bus bar connecting portion 18, the screw shaft portion 62 of the bus bar bolt 60 is inserted into the mounting hole 51 of the bus bar 50 and the first insertion hole 39 of the connecting member 38, and further the screw of the nut 57. It is screwed into the hole 58. In this state, the bus bar bolt 60 is fastened to the nut 57. In this way, the bus bar 50 is fastened to the connection member 38. The nut 57 and the bus bar bolt 60 constitute “fastening means” in the present specification.

  According to the secondary battery 10 described above, the non-conductive nut 57 can be disposed so as to contact the lid member 16 of the case 14. This eliminates the need to interpose the insulating member 29 that insulates between the lid member 16 and the nut 57. Therefore, the shape of the connection member 38 can be simplified, that is, flattened, and the cost can be reduced.

  Further, the bus bar bolt 60 can be detachably fastened to the nut 57. Therefore, if necessary, the bus bar 50 can be disassembled by removing the bus bar bolt 60 fastened to the nut 57, and maintenance such as repair and replacement of the secondary battery 10 can be performed.

  Further, a nut 57 is fitted or engaged with the rotation preventing groove 27 of the lid member 16. Thereby, the rotation of the nut 57 around the axis can be restricted. Further, the rotation of the insulating member 29 and the connecting member 38 with the caulking terminal member 22 as a fulcrum can be restricted.

  Further, since the nut 57 is fitted, that is, engaged with the fitting hole 31 of the insulating member 29, the rotation of the nut 57 around the axis can be restricted.

  Further, the bus bar bolt 60 is configured such that the tip (lower end) of the screw shaft portion 62 does not contact or approach the lid member 16 when the bus bar 50 is fastened. Further, the nut 57 corresponding to the bus bar bolt 60 may be a bottomed cap nut.

[Embodiment 4] Embodiment 4 is a modification of Embodiment 3 (see FIG. 10). FIG. 11 is a cross-sectional view showing the bus bar connecting portion. As shown in FIG. 11, the nut 57 is formed with an insulating portion (reference numeral 64) corresponding to the insulating member 29 in the third embodiment (see FIG. 10) by integral molding. That is, since the insulating part 64 is integrated with the nut 57, the number of parts can be reduced.

[Fifth Embodiment] In the fifth embodiment, the fastening by the bus bar bolt 34 and the nut 53 of the first embodiment (see FIG. 8) is changed to the fastening by the caulking member. FIG. 12 is a cross-sectional view showing the bus bar connecting portion. As shown in FIG. 12, the caulking member (reference numeral 66) is made of, for example, a thermoplastic resin and has non-conductivity. That is, the entire caulking member 66 forms a non-conductive portion. The caulking member 66 has a pedestal portion 67 and a caulking shaft portion 68. The pedestal portion 67 is formed in a quadrangular prism shape. The pedestal 67 is fitted in the fitting hole 31 of the insulating member 29 with almost no gap. Accordingly, the pedestal 67 is fitted into the rotation prevention groove 27 of the lid member 16 with almost no gap through the frame-shaped protrusion 32 of the insulating member 29, and comes into surface contact with the bottom surface of the rotation prevention groove 27. Has been. A first insertion hole 39 of the connection member 38 is fitted into the caulking shaft portion 68 of the caulking member 66. The caulking shaft portion 68 is exposed on the connecting member 38 (see the two-dot chain line 68 in FIG. 12). The caulking member 66 corresponds to the “fastened member” in this specification.

  When the bus bar 50 is connected to the bus bar connecting portion 18, the mounting hole 51 of the bus bar 50 is fitted into the caulking shaft portion 68 of the caulking member 66. As a result, the caulking shaft portion 68 of the caulking member 66 is exposed from the bus bar 50. Next, the caulking shaft portion 68 of the caulking member 66 is caulked by heat caulking. In the heat caulking, the heater 70 of the caulking device 68 is brought into contact with the front end surface (upper end surface) of the caulking shaft portion 68 from above the caulking shaft portion 68 of the caulking member 66, and the front end portion of the caulking shaft portion 68 is heated by the heater 70. This is done by depressing the heater 70 while melting. Thus, a flange-shaped caulking portion 69 having an outer shape larger than the outer diameter of the caulking shaft portion 68 is formed at the upper end portion of the caulking shaft portion 68 of the caulking member 66. Thereafter, the caulking portion 69 is cured by cooling. In this way, the bus bar 50 is fastened to the connection member 38. Note that heat caulking may be replaced with ultrasonic caulking. The caulking portion 69 corresponds to a “fastening member” in this specification. Further, the caulking member 66 and the caulking portion 69 constitute a “fastening means” in the present specification.

  According to the secondary battery 10 described above, the non-conductive caulking member 66 can be disposed so as to contact the lid member 16 of the case 14. Thereby, it is not necessary to interpose the insulating member 29 that insulates between the lid member 16 and the caulking member 66. Therefore, unlike the conventional example (see FIG. 15), there is no need to bend the connecting member 38 into a Z shape. Therefore, the shape of the connection member 38 can be simplified, that is, flattened, and the cost can be reduced.

  Further, the pedestal 67 of the caulking member 66 is fitted, that is, engaged with the anti-rotation groove 27 of the lid member 16. Thereby, the rotation of the caulking member 66 around the axis can be restricted. Further, the rotation of the insulating member 29 and the connecting member 38 with the caulking terminal member 22 as a fulcrum can be restricted.

  Further, it is not necessary to prevent the caulking member 66 from rotating about the axis. For this reason, you may abbreviate | omit the rotation prevention groove | channel 27 of the cover member 16 which is a rotation prevention means which stops the crimping member 66 rotation. For example, the pedestal 67 of the caulking member 66 may be cylindrical. Further, the frame-like protrusion 32 of the insulating member 29 may be omitted.

  Further, since the pedestal portion 67 of the caulking member 66 is fitted, that is, engaged with the fitting hole 31 of the insulating member 29, the rotation of the caulking member 66 around the axis can be restricted.

[Sixth Embodiment] A sixth embodiment is a modification of the fifth embodiment (see FIG. 12). FIG. 13 is a cross-sectional view showing the bus bar connecting portion. As shown in FIG. 13, the base 67 of the caulking member 66 is formed with an insulating portion (reference numeral 72) corresponding to the insulating member 29 in the fifth embodiment (see FIG. 12) by integral molding. That is, since the insulating portion 72 is integrated with the caulking member 66, the number of parts can be reduced. Further, the detent groove 27 of the lid member 16 (see FIG. 12) is omitted, and the frame-like protrusion 32 of the insulating member 29 is omitted. As a result, the caulking member 66 including the insulating portion 72 is in full surface contact with the lid member 16.

[Embodiment 7] Embodiment 7 is a modification of the bus bar bolt 34 of Embodiment 1 (see FIG. 8). FIG. 14 is a cross-sectional view showing the bus bar connecting portion. As shown in FIG. 14, the bus bar bolt (reference numeral 74) includes a bolt main body 75 having a head portion 76 and a screw shaft portion 77, and a non-conductive portion 78 having non-conductivity. The head 76 is formed in a quadrangular prism shape. The non-conductive portion 78 is formed on the top surface (the lower surface in FIG. 14) of the head portion 76, that is, the surface that contacts the lid member 16. The nonconductive part 78 is formed by coating the top surface of the head 76 with a nonconductive resin material, for example. Therefore, the bus bar bolt 74 can be arranged so that the non-conductive portion 78 contacts the lid member 16. Thereby, it is not necessary to interpose the insulating member 29 which insulates between the case 14 and the bus bar bolt 34 between them. Therefore, the shape of the connection member 38 can be simplified, that is, flattened, and the cost can be reduced. The non-conductive portion 78 only needs to be formed on at least the lower surface of the head portion 76, and the formation on the remaining portion is arbitrary. In addition, regarding the nut 57 of the second embodiment, the nut body may be made of metal, and the non-conductive portion 78 may be formed on the lower surface of the nut body. The bus bar bolt 74 corresponds to a “fastened member” or “bolt” in the present specification.

[Other Embodiments] The present invention is not limited to the embodiments and can be modified without departing from the gist of the present invention. For example, the present invention may be applied not only to the secondary battery 10 but also to a capacitor such as an electric double layer capacitor or a lithium ion capacitor. The secondary battery 10 is not limited to a lithium ion secondary battery, and may be a secondary battery such as a nickel hydride battery. Moreover, the to-be-fastened member should just have nonelectroconductivity, for example, may be made from a ceramic. Further, the frame-shaped protrusion 32 of the insulating member 29 is omitted, and the fastening member (the head 35 of the bus bar bolt 34, the nut 57, the pedestal portion 67 of the caulking member 66, the bus bar bolt 74 of the lid member 16 is omitted. The head 76) may be directly fitted (engaged). Further, the anti-rotation groove 27 of the lid member 16 only needs to have a shape that prevents the member to be fastened, and the member to be fastened (the head 35 of the bus bar bolt 34, the nut 57, the base portion 67 of the caulking member 66, the bus bar bolt The shape may be appropriately changed according to the shape of the 74 heads 76). In addition, the first insertion hole 39 of the connection member 38 is formed in the same shape as the fitting hole 31 of the insulating member 29, and the fastened member is fitted (engaged) to the first insertion hole 39, whereby The fastening member may be prevented from rotating. The fastening members (the nut 53 and the bus bar bolt 60) may be made of metal.

10 ... Secondary battery (power storage device)
12 ... Electrode assembly (electric storage element)
14 ... Case 16 ... Lid member 16a ... Upper surface (outer surface of case)
27 ... Non-rotating groove (Non-rotating means)
29 ... Insulating member 34 ... Busbar bolt (fastened member, bolt)
36 ... Screw shaft portion 38 ... Connection member 39 ... First insertion hole 47 ... Battery pack (storage module)
53 ... Nut (fastening member)
55. Insulating part (insulating member)
57 ... Nut (fastened member)
60 ... Bus bar bolt (fastening member, bolt)
64. Insulating part (insulating member)
66 ... caulking member (fastened member)
67 ... pedestal portion 68 ... caulking shaft portion 69 ... caulking portion (fastening member)
72. Insulating part (insulating member)
74 ... Bus bar bolt (fastening member, bolt)
75 ... Bolt body 78 ... Non-conductive part

Claims (7)

A storage element;
A metal case for housing the electricity storage element;
A connecting member disposed on the outer surface of the case and electrically connected to the power storage element;
An insulating member interposed between the case and the connecting member and insulating between the two;
A member to be fastened having a non-conductive non-conductive portion at least in a portion that is interposed between the case and the connection member in a state of penetrating the insulating member and that contacts the case;
With
A power storage device in which a bus bar can be fastened to the connection member by fastening a fastening member to the fastened member. The power storage device according to claim 1,
One of the members to be fastened and the fastening member is a bolt, and the other member is a nut. The power storage device according to claim 2,
The power storage device, wherein the case is provided with a detent means for restricting rotation of the fastened member around the axis. The power storage device according to claim 1,
The member to be fastened is a resin caulking member having a pedestal portion interposed between the case and the connection member, and a shaft portion inserted into an insertion hole formed in the connection member,
The electrical storage device, wherein the fastening member is a caulking portion formed by caulking a shaft portion of the caulking member. The power storage device according to any one of claims 1 to 4,
A power storage device in which the insulating member is integrated with the fastened member.   The power storage device according to any one of claims 1 to 5, wherein the power storage device is a secondary battery. A power storage module configured by connecting a plurality of power storage devices according to any one of claims 1 to 6,
A power storage module in which a bus bar is fastened to the connection member by fastening the fastening member to a fastened member of the power storage device.

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