JP2014102898A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device capable of preventing co-rotation of an electrode terminal when a fastening member is screwed with an electrode pole part.SOLUTION: A secondary battery 10 has: an electrode terminal group 47 including a positive electrode terminal 41 and a nut 55; and an insulation member 19 for insulating the electrode terminal group 47 and a lid 14. A flange part 25 of the insulation member 19 has a microfine recess 19c for preventing the electrode terminal group 47 from slipping relative to the nut 55 on a nut side opposite face 25b, and a microfine recess 19c for preventing the insulation member 19 from slipping to the lid 14 on a lid side opposite face 25a.

Description

  The present invention relates to a power storage device.

  A vehicle such as an EV (Electric Vehicle) or a PHV (Plug in Hybrid Vehicle) is equipped with a secondary battery such as a lithium ion battery as a power storage device that stores power supplied to an electric motor serving as a prime mover. This type of secondary battery is disclosed in Patent Document 1, for example. As shown in FIG. 10, the secondary battery of Patent Document 1 accommodates an electrode assembly 72 wound in a cylindrical case 71. The electrode assembly 72 has a layer shape in which a separator 75 is interposed between a positive electrode 73 and a negative electrode 74. Tabs 76 are drawn out from the positive electrode 73 and the negative electrode 74, and a plurality of tabs 76 having the same polarity are collected and connected to the electrode terminal 77. 10 shows a state in which some of the tabs 76 are connected to the electrode terminals 77, and the state in which the other tabs 76 are connected to the electrode terminals 77 is not shown. doing.

  The electrode terminal 77 has a base portion 78 and a protruding portion 79 formed so as to protrude from the base portion 78, and the protruding portion 79 has a screw portion on the entire outer peripheral surface thereof. The electrode terminal 77 is attached to the case 71 in a state where the protruding portion 79 is inserted through the insertion hole 80 of the case 71. An insulating member 81 made of polypropylene is attached to the insertion hole 80 of the case 71. In the secondary battery of Patent Document 1, such an insulating member 81 functions as a member for maintaining insulation between the case 71 and the electrode terminal 77, and has a sealing property between the case 71 and the electrode terminal 77. It also functions as a sealing member for maintaining. Further, a washer 82 and a first nut 83 and a second nut 84 are screwed into the protruding portion 79 of the electrode terminal 77 from the outside of the case 71. By tightening the first nut 83, the insulating member 81 is held between the base portion 78 and the washer 82 of the electrode terminal 77, and the sealing performance of the insulating member 81 is enhanced. Further, the second nut 84 is used for connection to an external circuit, and by tightening the second nut 84, for example, a bus bar or the like is sandwiched between the first nut 83 and the second nut 84.

JP 2000-149915 A

By the way, in the secondary battery of Patent Document 1, when the second nut 84 is tightened, the electrode terminal 77 may be rotated depending on the tightening torque.
This invention was made paying attention to the problem which exists in the said prior art, The objective is the electrical storage which can prevent the rotation of an electrode terminal when screwing a fastening member to a pole column part. To provide an apparatus.

  In order to solve the above problem, the power storage device according to claim 1 protrudes from the case through a case, an electrode assembly housed in the case, and an insertion hole formed in the case. A base having a cross-sectional area larger than an area of the insertion hole in a cross section parallel to a wall of the case having the insertion hole, provided at an end located inside the case among both ends of the pole column And an electrode terminal electrically connected to the electrode assembly, a seal member disposed between the base portion and the inner surface of the wall portion having the insertion hole, and attached to the pole column portion A narrow pressure member that sandwiches the case and the seal member with the base, an electrode terminal group including the electrode terminal and the narrow pressure member, and an insulating member that insulates the electrode terminal group from the case. A power storage device having The end of the pole column opposite to the base has a thread groove into which a fastening member for fixing the bus bar to the electrode terminal group is screwed, and the insulating member and the electrode terminal group The gist is to have an anti-slip structure that prevents at least one of slippage between the case and slippage between the case and the insulating member.

  According to this, when the fastening member is screwed into the pole column portion, a tightening torque acts on the electrode terminal. At this time, if the slip prevention structure prevents the electrode terminal group from slipping with respect to the insulating member, the electrode terminal group is prevented from being rotated by the tightening torque unless the insulating member slides with respect to the case. Further, the slip prevention structure prevents the insulating member from slipping with respect to the case. At this time, if the electrode terminal group does not slide relative to the insulating member, the electrode terminal group is prevented from being rotated by the tightening torque. Furthermore, if the slip prevention structure prevents the electrode terminal group from slipping with respect to the insulating member and prevents the insulation member from slipping with respect to the case, the electrode terminal group is prevented from being rotated by the tightening torque.

  Further, the anti-slip structure includes a plurality of contact surfaces each of a contact surface between the insulating member and the electrode terminal group and a contact surface between the case and the insulating member. You may be comprised by the recessed part or the convex part.

  According to this, any one contact surface becomes a rough surface by the plurality of concave portions or convex portions, and the frictional force against the contact surface with which the rough surface comes into contact is increased, and an anti-slip effect can be exhibited. For this reason, it is possible to prevent the rotation of the electrode terminals with a simple configuration only by processing the contact surface.

The plurality of concave portions or convex portions may be provided only on the contact surface of the insulating member.
According to this, the rotation of the electrode terminal can be prevented only by providing the concave portion or the convex portion only on the insulating member, and the slip prevention structure can be easily provided.

  The insulating member includes a cylindrical portion that is inserted into the insertion hole, and extends radially outward from one axial end of the cylindrical portion, and the narrow pressure member and the case around the insertion hole It is preferable to have the flange part pinched by.

  According to this, since the flange portion is clamped between the case and the narrow pressure member, the flange portion becomes a member that contacts both the case and the electrode terminal group. Therefore, an anti-slip structure that prevents at least one of the slip between the insulating member and the electrode terminal group and the slip between the case and the insulating member can be provided by using the flange portion.

Moreover, the said slip prevention structure may be provided in each contact surface between the said narrow pressure member and the said flange part, and each contact surface between the said flange part and the said case.
According to this, in the flange portion, the anti-slip structure can be provided by using both the contact surface to the narrow pressure member and the contact surface to the case.

  The anti-slip structure is provided only on each contact surface between the case and the flange portion, and the flange portion protrudes radially outward from the outer peripheral surface forming the outer peripheral shape of the narrow pressure member. ing.

  According to this, slipping of the narrow pressure member with respect to the flange portion can be prevented by causing the narrow pressure member to bite into the flange portion. Further, slipping of the flange portion with respect to the case can be prevented by the anti-slip structure, and it is only necessary to provide the anti-slip structure only on the contact surface between the case and the flange portion, so that the rotation of the electrode terminal can be prevented with a simpler configuration.

The anti-slip structure may be an uneven fitting structure between the case and the insulating member and an uneven fitting structure between the insulating member and the electrode terminal group.
According to this, each slip can be reliably prevented by a mechanical structure such as an uneven fitting structure.

  The power storage device is a secondary battery.

  ADVANTAGE OF THE INVENTION According to this invention, the accompanying rotation of an electrode terminal when screwing a fastening member on a pole part can be prevented.

The disassembled perspective view which shows the secondary battery of 1st Embodiment. The perspective view which shows the external appearance of the secondary battery of 1st Embodiment. The perspective view which shows the component of an electrode assembly. (A) is a perspective view which shows an insulating member from the flange part side, (b) is a perspective view which shows an insulating member from the cylindrical part side. (A) is sectional drawing which shows the state which fastened the bus-bar, (b) is an enlarged view. The perspective view which shows a battery module. (A) is a disassembled perspective view which shows a part of secondary battery of 2nd Embodiment, (b) is a perspective view which shows a positive electrode terminal (negative electrode terminal), (c) is a perspective view which shows an insulating member. Sectional drawing which shows the state which fastened the bus-bar. (A) is sectional drawing which shows another example of an electrode terminal group, (b) is an enlarged view. The figure which shows background art.

(First embodiment)
Hereinafter, a first embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, in the secondary battery 10, an electrode assembly 20 is accommodated in a metal case 12. The case 12 includes a rectangular parallelepiped case main body 13 having an opening 13 d and a rectangular flat plate-shaped lid 14 that closes the opening 13 d of the case main body 13. The case body 13 and the lid 14 are both made of metal (for example, stainless steel or aluminum), and the case body 13 and the lid 14 are joined by laser welding. The case body 13 includes a rectangular bottom plate 13a, a short side wall 13b erected from a pair of opposed short side edges of the bottom plate 13a, and a long side wall 13c erected from a pair of long side edges of the bottom plate 13a. With. The lid 14 has a pair of insertion holes 14b arranged in parallel at a predetermined interval. In the present embodiment, the lid 14 constitutes a wall portion of the case 12. Further, the secondary battery 10 of the present embodiment is a prismatic battery whose outer periphery forms a square shape. Further, the secondary battery 10 of the present embodiment is a lithium ion battery.

  As shown in FIG. 3, the electrode assembly 20 includes a positive electrode 21 and a negative electrode 22, and a laminated body having a layer shape with a separator 23 interposed between the positive electrode 21 and the negative electrode 22. Has been. The positive electrode 21 includes a rectangular metal foil for positive electrode (in this embodiment, an aluminum foil) 21a, and a positive electrode active material layer 21b formed on both surfaces of the metal foil for positive electrode 21a. The negative electrode 22 includes a rectangular negative electrode metal foil (copper foil in the present embodiment) 22a and negative electrode active material layers 22b formed on both surfaces of the negative electrode metal foil 22a.

  A positive electrode current collecting tab 31 formed by extending the positive electrode metal foil 21 a is provided in a part of one side direction (long side direction) of the positive electrode 21. The positive electrode current collecting tab 31 is formed in the same position and in the same shape in each positive electrode 21 constituting the electrode assembly 20. A part of one side direction (long side direction) of the negative electrode 22 is provided with a negative electrode current collecting tab 32 formed by extending the negative electrode metal foil 22a. The negative electrode current collecting tab 32 is formed in the same position and in the same shape in each negative electrode 22 constituting the electrode assembly 20.

  The positive electrodes 21 constituting the electrode assembly 20 are stacked such that the respective positive electrode current collecting tabs 31 are arranged in a line along the stacking direction. Similarly, the negative electrode 22 constituting the electrode assembly 20 is laminated so that the respective negative electrode current collecting tabs 32 are arranged in a row along the lamination direction so as not to overlap the positive electrode current collecting tabs 31. . The plurality of positive electrode current collecting tabs 31 are collected in a range from one end to the other end of the electrode assembly 20 in the stacking direction. Similarly, the plurality of negative electrode current collecting tabs 32 are collected in a range from one end to the other end in the stacking direction of the electrode assembly 20.

  As shown in FIG. 1, the electrode assembly 20 includes a positive electrode tab group 45 formed by collecting positive electrode current collecting tabs 31. At least the outermost positive electrode current collecting tab 31 of the positive electrode tab group 45 is welded to a positive electrode conductive member 33 as a conductive member. The electrode assembly 20 includes a negative electrode tab group 46 formed by collecting the negative electrode current collecting tabs 32. At least the outermost negative electrode current collecting tab 32 of the negative electrode tab group 46 is welded to a negative electrode conductive member 37 as a conductive member.

  As shown in FIGS. 1 and 5 (a), the positive electrode conductive member 33 and the negative electrode conductive member 37 have a terminal connection portion 34 having a square plate shape. In the terminal connecting portion 34, a surface to which a positive electrode terminal 41 or a negative electrode terminal 42 as an electrode terminal described later is welded is a first surface 34a, and a surface opposite to the first surface 34a is a second surface 34b. The positive electrode conductive member 33 and the negative electrode conductive member 37 have a rising portion 35 that rises from the second surface 34 b toward the first surface 34 a, and tab welding that extends from the rising portion 35 in a direction away from the terminal connection portion 34. The tab weld portion 36 has a rectangular plate shape.

  The positive electrode terminal 41 is welded to the terminal connection portion 34 of the positive electrode conductive member 33, and the negative electrode terminal 42 is welded to the terminal connection portion 34 of the negative electrode conductive member 37. Each of the positive electrode terminal 41 and the negative electrode terminal 42 has a base portion 43 having a square plate shape, and the planar shape of the base portion 43 is substantially the same as the planar shape of the first surface 34 a in each terminal connection portion 34. In the base portion 43, a surface facing the inner surface 14 a of the lid 14 is a seat surface 43 a, and a surface opposite to the seat surface 43 a in the thickness direction of the base portion 43 is an assembly side end surface 43 b.

  A cylindrical pole column 44 is erected from the center of the base 43, and a seating surface 43 a surrounds the pole column 44. The pole portion 44 has a male screw 44a on the outer peripheral surface and a female screw 44b as a screw groove on the inner peripheral surface. The male screw 44a and the female screw 44b are reverse screws.

  A resin terminal cover 50 is attached to the base 43. The terminal cover 50 includes a lid-side insulating plate 51 disposed between the seating surface 43 a of the base portion 43 and the inner surface 14 a of the lid 14. The lid-side insulating plate 51 has an insertion portion 51a into which the pole column portion 44 is inserted, and the inner peripheral edge of the lid-side insulating plate 51 is arcuate. The lid-side insulating plate 51 has a cut-out communication portion 51b that opens the insertion portion 51a to one side of the lid-side insulation plate 51. The lid-side insulation plate 51 is flat by the insertion portion 51a and the communication portion 51b. It has a U-shape. The lid-side insulating plate 51 has, on its inner edge, a protruding portion 51c that faces the communication portion 51b and protrudes toward the communication portion 51b.

  The lid-side insulating plate 51 includes a case-side insulating plate 52 at an edge located on the opposite side to the communicating portion 51b with the insertion portion 51a interposed therebetween, and the case-side insulating plate 52 is separated from the lid 14. Extends in the direction. The case side insulating plate 52 has a rectangular plate shape and extends perpendicularly to the lid side insulating plate 51. In the case-side insulating plate 52, an assembly-side insulating plate 53 extends in the same direction as the lid-side insulating plate 51 and along the assembly-side end surface 43 b at the distal end on the side away from the lid 14. The case side insulating plate 52 is formed in a rectangular plate shape. The terminal cover 50 configured as described above is attached to the positive terminal 41 and the negative terminal 42 from the side of the short side wall 13b of the case body 13.

  The pole column portion 44 is inserted into the insertion portion 51 a of the lid side insulating plate 51, and the lid side insulating plate 51 surrounds almost the entire circumference of the pole column portion 44. The lid-side insulating plate 51 is supported on the seating surface 43 a of the base 43. On the seat surface 43 a of the base portion 43, an O-ring 56 as a seal member is provided so as to surround the pole column portion 44. The O-ring 56 is disposed in the insertion portion 51 a of the lid-side insulating plate 51, and the O-ring 56 is surrounded by the lid-side insulating plate 51 on almost the entire circumference. That is, the O-ring 56 is surrounded by the inner peripheral edge of the lid-side insulating plate 51 except for the portion facing the communication portion 51b, and is positioned by the lid-side insulating plate 51 so as to be positioned on the outer periphery of the pole column portion 44. . The assembly-side insulating plate 53 is disposed closer to the electrode assembly 20 than the assembly-side end surface 43b of the base portion 43, and extends along the assembly-side end surface 43b opposite to the seating surface 43a. The assembly-side insulating plate 53 is interposed between the base portion 43 and the electrode assembly 20.

  The lid 14, the positive terminal 41, and the negative terminal 42 are electrically insulated by the lid-side insulating plate 51 in the terminal cover 50. In addition, the case main body 13 is electrically insulated from the positive terminal 41 and the negative terminal 42 by the case-side insulating plate 52. Further, the assembly side insulating plate 53 electrically insulates the electrode assembly 20 from the positive terminal 41 and the negative terminal 42.

  The pole part 44 inserted into the insertion part 51 a of the lid-side insulating plate 51 protrudes (exposes) from the insertion hole 14 b of the lid 14 to the outside of the case 12. The base portions 43 of the positive electrode terminal 41 and the negative electrode terminal 42 are provided at end portions located inside the case main body 13 among both end portions of the pole column portion 44. Further, the base 43 is set so that the cross-sectional area parallel to the lid 14 is larger than the area of the insertion hole 14b. For this reason, the base 43 cannot be removed from the insertion hole 14 b inside the case body 13. The inner peripheral surface of the insertion hole 14 b of the lid 14 and the outer peripheral surface of the pole column portion 44 are insulated by the insulating member 19.

  As shown in FIGS. 4A and 4B, the insulating member 19 includes an annular tubular portion 24 and a flange portion extending radially outward from one axial end of the tubular portion 24. 25. The cylindrical portion 24 is interposed between the inner peripheral surface of the insertion hole 14 b and the outer peripheral surface of the pole column portion 44. The flange portion 25 is locked around the insertion hole 14 b on the outer surface 14 c of the lid 14.

  As shown in FIGS. 1 and 5A, a nut 55 as a narrow pressure member is screwed into the male screw 44 a of the pole column portion 44, and the nut 55 is attached to the pole column portion 44. In the present embodiment, the electrode terminal group 47 includes a positive electrode terminal 41 or a negative electrode terminal 42 and a nut 55 that is screwed to each pole column portion 44.

  The flange portion 25 of the insulating member 19 is pinched between the outer surface 14c of the lid 14 and the end surface 55a of the nut 55 on the lid 14 side, and the nut 55 and the lid 14 are insulated by the flange portion 25. The flange portion 25 protrudes radially outward from the outer peripheral surface 55 b that forms the outer peripheral shape of the nut 55, and the entire end surface 55 a of the nut 55 is placed on the flange portion 25. Then, when the nut 55 is screwed to the pole column portion 44, the flange portion 25, the lid 14, the O-ring 56, and the lid-side insulating plate 51 are narrowed between the nut 55 and the base portion 43, and the pole The column portion 44 is fastened to the lid 14. In this fastened state, the O-ring 56 is in close contact with the inner surface 14a of the lid 14 and the seating surface 43a of the base portion 43 in a compressed state, and seals the periphery of the insertion hole 14b.

  As shown in FIGS. 1, 5A, and 6, the bus bar 60 that electrically connects the secondary batteries 10 has a rectangular plate shape and includes a pair of insertion portions 60a. The bus bar 60 is supported on the distal end surface of the pole column portion 44. A bolt 61 as a fastening member is screwed into the female screw 44 b of the pole column 44. Therefore, the female screw 44b of the pole post 44 is provided at the end opposite to the base 43, and the bolt 61 for fixing the bus bar 60 to the electrode terminal group 47 (the pole post 44) is provided on the female screw 44b. Are screwed together. The bolt 61 has a bolt screw portion 61a that is screwed into the female screw 44b, and a head portion 61b at one end in the axial direction of the bolt screw portion 61a. The bus bar 60 is pressed against the distal end surface of the pole post 44 by the head 61b of the bolt 61, and the pole post 44 and the bus bar 60 are electrically connected.

Next, a slip prevention structure for the positive electrode terminal 41 and the negative electrode terminal 42 in the secondary battery 10 will be described.
As shown in FIG. 5B, the contact surfaces between the lid 14 and the insulating member 19 are the outer surface 14 c of the lid 14 and the lid-side facing surface 25 a of the flange portion 25. Of the outer surface 14c of the lid 14 and the lid-side facing surface 25a of the flange portion 25, one lid-side facing surface 25a has a plurality of fine recesses 19c as recesses, and the lid-side facing surface 25a is a rough surface. It has become. The lid-side facing surface 25a is a rough surface to constitute a slip prevention structure, and slip between the lid 14 and the insulating member 19 is prevented.

  The contact surfaces between the nut 55 of the electrode terminal group 47 and the insulating member 19 are an end surface 55a of the nut 55 on the insulating member 19 side and a nut side facing surface 25b of the flange portion 25. Of the end surface 55a of the nut 55 and the nut-side facing surface 25b of the flange portion 25, one nut-side facing surface 25b has a plurality of fine recesses 19c as recesses, and the nut-side facing surface 25b is a rough surface. It has become. The nut-side facing surface 25 b is a rough surface to constitute a slip prevention structure, and slip between the insulating member 19 and the electrode terminal group 47 is prevented.

Next, the operation of the secondary battery 10 will be described.
Now, when the secondary batteries 10 are brought into conduction with each other by the bus bar 60, the periphery of the insertion portion 60 a in the bus bar 60 is supported by the tip surface of the polar column portion 44. Next, the bolt screw portion 61a of the bolt 61 is inserted into the insertion portion 60a, and the bolt screw portion 61a is screwed into the female screw 44b. At this time, with the case 12 of the secondary battery 10 held by a jig or the like and prevented from rotating, the bolt screw portion 61 a is screwed into the female screw 44 b of the pole column portion 44. Then, the tightening torque of the bolt 61 acts on the pole column 44 and the nut 55 screwed to the pole column 44.

  At this time, the nut-side facing surface 25b of the insulating member 19 is a rough surface, and the nut 55 of the electrode terminal group 47 is prevented from sliding with respect to the flange portion 25 by this rough surface. Further, torque acts on the flange portion 25 of the insulating member 19 from the nut 55, but the cover-side facing surface 25a of the flange portion 25 is also a rough surface. For this reason, it is prevented that the flange part 25 slips also with respect to the lid | cover 14. FIG. As a result, the accompanying rotation of the positive terminal 41 and the negative terminal 42 is prevented.

According to the above embodiment, the following effects can be obtained.
(1) The insulating member 19 that insulates the lid 14 from the positive electrode terminal 41 and the negative electrode terminal 42 has a plurality of fine recesses 19c on the lid-side facing surface 25a and the nut-side facing surface 25b, and each has a rough surface. ing. For this reason, when the bus bar 60 is fastened to the pole column portion 44, even if a tightening torque is applied to the pole column portion 44, the flange portion 25 prevents the insulating member 19 from sliding relative to the lid 14, and the insulating member 19 In contrast, the nut 55 of the electrode terminal group 47 can be prevented from slipping. As a result, when the bus bar 60 is fastened, the positive terminal 41 and the negative terminal 42 can be prevented from being rotated, and the tab welded portion 36 can be prevented from contacting the case main body 13.

  (2) The anti-slip structure of the insulating member 19 is a plurality of fine recesses 19 c provided in the flange portion 25. By providing a plurality of fine recesses 19c in the flange portion 25, the lid-side facing surface 25a and the nut-side facing surface 25b of the flange portion 25 are roughened, and the friction of the flange portion 25 against the lid 14 and the nut 55 (electrode terminal group 47). As a result of increasing the force, each slip can be prevented. Therefore, it is possible to prevent the positive terminal 41 or the negative terminal 42 from being rotated with a simple configuration only by processing the lid-side facing surface 25a and the nut-side facing surface 25b.

  (3) The insulating member 19 includes a tubular portion 24 and a flange portion 25 that extends radially outward from one axial end of the tubular portion 24. The flange portion 25 is sandwiched between the nut 55 of the electrode terminal group 47 and the lid 14. And the fine recessed part 19c was provided in both surfaces of the flange part 25 of this insulating member 19, and it was set as the slip prevention structure. Therefore, the rotation of the positive electrode terminal 41 and the negative electrode terminal 42 can be prevented simply by forming the fine concave portions 19c on both surfaces of the flange portion 25, and a slip prevention structure can be easily provided.

  (4) The lid-side facing surface 25 a is in surface contact with the lid 14, and the nut-side facing surface 25 b is in surface contact with the end surface 55 a of the nut 55. For this reason, the contact area between the lid-side facing surface 25a and the lid 14 and the contact area between the nut-side facing surface 25b and the end surface 55a of the nut 55 can be ensured to prevent slipping more reliably.

  (5) When the bus bar 60 is fastened, the positive electrode terminal 41 and the negative electrode terminal 42 can be prevented from being rotated by the anti-slip structure even if the bolt 61 is screwed into the pole post 44 with the case 12 held. . Therefore, the fastening operation of the bus bar 60 can be performed while holding the case 12, and the productivity of the secondary battery 10 can be increased by providing the anti-slip structure.

(Second Embodiment)
Next, a second embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIGS. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description thereof is omitted or simplified.

  As shown in FIG. 7A, the lid 14 includes a plurality of fitting grooves 14d at regular intervals around the insertion hole 14b. As shown in FIG. 7B, the positive electrode terminal 41 and the negative electrode terminal 42 are provided with a pair of fitting concave shapes 44 c in the polar column portion 44 at positions facing the polar column portion 44 in the radial direction. As illustrated in FIG. 7C, the insulating member 19 includes a plurality of fitting protrusions 25 d at equal intervals on the lid-side facing surface 25 a of the flange portion 25. The insulating member 19 includes a pair of fitting protrusions 24 a on the inner peripheral surface of the tubular portion 24 over the entire axial direction of the tubular portion 24.

  As shown in FIG. 8, the fitting protrusion 25 d of the insulating member 19 is fitted into the fitting groove 14 d of the lid 14, and the insulating member 19 is prevented from rotating with respect to the lid 14. Therefore, in the second embodiment, the anti-slip structure of the insulating member 19 with respect to the lid 14 is configured by the concave and convex fitting structure from the fitting groove 14 d of the lid 14 and the fitting protrusion 25 d of the insulating member 19. Yes. Further, the fitting protrusion 24 a of the insulating member 19 is fitted into the fitting concave shape 44 c of the pole column portion 44, and the positive electrode terminal 41 and the negative electrode terminal 42 are prevented from rotating with respect to the insulating member 19. Therefore, in the second embodiment, the electrode with respect to the insulating member 19 is formed by the concave and convex fitting structure from the fitting concave shape 44c of the pole column portion 44 (electrode terminal group 47) and the fitting protrusion 24a of the insulating member 19. A slip prevention structure for the terminal group 47 is configured.

Therefore, according to the second embodiment, the following effects can be obtained.
(6) When the bus bar 60 is fastened to the pole column portion 44 of the positive electrode terminal 41 and the negative electrode terminal 42, the fitting groove 14 d of the lid 14 and the insulating member 19 are fitted even if a tightening torque is applied to the pole column portion 44. The insulating member 19 is prevented from sliding with respect to the lid 14 by fitting with the mating protrusion 25d. In addition, the positive terminal 41 and the negative terminal 42 of the electrode terminal group 47 may slide with respect to the insulating member 19 due to the fitting between the fitting recess 44 c of the pole 44 and the fitting protrusion 24 a of the insulating member 19. Is prevented. Therefore, when the bus bar 60 is fastened, the positive terminal 41 and the negative terminal 42 can be prevented from being rotated, and the tab welded portion 36 can be prevented from coming into contact with the case body 13.

  (7) The fitting between the fitting groove 14 d of the lid 14 and the fitting protrusion 25 d of the insulating member 19 prevents the insulating member 19 from sliding with respect to the lid 14, and the fitting concave shape 44 c of the pole column portion 44. And the fitting with the fitting protrusion 24a of the insulating member 19 prevents the positive terminal 41 and the negative terminal 42 of the electrode terminal group 47 from slipping with respect to the insulating member 19. Therefore, since the anti-slip structure is a mechanical structure such as an uneven fitting structure, each slip can be reliably prevented.

In addition, you may change the said embodiment as follows.
In the first embodiment, the fine concave portions 19c are provided on both contact surfaces of the flange portion 25. However, the fine concave portions 19c are the respective contact surfaces between the lid 14 (case 12) and the flange portion 25. You may provide only in the opposing surface 25a. In this case, prevention of slipping of the nut 55 of the electrode terminal group 47 with respect to the nut-side facing surface 25b is configured by tightening the nut 55 until it bites into the nut-side facing surface 25b.

  If comprised in this way, since the fine recessed part 19c should just be provided only in the cover side opposing surface 25a of the flange part 25, the accompanying rotation of the positive electrode terminal 41 or the negative electrode terminal 42 can be prevented with a simpler structure. Note that the anti-slip structure may have a configuration in which a plurality of fine convex portions are provided instead of the fine concave portions 19c as the concave portions.

  In the first embodiment, fine concave portions are also provided on the end surface 55a of the nut 55 and the outer surface 14c of the lid 14, and the end surface 55a of the nut 55 and the outer surface 14c of the lid 14 are roughened. The slip of the electrode terminal group 47 with respect to the insulating member 19 is prevented by both the rough surface of the end surface 55a of the nut 55 and the rough surface of the nut-side facing surface 25b of the insulating member 19. That is, the anti-slip structure is provided on both the contact surfaces between the insulating member 19 (flange portion 25) and the nut 55 of the electrode terminal group 47. Similarly, the sliding of the insulating member 19 with respect to the lid 14 is prevented by both the outer surface 14 c of the lid 14 and the rough surface of the lid-side facing surface 25 a of the insulating member 19. That is, the anti-slip structure is provided on both of the contact surfaces between the insulating member 19 and the lid 14.

  Or, while eliminating the fine concave portion 19c of the nut-side facing surface 25b in the flange portion 25, the end surface 55a of the nut 55 is roughened, and the anti-slip structure is formed between the insulating member 19 (flange portion 25) and the electrode terminal group 47. It is provided only on the electrode terminal group 47 side in each contact surface with the nut 55.

  Alternatively, the fine concave portion 19c of the lid-side facing surface 25a in the flange portion 25 is eliminated, while the outer surface 14c of the lid 14 is roughened, and the anti-slip structure is provided between the insulating member 19 (flange portion 25) and the lid 14. Of these contact surfaces, the contact surface is provided only on the lid 14 side.

Note that the anti-slip structure may have a configuration in which a plurality of fine convex portions are provided instead of the fine concave portions 19c as the concave portions.
In the second embodiment, the flange 25 of the insulating member 19 is not provided with the fitting protrusion 25d, the fitting protrusion is provided on the cylindrical portion 24, and the fitting groove is formed on the inner peripheral surface of the insertion hole 14b in the lid 14. May be provided and fitted together. Then, the insulating member 19 may be prevented from slipping with respect to the lid 14 by a concave-convex fitting structure between the fitting protrusion of the cylindrical portion 24 and the fitting groove of the lid 14.

  (Circle) You may provide a slip prevention structure using the terminal cover 50 instead of the insulating member 19 as an insulating member. For example, a fitting protrusion is provided on the lid-side insulating plate 51 of the terminal cover 50, and a fitting recess in which the fitting protrusion can be fitted is provided on the inner surface 14 a of the lid 14. Further, at least one of the lid-side insulating plate 51, the case-side insulating plate 52, and the assembly-side insulating plate 53 is provided with a fitting projection, and a fitting recess in which the fitting projection can be fitted is provided in the base portion 43. . The sliding of the lid-side insulating plate 51 with respect to the lid 14 is prevented by fitting the fitting protrusion of the lid-side insulating plate 51 with the fitting recess of the lid 14. Further, the fitting of the fitting protrusion of the terminal cover 50 and the fitting recess of the base portion 43 prevents the electrode terminal group 47 from slipping with respect to the terminal cover 50. As a result, the positive terminal 41 and the negative terminal 42 are prevented from slipping with respect to the insulating member 19.

  ○ The electrode terminal group 47 is integrated by attaching the nut 55 to the positive electrode terminal 41 or the negative electrode terminal 42, but as shown in FIGS. 9A and 9B, the electrode terminal group 49 is A ring member 48 as a narrow pressure member may be welded and attached to the positive electrode terminal 41 or the negative electrode terminal 42. The ring member 48 is electrically joined to the pole column portion 44. Then, the bus bar 60 may be fastened toward the ring member 48 by the nut 57 as a fastening member in a state where the bus bar 60 is supported by the ring member 48.

  Further, the fine recess 19c as an anti-slip structure is provided only on the lid-side facing surface 25a of the flange portion 25, and the ring member 48 is welded in a state of biting into the nut-side facing surface 25b. The ring member 48 bites into the flange portion 25 of the insulating member 19 to prevent the electrode terminal group 49 (ring member 48) from slipping with respect to the insulating member 19, and the cover-side facing surface 25a having a rough surface prevents the electrode member group 49 from slipping. The sliding of the insulating member 19 is prevented. Therefore, the anti-slip structure is provided only on the contact surface between the lid 14 and the flange portion 25 in the insulating member 19. The anti-slip structure may be provided on the outer surface 14c of the lid 14 which is the other contact surface instead of the lid-side facing surface 25a of the flange portion 25 which is one contact surface. Further, the anti-slip structure may have a configuration in which a plurality of fine convex portions are provided instead of the fine concave portions 19c as concave portions.

In the first embodiment, the fine recess 19c provided in the flange portion 25 may be a random or patterned groove.
In each embodiment, the O-ring 56 is embodied as a seal member, but may be changed to an annular seal member other than an annular gasket or an annular shape.

The number of the positive electrode 21 and the negative electrode 22 which comprise the electrode assembly 20 may be changed suitably.
The electrode assembly 20 is a winding type configured by interposing a strip-shaped separator 23 between a strip-shaped positive electrode 21 and a negative electrode 22 and winding them around a winding axis in a spiral manner. Also good.

The case 12 may be formed in a columnar shape or an elliptical columnar shape.
The power storage device may be embodied as a nickel hydride secondary battery or an electric double layer capacitor.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery as an electrical storage device, 12 ... Case, 14 ... Lid as wall part, 14a ... Inner surface, 14b ... Insertion hole, 14c ... Outer surface as a contact surface, 14d ... Fitting groove which comprises anti-slip structure 19 ... an insulating member, 19c ... a fine recess as a recess constituting an anti-slip structure, 20 ... an electrode assembly, 24 ... a cylindrical part, 24a ... a fitting protrusion constituting an anti-slip structure, 25 ... a flange part, 25a: Cover side facing surface as a contact surface, 25b: Nut side facing surface as a contact surface, 25d: Fitting protrusion constituting an anti-slip structure, 41 ... Positive electrode terminal as an electrode terminal, 42 ... Negative electrode as an electrode terminal Terminals 43... Base portion 44. Polar pole portion 44 b Female thread as a screw groove 44 c Fitting concave shape constituting an anti-slip structure 47, 49 Electrode terminal group 48 48 Ring member as a narrow pressure member 55 ... Narrow pressure member End surface, 55b ... outer circumferential surface of the nut, as 55a ... contact surface of and, 56 ... O-ring as a sealing member, 57 ... nut as fastening members, 60 ... busbar 61 ... bolt as a fastening member.

Claims (8)

Case and
An electrode assembly housed in the case;
Of the both ends of the pole post projecting from the case through the insertion hole formed in the case, provided at the end located on the inside of the case and parallel to the wall of the case having the insertion hole An electrode terminal having a base having a cross-sectional area larger than the area of the insertion hole in cross section, and electrically connected to the electrode assembly;
A seal member disposed between the base and the inner surface of the wall having the insertion hole;
A narrow pressure member attached to the pole portion and sandwiching the case and the seal member with the base; and
An electrode terminal group including the electrode terminal and the narrow pressure member;
An insulating member for insulating the electrode terminal group and the case;
A power storage device having
The end of the pole column opposite to the base has a thread groove into which a fastening member for fixing the bus bar to the electrode terminal group is screwed.
A power storage device having an anti-slip structure that prevents at least one of slip between the insulating member and the electrode terminal group and slip between the case and the insulating member.   The anti-slip structure includes a plurality of recesses provided on any one of the contact surfaces between the insulating member and the electrode terminal group and the contact surfaces between the case and the insulating member. The electrical storage apparatus of Claim 1 comprised by the convex part.   The power storage device according to claim 2, wherein the plurality of concave portions or convex portions are provided only on the contact surface of the insulating member.   The insulating member includes a cylindrical portion inserted through the insertion hole, and extends radially outward from one axial end of the cylindrical portion, and is sandwiched between the narrow pressure member and the case around the insertion hole. The power storage device according to any one of claims 1 to 3, further comprising a flange portion to be operated.   The power storage device according to claim 4, wherein the anti-slip structure is provided on each contact surface between the narrow pressure member and the flange portion, and on each contact surface between the flange portion and the case.   The anti-slip structure is provided only on each contact surface between the case and the flange portion, and the flange portion protrudes radially outward from the outer peripheral surface forming the outer peripheral shape of the narrow pressure member. The power storage device according to claim 4.   2. The power storage device according to claim 1, wherein the anti-slip structure includes an uneven fitting structure between the case and the insulating member, and an uneven fitting structure between the insulating member and the electrode terminal group.   The power storage device according to any one of claims 1 to 7, wherein the power storage device is a secondary battery.