JP2015153741A - Electricity storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electricity storage device capable of suppressing co-rotation of an electrode terminal.SOLUTION: In a secondary battery 10, a positive electrode terminal 41 and a negative electrode terminal 42 have an engagement part 57 for a jig, to which a jig engages. A positive electrode terminal cover 50 has a first engaging part engaging to a positive electrode base portion 43 and a second engaging part 52b engaging to a lid 14. A negative electrode terminal cover 58 has a first engaging part engaging to a negative electrode base portion 53 and a second engaging part 60b engaging to the lid 14. The lid 14 has an engaging part for a wall part, to which the second engaging parts 52b, 60b engage.

Description

  The present invention relates to a power storage device that includes an electrode terminal having a pole portion and a base portion, a nut screwed into a male screw portion on an outer peripheral surface of the pole post portion, and a terminal cover that insulates the wall portion and the base portion.

  Power storage devices such as secondary batteries and capacitors are widely used as power sources because they can be recharged and can be used repeatedly. In general, a secondary battery (power storage device) having a large capacity includes a case in which an electrode assembly and an electrolytic solution are accommodated, and an electrode terminal for taking out electricity from the electrode assembly includes a conductive member. To the electrode assembly. Moreover, the electrode terminal has a pole column part which penetrates the lid of the case and protrudes outside the case, and this pole column part has a structure including an external thread part on the outer peripheral surface. In the above structure, the electrode terminal connected to the electrode assembly is fixed to the lid by screwing a nut into the male screw portion.

  By the way, when the nut is screwed together with the electrode terminal, if the electrode terminal is rotated together with the nut, the conductive member integral with the electrode terminal may come into contact with the case and cause a short circuit. In view of this, a structure has been proposed that suppresses the accompanying rotation of the electrode terminals when the nuts are screwed together (see, for example, Patent Document 1).

  As shown in FIG. 10, the electric double layer capacitor disclosed in Patent Document 1 has an electrode terminal 82 fixed to a sealing lid 81 of a metal case 80. The electrode terminal 82 includes a screw terminal 80a. A locking plate 83 is provided at one axial end of the screw terminal 80a. The electrode terminal 82 is fastened to the sealing lid 81 by a nut 85 via a washer 84.

  In addition, a resin electrical insulator 86 that insulates the screw terminal 80 a, the washer 84, and the locking plate 83 from the sealing lid 81 is provided inside the sealing lid 81. The electrical insulator 86 has an engagement surface 86 a that engages with the locking plate 83. Since the locking plate 83 is integrated with the electrical insulator 86, when the nut 85 is screwed into the screw terminal 80a, the locking plate 83 is electrically insulated even if the screw terminal 80a tries to rotate. Engaging with the engaging surface 86a of the body 86, the rotation of the screw terminal 80a is suppressed.

JP-A-11-195561

  By the way, if the electrode terminal 82 rattles with respect to the sealing lid body 81, the sealing performance of the insertion part of the electrode terminal 82 in the sealing lid body 81 will fall. Therefore, the electrode terminal 82 needs to be fastened so as not to move with respect to the sealing lid 81, and the nut 85 is screwed with an appropriate tightening torque, and the electrode terminal 82 is sealed with an appropriate axial force. It is necessary to fasten to 81. However, the resin electrical insulator 86 is difficult to withstand an appropriate tightening torque, and the rotation of the screw terminal 80a may not be suppressed.

  Further, the secondary batteries are electrically connected by connecting electrode terminals of different poles with a plate-like conductive member. Also when the conductive member is connected to the screw terminal 80a, a bolt is screwed into the female screw portion formed on the inner peripheral surface of the screw terminal 80a. At this time, the nut 85 and the bolt are screwed together with an appropriate tightening torque. However, the resin-made electrical insulator 86 is difficult to withstand the appropriate tightening torque, and the rotation of the screw terminal 80a may not be suppressed. .

  An object of the present invention is to provide a power storage device that can suppress the accompanying rotation of electrode terminals.

  A power storage device for solving the above problems includes an electrode assembly in a case, a conductive member connected to the electrode assembly, and connected to the conductive member. An electrode terminal having a base portion integral with an end portion of the pole column portion, and a nut screwed into a male screw portion of the outer peripheral surface of the pole column portion; A power storage device having a terminal cover that insulates the wall portion and the base portion, and when connecting a conductive member to the pole column portion for connecting the power storage devices, the pole column portion A connecting member is screwed into the female screw portion included in the jig, and a jig that prevents the electrode terminal from rotating when the nut is screwed into the male screw portion is used. The electrode terminal is engaged with the jig. Engaging terminal for jig to be joined, and the terminal cover is attached to the base A first engaging portion to be engaged and a second engaging portion to be engaged with the wall portion, and the wall portion has an engaging portion for a wall portion with which the second engaging portion is engaged. And

  According to this, when the nut is screwed into the male screw portion of the electrode terminal, the jig is engaged with the jig engaging portion, and the nut is screwed into the male screw portion while the jig is prevented from rotating. The electrode terminal tries to rotate with the rotation, but the jig engaging portion engages with the jig that is prevented from rotating, and the rotation of the electrode terminal is suppressed.

  Further, when the connecting member is screwed into the female screw portion of the electrode terminal, the second engaging portion of the terminal cover is engaged with the engaging portion for the wall portion. The terminal cover is prevented from rotating by the first engagement portion engaging the base portion of the electrode terminal. For this reason, the electrode terminal tries to rotate with the rotation of the connection member, but the terminal cover is engaged with the lid and is prevented from rotating, so that the electrode terminal with the terminal cover being prevented from rotating is also suppressed. .

  In the power storage device, the wall engaging portion and the second engaging portion have inclined surfaces, and the inclined surface of the wall engaging portion includes the jig and the jig engaging portion. Even if the electrode terminal rotates within a clearance range between the wall, the wall engaging portion and the second engaging portion may be formed in a range where the inclined surfaces can be maintained in contact with each other.

  According to this, for example, when the nut is screwed into the male threaded portion with the wall engaging portion of the wall portion riding on the second engaging portion of the terminal cover, the electrode terminal is within the clearance range. Rotates. However, even if the electrode terminal rotates, the wall engaging portion and the second engaging portion are in contact with each other at the inclined surfaces. The wall portion can be moved so that the engaging portion and the second engaging portion are engaged.

In the power storage device, it is preferable that the jig has a bar-shaped hexagonal cross section, and the jig engaging portion has a hexagonal shape in plan view.
According to this, a plurality of engagement surfaces are provided in the jig engaging portion, and a plurality of engagement surfaces are also provided in the jig. For this reason, a plurality of engagement points between the engagement surfaces are formed, and even if the force in the rotation direction of the nut acts on the engagement points, the stress generated at each engagement point is dispersed and the electrode terminals are rotated. Can be suppressed.

  In the power storage device, the wall portion and the terminal cover are sandwiched between the base portion and the nut, and a length along the thickness direction of the wall portion in the wall engaging portion is along the thickness direction. Further, it may be set longer than the tolerance of the length from the outer surface of the wall portion to the tip of the polar column portion.

  According to this, when the inner surface of the wall portion rides on the second engaging portion, the outer surface of the wall portion approaches the tip surface of the polar column portion. For this reason, when measuring the length of the outer surface of the wall portion and the tip end surface of the pole column portion, this length does not fall within the difference caused by the tolerance, and it is detected that the wall portion has run on the second engaging portion. it can.

In the power storage device, a current interrupt device is integrated with the base of the negative electrode terminal.
According to this, in order to make the current interrupting device function, for example, the breaking member is provided in the conductive member joined to the electrode terminal. By suppressing the accompanying rotation of the electrode terminal, it is possible to suppress the breakage of the fracture groove without causing stress in the conductive member joined to the electrode terminal.

  According to the present invention, the accompanying rotation of the electrode terminals can be suppressed.

The disassembled perspective view which shows the secondary battery of embodiment. The disassembled perspective view which shows the fastening structure of a positive electrode terminal and a negative electrode terminal from the inner surface side of a lid | cover. The disassembled perspective view which shows the fastening structure of a positive electrode terminal and a negative electrode terminal from the outer surface side of a lid | cover. (A) is a sectional side view showing the fastening structure of the negative electrode terminal, (b) is an enlarged sectional view showing the wall engaging portion and the second engaging portion. (A) is a sectional side view showing the fastening structure of the positive electrode terminal, (b) is an enlarged sectional view showing the wall engaging portion and the second engaging portion. The perspective view which shows the screwing of a nut. Sectional drawing which shows the state which carried out the rotation stop with the jig | tool. The cross-sectional view which shows the state which stopped rotation with the jig | tool. Sectional drawing which shows the state which connected the conduction | electrical_connection member. The figure which shows background art.

Hereinafter, an embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIGS.
As shown in FIG. 1, in the secondary battery 10, an electrode assembly 20 and an electrolytic solution (not shown) are accommodated in a metal case 12. In addition, 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. Further, the secondary battery 10 of the present embodiment is a square battery whose outer periphery forms a square shape, and is a lithium ion battery. The lid 14 includes circular insertion holes 14b on both sides in the longitudinal direction. Moreover, in the lid | cover 14, the surface which faces the inner side of the case main body 13 is made into the inner surface 14a, and the surface exposed to the outer side of the case 12 is made into the outer surface 14c.

  As shown in FIG. 2, the lid 14 as a wall portion includes a substantially circular recess 15 surrounding the insertion hole 14 b, and the recess 15 is recessed from the inner surface 14 a of the lid 14. Of the outer edge portions of the recess 15, a pair of outer edge portions extending linearly in the longitudinal direction of the lid 14 are wall engaging portions 15 a. Each of the wall engaging portions 15 a is an inclined surface that increases the opening width of the recess 15 as it goes from the recess 15 toward each long side of the lid 14.

  As shown in FIG. 1, the electrode assembly 20 includes a positive electrode 21, a negative electrode 22, and a separator that insulates the positive electrode 21 from the negative electrode 22. The positive electrode 21 includes a positive electrode active material on both surfaces of a positive metal foil (aluminum foil). The negative electrode 22 includes a negative electrode active material on both surfaces of a negative electrode metal foil (copper foil). The electrode assembly 20 has a laminated structure in which a plurality of positive electrodes 21 and a plurality of negative electrodes 22 are alternately laminated, and a separator is interposed between the two electrodes.

  The positive electrode 21 has a positive current collecting tab 31 on a part of one side (long side), and the negative electrode 22 has a negative current collecting tab 32 on a part of one side (long side). The plurality of positive electrodes 21 are stacked such that the respective positive electrode current collecting tabs 31 are arranged in a line along the stacking direction. Similarly, the plurality of negative electrode electrodes 22 are stacked such that the respective negative electrode current collecting tabs 32 are arranged in a row along the stacking direction so as not to overlap the positive electrode current collecting tabs 31.

  The electrode assembly 20 includes a positive electrode tab group 45 formed by collecting positive electrode current collecting tabs 31. The positive electrode tab group 45 is welded to a positive electrode conductive member 33 as a conductive member, and the electrode assembly 20 and the positive electrode conductive member 33 are connected. A positive electrode terminal 41 as an electrode terminal is joined to the positive electrode conductive member 33.

  The electrode assembly 20 includes a negative electrode tab group 46 formed by collecting the negative electrode current collecting tabs 32. The negative electrode tab group 46 is welded to a negative electrode conductive member 37 as a conductive member, and the electrode assembly 20 and the negative electrode conductive member 37 are connected. Further, a negative electrode terminal 42 as an electrode terminal is joined to the negative electrode conductive member 37.

  As shown in FIGS. 2, 3 and 5A, the positive electrode conductive member 33 is formed by bending a rectangular plate. The positive electrode conductive member 33 includes a rectangular tab weld piece 33a on one side in the longitudinal direction from the bent portion, and a rectangular terminal weld piece 33b on the other side in the longitudinal direction from the bent portion. A circular welding hole 33c is formed in the terminal welding piece 33b. The positive electrode terminal 41 is welded to the terminal weld piece 33 b of the positive electrode conductive member 33.

  The positive electrode terminal 41 has a plate-like positive electrode base portion 43 as a base portion. The positive electrode terminal 41 has a cylindrical positive electrode column portion 44 as a pole column portion erected from the center of the positive electrode base portion 43, and a male screw portion 44 a on the outer peripheral surface of the positive electrode column portion 44. The positive electrode base portion 43 is located inside the case 12 and is integral with one end portion of the positive electrode column portion 44 in the axial direction. The positive electrode base portion 43 surrounds the positive electrode column portion 44 and has a seal seat surface 43a facing the inner surface 14a of the lid 14, and surrounds the seal seat surface 43a and has a seat surface 43b at a position lower than the seal seat surface 43a. Moreover, the positive electrode base 43 has a cylindrical weld piece 43c on the surface opposite to the seal seat surface 43a in the thickness direction. The tip of the weld piece 43c is welded around the weld hole 33c in the terminal weld piece 33b in a state where the weld piece 43c is inserted into the weld hole 33c of the positive electrode conductive member 33, and the positive terminal 41 and the positive electrode conductive member 33 are welded. Are joined.

  The positive electrode base 43 has four locking surfaces 43 d on the outer peripheral surface thereof, and the four locking surfaces 43 d are provided at equal intervals in the circumferential direction of the positive electrode base 43. Each locking surface 43d is a flat surface. A resin-made and cylindrical positive electrode terminal cover 50 is attached to the positive electrode base portion 43. The positive electrode terminal cover 50 includes a cylindrical insulating cylinder portion 51 that covers the outer peripheral surface of the positive electrode base portion 43 and closes to the seat surface 43 b, and an annular lid-side insulating portion 52 provided at one axial end of the insulating cylinder portion 51. And have.

  As shown in FIG. 2, the insulating cylinder part 51 has the 1st engaging part 51b in four places in the internal peripheral surface. The first engaging portions 51b are provided at equal intervals in the circumferential direction of the insulating cylinder portion 51 and have a flat surface shape. Each first engagement portion 51 b engages with a locking surface 43 d of the positive electrode base portion 43 and prevents rotation of the positive electrode terminal cover 50 along the circumferential direction.

  As shown in FIGS. 3 and 5A, the lid-side insulating portion 52 has an engaging protrusion 52 a that protrudes outward along the inner peripheral edge of the lid-side insulating portion 52. 52a has an annular shape. The lid-side insulating portion 52 has second engaging portions 52b at four locations on the outer peripheral surface of the engaging protrusion 52a. The second engaging portions 52b are provided at equal intervals in the circumferential direction of the engaging protrusions 52a. The second engaging portion 52b has an inclined surface shape that inclines downward from the distal end surface of the engaging protrusion 52a toward the proximal end.

  The lid-side insulating portion 52 is supported by the seating surface 43 b and insulates between the seating surface 43 b of the positive electrode base portion 43 and the inner surface 14 a of the lid 14, and the lid-side insulating portion 52 is the root of the positive electrode column portion 44. It surrounds the entire circumference and the seal seat surface 43a. The lid-side insulating portion 52 surrounds the O-ring 56 supported on the seal seat surface 43a.

  As shown in FIG. 5 (b), the sum of the protruding height H 1 of the seal seat surface 43 a from the seat surface 43 b and the diameter R of the O-ring 56 before being crushed is the thickness direction of the lid-side insulating portion 52. Is set to be longer than the length L1. For this reason, in the state where the lid-side insulating portion 52 is supported by the seat surface 43b, the O-ring 56 protrudes from the tip of the engaging protrusion 52a, and the protruding portion is pressed against the inner surface 14a of the cover 14, This is a crushing allowance for the O-ring 56.

  Here, as shown in FIG. 5A, in the positive electrode column portion 44, a surface located at the front end in the protruding direction from the positive electrode base portion 43 is defined as a front end surface 44f. In the recess 15 of the lid 14, when the length from the inner surface 14 a along the thickness direction of the lid 14 is a depth F, the depth F is from the outer surface 14 c of the lid 14 to the tip surface 44 f of the positive electrode column portion 44. It is set longer than the tolerance of the length. The tolerance of the length from the outer surface 14c to the front end surface 44f of the positive pole post 44 is the thickness of the engaging protrusion 52a of the lid-side insulating portion 52, the length from the seat surface 43b to the front end surface 44f, an external cover described later It consists of the sum of the tolerances of the thickness of the 19 flange portions 25 and the thickness of the lid 14.

  As shown in FIGS. 2, 3 and 5A, an assembly-side insulating plate 49 is mounted on the surface of the positive electrode base 43 opposite to the seal seat surface 43a in the thickness direction. The assembly-side insulating plate 49 has a square plate shape that covers the positive electrode base portion 43, and has latching claws 49a at four locations. The latching claw 49a is latched on a portion of the terminal weld piece 33b that protrudes from the outer peripheral surface of the positive electrode base 43 in a state where the positive electrode base 43 and the terminal weld piece 33b are welded. The assembly-side insulating plate 49 has an insertion hole 49b into which the weld piece 43c is inserted in a state where the terminal weld piece 33b is welded to the positive electrode base portion 43. The assembly-side insulating plate 49 insulates the positive electrode base portion 43 from the electrode assembly 20.

  The lid 14 and the positive terminal 41 are electrically insulated by the lid-side insulating portion 52 in the positive terminal cover 50. Further, the case main body 13 and the positive electrode terminal 41 are electrically insulated by the insulating cylinder portion 51. Further, the electrode assembly 20 and the positive terminal 41 are electrically insulated by the assembly-side insulating plate 49.

  As shown in FIGS. 2, 3, and 4A, the negative electrode conductive member 37 is formed by bending a plate material. The negative electrode conductive member 37 includes a rectangular tab weld piece 37a on one side in the longitudinal direction from the bent portion, and a circular terminal weld piece 37b on the other side in the longitudinal direction from the bent portion. The terminal weld piece 37b includes an annular fracture groove 37c at the center and a first contact portion 37d surrounded by the fracture groove 37c. The bent portion of the negative electrode conductive member 37 is thinner than the tab weld piece 37a and the terminal weld piece 37b. A negative electrode terminal 42 as an electrode terminal is welded to the terminal weld piece 37b.

  As shown in FIG. 4A, the negative electrode terminal 42 has a disc-shaped negative electrode base 53 as a base. Further, the negative electrode terminal 42 has a cylindrical negative electrode column portion 54 as a pole column portion erected from the center of the negative electrode base portion 53, and a male screw portion 54 a on the outer peripheral surface of the negative electrode column portion 54. The negative electrode base portion 53 surrounds the negative electrode column portion 54 and has a seal seat surface 53a facing the inner surface 14a of the lid 14, and surrounds the seal seat surface 53a and has a seat surface 53b at a position lower than the seal seat surface 53a. The negative electrode base 53 has a relief recess 53c on the surface opposite to the seal seat surface 53a in the thickness direction.

  As shown in FIG. 3, the negative electrode base 53 has four locking surfaces 53 d on its outer peripheral surface, and the four locking surfaces 53 d are provided at equal intervals in the circumferential direction of the negative electrode base 53. Each locking surface 53d is a flat surface. A resin-made and cylindrical negative electrode terminal cover 58 is attached to the negative electrode base 53. The negative electrode terminal cover 58 includes a cylindrical insulating cylinder part 59 that covers the outer peripheral surface of the negative electrode base 53, and an annular lid-side insulating part 60 provided at one end in the axial direction of the insulating cylinder part 59.

  As shown in FIG. 2, the insulating cylinder part 59 has the 1st engaging part 59b in four places in the internal peripheral surface. The first engaging portions 59b are provided at equal intervals in the circumferential direction of the insulating cylinder portion 59 and have a flat surface shape. Each first engagement portion 59 b engages with the locking surface 53 d of the negative electrode base portion 53 to prevent the negative electrode terminal cover 58 from rotating in the circumferential direction.

  As shown in FIGS. 3 and 4A, the lid-side insulating portion 60 has an engaging protrusion 60a along the inner peripheral edge of the lid-side insulating portion 60, and the outer peripheral surface of the engaging protrusion 60a. There are second engaging portions 60b at four locations. The second engaging portions 60b are provided at equal intervals in the circumferential direction of the engaging protrusion 60a. Further, the second engaging portion 60b has an inclined surface shape that inclines downward from the front end surface of the engaging protrusion 60a toward the base end.

  The lid-side insulating part 60 is supported by the seating surface 53 b of the negative electrode base 53 to insulate between the negative electrode base 53 and the inner surface 14 a of the lid 14, and the lid-side insulating part 60 is completely attached to the negative pole column part 54. The circumference and the seal seat surface 53a are surrounded. The lid-side insulating portion 60 surrounds the O-ring 56 supported on the seal seat surface 53a.

  Here, as shown in FIG. 4B, the sum of the protrusion height H2 of the seal seat surface 53a from the seat surface 53b and the diameter R of the O-ring 56 before being crushed is the lid-side insulating portion 60. Longer than the length L2 along the thickness direction. For this reason, in the state where the lid-side insulating portion 60 is supported by the seat surface 53b, the O-ring 56 protrudes from the tip of the engaging protrusion 60a, and the protruding portion is pressed against the inner surface 14a of the cover 14, This is a crushing allowance for the O-ring 56.

  As shown in FIG. 4A, in the negative electrode column portion 54, a surface located at the front end in the protruding direction from the negative electrode base portion 53 is defined as a front end surface 54f. And the depth F of the recessed part 15 is set longer than the tolerance of the length from the outer surface 14c of the lid | cover 14 to the front end surface 54f of the negative electrode pillar part 54. FIG. The tolerance of the length from the outer surface 14c to the front end surface 54f of the negative pole post 54 is the thickness of the engagement protrusion 60a of the lid-side insulating portion 60, the length from the seat surface 53b to the front end surface 54f, an external cover described later It consists of the sum of the tolerances of the thickness of the 19 flange portions 25 and the thickness of the lid 14.

  In addition, a current interrupt device 62 is integrated with the negative terminal 42. The current interrupt device 62 electrically connects the electrode assembly 20 and the negative terminal 42. In addition, the current interrupt device 62 interrupts the serial energization path between the electrode assembly 20 and the negative terminal 42 when the internal pressure of the case 12 rises above a predetermined level. The “predetermined level of internal pressure” means the internal pressure of the case 12 when the secondary battery 10 is overcharged (overvoltage) or overheated (thermal runaway temperature of the active material). The “predetermined level of internal pressure” is set according to conditions such as the capacity of the secondary battery 10 and the output voltage.

  The current interrupt device 62 is disposed inside the case 12. The current interrupt device 62 is arranged from the electrode assembly 20 side toward the lid 14, and includes a support member 66, a deformation plate 63, a terminal weld piece 37 b of the negative electrode conductive member 37, a seal member 67, an insulating ring 68, and a contact plate. 65. The negative electrode terminal cover 58, the negative electrode base 53, the seal member 67, the insulating ring 68, the deformation plate 63, the terminal weld piece 37b, and the support member 66 are integrated by a metal caulking member 69. ing.

  The deformation plate 63 is a metal-made and disk-shaped diaphragm, and the outer peripheral part of the deformation plate 63 is joined to the terminal welding piece 37b by welding. The deformation plate 63 prevents the gas from flowing from the inside of the case 12 into the negative electrode terminal 42. Further, the deformable plate 63 includes a pressure receiving portion 63a at a portion surrounded by a welded portion to the terminal weld piece 37b, and the pressure receiving portion 63a receives the internal pressure of the case 12. Further, the deformable plate 63 includes a protrusion 63b at the center of the pressure receiving portion 63a, and the protrusion 63b protrudes toward the first contact portion 37d of the terminal weld piece 37b. When the internal pressure of the case 12 is less than the above-mentioned predetermined level of internal pressure, the deformable plate 63 is in a state of expanding away from the terminal weld piece 37b, and the protrusion 63b is separated from the terminal weld piece 37b.

  The contact plate 65 is a conductive metal and disc-shaped diaphragm, and the outer periphery of the contact plate 65 is sandwiched between the negative electrode base 53 and the insulating ring 68 as the current interrupting device 62 is assembled. Yes. The contact plate 65 includes a second contact portion 65 a at the center, and the second contact portion 65 a is in contact with the first contact portion 37 d of the negative electrode conductive member 37.

  The insulating ring 68 is interposed between the outer peripheral portion of the contact plate 65 and the terminal weld piece 37b, and the contact plate 65 and the terminal weld piece 37b are electrically insulated by the insulating ring 68. The contact plate 65 is provided with a communication hole 65b.

  The support member 66 is made of, for example, resin, has a ring shape in plan view, and supports the deformation plate 63 from the electrode assembly 20 side. The support member 66 has a gas hole 66 a at the center, and introduces the gas in the case 12 into the current interrupt device 62.

In the current interrupt device 62 configured as described above, when the internal pressure of the case 12 rises above a predetermined level, gas is introduced into the current interrupt device 62 from the gas hole 66a of the support member 66.
As shown by the two-dot chain line in FIG. 4A, the deformable plate 63 receives the internal pressure of the case 12 and deforms toward the terminal weld piece 37b. Then, the protrusion 63b moves toward the terminal weld piece 37b, and gives an impact to the first contact portion 37d of the terminal weld piece 37b and the second contact portion 65a of the contact plate 65. As a result, the terminal weld piece 37b breaks from the break groove 37c, the first contact portion 37d is separated from the terminal weld piece 37b, and the series current path between the electrode assembly 20 and the negative electrode terminal 42 is interrupted. Further, the second contact portion 65 a of the contact plate 65 enters the relief recess 53 c of the negative electrode base portion 53.

  As shown in FIG. 3, the positive electrode column portion 44 and the negative electrode column portion 54 include a jig engaging portion 57 that is recessed from the front end surfaces 44 f and 54 f along the axial direction. The jig engaging portion 57 has a hexagonal shape in a plan view along the axial direction of the positive electrode column portion 44 and the negative electrode column portion 54, and is recessed in a hexagonal shape from the front end surfaces 44f and 54f along the axial direction. The jig engaging portion 57 includes six engaging surfaces 57a formed from six inner surfaces at regular intervals.

  As shown in FIG. 8, a metal jig 48 can be engaged with the jig engaging portion 57. The jig 48 has a hexagonal bar shape in cross section along the entire axial direction, and includes six engaging surfaces 48a formed from six side surfaces.

  When the jig 48 is inserted into the jig engaging portion 57, the six engaging surfaces 57a of the jig engaging portion 57 and the six engaging surfaces 48a of the jig 48 can be engaged. Six joints are formed. The jig 48 has a length protruding from the tip surfaces 44f and 54f in a state where the engagement surface 48a is engaged with the engagement surface 57a of the jig engagement portion 57. In the state where the jig 48 is inserted into the jig engaging portion 57, a clearance is formed between the outer surface of the jig 48 and the inner surface of the jig engaging portion 57. The negative electrode terminal 42 can rattle (rotate) within the clearance range.

  As shown in FIGS. 4A and 5A, the positive electrode terminal 41 has a female screw portion 44b on the inner side in the axial direction from the jig engagement portion 57, and the negative electrode terminal 42 has a jig engagement. An internal thread portion 54b is provided on the inner side in the axial direction from the joint portion 57.

  In the positive electrode terminal 41 and the negative electrode terminal 42 configured as described above, the positive electrode column portion 44 and the negative electrode column portion 54 protrude from the case 12 through the insertion hole 14 b of the lid 14. Outside the case 12, a nut 55 is screwed from the outside of the case 12 to the male screw portion 44 a of the positive electrode column portion 44 and the male screw portion 54 a of the negative electrode column portion 54, and the positive electrode terminal 41 and the negative electrode terminal 42 are fastened to the lid 14. ing.

  Further, the inner peripheral surface of the insertion hole 14 b of the lid 14 and the outer peripheral surface of the positive electrode column portion 44 or the negative electrode column portion 54 are insulated by the external cover 19. The outer cover 19 includes an annular cylindrical portion 24 and a flange portion 25 that extends radially outward from one axial end of the cylindrical portion 24. The cylindrical portion 24 is interposed between the inner peripheral surface of the insertion hole 14 b and the outer peripheral surface of the positive electrode column portion 44 or the negative electrode column portion 54. The flange portion 25 is provided around the insertion hole 14 b on the outer surface 14 c of the lid 14.

  In the secondary battery 10, the flange portion 25 of the outer cover 19 is sandwiched between the peripheral edge of the insertion hole 14 b in the outer surface 14 c of the lid 14 and the end surface of the nut 55 on the lid 14 side. 55 and the lid 14 are insulated. Further, the nut 55 is screwed into the positive electrode column portion 44 and the negative electrode column portion 54, whereby the flange portion 25, the lid 14, the O-ring 56, and the lid side are provided between the nut 55 and the positive electrode base portion 43 and the negative electrode base portion 53. The insulating parts 52 and 60 are sandwiched. In this fastened state, the O-ring 56 is in close contact with the inner surface 14a of the lid 14 and the seal seat surfaces 43a and 53a in a compressed state, and seals the periphery of the insertion hole 14b.

  As shown in FIGS. 1 and 9, the secondary batteries 10 are electrically connected to the negative terminal 42 of the secondary battery 10 where the positive terminal 41 is adjacent to the positive terminal 41 of the secondary battery 10 where the negative terminal 42 is adjacent. It is connected via the member 70. The conducting member 70 has a rectangular plate shape and has a pair of insertion portions 70a. The conducting member 70 is fixed to the positive column 44 and the negative column 54 by a bolt-shaped connecting member 71. The connecting member 71 includes a connecting male screw portion 71a that is screwed into the female screw portions 44b and 54b, and a head portion 71b at one axial end of the connecting male screw portion 71a.

Next, the manufacturing method of the secondary battery 10 will be described together with the operation.
As shown in FIG. 5A, the positive terminal 41 is welded to the positive terminal welding piece 33b. Next, the tab weld piece 33 a is welded to the positive electrode tab group 45. Subsequently, the O-ring 56 is placed on the seal seat surface 43 a of the positive terminal 41, and the positive terminal cover 50 is attached to the positive base 43 so as to surround the O-ring 56. At this time, the first engagement portion 51b of the positive electrode terminal cover 50 is engaged with the locking surface 43d of the positive electrode base portion 43 so that the positive electrode terminal cover 50 is prevented from rotating.

  Next, in the terminal welding piece 33 b, the latching claw 49 a of the assembly-side insulating plate 49 is hooked at a portion protruding from the outer peripheral surface of the positive electrode base 43, and the assembly-side insulating plate 49 is attached to the positive electrode base 43.

  Next, as shown in FIG. 4 (a), the negative electrode terminal 42 is welded to the negative electrode terminal weld piece 37 b and the negative electrode terminal cover 58 is attached to the negative electrode base 53 while the current blocking device 62 is assembled to the negative electrode base 53. To do. At this time, the first engaging portion 59b of the negative electrode terminal cover 58 is engaged with the locking surface 53d of the negative electrode base portion 53 so that the negative electrode terminal cover 58 is prevented from rotating. Then, the negative electrode base 53, the terminal welding piece 37 b, the current interrupt device 62, and the negative electrode terminal cover 58 are integrated with a caulking member 69. Further, the O-ring 56 is placed on the seal seat surface 53 a of the negative terminal 42.

  Next, as shown in FIG. 6, the lid 14 is placed on the lid-side insulating portion 52 of the positive electrode terminal cover 50 and the lid-side insulating portion 60 of the negative electrode terminal cover 58, and the positive pole portion 44 is placed in one insertion hole 14 b. The negative pole portion 54 is inserted through the other insertion hole 14b. Further, the outer cover 19 is interposed between the inner peripheral surface of the insertion hole 14 b and the positive electrode column portion 44 and between the inner peripheral surface of the insertion hole 14 b and the negative electrode column portion 54.

  Next, as shown in FIGS. 7 and 8, the jig 48 is inserted into the jig engaging portion 57 of the positive electrode column portion 44 and the negative electrode column portion 54, and the engagement surface 48 a of the jig 48 is set to the jig. The engagement portion 57 is engaged with the engagement surface 57a to form six engagement portions. Then, the nuts 55 are screwed into the male screw portions 44 a of the positive electrode column portion 44 and the male screw portions 54 a of the negative electrode column portion 54 with both the jigs 48 being prevented from rotating with the tool K.

  As a result, the positive terminal 41 and the negative terminal 42 are fastened to the lid 14 by the nut 55. Next, after the jig 48 is removed from the jig engaging portion 57, the electrode assembly 20 is accommodated in the case main body 13 and the lid 14 is joined to the case main body 13 to form the case 12. The secondary battery 10 is assembled.

  As shown in FIG. 9, when connecting a plurality of secondary batteries 10, the connection male screw portion 71 a of the connection member 71 is inserted into the insertion portion 70 a of the conduction member 70, and the connection male screw portion 71 a is connected to each female screw portion. 44b and 54b. Then, the head 71b presses the conduction member 70 toward the front end surfaces 44f and 54f, and presses the periphery of the insertion portion 70a against the front end surfaces 44f and 54f. Then, the conducting member 70 is fixed to the positive terminal 41 and the negative terminal 42 by the connecting member 71, and the secondary batteries 10 are electrically connected by the conducting member 70.

According to the above embodiment, the following effects can be obtained.
(1) The jig 48 is engaged with the jig engaging portion 57, and the nut 55 is screwed into the male screw portions 44a and 54a while the jig 48 is prevented from rotating. Therefore, when the nut 55 is screwed, the positive electrode terminal 41 and the negative electrode terminal 42 try to rotate with the nut 55, but the jig engaging portion 57 engages with the jig 48 that is prevented from rotating, The positive terminal 41 and the negative terminal 42 are prevented from rotating (following). Therefore, rotation prevention of the positive electrode terminal 41 and the negative electrode terminal 42 is performed by engagement of the metal jig 48 and the positive electrode terminal 41 and the negative electrode terminal 42, and rotation prevention can be suppressed without damaging components. .

  Further, the positive terminal cover 50 is locked by the first engaging portion 51 b engaging the locking surface 43 d of the positive base portion 43, and the negative terminal cover 58 is engaged with the negative base portion 53 by the first engaging portion 59 b. The rotation is stopped by engaging with the stop surface 53d. When the connection member 71 is screwed into the female screw portions 44b and 54b, the positive terminal 41 and the negative terminal 42 try to rotate with the connection member 71. However, the second engagement portions 52b of the terminal covers 50 and 58 are used. , 60b engage with the wall engaging portion 15a of the lid 14. For this reason, the accompanying rotation of the positive terminal 41 and the negative terminal 42 in which the terminal covers 50 and 58 are prevented from rotating is suppressed. Therefore, since the rotation prevention of the positive electrode terminal 41 and the negative electrode terminal 42 is performed by the engagement formed in a plurality of places, the rotation prevention can be suppressed without damaging the engaged parts.

  (2) The wall engaging portion 15a of the lid 14 has an inclined surface, and each of the second engaging portions 52b and 60b also has an inclined surface. For this reason, even if the wall engaging portion 15a rides on the second engaging portions 52b, 60b, if the lid 14 is pressed toward the electrode assembly 20 by the screwing of the nut 55, The inclined surface can guide the lid 14 to move toward the electrode assembly 20 along the inclined surface. Therefore, it is possible to suppress the positive terminal 41 and the negative terminal 42 from being fastened to the lid 14 while the wall engaging portion 15a has run over the second engaging portions 52b and 60b.

  (3) Even if the positive electrode terminal 41 or the negative electrode terminal 42 rotates within the clearance range between the jig 48 and the jig engagement part 57, the inclined surface of the wall engagement part 15 a is The engagement portion 15a is formed in a range in which the engagement between the second engagement portions 52b and 60b can be maintained. Accordingly, when the nut 55 is screwed, even if the wall engaging portion 15a rides on the second engaging portions 52b and 60b, the second engaging portions 52b and 60b are screwed into the recess 15 by the screwing of the nut 55. It is possible to prevent the lid 14 from being assembled incorrectly.

  (4) The jig engaging portion 57 has a hexagonal shape in plan view and includes six engaging surfaces 57a. The jig 48 also has a hexagonal cross section and has six engaging surfaces 48a. Therefore, when the jig 48 is engaged with the jig engaging portion 57, six engagement points are formed. Therefore, even if the force in the rotation direction of the nut 55 acts on the engaging portion, the stress generated at each engaging portion is dispersed, and the accompanying rotation of the terminals 41 and 42 can be easily suppressed.

  (5) The depth F of the concave portion 15 of the lid 14 is set to be longer than the tolerance of the length from the outer surface 14c of the lid 14 to each of the front end surfaces 44f and 54f. For this reason, when the inner surface 14a of the lid 14 has ridden on the second engaging portions 52b and 60b, the outer surface 14c of the lid 14 exceeds the tolerance range, and the front end surface 44f of the positive electrode terminal 41 or the negative electrode terminal 42, It approaches 54f. For this reason, when the distance between the outer surface 14c of the lid 14 and each of the front end surfaces 44f and 54f is measured, the distance does not fall within the difference caused by the tolerance, and the lid 14 rides on the second engagement portions 52b and 60b. Can be detected.

  (6) The negative electrode terminal 42 is integrally provided with a current interrupting device 62, and a breaking groove 37c is provided in the negative electrode conductive member 37 in order to make the current interrupting device 62 function. In the present embodiment, in the negative electrode, the negative electrode terminal 42 is rotated by the engagement of the locking surface 53d, the first engaging portion 59b, the second engaging portion 60b, and the wall engaging portion 15a. Can be suppressed. For this reason, it can suppress that the fracture | rupture groove | channel 37c will fracture | rupture by the accompanying rotation of the negative electrode terminal 42. FIG.

  (7) The positive electrode terminal 41 is integrated with the positive electrode conductive member 33 by welding a cylindrical weld piece 43c to the terminal weld piece 33b. In the present embodiment, in the positive electrode, the positive terminal 41 is rotated by the engagement of the locking surface 43d, the first engaging portion 51b, the second engaging portion 52b, and the wall engaging portion 15a. Can be suppressed. For this reason, it can suppress that the welding piece 43c fractures | ruptures from the terminal welding piece 33b by the accompanying rotation of the positive electrode terminal 41. FIG.

  (8) The wall engaging portion 15 a of the lid 14 is provided so as to extend in the longitudinal direction of the lid 14. For this reason, when the nut 55 is screwed or when the connection member 71 is screwed, the tab weld pieces 33a and 37a are prevented from being rotated by the engagement between the wall engaging portion 15a and the second engaging portions 52b and 60b. However, it can suppress contacting the inner surface of the long side wall of the case main body 13.

  (9) Each seal seat surface 43a, 53a protrudes from each seat surface 43b, 53b. For this reason, when the O-ring 56 is placed on each seal seat surface 43a, the O-ring 56 protrudes from the tips of the engaging projections 52a and 60a supported by the seat surfaces 43b and 53b. Therefore, a crushing allowance can be secured for the O-ring 56 and the insertion hole 14 b can be sealed by the O-ring 56.

In addition, you may change the said embodiment as follows.
The current interrupting device 62 may not be integrated with the negative terminal 42, and the negative terminal 42 may have the same structure as the positive terminal 41.

The depth F of the recess 15 may be the same as the tolerance of the length from the outer surface 14 c of the lid 14 to the tip surfaces 44 f and 54 f of the pole columns 44 and 54.
The shape of the jig 48 and the jig engaging portion 57 may be appropriately changed as long as they can be engaged with each other.

  The wall engaging portion 15a may not have an inclined surface and may be formed to be orthogonal to the inner surface 14a and the outer surface 14c of the lid 14. Alternatively, the wall engaging portion 15a may have a shape that has a surface orthogonal to the inner surface 14a and the outer surface 14c of the lid 14 and is chamfered at a portion that intersects the inner surface 14a.

Alternatively, the wall engaging portion 15a may have a gently curved surface instead of an inclined surface.
In this case, the second engaging portions 52b and 60b may have an inclined surface or may not have an inclined surface. For example, the engagement protrusions 52a and 60a have vertical surfaces extending along the axial direction of the positive electrode terminal cover 50 and the negative electrode terminal cover 58, and the front end surfaces of the engagement protrusions 52a and 60a orthogonal to the vertical surfaces. And a chamfered portion or a rounded portion may be provided at a portion where the vertical surface and the tip surface intersect.

The number of the first engaging portions 51b and 59b and the second engaging portions 52b and 60b may be changed as appropriate, and the number of the wall engaging portions 15a may be changed as appropriate.
Although the wall engaging portion 15a is formed to extend in the longitudinal direction of the lid 14, the wall engaging portion 15a may be formed to extend in the short direction of the lid 14.

In the embodiment, the wall portion of the case 12 is embodied as the lid 14, but the side wall or the bottom wall of the case body 13 may be the wall portion of the case 12.
The number of the positive electrode 21 and the negative electrode 22 which comprise the electrode assembly 20 may be changed suitably.

The shape of the case 12 may be formed in a columnar shape or an elliptical column shape that is flat in the left-right direction.
The present invention may be embodied as a nickel hydride secondary battery as an electricity storage device or an electric double layer capacitor.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery as a power storage device, 12 ... Case, 14 ... Lid as wall part, 14b ... Insertion hole, 14c ... Outer surface, 15a ... Engagement part for wall part, 20 ... Electrode assembly, 33 ... Conductive member Positive electrode conductive member as 37, negative electrode conductive member as conductive member, 41 ... positive electrode terminal as electrode terminal, 42 ... negative electrode terminal as electrode terminal, 43 ... positive electrode base as base, 44 ... positive electrode as pole column Column part, 44a, 54a ... male screw part, 44b, 54b ... female screw part, 48 ... jig, 50 ... positive electrode terminal cover, 51b, 59b ... first engagement part, 52b, 60b ... second engagement part, 53 ... Negative electrode base as base, 54 ... Negative pole column as pole post, 55 ... Nut, 57 ... Jig engagement part, 58 ... Negative terminal cover, 62 ... Current interrupt device, 70 ... Conductive member, 71 ... Connection Element.

Claims (5)

An electrode assembly in the case, a conductive member connected to the electrode assembly, a pole column connected to the conductive member and projecting out of the case from an insertion hole in the wall of the case, and inside the case An electrode terminal that is positioned and has a base portion integral with an end portion of the pole column portion, a nut that is screwed to a male screw portion on the outer peripheral surface of the pole column portion, and a terminal that insulates the wall portion and the base portion A power storage device having a cover,
When connecting a conductive member to the pole column portion for connecting the power storage devices, a connection member is screwed into a female screw portion included in the pole column portion, and the nut is screwed into the male screw portion. When doing so, a jig to stop the electrode terminal is used,
The electrode terminal has a jig engaging portion with which the jig is engaged,
The terminal cover has a first engagement portion that engages with the base portion and a second engagement portion that engages with the wall portion,
The power storage device, wherein the wall portion includes a wall engaging portion with which the second engaging portion is engaged.   The wall engaging portion and the second engaging portion have inclined surfaces, and the inclined surface of the wall engaging portion is a clearance range between the jig and the jig engaging portion. The power storage device according to claim 1, wherein the wall portion engaging portion and the second engaging portion are formed in a range in which the inclined surfaces can be maintained in contact with each other even when the electrode terminal rotates.   The power storage device according to claim 1, wherein the jig has a bar-shaped hexagonal cross section, and the jig engaging portion has a hexagonal shape in plan view.   The wall portion and the terminal cover are sandwiched between the base portion and the nut, and the length of the wall portion engaging portion along the thickness direction of the wall portion is the outer surface of the wall portion along the thickness direction. The power storage device according to any one of claims 1 to 3, wherein the power storage device is set to be longer than a tolerance of a length from a tip to a tip of the pole portion.   The electrical storage apparatus as described in any one of Claims 1-4 with which the electric current interruption apparatus is integrated in the base part of the electrode terminal of a negative electrode.