JP6488831B2 - Power storage device - Google Patents

Description

  The present invention is a metal external connection terminal that can fix the bus bar outside the wall portion of the case, a lead terminal that protrudes outside from the wall portion, and a metal that connects the lead terminal and the external connection terminal. The present invention relates to a power storage device including the terminal connection member, and an insulating member that insulates the terminal connection member from the wall.

  Vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles) are equipped with battery modules that store electric power supplied to electric motors serving as prime movers. The battery module is configured by electrically connecting secondary batteries as power storage devices with a bus bar. For example, as shown in FIG. 8, the battery device (secondary battery) of Patent Document 1 includes a metal terminal 81 extending from the battery module, a bolt (external connection terminal) 82 penetrating the metal terminal 81, and a metal terminal. 81 and an insulator 84 that insulates the battery module housing 83 from each other. The insulator 84 includes an engagement protrusion 84 b protruding toward the housing 83, and the engagement protrusion 84 b is inserted into a recess 83 a that is recessed from the surface of the housing 83.

  The metal terminal 81 has a crank shape. The metal terminal 81 includes a fixed piece 81 a, and the fixed piece 81 a is fixed to the housing 83 by a rivet (drawer terminal) 86 through an insulator 84. The rivet 86 is connected to a terminal (not shown), and this terminal is electrically connected to the battery cell. In addition, the metal terminal 81 includes a terminal piece 81b that is located farther from the housing 83 than the fixed piece 81a.

  The bolt 82 includes a hexagonal enlarged portion 82a, a flange portion 82b protruding outward from the enlarged portion 82a along the radial direction of the bolt 82, and a shaft portion 82c having a male screw. The insulator 84 includes a drop prevention portion 85 that comes into contact with the flange portion 82 b of the bolt 82 from below and prevents the bolt 82 from dropping from the metal terminal 81. The drop-off prevention portion 85 has a shape surrounding the enlarged portion 82a of the bolt 82.

  In the battery module of Patent Document 1, the battery cell and the bolt 82 are electrically connected through a terminal (not shown), a rivet 86, and a metal terminal 81, and electricity is transferred. Then, the bolt 82 is inserted into the through hole 88a provided in the bus bar 88, and the bus bar 88 is placed on the terminal piece 81b. By screwing the nut 89 into the shaft portion 82c of the bolt 82, the bus bar 88 is sandwiched between the bolt 82 and the nut 89, and the bus bar 88 and the metal terminal 81 are electrically connected. As a result, the battery modules are electrically connected via the bus bar 88.

  Moreover, in patent document 1, in order to suppress the joint rotation of the volt | bolt 82 at the time of screwing the nut 89 to the axial part 82c of the volt | bolt 82, the insulator 84 is provided with the drop-off prevention part 85, and this drop-off prevention part 85 is It is a wall part surrounding the enlarged part 82a. And in patent document 1, the expansion part 82a of the volt | bolt 82 latches to the inner surface of the drop-off prevention part 85 at the time of screwing of the nut 89. FIG. At this time, since the rotation of the insulator 84 is restricted by the engagement between the engagement protrusion 84b of the insulator 84 and the recess 83a of the housing 83, the drop prevention portion 85 integral with the insulator 84 causes the bolt The rotation of 82 is prevented, and the joint rotation of the bolt 82 is suppressed.

Japanese Patent No. 4670958

  By the way, in Patent Document 1, the bus bar 88 is sandwiched between the bolt 82 and the nut 89, and in order to suppress the joint rotation of the bolt 82 when the nut 89 is screwed, the bus bar 88 is prevented from falling off from the metal terminal 81 to the housing 83 side. A portion 85 is provided. The drop-off prevention part 85 receives the torque of the nut 89 and prevents the bolt 82 from rotating, but since it is made of synthetic resin, the drop-off prevention part 85 is enlarged in the axial direction of the bolt 82 to receive the torque. Cheap. Therefore, the bolt 82 is separated from the housing 83, and the terminal piece 81 b supported by the bolt 82 is also separated from the housing 83, and the rivet 86 and the bolt 82 are separated as the terminal piece 81 b is separated from the housing 83. As a result, the conductive distance increases and the electrical resistance increases.

  The present invention has been made paying attention to such problems existing in the prior art, and its purpose is a power storage device capable of shortening the conduction distance between the lead terminal and the external connection terminal. Is to provide.

  A power storage device for solving the above problems includes an electrode assembly in which electrodes of different polarities are insulated from each other, a case for housing the electrode assembly, and an outer side of the wall of the case. A metal external connection terminal that is disposed on the outer surface of the wall portion so that the bus bar can be fixed and can be inserted into the shaft insertion hole of the bus bar, and is electrically connected to the electrode assembly in the case. And a lead terminal in a state of projecting outward from the wall portion of the case, and a metal terminal connecting member disposed outside the wall portion of the case and connecting the lead terminal and the external connection terminal And an insulating member that insulates the terminal connection member and the wall portion and prevents the terminal connection member from rotating and is also prevented from rotating around the wall portion, ,Previous When the direction along the protruding direction from the wall portion of the external connection terminal is the thickness direction, the terminal connection member has a through hole penetrating in the thickness direction, and includes a rotation preventing portion present in the through hole, The external connection terminal is connected to a shaft portion to which a nut for fastening the bus bar can be screwed, and is connected to the wall portion side of the shaft portion, and is locked to the rotation preventing portion in the through hole. And the crimping portion connected to the wall portion side of the locking portion, the shaft portion side of the crimping portion, and the terminal connecting member in the thickness direction together with the crimping portion. The gist of the present invention is to provide a clamping unit for clamping.

  According to this, in the power storage device, the locking portion of the external connection terminal is locked to the rotation preventing portion within the thickness of the terminal connection member. Moreover, the external connection terminal is being fixed to the terminal connection member by pinching the terminal connection member by the clamping part and the crimping part. When the nut is screwed onto the shaft portion of the external connection terminal to fix the bus bar to the external connection terminal, the torque applied to the nut is caused by the locking portion of the external connection terminal being applied to the rotation prevention portion of the terminal connection member. By being locked, it is received by the terminal connection member. The terminal connection member is prevented from rotating by an insulating member that is prevented from rotating around the wall. For this reason, the co-rotation of the external connection terminals is suppressed by the insulating member that is prevented from rotating.

  And since a terminal connection member and an external connection terminal are metal, it can suppress that a latching | locking part and a rotation stop part receive torque, and are damaged. Therefore, in order to receive the torque at the anti-rotation portion, the size of the anti-rotation portion does not need to be increased, and the size of the locking portion does not need to be increased in the axial direction.

  For example, the case where a bolt-shaped thing is used as an external connection terminal, and a terminal connection member is supported and connected on the bolt head of an external connection terminal is made into a comparative example. In this comparative example, the rotation of the external connection terminal is performed by preventing the bolt head from rotating at a position closer to the wall than the terminal connection member. On the other hand, since the rotation of the external connection terminal is performed within the thickness of the terminal connection member, the terminal connection member can be brought closer to the wall as compared with the comparative example. As a result, the protruding amount of the lead terminal from the wall can be made shorter than that of the comparative example, and the conduction distance from the lead terminal to the external connection terminal can be made shorter than that of the comparative example.

Moreover, about the electrical storage apparatus, the said latching | locking part may serve as the said clamping part.
According to this, the clamping part is also located within the thickness of the terminal connection member, and the bus bar is supported on the surface of the terminal connection member even when the terminal connection member is clamped between the clamping part and the crimping part. Can do. For this reason, for example, as compared with the case where the clamping part is arranged on the surface of the terminal connection member and the bus bar is supported on the clamping part, the bus bar is brought closer to the wall part, and the conduction distance from the electrode assembly to the bus bar is Can be shortened.

In the power storage device, it is preferable that the locking portion has a polygonal shape or a shape including a pair of sides extending in parallel when viewed from the axial direction of the external connection terminal.
According to this, for example, when the locking portion is manufactured by forging, the locking portion can be easily formed.

  The power storage device is a secondary battery.

  According to the present invention, the conduction distance between the lead terminal and the external connection terminal can be shortened.

The disassembled perspective view which shows the secondary battery of embodiment. The perspective view which shows the external appearance of a secondary battery. The disassembled perspective view which shows the component of an electrode assembly. The perspective view which shows an external connection terminal. (A) is a fragmentary sectional view which shows the inside of the secondary battery of embodiment, (b) is a fragmentary sectional view which shows the inside of the secondary battery of a comparative example. The perspective view which shows another example of an external connection terminal. The fragmentary sectional view which shows the external connection terminal of another example. 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 or FIG. 2, the secondary battery 10 as a power storage device includes a case 11, and an electrode assembly 12 is accommodated in the case 11. The case 11 includes a rectangular box-shaped case main body 14 and a lid member 15 as a rectangular flat wall portion that closes the opening 14 a of the case main body 14. In addition, the secondary battery 10 of this embodiment is a lithium ion battery. The secondary battery 10 includes a positive terminal structure 16 and a negative terminal structure 17 that exchange electricity with the electrode assembly 12.

  As shown in FIG. 3, the electrode assembly 12 includes a sheet-like positive electrode 21 and a sheet-like negative electrode 31. The positive electrode 21 has a positive metal foil (aluminum foil in this embodiment) 22 and a positive electrode active material layer 23 formed by applying a positive electrode active material on both surfaces thereof. The negative electrode 31 includes a negative electrode metal foil (copper foil in the present embodiment) 32 and a negative electrode active material layer 33 configured by applying a negative electrode active material on both surfaces thereof. The electrode assembly 12 has a laminated structure in which a separator 24 is interposed between the positive electrode 21 and the negative electrode 31 to form a layer.

  The positive electrode 21 has a positive electrode uncoated portion 22 b that is not coated with a positive electrode active material along one side 22 a of the positive metal foil 22. The positive electrode 21 has a tab 25 having a shape protruding from a part of one side 22a. The negative electrode 31 has a negative electrode uncoated portion 32 b that is not coated with a negative electrode active material along one side 32 a of the negative electrode metal foil 32. The negative electrode 31 has a tab 35 having a shape protruding from a part of one side 32a.

  As shown in FIG. 1, the positive electrode tab 25 and the negative electrode tab 35 are provided at positions where the positive electrode tab 25 and the negative electrode tab 35 do not overlap with each other in a state where the positive electrode 21 and the negative electrode 31 are laminated. ing. The positive electrodes 21 constituting the electrode assembly 12 are stacked such that the tabs 25 are arranged in a row along the stacking direction L. Similarly, the negative electrodes 31 constituting the electrode assembly 12 are stacked such that the tabs 35 are arranged in a row along the stacking direction L.

  The secondary battery 10 includes a positive electrode tab group 36. The positive electrode tab group 36 is configured by collecting and stacking all the positive electrode tabs 25 on one end side in the stacking direction L of the electrode assembly 12. Further, the secondary battery 10 includes a negative electrode tab group 36. The negative electrode tab group 36 is configured by collecting and stacking all the negative electrode tabs 35 on one end side in the stacking direction L of the electrode assembly 12.

  A positive electrode conductive member 51 for electrically connecting the electrode assembly 12 and a positive electrode terminal structure 16 described later is joined to the positive electrode tab group 36. The negative electrode tab group 36 is joined with a negative electrode conductive member 51 for electrically connecting the electrode assembly 12 and a negative electrode terminal structure 17 to be described later. Each conductive member 51 has a rectangular plate shape. The conductive member 51 has an insertion hole 52a at one end along the extending direction of the long side, and a later-described lead terminal 61 can be inserted into the insertion hole 52a.

Next, the inner insulating cover 55 provided in the secondary battery 10 will be described.
As shown in FIG. 1, the secondary battery 10 includes an inner insulating cover 55 in the case 11, and the inner insulating cover 55 is interposed between the negative electrode conductive member 51 and the positive electrode conductive member 51 and the lid member 15. Intervene. The inner insulating cover 55 has insertion holes 56 at both ends in the extending direction of the long side.

  Next, the positive terminal structure 16 and the negative terminal structure 17 will be described. 5A shows the negative electrode terminal structure 17, the positive electrode terminal structure 16 is the same as the negative electrode terminal structure 17, and therefore illustration thereof is omitted.

First, the configuration of the lid member 15 for providing the positive terminal structure 16 and the negative terminal structure 17 will be described.
As shown in FIG. 1 or FIG. 5A, the lid member 15 has an outer surface 15c facing the outer side of the case 11 and an inner surface 15d facing the inner side of the case 11. The lid member 15 has an outer surface 15c and an inner surface 15d. The direction connecting at the shortest distance is the thickness direction. The lid member 15 includes locking recesses 15f on both end sides along the direction in which the long side extends. Each locking recess 15f is recessed from the outer surface 15c along the thickness direction. When the lid member 15 is viewed from the outer surface 15c, the locking recess 15f has a rectangular shape. The locking recess 15f is formed by pressing the lid member 15. Moreover, the cover member 15 is provided with the insertion hole 15b inside each latching recessed part 15f in the direction where a long side is extended.

  The positive terminal structure 16 and the negative terminal structure 17 include an insulating member 57 disposed on the outer surface 15 c of the lid member 15. The insulating member 57 is made of synthetic resin. The insulating member 57 has a rectangular shape when viewed from the outer surface 15 c of the lid member 15. The insulating member 57 includes a locking convex portion 57 b that protrudes from the back surface 57 a that faces the lid member 15. The locking projection 57 b is located on one end side along the direction in which the long side of the insulating member 57 extends. The locking convex portion 57 b has a shape protruding in a quadrangular prism shape toward the lid member 15. The locking projection 57 b is inserted into the locking recess 15 f of the lid member 15. The four side surfaces of the locking projection 57b are in contact with and locked to the four inner surfaces of the locking recess 15f. By this contact, the insulating member 57 is restricted from moving in the direction along the outer surface 15c of the lid member 15, and in particular, the rotation on the outer surface 15c is restricted.

  Further, the insulating member 57 includes a square frame-shaped locking rib 57g erected from the four side edges of the surface 57c. The insulating member 57 includes an accommodation recess 57h that is recessed from the front surface 57c surrounded by the locking rib 57g toward the back surface 57a. The insulating member 57 includes an insertion hole 57e on the other end side along the direction in which the long side extends. The insertion hole 57e penetrates in the direction connecting the front surface 57c and the back surface 57a of the insulating member 57 with the shortest distance, and is at a position that matches the insertion hole 15b of the lid member 15.

  The positive electrode terminal structure 16 and the negative electrode terminal structure 17 have a rectangular flat terminal connection member 53. The terminal connection member 53 has a back surface 53a facing the insulating member 57 and a front surface 53b parallel to the back surface 53a, and a direction in which a straight line connecting the back surface 53a and the front surface 53b with the shortest distance is defined as a thickness direction of the terminal connection member 53. To do. The terminal connection member 53 has a through hole 54 on one end side in the direction in which the long side extends, and an insertion hole 53c on the other end side in the direction in which the long side extends. The insertion hole 53c penetrates the terminal connection member 53 in the thickness direction.

  The through hole 54 includes a detent portion 54 a that is recessed in a hexagonal shape from the surface 53 b of the terminal connection member 53. The anti-rotation portion 54 a exists on a part of the surface 53 b side along the thickness direction of the terminal connection member 53. The dimension along the thickness direction of the terminal connection member 53 in the rotation stopper 54a is defined as a depth F. The depth F of the rotation stopper 54a is a predetermined value. The through hole 54 includes a communication hole 54d that connects the inner bottom surface of the rotation stopper 54a and the back surface 53a.

  The terminal connection member 53 is supported on the surface 57c of the insulating member 57 and is accommodated inside the locking rib 57g. The locking rib 57g is in contact with the side edge portions along the four sides of the terminal connection member 53. By this contact, the terminal connection member 53 is restricted from moving in the direction along the surface 57c of the insulating member 57, and the insulating member 57 On the other hand, it is prevented from rotating. In a state in which the terminal connection member 53 is prevented from rotating, the insertion hole 53 c of the terminal connection member 53 matches the insertion hole 57 e of the insulating member 57.

  The positive terminal structure 16 and the negative terminal structure 17 include a lead terminal 61 that is electrically connected to each tab group 36 of the electrode assembly 12 via a conductive member 51. The lead terminal 61 includes a first connection portion 61a that is electrically connected to the terminal connection member 53, a second connection portion 61b that is electrically connected to the conductive member 51, and a first connection portion 61a and a second connection portion. And a connecting portion 61c for connecting 61b. The first connection portion 61a and the second connection portion 61b are formed by caulking the lead terminal 61 in the axial direction.

  The first connection portion 61 a of the lead terminal 61 is locked to the surface 53 b of the terminal connection member 53, and the lead terminal 61 and the terminal connection member 53 are electrically connected by this locking. The connecting portion 61 c passes through the insertion hole 53 c of the terminal connection member 53, the insertion hole 57 e of the insulating member 57, the insertion hole 15 b of the lid member 15, the insertion hole 56 of the inner insulating cover 55, and the insertion hole 52 a of the conductive member 51. ing. Further, the second connecting portion 61b of the lead terminal 61 is locked to the joined surface of each tab group 36 in the conductive member 51, and the lead terminal 61 and the conductive member 51 are electrically connected by this lock. ing. Therefore, the lead terminal 61 electrically connects the conductive member 51 and the terminal connecting member 53, and also connects the terminal connecting member 53, the insulating member 57, the lid member 15, the inner insulating cover 55, and the conductive member 51. Are integrated.

  The positive terminal structure 16 and the negative terminal structure 17 include an external connection terminal 66 connected to the terminal connection member 53. The external connection terminal 66 is insulated from the lid member 15 by an insulating member 57. The external connection terminal 66 is made of metal.

  As shown in FIG. 4, the external connection terminal 66 includes a shaft portion 67, a locking portion 68, and a caulking portion 69 in a state of being continuous in the axial direction of the external connection terminal 66. The shaft portion 67 has a male screw on its outer peripheral surface, and a nut 70 for fastening a bus bar can be screwed onto the male screw of the shaft portion 67. Note that the bus bar 60 for connecting the secondary batteries 10 to each other has a rectangular plate shape. The bus bar 60 includes shaft portion insertion holes 60a at both ends in the direction in which the long side extends.

  As shown in FIG. 2, the locking portion 68 of the external connection terminal 66 has a hexagonal shape when viewed from the direction in which the axis of the external connection terminal 66 extends. The locking portion 68 is accommodated in the rotation preventing portion 54 a of the through hole 54. The six side surfaces of the locking portion 68 are locked to the six inner side surfaces of the rotation preventing portion 54 a, and the rotation of the external connection terminal 66 relative to the terminal connection member 53 is restricted by this locking. When the dimension of the locking portion 68 along the axial direction of the external connection terminal 66 is the thickness, the thickness of the locking portion 68 is the same as the depth F of the rotation preventing portion 54a. Therefore, the exposed surface of the locking portion 68 from the rotation preventing portion 54 a is flush with the surface 53 b of the terminal connection member 53.

  A part of the caulking portion 69 of the external connection terminal 66 passes through the communication hole 54d of the through hole 54, and a protruding portion of the terminal connection member 53 toward the back surface 53a is locked around the communication hole 54d. The crimping portion 69 and the locking portion 68 sandwich the terminal connection member 53 in the thickness direction, and the external connection terminal 66 is integrally assembled with the through hole 54 and is electrically connected. Further, the caulking portion 69 protruding from the back surface 53 a of the terminal connection member 53 is accommodated in the accommodating recess 57 h of the insulating member 57. The external connection terminal 66 is insulated from the lid member 15 by the insulating member 57.

  In the secondary battery 10, the positive external connection terminal 66 is electrically connected to the positive electrode tab group 36 of the positive electrode 21 through the terminal connection member 53, the extraction terminal 61, and the conductive member 51. The negative external connection terminal 66 is electrically connected to the tab group 36 of the negative electrode 31 via the terminal connection member 53, the lead terminal 61, and the conductive member 51.

  In the secondary battery 10 of the present embodiment, the protruding amount of the lead terminal 61 from the lid member 15 is N1, and the conduction distance from the lead terminal 61 to the external connection terminal 71 is K1. The conduction distance K1 is a distance from the connection point P1 between the second connection portion 61b of the lead terminal 61 and the conductive member 51 to the connection point P2 between the locking portion 68 and the terminal connection member 53.

  As shown in FIG. 5B, a case where a bolt-shaped external connection terminal is used will be described as a comparative example. The bolt-shaped external connection terminal 71 includes a hexagonal bolt head 72 and a bolt shaft portion 73 having a shape protruding from the bolt head 72. In this case, in the comparative example, the insulating member 77 has a hexagonal non-rotating wall portion 77a that accommodates the entire axial direction of the bolt head 72, and the external connection terminal 71 is prevented from rotating by the non-rotating wall portion 77a. . The terminal connecting member 53 is housed in the insulating member 77 and is prevented from rotating, and the insulating member 77 is engaged with the locking convex portion 77b in the locking concave portion 15f of the lid member 15 as in the embodiment. It is locked. The bus bar 60 is supported on the bolt head 72 of the external connection terminal 71 and the terminal connection member 53. When the nut 70 is screwed into the bolt shaft portion 73, the external connection terminal 71 is prevented from rotating by the rotation preventing wall portion 77 a of the insulating member 77.

  In the comparative example, the protruding amount of the lead terminal 61 from the lid member 15 is N2, and the conduction distance from the lead terminal 61 to the external connection terminal 71 is K2. In the comparative example, the bolt head 72 is prevented from rotating by the rotation-preventing wall portion 77 a on the lid member 15 side from the terminal connection member 53. For this reason, the terminal connection member 53 is supported on the bolt head 72. Further, in order to prevent the bolt head 72 from rotating, the rotation preventing wall 77 a covers the entire bolt head 72. For this reason, in the comparative example, the terminal connection member 53 is arrange | positioned in the position away from the cover member 15 rather than embodiment.

  In the present embodiment, since the locking portion 68 that prevents the external connection terminal 66 from rotating is disposed within the thickness of the terminal connection member 53, the terminal connection member 53 is closer to the lid member 15 than in the comparative example. . For this reason, with respect to the lead terminal 61 connected to the terminal connection member 53, the protrusion amount N1 from the lid member 15 is shorter than the protrusion amount N2 of the lead terminal 61 in the comparative example, and from the lead terminal 61 to the external connection terminal 66. The conduction distance K1 is shorter than the conduction distance K2 of the comparative example.

Next, the operation of the secondary battery 10 will be described.
In different secondary batteries 10, the positive shaft portion 67 is inserted into one shaft insertion hole 60 a of the bus bar 60, and the negative shaft portion 67 of another secondary battery 10 is inserted into the other shaft insertion hole 60 a. It is inserted. The bus bar 60 is supported on the locking portion 68 of each external connection terminal 66 and on the surface 53 b of the terminal connection member 53.

  When the nut 70 is screwed to each shaft portion 67, the bus bar 60 is sandwiched between the nut 70, the terminal connection member 53, and the locking portion 68, and the bus bar 60 is electrically connected to the terminal connection member 53. It is connected to the. Torque for screwing the nut 70 is transmitted to the locking portion 68 of the external connection terminal 66 and is received by the rotation preventing portion 54 a of the terminal connection member 53. Here, the terminal connection member 53 is housed in the insulating member 57 and is prevented from rotating, and the insulating member 57 is prevented from rotating by the locking convex portion 57 b being locked to the locking concave portion 15 f of the lid member 15. As a result, the terminal connection member 53 accommodated in the insulating member 57 that is prevented from rotating is prevented from rotating. For this reason, when the rotation of the locking portion 68 is transmitted to the rotation preventing portion 54a, the rotation of the external connection terminal 66 is suppressed by the terminal connection member 53 that is prevented from rotating.

According to the above embodiment, the following effects can be obtained.
(1) A locking portion 68 is provided on the external connection terminal 66, and the locking portion 68 is locked to the rotation preventing portion 54 a within the thickness of the terminal connection member 53. For this reason, when the nut 70 is screwed onto the shaft portion 67 of the external connection terminal 66, the external connection terminal 66 is prevented from rotating by the metal terminal connection member 53, and the joint rotation of the external connection terminal 66 is suppressed. Therefore, the terminal connection member 53 can be brought closer to the lid member 15 than the case where the rotation of the external connection terminal 66 is performed on the lid member 15 side with respect to the terminal connection member 53, and the protruding amount of the lead terminal 61 from the lid member 15. Can also be shortened. As a result, the conduction distance K1 from the lead terminal 61 to the external connection terminal 66 can be shortened, and the electrical resistance in the conduction path can also be reduced.

  (2) The locking portion 68 of the external connection terminal 66 holds the terminal connection member 53 together with the crimping portion 69, and also serves as a holding portion. And even if it is the latching | locking part 68 which functions as a clamping part, it is located in the thickness of the terminal connection member 53. FIG. Accordingly, the conduction distance from the lead terminal 61 to the bus bar 60 can be shortened as compared with the case where the clamping part is disposed on the surface 53b of the terminal connection member 53 and the bus bar 60 is supported on the clamping part. .

  (3) The locking portion 68 has a hexagonal shape when viewed from the axial direction of the external connection terminal 66. For this reason, for example, the hexagonal locking portion 68 can be easily manufactured by forging, and as a result, the external connection terminal 66 capable of shortening the conduction distance with the extraction terminal 61 can be easily manufactured.

  (4) The locking portion 68 functions as a rotation stopper for the external connection terminal 66 by being locked with the rotation prevention portion 54 a, and is externally connected to the terminal connection member 53 by sandwiching the crimping portion 69 and the terminal connection member 53. It functions as a fixed part of the connection terminal 66. Therefore, the locking function of the external connection terminal 66 and the fixing function to the terminal connection member 53 can be compatible with one of the locking portions 68.

  (5) A locking portion 68 is provided on the external connection terminal 66, and the locking portion 68 is locked to the rotation preventing portion 54 a of the terminal connection member 53 so as to suppress the joint rotation of the external connection terminal 66. As a result, the terminal connection member 53 can be brought close to the lid member 15, and the terminal connection member 53 that connects the extraction terminal 61 and the external connection terminal 66 can be flat. Therefore, compared with the crank-shaped terminal connection member 53, the dimension in the direction along the long side of the terminal connection member 53 can be shortened, and the material cost can be suppressed.

  (6) A locking portion 68 is provided on the external connection terminal 66, and the locking portion 68 is locked to the rotation preventing portion 54 a of the terminal connection member 53 so as to suppress the joint rotation of the external connection terminal 66. For this reason, as in the comparative example, in order to prevent the external connection terminal 71 from rotating, the insulating member 77 does not require the rotation preventing wall portion 77a for accommodating the bolt head 72, and the thickness of the insulating member 57 can be reduced. In addition, the material cost of the insulating member 57 can be reduced.

In addition, you may change the said embodiment as follows.
As shown in FIG. 6 or 7, the dimension (thickness) of the locking portion 68 along the axial direction of the external connection terminal 66 may be increased. The thickness of the locking portion 68 is the same as the thickness of the terminal connection member 53. The through hole 54 of the terminal connection member 53 penetrates in a hexagonal shape over the entire thickness direction of the terminal connection member 53. In this case, the external connection terminal 66 includes a sandwiching portion 66 a closer to the shaft portion 67 than the locking portion 68. The clamping portion 66 a is larger in dimension along the radial direction of the shaft portion 67 than the locking portion 68, and comes into contact with the periphery of the through hole 54 in the surface 53 b of the terminal connection member 53. The terminal connection member 53 is sandwiched between the sandwiching portion 66a and the crimping portion 69.

  ○ The locking portion 68 has a hexagonal shape in a plan view as viewed from the axial direction of the external connection terminal 66, but the locking portion 68 has a triangular shape, a quadrangular shape, a pentagonal shape, an octagonal shape, etc. The polygonal shape may be sufficient. Alternatively, the planar shape of the locking portion 68 may be a shape having a pair of sides extending parallel to each other in a plan view, and may be a rectangular shape or an elliptical shape in addition to the hexagonal shape of the embodiment. Alternatively, it may be oval.

  In the embodiment, the depth F of the locking part 54a and the thickness of the locking part 68 so that the exposed surface of the locking part 68 from the terminal connection member 53 is flush with the surface 53b of the terminal connection member 53. However, the depth F of the locking part 54a and the thickness of the locking part 68 may be set so that the upper surface of the locking part 68 protrudes from the surface 53b of the terminal connection member 53.

  ○ The insulating member 57 is provided with a rectangular frame-shaped locking rib 57g surrounding the entire terminal connecting member 53, and the terminal connecting member 53 is prevented from rotating by the locking rib 57g. The locking rib 57g may not be a square frame shape. For example, it may be two locking ribs 57g that can come into contact with a pair of side edges along the long side of the terminal connecting member 53, or L-shaped provided at four locations along the four corners of the insulating member 57. The locking rib 57g may be used.

  ○ The insulating member 57 is provided with a locking projection 57b, and the locking projection 57b is locked to the locking recess 15f of the lid member 15 to prevent the insulating member 57 from rotating. You may change suitably. For example, the locking recess 15f of the lid member 15 may be changed to a rectangular shape into which the entire insulating member 57 enters.

The connection between the lead terminal 61 and the conductive member 51 is not caulking, but may be welding or screwing.
The wall portion may be the side wall of the case body 14.

  In the embodiment, the positive electrode 21 has the positive electrode active material layer 23 on both sides of the positive electrode metal foil 22, but may have the positive electrode active material layer 23 only on one side of the positive electrode metal foil 22. Similarly, the negative electrode 31 has the negative electrode active material layer 33 on both sides of the negative electrode metal foil 32, but may have the negative electrode active material layer 33 only on one side of the negative electrode metal foil 32.

  In the embodiment, the secondary battery 10 is a lithium ion secondary battery, but is not limited thereto, and may be another secondary battery. In short, any ion may be used as long as ions move between the positive electrode active material layer 23 and the negative electrode active material layer 33 through the separator 24 and the electrolytic solution, and charge is transferred.

The power storage device may be applied to other power storage devices such as an electric double layer capacitor.
Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.
(A) The insulating member includes a locking projection that protrudes toward the wall, and the wall includes a locking recess that is locked by the locking projection, A power storage device in which rotation of the insulating member in a direction along the outer surface of the wall portion is restricted by locking with the locking recess.

  (B) The insulating member includes a locking rib that is locked to a side edge of the terminal connection member, and the surface of the insulating member is locked by the locking of the side edge of the terminal connection member and the locking rib. A power storage device in which rotation of the terminal connecting member in a direction along the direction is restricted.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery as an electrical storage device, 11 ... Case, 12 ... Electrode assembly, 15 ... Lid member as a wall part, 15c ... Outer surface, 21 ... Positive electrode as an electrode, 31 ... Negative electrode as an electrode, 53 ... Terminal connecting member, 54 ... Through hole, 54a ... Non-rotating part, 57 ... Insulating member, 60 ... Busbar, 60a ... Shaft insertion hole, 61 ... Lead-out terminal, 66 ... External connecting terminal, 66a ... Holding part, 67 ... Shaft portion, 68 ... locking portion, 69 ... crimping portion, 70 ... nut.

Claims (4)

An electrode assembly in which electrodes having different polarities are insulated from each other, a case for housing the electrode assembly, and an outer surface of the wall portion so that the bus bar can be fixed outside the wall portion of the case And an external connection terminal made of metal that can be inserted into the shaft portion insertion hole of the bus bar, electrically connected to the electrode assembly in the case, and protrudes from the wall portion of the case to the outside A drawn-out terminal in a state of being made, a metal terminal connecting member arranged outside the wall portion of the case and connecting the drawn-out terminal and the external connecting terminal, and the terminal connecting member and the wall portion. An insulating member that insulates and prevents rotation of the terminal connection member and is prevented from rotating around the wall,
In the terminal connection member, when a direction along the protruding direction from the wall portion of the external connection terminal is a thickness direction, the terminal connection member has a through hole penetrating in the thickness direction and exists in the through hole. The external connection terminal includes a shaft portion to which a nut for fastening the bus bar can be screwed, a continuous portion closer to the wall portion side than the shaft portion, and in the through hole. A locking portion locked to the rotation preventing portion, a crimping portion connected to the wall portion side of the locking portion, and a shaft portion side of the crimping portion, and together with the crimping portion, the A power storage device comprising: a clamping portion that clamps the terminal connection member in the thickness direction.   The power storage device according to claim 1, wherein the locking portion also serves as the clamping portion.   3. The power storage device according to claim 1, wherein when viewed from the axial direction of the external connection terminal, the locking portion has a polygonal shape or a shape including a pair of sides extending in parallel.   The power storage device according to any one of claims 1 to 3, wherein the power storage device is a secondary battery.