JP6007659B2 - Power storage device and method for manufacturing power storage device - Google Patents

Description

The present invention relates to a power storage device and a method for manufacturing the power storage device .

  Conventionally, lithium ion secondary batteries, nickel-hydrogen secondary batteries, and the like are well known as power storage devices mounted on vehicles such as EVs (Electric Vehicles) and PHVs (Plug-in Hybrid Vehicles). For example, as a lithium ion secondary battery, an electrode assembly is formed by laminating or winding sheet-like electrodes, and an uncoated portion group formed by overlapping uncoated portions of active materials in electrodes in layers. And an electrode terminal protruding outside the case are electrically connected by a conductive member (for example, Patent Document 1).

JP 2011-210717A

  By the way, since an electrode terminal and an electrically-conductive member are generally metal, an oxide film (passive film) will be formed in the surface. For this reason, when an electrode terminal and a conductive member are in contact via an oxide film and are electrically connected, there is a problem that an electrical resistance at a contact portion between the electrode terminal and the conductive member is increased.

The present invention has been made paying attention to the problems existing in the above-described prior art, and an object of the present invention is to provide a power storage device and a power storage device that can reduce the electrical resistance of a connection portion that electrically connects an electrode terminal and a conductive member. It is to provide a method for manufacturing an apparatus .

In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that an electrode in which an active material layer is formed on the surface of a metal foil is layered, and the active material layer is formed in the metal foil. An electrode assembly having a non-formation portion group in which non-formation portions overlap each other in layers, a case having a terminal wall provided with electrode terminals for transmitting and receiving electricity to and from the electrode assembly, and housing the electrode assembly, And a conductive member electrically connecting the electrode group to the electrode group, wherein the electrode terminal is disposed outside the case and an external terminal portion protruding outside the case. A metal first connection portion that is electrically connected to the external terminal portion, and the conductive member is a metal second connection electrically connected to the first connection portion. has a section, the first connecting portion, and the second connecting portion are the same Consists of a fee, the first connecting portion, and at least one of said second connecting portion is convex portion is provided in contact in a state of biting the connection portion of the protruding and the other toward the other The convex part is a sharp part with a triangular cross section and a sharp tip, and the convex part penetrates the oxide film on the surface of the other connection part, and the convex part and the other connection A part makes it a summary to be in contact with the new surfaces which do not have an oxide film.

  According to this, at least one of the first connection portion constituting the electrode terminal and the second connection portion constituting the conductive member protrudes toward the other connection portion and contacts the other connection portion. The convex part to be formed is formed. For this reason, by bringing the convex portion into contact with the other connecting portion, or by moving the convex portion in a direction perpendicular to the protruding direction of the convex portion while being in contact with the other connecting portion, The oxide film at the contact portion between the convex portion and the other connecting portion can be broken to expose the new metal surface. For this reason, the electrical resistance of the connection part which electrically connects an electrode terminal and a electrically-conductive member can be reduced.

In addition , since the convex portion penetrates the oxide film formed on the surface of the other joint portion, the electrode terminal and the conductive member are brought into contact with each other without interposing the oxide film on the convex portion, and the electrode terminal and the conductive member are electrically connected. The electrical resistance of the connecting portion with the member can be further reduced.

Moreover , since the tip of the convex portion is sharp, the oxide film can be easily broken by exposing the convex portion to the other connecting portion, and the new metal surface can be exposed.

Invention according to claim 2, in the electric storage device according to claim 1, wherein the conductive member is a metal plate member, said convex portion, the bent portion of the plate-like member protruding bent It is a summary.

  According to this, the convex part is formed by bending a metal plate-like member having elasticity. For this reason, even if the distance between the 1st connection part and the 2nd connection part along the protrusion direction of a convex part is fluctuate | varied, a convex part and the other connection part are elastically deformed. Can be prevented from separating.

The invention according to claim 3 is the power storage device according to claim 1 or 2 , wherein the power storage device is a secondary battery. According to this, the electrical resistance of the connection part which electrically connects an electrode terminal and an electroconductive member as a secondary battery can be reduced.
According to a fourth aspect of the present invention, an electrode in which an active material layer is formed on the surface of a metal foil overlaps in a layered manner, and a non-formed portion where the active material layer is not formed in the metal foil overlaps in a layered manner. An electrode assembly having a non-formed portion group, a case having a terminal wall provided with an electrode terminal for transmitting and receiving electricity to and from the electrode assembly, and housing the electrode assembly; the non-formed portion group and the electrode terminal; And a conductive member for electrically connecting the conductive member to the non-forming portion group of the conductive member, and a distal end portion on the other side of the base end side connected to the non-forming portion group. A metal fastening member disposed inside and electrically connected to the electrode terminal, the fastening member made of the same material as the conductive member is disposed opposite to the fastening member, and the fastening member In front of the insulating member provided inside the terminal wall By sandwiching the leading end portion of the conductive member, the convex portion provided on at least one of the leading end portion of the conductive member and the fastening member bites into the other, and an oxide film formed on the other surface is formed on the convex portion. The gist is that the oxide film formed on the surface of the convex portion is scraped off.

  ADVANTAGE OF THE INVENTION According to this invention, the electrical resistance of the connection part which electrically connects an electrode terminal and a electrically-conductive member can be reduced.

Sectional drawing which shows a lithium ion secondary battery typically. The perspective view which shows typically the lithium ion secondary battery decomposed | disassembled partially. The perspective view which shows typically the decomposed | disassembled electrode assembly. Sectional drawing which expands and shows a lithium ion secondary battery typically. The perspective view which shows typically the decomposed | disassembled positive electrode terminal. (A) And (b) is sectional drawing which expands and shows typically a lithium ion secondary battery. (A) is the bottom view which shows typically a part of electrically-conductive member in 2nd Embodiment, (b) is the 1-1 sectional view taken on the line shown to (a). (A) And (b) is sectional drawing which expands and shows typically the lithium ion secondary battery in 2nd Embodiment. (A) And (b) is a perspective view which shows typically the electrically-conductive member in another embodiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, for example, a lithium ion secondary battery (hereinafter referred to as “secondary battery”) 10 as a power storage device mounted on a vehicle such as a passenger vehicle or an industrial vehicle includes a case 11 and an electrode assembly 12. Contained.

  As shown in FIG. 2, the case 11 includes a bottomed square box-shaped main body member 13 that houses the electrode assembly 12, and a square plate-shaped lid member 14 that closes the opening of the main body member 13. ing. The main body member 13 and the lid member 14 are made of a metal such as stainless steel or aluminum.

  The main body member 13 includes a rectangular plate-shaped bottom wall 13a, a rectangular plate-shaped first side wall 13b, a second side wall 13c, a third side wall 13d, and a fourth side wall that are erected from four edges of the bottom wall 13a. The side wall 13e is formed.

  As shown in FIG. 1, the first side wall 13b is provided with a communication hole 13f that communicates the inner surface and the outer surface of the first side wall 13b. Moreover, the positive electrode terminal 15 as an electrode terminal and the negative electrode terminal 16 as an electrode terminal are provided in the 1st side wall 13b. Details of the positive terminal 15 and the negative terminal 16 will be described later. The 1st side wall 13b of this embodiment turns into a terminal wall in which an electrode terminal is provided.

  As shown in FIG. 3, the electrode assembly 12 insulates the positive electrode sheet 18 as an electrode, the negative electrode sheet 19 as an electrode having a polarity different from that of the positive electrode sheet 18, and the positive electrode sheet 18 and the negative electrode sheet 19. And a rectangular sheet-like separator 20. The electrode assembly 12 is a stacked electrode assembly in which a plurality of positive electrode sheets 18 and a plurality of negative electrode sheets 19 are stacked so as to be alternately layered with a separator 20 interposed therebetween. . In the following description, the simple “stacking direction (overlapping direction)” means the stacking direction (overlapping direction) of the positive electrode sheet 18 and the negative electrode sheet 19 in the electrode assembly 12.

  As shown in FIG. 3, the positive electrode sheet 18 includes a positive electrode metal foil (aluminum foil in this embodiment) 21 and a positive electrode active material layer 22 formed by applying a positive electrode active material on both surfaces thereof. The portion of the metal foil 21 where the positive electrode active material layer 22 is not formed constitutes a non-coated portion 23 as a non-formed portion. A positive electrode current collecting tab 24 is formed to protrude from the edge 18 a of the positive electrode sheet 18. The positive electrode current collecting tab 24 is a part of the metal foil 21 constituting the non-coated portion 23.

  The positive electrode current collecting tab 24 is formed in the same position and in the same shape in each positive electrode sheet 18 constituting the electrode assembly 12. Therefore, as shown in FIG. 1, among the four edge portions extending along the stacking direction in the electrode assembly 12, a plurality of positive electrode current collecting tabs are provided on one edge portion 12 a facing the first side wall 13 b. A positive electrode current collecting tab group 24a as a non-formed part group in which 24 is layered is formed to protrude.

  Further, the negative electrode sheet 19 includes a negative electrode metal foil (copper foil in this embodiment) 25 and a negative electrode active material layer 26 formed by applying a negative electrode active material on both surfaces thereof. The portion of the metal foil 25 where the negative electrode active material layer 26 is not formed constitutes a non-coated portion 27 as a non-formed portion. A negative electrode current collecting tab 28 is formed so as to protrude from the edge 19 a of the negative electrode sheet 19. The negative electrode current collecting tab 28 is a part of the metal foil 25 constituting the non-coated portion 27.

  The negative electrode current collecting tab 28 is formed in the same position and in the same shape in each negative electrode sheet 19 constituting the electrode assembly 12. The negative electrode current collecting tab 28 is provided at a position that does not overlap the positive electrode current collecting tab 24 when the positive electrode sheet 18 and the negative electrode sheet 19 are laminated. For this reason, as shown in FIG. 1, the edge portion 12a of the electrode assembly 12 is formed as a non-formed portion group in which a plurality of negative electrode current collecting tabs 28 are layered on a portion different from the positive electrode current collecting tab group 24a. The negative electrode current collecting tab group 28a is formed to protrude.

  A positive electrode conductive member 30 as a conductive member for electrically connecting the positive electrode current collector tab group 24a and the positive electrode terminal 15 is joined to and electrically connected to the positive electrode current collector tab group 24a by welding or the like. Yes. The positive electrode conductive member 30 is made of metal (in this embodiment, made of aluminum). In addition, a negative electrode conductive member 31 as a conductive member for electrically connecting the negative electrode current collector tab group 28a and the negative electrode terminal 16 is joined to and electrically connected to the negative electrode current collector tab group 28a by welding or the like. Yes. The negative electrode conductive member 31 is made of metal (in the present embodiment, copper). The positive electrode conductive member 30 is electrically connected to the electrode assembly 12 and the positive electrode terminal 15, and the negative electrode conductive member 31 is electrically connected to the electrode assembly 12 and the negative electrode terminal 16. The negative electrode terminal 16 can exchange electricity with the electrode assembly 12.

  Each conductive member 30, 31 is a rectangular thin plate member extending along the edge 12 a of the electrode assembly 12. In the positive electrode conductive member 30, a through hole 30b is formed in a distal end portion 30a as a second connection portion on the other side of the base end portion joined to the positive electrode current collecting tab group 24a. Similarly, in the negative electrode conductive member 31, a through hole 31b is formed at a distal end portion 31a opposite to a base end portion joined to the negative electrode current collecting tab group 28a.

Next, the positive electrode terminal 15 and the negative electrode terminal 16 will be described. In addition, since the negative electrode terminal 16 of this embodiment is the same as that of the positive electrode terminal 15, the detailed description is abbreviate | omitted.
As shown in FIGS. 4 and 5, the positive electrode terminal 15 is disposed inside the case 11 and an external terminal member 32 as an external terminal portion made of metal (aluminum in the present embodiment) protruding outside the case 11. And a fastening member 33 as a first connection portion made of metal (aluminum in the present embodiment) electrically connected to the external terminal member 32. The external terminal member 32 and the fastening member 33 constituting the negative electrode terminal 16 are made of copper. The positive terminal 15 has an insulating member 35 for insulating the positive electrode conductive member 30, the external terminal member 32, and the fastening member 33 from the case 11.

  Here, in the positive electrode conductive member 30, the surface facing the edge portion 12 a of the electrode assembly 12 is a first contact surface 30 c that is in contact with and electrically connected to the fastening member 33. The surface facing the side wall 13b is a second contact surface 30d that is in contact with the insulating member 35 and insulated from the first side wall 13b (main body member 13).

  The fastening member 33 is disposed on the electrode assembly 12 side of the positive electrode conductive member 30 and has a square block-like fastening portion 33b having a facing surface 33a facing the first contact surface 30c of the positive electrode conductive member 30. Have. At the center of the facing surface 33a, a cylindrical (in this embodiment, rectangular tube-shaped) locking portion 33c having an internal thread formed on the inner surface protrudes toward the external terminal member 32 side.

  The opposing surface 33 a is provided with a convex portion 36 that protrudes toward the positive electrode conductive member 30 (tip portion 30 a) and contacts the positive electrode conductive member 30. The convex portion 36 is formed in an annular shape (concentric circle) surrounding the locking portion 33c on the opposing surface 33a, and the second convexity on the opposite side (outside) from the first convex surface 36a on the locking portion 33c side. It is a sharp pointed portion having an acute angle with the surface 36b.

  The insulating member 35 has a rectangular thin plate-like top plate 35a provided with a through hole 35b in the center. The top plate 35a is assembled to the first side wall 13b in a state where the communication hole 13f of the first side wall 13b and the through hole 35b are aligned. The top plate 35a is formed with a first insulating contact surface 35c in surface contact with the inner surface of the first side wall 13b, and in surface contact with the second contact surface 30d on the opposite side of the first insulating contact surface 35c. A second insulating contact surface 35e is formed.

  Further, at the edge of the top plate 35a, a bottom wall 13a disposed on both sides of the electrode assembly 12 in the stacking direction, a lid member 14, and a fourth side wall 13e extending along the edge of the electrode assembly 12 are provided. A rectangular thin plate-like insulating wall 35d that hangs down is provided.

  The external terminal member 32 has a disk-shaped disk portion 32a. On the surface of the disk portion 32a on the main body member 13 side, a cylindrical first male screw 32b projects (hangs down) toward the fastening member 33, while on the surface opposite to the main body member 13 A cylindrical second male screw 32c is projected. In addition, the disk part 32a and the 1st side wall 13b are insulated by the annular | circular shaped insulating member 37 and the O-ring 38 which are arrange | positioned between the disk part 32a and the 1st side wall 13b.

  As shown in FIG. 4, the locking portion 33 c is inserted into the through hole 30 b of the positive electrode conductive member 30 and the through hole 35 b of the insulating member 35, and an external terminal is connected to the female screw of the locking portion 33 c. A first male screw 32b of the member 32 is screwed. Thereby, the fastening member 33 and the external terminal member 32 are electrically connected. Further, the positive electrode conductive member 30 has a top plate 35a (second insulating contact surface 35e), a fastening member 33 (opposing surface 33a), and a fastening force (clamping force) generated when the second male screw 32c is screwed. And are fixed to the main body member 13 by this.

  Here, as shown in an enlarged view in FIG. 4, an oxide film (passive film) 40 is formed on the surfaces of the positive electrode conductive member 30 made of metal (made of aluminum in this embodiment) and the fastening member 33. Yes (colored in light ink) The oxide film 40 is made of an oxide of aluminum and has a lower conductivity than aluminum.

  And the convex part 36 of this embodiment penetrates the oxide film 40 of the positive electrode conductive member 30, and the oxide film 40 is not formed on the surface of the convex part 36. And the convex part 36 bites into the positive electrode conductive member 30 (tip part 30a), and the whole is embedded (embedded) in the positive electrode conductive member 30. Therefore, the positive electrode conductive member 30 and the fastening member 33 are in contact with each other without interposing the oxide film 40 at the convex portion 36 and are electrically connected. In addition, the 1st contact surface 30c and the opposing surface 33a are surface-contacting in the state which interposed the oxide film 40 except the formation part of the convex part 36. FIG.

Next, the operation of the secondary battery 10 configured as described above will be described.
As shown in FIG. 4, the convex portion 36 penetrates the oxide film 40 of the positive electrode conductive member 30, and the oxide film 40 is not formed on the surface of the convex portion 36. For this reason, the conductive path Y between the positive electrode conductive member 30 and the fastening member 33 is formed by the convex portion 36 without the oxide film 40 interposed therebetween. Therefore, compared to the configuration in which the positive electrode conductive member 30 and the fastening member 33 are brought into contact with each other and electrically connected in a state where the oxide film 40 is interposed, the positive conductive member 30 and the fastening member 33 are electrically connected. The electrical resistance of the part can be suitably reduced. The same applies to the fastening of the negative electrode terminal 16 and the negative electrode conductive member 31.

  Next, a fastening method (a manufacturing method of the secondary battery 10) between the positive electrode terminal 15 and the positive electrode conductive member 30 will be described with reference to FIGS. 6 (a) and 6 (b). In addition, since the fastening method of the negative electrode terminal 16 and the negative electrode electrically-conductive member 31 is the same as the fastening method of the positive electrode terminal 15 and the positive electrode electrically-conductive member 30, the description is abbreviate | omitted.

  As shown in FIG. 6A, the insulating member 35 is assembled to the first side wall 13b so that the communication hole 13f and the through hole 35b are aligned. Next, the engaging portion 33c of the fastening member 33 is inserted in the order of the through hole 30b and the through hole 35b, while the first male screw 32b of the external terminal member 32 is inserted through the insulating member 37 and the O-ring 38. Then, the positive electrode conductive member 30 is sandwiched between the fastening member 33 and the insulating member 35 by screwing the first male screw 32b into the female screw of the locking portion 33c.

  At this time, as shown in an enlarged view in FIG. 6A, an oxide film 40 is formed on the entire surface of the positive electrode conductive member 30. Further, an oxide film 40 is formed on the entire surface of the fastening member 33 including the convex portion 36.

  Then, as shown in FIG. 6B, the fastening member 33 is moved toward the first side wall 13b by the fastening force generated by further screwing the first male screw 32b into the female screw of the locking portion 33c. . Along with this, the convex portion 36 bites into the positive electrode conductive member 30 (tip portion 30a) while breaking the oxide film 40 of the positive electrode conductive member 30, and at the same time, the oxide film 40 of the convex portion 36 is scraped off.

  For this reason, in the contact part of the positive electrode conductive member 30 and the convex part 36, while forming the new surface which does not have the oxide film 40 in the surface of the positive electrode conductive member 30 and the convex part 36, these new surfaces contact each other (Contact). Thereby, the positive electrode conductive member 30 and the fastening member 33 are electrically connected without interposing the oxide film 40. At this time, the first contact surface 30c and the facing surface 33a are in surface contact with the oxide film 40 interposed therebetween except for the portion where the convex portion 36 is formed.

Therefore, according to the present embodiment, the following effects can be obtained.
(1) The fastening member 33 constituting the positive electrode terminal 15 is formed with a convex portion 36 that protrudes toward the positive electrode conductive member 30 and contacts the positive electrode conductive member 30. For this reason, the oxide film 40 in the contact part of the convex part 36 and the positive electrode conductive member 30 can be broken, and the new metal surface can be exposed by bringing the convex part 36 into contact with the positive electrode conductive member 30. For this reason, the electrical resistance of the connection part which electrically connects the positive electrode terminal 15 and the positive electrode electrically-conductive member 30 can be reduced. The same applies to the fastening of the negative electrode terminal 16 and the negative electrode conductive member 31.

  (2) Since the convex portion 36 penetrates the oxide film 40 formed on the surface of the positive electrode conductive member 30, the positive electrode terminal 15 and the positive electrode conductive member 30 are interposed between the oxide film 40 in the convex portion 36. The electrical resistance of the connecting portion between the positive electrode terminal 15 and the positive electrode conductive member 30 can be further reduced. The same applies to the fastening of the negative electrode terminal 16 and the negative electrode conductive member 31.

  (3) Since the tip of the convex portion 36 is sharp, the oxide film 40 can be easily broken by exposing the convex portion 36 to the positive electrode conductive member 30, and the new metal surface can be exposed. The same applies to the fastening of the negative electrode terminal 16 and the negative electrode conductive member 31.

  (4) In this embodiment, as the secondary battery 10, the electrical resistance of the connection portion that electrically connects the positive electrode terminal 15 and the positive electrode conductive member 30 can be reduced. Therefore, it can suppress suitably that internal resistance as the secondary battery 10 becomes high, or the connection part of the positive electrode terminal 15 and the positive electrode conductive member 30 generates heat. The same applies to the fastening of the negative electrode terminal 16 and the negative electrode conductive member 31.

(5) The first contact surface 30 c of the positive electrode conductive member 30 and the facing surface 33 a of the fastening member 33 are in surface contact at a portion excluding the convex portion 36. Therefore, the electrical resistance of the connection portion that electrically connects the positive electrode terminal 15 and the positive electrode conductive member 30 can be further reduced. The same applies to the fastening of the negative electrode terminal 16 and the negative electrode conductive member 31.
(Second Embodiment)
Next, a second embodiment embodying the present invention will be described with reference to FIGS. In the following description, the same components as those described in the above embodiments are denoted by the same reference numerals, and redundant descriptions are omitted or simplified. The present embodiment is different from the first embodiment in that a convex portion 36 is formed on each conductive member 30, 31 instead of the fastening member 33. Since the negative electrode conductive member 31 has the same shape as the positive electrode conductive member 30, the positive electrode conductive member 30 will be described in detail and the description of the negative electrode conductive member 31 will be omitted.

  As shown in FIGS. 7A and 7B, the positive electrode conductive member 30 is bent at the tip 30a of the positive electrode conductive member 30 by bending the periphery of the through hole 30b by press working or the like. A convex portion 36 that is a bent portion protruding toward the fastening member 33 (fastening portion 33b) is formed. The convex portion 36 is formed in an annular shape (concentric shape) that continuously surrounds the through hole 30b.

  Moreover, as shown in FIG.8 (b), the cutting surface 41 formed by scraping the surface by the convex part 36 is formed in the opposing surface 33a of the fastening part 33b. The shaving surface 41 is a very shallow concave portion in an annular shape (concentric circle shape) centering on the locking portion 33c on the facing surface 33a. And the front-end | tip of the convex part 36 is in contact with the cutting surface 41 in the state which does not interpose the oxide film 40. FIG. Note that an oxide film 40 is formed on the surface of the shaving surface 41 except for a contact portion between the shaving surface 41 and the convex portion 36.

  Moreover, the convex part 36 is compressed within the range of elastic deformation between the insulating member 35 and the fastening member 33 in the protruding direction of the convex part 36, that is, the direction in which the first male screw 32b extends. Therefore, the tip of the convex portion 36 is in contact with the opposing surface 33a (the shaving surface 41) of the fastening member 33 by a repulsive force that the convex portion 36 tries to restore.

Next, the operation of the secondary battery 10 configured as described above will be described.
As shown in FIG. 8B, the tip of the convex portion 36 is in contact with the fastening member 33 without the oxide film 40 interposed. For this reason, the conductive path Y between the positive electrode conductive member 30 and the fastening member 33 is formed by the convex portion 36 without interposing the oxide film 40. Therefore, in this embodiment, the positive electrode conductive member 30 and the fastening member 33 are electrically connected as compared with the configuration in which the positive electrode conductive member 30 and the fastening member 33 are brought into contact with each other via the oxide film 40 and are electrically connected. The electrical resistance of the connecting portion to be connected can be reduced. The same applies to the fastening of the negative electrode terminal 16 and the negative electrode conductive member 31.

  Further, the convex portion 36 is formed as a bent portion obtained by bending the metal positive electrode conductive member 30. For this reason, the convex portion 36 is caused by, for example, looseness of the external terminal member 32 or the like, a separation distance between the top plate 35 a of the insulating member 35 and the fastening member 33, in other words, between the positive electrode conductive member 30 and the fastening member 33. Even when the separation distance changes, the protrusion 36 is deformed so as to contact the fastening member 33 according to the separation distance, and the protrusion 36 and the fastening member 33 are prevented from separating.

  Next, a method for fastening the positive electrode terminal 15 and the positive electrode conductive member 30 (a method for manufacturing the secondary battery 10) will be described with reference to FIGS. 8 (a) and 8 (b). In addition, since the fastening method of the negative electrode terminal 16 and the negative electrode electrically-conductive member 31 is the same as the fastening method of the positive electrode terminal 15 and the positive electrode electrically-conductive member 30, the description is abbreviate | omitted.

  As shown in FIG. 8A, in the state where the engaging portion 33c is inserted into the through hole 30b and the through hole 35b and the first male screw 32b is screwed into the female screw of the engaging portion 33c, the positive electrode conductive member An oxide film 40 is formed on the entire surface of 30, and an oxide film 40 is formed on the entire surface of the fastening member 33 including the convex portion 36.

  As shown in FIG. 8B, the fastening member 33 is moved to the first side wall 13b side by a fastening force generated by further screwing the first male screw 32b into the female screw of the locking portion 33c. The When the distance between the top plate 35a (second insulating contact surface 35e) and the fastening member 33 (opposing surface 33a) becomes narrower than the thickness of the convex portion 36, the tip of the convex portion 36 comes into contact with the fastening member 33. While maintaining this state, it is elastically deformed and its thickness is reduced.

  At this time, the tip of the convex portion 36 is slid in a direction in which the diameter of the through hole 30b is reduced (a direction close to the locking portion 33c) while being in contact with the opposing surface 33a of the fastening member 33. For this reason, an annular shaving surface 41 is formed on the facing surface 33a as the convex portion 36 slides, and the oxide film 40 is scraped off. At the same time, the oxide film 40 at the tip of the convex portion 36 is also scraped off. .

  For this reason, while the new surface which does not have the oxide film 40 is formed in the fastening member 33 and the convex part 36, these new surfaces contact (contact | abut). At this time, since the entire shaving surface 41 becomes a new surface without the oxide film 40, the new surface is formed over a wide area. The positive electrode conductive member 30 and the fastening member 33 are electrically connected without interposing the oxide film 40.

Therefore, according to this embodiment, in addition to the effects (1) to (4) of the first embodiment, the following effects can be obtained.
(6) On the facing surface 33 a of the fastening member 33, a shaving surface 41 is formed by shaving the surface. According to this, by increasing the formation area of the new surface, the convex portion 36 and the fastening member 33 are more reliably brought into contact with each other without the oxide film 40 interposed therebetween, and the positive electrode terminal 15 and the positive electrode conductive member 30 are electrically connected. It is possible to further reduce the electrical resistance of the connecting portion connected to the. The same applies to the fastening of the negative electrode terminal 16 and the negative electrode conductive member 31.

  (7) The convex portion 36 is formed by bending a metal positive electrode conductive member 30 having elasticity. For this reason, even if the distance between the positive electrode conductive member 30 and the fastening member 33 along the projecting direction of the convex portion 36 varies, the convex portion 36 and the fastening member are elastically deformed. 33 can be prevented from separating.

The embodiment is not limited to the above, and may be embodied as follows, for example.
As shown in FIG. 9A and FIG. 9B, the convex portion 36 may be formed on the positive electrode conductive member 30 or the negative electrode conductive member 31. Further, the convex portion 36 may be formed on both the fastening member 33 and the positive electrode conductive member 30. The fastening of the negative electrode terminal 16 and the negative electrode conductive member 31 can be similarly changed.

  As shown in FIG. 9A, the convex portion 36 formed on the positive electrode conductive member 30 may be a convex portion formed without bending the positive electrode conductive member 30 as in the first embodiment. The fastening of the negative electrode terminal 16 and the negative electrode conductive member 31 can be similarly changed.

  ○ The shape of the convex portion 36 may be changed. For example, as shown in FIG. 9B, the convex portion 36 may have a shape in which sharpened portions are arranged in a lattice shape by pressing or cutting. Moreover, the convex part 36 may arrange | position the several independent convex part in an annular | circular shape, or may make it the protruding item | line extended along the direction where the positive electrode electrically-conductive member 30 is extended, or the direction orthogonal to this extending direction. The fastening of the negative electrode terminal 16 and the negative electrode conductive member 31 can be similarly changed.

O The convex part 36 which is a bending part may be formed by providing a metal plate-like part in the fastening member 33 and bending the plate-like part.
(Circle) the convex part 36 may have a plane at the front-end | tip, and the cross section may be formed in semicircle shape. That is, it does not have to be a sharp point.

In addition, the tip of the convex portion 36 may have an obtuse angle.
O The convex part 36 in any of the positive electrode conductive member 30 and the positive electrode terminal 15, and the negative electrode conductive member 31 and the negative electrode terminal 16 may be abbreviate | omitted.

The metal forming each conductive member 30, 31, external terminal member 32, and fastening member 33 may be changed.
The external terminal member 32 and the fastening member 33 may be integrally formed. In this case, the positive terminal 15 is provided with a rivet having a columnar portion projecting from the opposing surface 33a of the fastening member 33, and the columnar portion is beaten and caulked to thereby provide a space between the fastening member 33 and the insulating member 35. The positive electrode conductive member 30 may be sandwiched. The fastening of the negative electrode terminal 16 and the negative electrode conductive member 31 can be similarly changed.

○ Of the fastening member 33 and the positive electrode conductive member 30, it is only necessary that the tip of the convex portion 36 is in contact with the other member, and the first contact surface 30c and the facing surface 33a do not have to be in contact with each other.
The electrode assembly 12 may be a wound-type electrode assembly in which the positive electrode sheet 18 and the negative electrode sheet 19 are formed in a band shape and wound with a band-shaped separator 20 interposed therebetween.

  The positive electrode sheet 18 and the negative electrode sheet 19 may be formed by applying an active material to a metal plate having a predetermined thickness. Moreover, the positive electrode sheet 18 and the negative electrode sheet 19 may be formed by applying an active material on one side.

O You may actualize in electrical storage apparatuses, such as a nickel hydride secondary battery and an electric double layer capacitor.
O You may actualize in the electrical storage apparatus used other than a vehicle.

  DESCRIPTION OF SYMBOLS 10 ... Lithium ion secondary battery (secondary battery, electrical storage apparatus), 11 ... Case, 12 ... Electrode assembly, 13b ... 1st side wall (terminal wall), 15 ... Positive electrode terminal (electrode terminal), 16 ... Negative electrode terminal ( Electrode terminal), 18 ... Positive electrode sheet (electrode), 19 ... Negative electrode sheet (electrode), 21 ... Metal foil, 22 ... Positive electrode active material layer (active material layer), 23 ... Non-coated part (non-formed part), 24 ... positive electrode current collecting tab, 24a ... positive electrode current collecting tab group (non-formed part group), 25 ... metal foil, 26 ... negative electrode active material layer (active material layer), 27 ... non-coated part (non-formed part), 28 ... negative electrode current collecting tab, 28a ... negative electrode current collecting tab group (non-forming part group), 30 ... positive electrode conductive member (conductive member), 30a ... tip part (second connecting part), 31 ... negative electrode conductive member (conductive member) 32 ... External terminal member (external terminal portion), 33 ... Fastening member (first connecting portion), 36 ... Convex portion, 40 ... Oxidized coating , 41 ... scraping surface.

Claims (4)

The electrode with the active material layer formed on the surface of the metal foil is layered,
An electrode assembly having a non-formed part group in which the non-formed part in which the active material layer is not formed of the metal foil overlaps in layers,
A case having a terminal wall provided with an electrode terminal for transferring electricity to and from the electrode assembly, and housing the electrode assembly;
A power storage device comprising: a conductive member that electrically connects the non-formed part group and the electrode terminal;
The electrode terminal includes an external terminal portion protruding outside the case, and a metal first connection portion disposed inside the case and electrically connected to the external terminal portion,
The conductive member has a metal second connection portion that is electrically connected to the first connection portion,
The first connection part and the second connection part are made of the same material,
At least one of the first connection part and the second connection part is provided with a protrusion that protrudes toward the other and contacts the other connection part, and the protrusion is A sharp section with a triangular cross section and a sharp tip, and the convex portion penetrates an oxide film on the surface of the other connecting portion, and the convex portion and the other connecting portion have an oxide film. A power storage device in which the new surfaces that are not in contact are in contact with each other. The conductive member is a metal plate member,
The power storage device according to claim 1, wherein the convex portion is a bent portion in which the plate-like member is bent and protruded. The power storage device electric storage device according to claim 1 or 2 is a secondary battery. The electrode with the active material layer formed on the surface of the metal foil is layered,
An electrode assembly having a non-formed part group in which the non-formed part in which the active material layer is not formed of the metal foil overlaps in layers,
A case having a terminal wall provided with an electrode terminal for transferring electricity to and from the electrode assembly, and housing the electrode assembly;
A conductive member for electrically connecting the non-formed part group and the electrode terminal, and a method of manufacturing a power storage device comprising:
And the distal end portion of the other side to the base end side connected to the non-formation portion group in the conductive member, a metal fastening member electrically connected with the electrode terminals are disposed within the casing There is a fastening member made of the same material as that of the conductive member, and is arranged opposite to the fastening member .
By sandwiching the leading end portion of the conductive member between the fastening member and the insulating member provided inside the terminal wall, the convex portion provided on at least one of the leading end portion of the conductive member and the fastening member bites into the other. Let
A method of manufacturing a power storage device, wherein the oxide film formed on the other surface is penetrated by the convex portion, and the oxide film formed on the surface of the convex portion is scraped off.