JP5825207B2 - Power storage device and secondary battery - Google Patents

Description

  The present invention relates to a power storage device and a secondary battery.

  In a secondary battery such as a nickel metal hydride secondary battery or a lithium ion secondary battery, a metal foil coated with an active material is used as an electrode. And the laminated electrode assembly which laminated | stacked in the state which interposed the separator between the positive electrode and the negative electrode, and the winding type wound in the state which interposed the strip-shaped separator between the strip-shaped positive electrode and the strip-shaped negative electrode The electrode assembly is accommodated in a case to constitute a secondary battery. And extraction of the electric power from an electrode assembly is performed via the electrically-conductive member connected to the active material uncoated part of an electrode.

  When inserting the electrode assembly into the case, with the wound electrode assembly attached to the lid of the case, specifically, the electrode assembly is attached to the electrode terminal protruding from the case lid. The electrode assembly may be inserted into the case from the electrode assembly side while being supported via a conductive member (current collector) in a state where the direction extends in parallel with the bottom of the case (see, for example, Patent Document 1).

  Further, in the secondary battery housed in the case in which the wound electrode assembly extends in a direction orthogonal to the protruding direction of the electrode terminal protruding from the case lid, the conductive member (collector) is provided. A part of which is positioned between the outer peripheral surface of the electrode assembly and the lid of the case, and an insulating member is disposed between that portion and the outer peripheral surface of the electrode assembly. (Patent Document 2).

JP 2011-165437 A JP 2005-32477 A

  In the case where an electrode assembly attached to the case lid, that is, the lid-electrode assembly ASSY (assembly) is inserted into the case, in the configuration of Patent Document 1, the insertion load is set between the active material uncoated portion and the conductive member. Due to the structure received by the welded portion, the active material uncoated portion near the welded portion is likely to break during insertion, and the productivity is deteriorated. In the configuration of Patent Document 2, the insulating member is disposed between a part of the conductive member (current collector) and the outer peripheral surface of the electrode assembly. The purpose of the insulating member is to use the secondary battery as an electrode terminal. Is to prevent the active material uncoated part group (electrode group) from coming into contact with the corners of the current collector and breaking. The insulating member is not fitted between the conductive member and the outer peripheral surface of the electrode assembly, but is disposed in a state where there is play. Therefore, when the lid-electrode assembly ASSY (assembly) is inserted into the case, after the outer peripheral surface of the electrode assembly is engaged with a part of the conductive member, the conductive member is part of the insertion load via the insulating member. However, until then, the insertion load is received by the welded portion between the active material uncoated portion and the conductive member, so that the active material uncoated portion is likely to break during insertion. Further, not only the secondary battery but also a capacitor such as an electric double layer capacitor or a lithium ion capacitor has the same problem.

  The present invention has been made in view of the above problems, and its purpose is to provide an active material uncoated part that constitutes an electrode when the lid-electrode assembly ASSY is inserted into a case in the manufacturing process. An object of the present invention is to provide a power storage device and a secondary battery that can reduce the applied load and prevent the active material uncoated portion from being damaged.

In order to achieve the above object, the invention according to claim 1 is a positive electrode having a positive electrode active material layer coated with a positive electrode active material, a positive electrode uncoated portion not coated with the positive electrode active material, and a negative electrode A negative electrode active material layer coated with an active material, and a negative electrode having a negative electrode uncoated portion to which the negative electrode active material is not coated, and is laminated with a separator interposed between the positive electrode and the negative electrode An electrode assembly having a stacked structure is housed in a case constituted by a case main body and a lid, and is a power storage device including a positive electrode terminal and a negative electrode terminal that exchange electricity with the electrode assembly, wherein the case The positive electrode terminal and the negative electrode terminal are provided in a state protruding from the lid, the electrode assembly is a wound type, and the outer shape of the electrode assembly extends along a winding axis. Having a curved surface, the positive electrode uncoated portion and the Gokumi the coated portion is formed so as to be located in different ends of the winding axis direction of the electrode assembly, the positive electrode terminal and the positive electrode uncoated portion and Seikyokushirubeden member for electrically connecting the, and A negative electrode conductive member that electrically connects the negative electrode terminal and the negative electrode uncoated portion; and the positive electrode conductive member is integrated with the positive electrode connection portion connected to the positive electrode uncoated portion and the positive electrode connection portion. an engagement portion formed, the negative electrode conductive member has the negative electrode non-negative connection portion is connected to the coated portion and the negative electrode connecting portion are integrally formed with the engaging portion, the electrode unit The solid body has a separator on the outermost periphery, and the engaging portion of the positive electrode conductive member and the engaging portion of the negative electrode conductive member are formed in a shape along the curved surface of the electrode assembly, respectively. The electrode assembly is engaged by contacting the surface .

  When inserting the lid-electrode assembly ASSY into the case in the manufacturing process of the power storage device, a load is applied to the electrode assembly due to friction between the outer surface of the electrode assembly and the inner surface of the case, but there is an engaging portion. If not, the load is received at the joint (welded portion) between the positive electrode conductive member and the positive electrode uncoated portion and the joint portion (welded portion) between the negative electrode conductive member and the negative electrode uncoated portion. As a result, a large load is applied to the positive electrode uncoated portion and the negative electrode uncoated portion following the bonded portion, and the positive electrode uncoated portion and the negative electrode uncoated portion in the vicinity of the bonded portion (welded portion) are broken. easy. However, in this invention, the positive electrode conductive member that electrically connects the positive electrode terminal and the positive electrode uncoated portion, and the negative electrode conductive member that electrically connects the negative electrode terminal and the negative electrode uncoated portion are each an electrode assembly. When the lid-electrode assembly ASSY is inserted into the case, when the load is applied to the electrode assembly, the engaging portion also bears the load. As a result, the load applied to the joint portion (welded portion) between the positive electrode conductive member and the positive electrode uncoated portion and the joint portion (welded portion) between the negative electrode conductive member and the negative electrode uncoated portion is reduced. Accordingly, in the manufacturing process, when the lid-electrode assembly ASSY is inserted into the case, the load applied to the positive electrode uncoated portion and the negative electrode uncoated portion constituting the electrode is reduced, and the positive electrode uncoated portion and the negative electrode are reduced. It is possible to prevent the uncoated part from being damaged.

Further, since the engaging portion contacts and engages with the curved surface of the electrode assembly, the shape of the engaging portion viewed from the insertion direction is larger than when engaging with the end surface of the wound electrode assembly. Even if it is the same, the engagement area of an engaging part and an electrode assembly becomes large. As a result, the degree of reduction of the load applied to the positive electrode uncoated portion and the negative electrode uncoated portion constituting the positive electrode and the negative electrode is increased.

According to a second aspect of the present invention, in the first aspect , the positive electrode terminal and the negative electrode terminal protrude in the same direction, and the electrode assembly has the winding axis direction in the positive electrode. The case and the negative electrode terminal are accommodated in the case in a state orthogonal to the protruding direction of the negative electrode terminal, and the engaging portion is in contact with the curved surface.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the engaging portion has an extending portion that extends in a direction orthogonal to a protruding direction of the positive electrode terminal and the negative electrode terminal. In the present invention, the presence of the extended portion increases the engagement area with the electrode assembly as compared to the case where the extended portion does not exist, and the positive electrode uncoated portion and the negative electrode uncoated portion constituting the electrode The degree of reduction of the load applied to is increased. Moreover, the extension part can receive the load at the time of insertion compared with the structure extended in parallel with the protrusion direction of a positive electrode terminal and a negative electrode terminal.

The invention according to claim 4 is a secondary battery provided with the configuration of the power storage device according to any one of claims 1 to 3 . Therefore, the secondary battery of the present invention has the same effect as the power storage device according to any one of claims 1 to 5.

  According to the present invention, in the manufacturing process, when the lid-electrode assembly ASSY is inserted into the case, the active material uncoated portion (the positive electrode uncoated portion and the negative electrode uncoated portion) constituting the electrode (positive electrode and negative electrode). The power storage device and the secondary battery that can prevent the active material uncoated portion from being damaged can be provided.

The schematic cross section of the secondary battery of 1st Embodiment. The partial expansion schematic perspective view of an electrode assembly. (A) is a schematic partial perspective view of the state in which the positive electrode conductive member is welded to the electrode assembly, and (b) is a schematic perspective view before welding the positive electrode conductive member to the electrode assembly. The schematic cross section of the secondary battery of 2nd Embodiment. (A) is a general | schematic partial perspective view before welding a positive electrode electrically-conductive member to an electrode assembly, (b) is a general | schematic partial perspective view of the state by which the positive-electrode electrically conductive member was welded to the electrode assembly. The perspective view of the positive electrode electrically-conductive member of another embodiment. The perspective view which shows the cover of another embodiment, an electrode assembly, a positive electrode conductive member, and a negative electrode conductive member. (A) is a perspective view of the electrode assembly of another embodiment, (b) is a perspective view of a positive electrode conductive member and a negative electrode conductive member.

(First embodiment)
Hereinafter, a first embodiment in which the present invention is embodied in a secondary battery including a wound electrode assembly will be described with reference to FIGS.

  As shown in FIG. 1, a secondary battery 10 as a power storage device includes a wound-type electrode assembly 12 in a rectangular box-shaped case 11 that includes a case body 11 a and a lid 11 b that covers the opening. And an electrolyte solution (not shown).

  As shown in FIG. 2, the electrode assembly 12 includes a positive electrode active material layer 15a in which a positive electrode active material is applied to a strip-shaped metal foil 14, and a positive electrode uncoated portion 15b in which no positive electrode active material is applied. 15, a negative electrode active material layer 16 a in which a negative electrode active material is applied to a strip-shaped metal foil 14, and a negative electrode 16 having a negative electrode uncoated portion 16 b in which a negative electrode active material is not applied. 16 and a laminated structure in which the belt-like separators 17 are interposed between the two. The secondary battery 10 includes a positive terminal 18 and a negative terminal 19 that exchange electricity with the electrode assembly 12.

  In this embodiment, two separators 17 are used, the separator 17 exists on the outermost periphery of the electrode assembly 12, and the separator 17, the positive electrode 15, the separator 17, and the negative electrode 16 are layered in this order from the outer peripheral side. It has been turned. When the secondary battery 10 is a lithium ion secondary battery, the metal foil 14 for the positive electrode 15 is preferably an aluminum foil, and the metal foil 14 for the negative electrode 16 is preferably a copper foil.

  The positive electrode 15 and the negative electrode 16 are respectively formed with a positive electrode active material layer 15a and a negative electrode active material layer 16a so that a positive electrode uncoated portion 15b and a negative electrode uncoated portion 16b of a certain width exist on one side in the width direction. . The positive electrode 15 and the negative electrode 16 are formed to have the same width, and the positive electrode active material layer 15 a and the negative electrode active material layer 16 a are arranged in a state of facing each other with the separator 17 interposed therebetween. The separator 17 is formed to be slightly wider than the widths of the positive electrode active material layer 15a and the negative electrode active material layer 16a, and the electrode assembly 12 has a positive electrode uncoated portion 15b at one end in the winding axis direction. The positive electrode 15, the separator 17, and the negative electrode 16 are wound so that the negative electrode uncoated portion 16b is positioned at the other end. That is, the electrode assembly 12 is formed so that the positive electrode uncoated portion 15b of the positive electrode 15 and the negative electrode uncoated portion 16b of the negative electrode 15 are located at different ends in the winding axis direction of the electrode assembly 12. Yes.

  As shown in FIG. 1, the case 11 is provided with a positive terminal 18 and a negative terminal 19 protruding from the lid 11b. The positive electrode terminal 18 and the positive electrode uncoated portion 15 b are electrically connected by a positive electrode conductive member 20. The negative electrode terminal 19 and the negative electrode uncoated portion 16 b are electrically connected by a negative electrode conductive member 21. Electricity is transferred to and from the electrode assembly 12 through the positive terminal 18 and the negative terminal 19. In this embodiment, the positive electrode terminal 18 is formed integrally with the positive electrode conductive member 20, and the negative electrode terminal 19 is formed integrally with the negative electrode conductive member 21.

  Since the positive electrode conductive member 20 and the negative electrode conductive member 21 are formed in the same shape, the positive electrode conductive member 20 will be described in detail with reference to FIGS. The positive electrode conductive member 20 includes a rectangular support portion 20a. The positive electrode terminal 18 protrudes on one side of the support portion 20a, and the pair of arm portions 20b on the other side is opposite to the protruding direction of the positive electrode terminal 18. It is provided to protrude. And the welding part 20c is formed in the front-end | tip (FIG. 3 (a) lower end) side of the arm part 20b. The welded portion 20c becomes the positive electrode connecting portion 20d connected to the positive electrode uncoated portion 15b in a state welded to the positive electrode uncoated portion 15b.

  The positive electrode conductive member 20 includes an engaging portion 24 that engages with the electrode assembly 12 in a state where the welded portion 20c is welded to the positive electrode uncoated portion 15b. The engaging portion 24 is formed to protrude from the support portion 20 a in the direction opposite to the protruding direction of the positive electrode terminal 18, and the tip (the lower end in FIGS. 1 and 3) follows the outer shape of the electrode assembly 12. It is formed into a shape. The distal end of the engaging portion 24 is in contact with the curved surface of the electrode assembly 12. That is, the positive electrode conductive member 20 is in contact with the curved surface of the electrode assembly 12. That is, since the tip of the engaging portion 24 has a shape along the outer shape of the electrode assembly 12, the positive electrode conductive member 20 is engaged with the electrode assembly 12 by surface contact at the tip of the engaging portion 24. Can do.

Since the negative electrode conductive member 21 is configured in the same manner, as shown in FIG. 1, the negative electrode conductive member 21 includes a support portion 21a, an arm portion 21b, a weld portion 21c, and a negative electrode connection portion 21d.
The welded portion 20 c of the positive electrode conductive member 20 is welded to the laminated group of the positive electrode uncoated portions 15 b on the outer surface of the electrode assembly 12. That is, the pair of welded portions 20c are welded so as to sandwich the stacked group of the positive electrode uncoated portions 15b. The interval between the pair of welded portions 20c is formed to be narrower than the width between both side surfaces of the electrode assembly 12, and as shown in FIG. 3 (a), the pair of welded portions 20c is recessed in the electrode assembly 12 at the welding location. It is welded in the state. The engaging portions 24 of the positive electrode conductive member 20 and the negative electrode conductive member 21 are engaged with the curved surfaces 12a of the electrode assembly 12 near the positive electrode terminal 18 and the negative electrode terminal 19, respectively.

  As shown in FIG. 1, the positive terminal 18 has a male screw portion 18a, and is fastened and fixed to the lid 11b by a nut 22 that is screwed into the male screw portion 18a penetrating the lid 11b. The negative terminal 19 also has a male threaded portion 19a, and is fastened and fixed to the lid 11b by a nut 22 that is screwed into the male threaded portion 19a penetrating the lid 11b. A seal member 23 made of an electrically insulating material is interposed between the lid 11b and the nut 22 and between the lid 11b and the support portions 20a and 21a.

Next, the housing process of the electrode assembly 12 that houses the electrode assembly 12 in the case 11 among the manufacturing processes of the secondary battery 10 configured as described above will be described.
When housing the electrode assembly 12 in the case 11, after assembling the lid-electrode assembly ASSY with the lid 11b attached to the electrode assembly 12, the lid-electrode assembly ASSY is gripped by the lid 11b, The electrode assembly 12 is inserted into the case 11 with the winding axis direction of the assembly 12 held parallel to the bottom surface of the case 11. The insertion of the electrode assembly 12 into the case 11 is completed, and the lid 11b is welded to the case body 11a in a state where the lid 11b is in contact with the case body 11a, and the case 11 is sealed.

  When the lid-electrode assembly ASSY is inserted into the case, a load is applied to the electrode assembly 12 due to friction between the outer surface of the electrode assembly 12 and the inner surface of the case 11. When the engaging portion 24 does not exist, the load is received at the joint portion (welded portion) between the positive electrode conductive member 20 and the negative electrode conductive member 21, the positive electrode uncoated portion 15b, and the negative electrode uncoated portion 16b. As a result, a large load is applied to the positive electrode uncoated portion 15b and the negative electrode uncoated portion 16b following the joined portion, and the positive electrode uncoated portion 15b and the negative electrode uncoated portion 16b are likely to break. However, since the positive electrode conductive member 20 and the negative electrode conductive member 21 each have the engaging portion 24 engaged with the electrode assembly 12, the electrode assembly is inserted when the lid-electrode assembly ASSY is inserted into the case 11. When a load is applied to 12, the engaging portion 24 also bears the load. As a result, the load applied to the joint between the positive electrode conductive member 20 and the negative electrode conductive member 21, the positive electrode uncoated portion 15b, and the negative electrode uncoated portion 16b is reduced.

Next, the operation of the secondary battery 10 configured as described above will be described.
Although the secondary battery 10 is used alone, it is generally used as an assembled battery in which a plurality of secondary batteries 10 are connected in series or in parallel. The secondary battery 10 is used for various applications. For example, the secondary battery 10 is mounted on a vehicle and used as a power source for a traveling motor or a power source for other electrical devices.

According to this embodiment, the following effects can be obtained.
(1) In the secondary battery 10, the electrode assembly 12 having a stacked structure in which the positive electrode 15 and the negative electrode 16 are stacked with the separator 17 interposed between the positive electrode 15 and the negative electrode 16 includes a case body 11a and a lid. It is accommodated in the case 11 comprised with 11b. The case 11 includes a positive terminal 18 and a negative terminal 19 that exchange electricity with the electrode assembly 12. The positive electrode 15 includes a positive electrode active material layer 15a coated with a positive electrode active material, and a positive electrode uncoated portion 15b coated with no positive electrode active material. The negative electrode 16 includes a negative electrode active material layer 16a coated with a negative electrode active material. And a negative electrode uncoated portion 16b to which no negative electrode active material is applied. The case 11 is provided with a positive electrode terminal 18 and a negative electrode terminal 19 protruding from the lid 11b, and a positive electrode conductive member 20 that electrically connects the positive electrode terminal 18 and the positive electrode uncoated portion 15b, and a negative electrode terminal 19 and a negative electrode conductive member 21 that electrically connects the negative electrode uncoated portion 16b. The positive electrode conductive member 20 has a positive electrode connection portion 20d connected to the positive electrode uncoated portion 15b, and the negative electrode conductive member 21 has a negative electrode connection portion 21d connected to the negative electrode uncoated portion 16b. The negative electrode conductive member 21 includes an engaging portion 24 engaged with the electrode assembly 12. Therefore, in the manufacturing process, when the lid-electrode assembly ASSY is inserted into the case 11, the load applied to the positive electrode uncoated portion 15b and the negative electrode uncoated portion 16b constituting the positive electrodes 15 and 16 is reduced. It is possible to prevent the uncoated portion 15b and the negative electrode uncoated portion 16b from being damaged.

  (2) The engaging portion 24 is formed in a shape along the outer shape of the electrode assembly 12. If the engaging part 24 is engaged with the electrode assembly 12, the engaging part 24 bears a part of the load applied to the electrode assembly 12 when the lid-electrode assembly ASSY is inserted into the case 11. If the engaging portion 24 is formed in a shape along the outer shape of the electrode assembly 12, the engagement area between the engaging portion 24 and the electrode assembly 12 is increased. As a result, the degree of reduction of the load applied to the positive electrode uncoated portion 15b and the negative electrode uncoated portion 16b constituting the positive electrode 15 and the negative electrode 16 is increased.

  (3) The electrode assembly 12 is a wound type, and the outer shape of the electrode assembly 12 has a curved surface extending along the winding axis, and the positive electrode uncoated portion 15b and the negative electrode uncoated portion. 16b are formed so as to be located at different ends of the electrode assembly 12 in the winding axis direction. Therefore, in the wound electrode assembly 12, the effects (1) and (2) can be obtained.

  (4) The positive electrode terminal 18 and the negative electrode terminal 19 protrude in the same direction, and the electrode assembly 12 is arranged in the case 11 with the winding axis direction orthogonal to the protruding directions of the positive electrode terminal 18 and the negative electrode terminal 19. The engaging portion 24 is in contact with the curved surface. Therefore, compared with the case of engaging with the end face of the wound electrode assembly 12, the engagement area is increased even when the shape of the engagement portion 24 as viewed from the insertion direction is the same, and the positive electrode 15 and the negative electrode 16 are configured. The degree of reduction of the load applied to the positive electrode uncoated portion 15b and the negative electrode uncoated portion 16b increases.

  (5) The positive electrode terminal 18 and the negative electrode terminal 19 are formed integrally with the positive electrode conductive member 20 and the negative electrode conductive member 21, respectively. Therefore, compared with the case where the positive electrode terminal 18 and the negative electrode terminal 19 are formed separately from the positive electrode conductive member 20 and the negative electrode conductive member 21, respectively, the number of parts is reduced, and the number of man-hours for assembling the lid-electrode assembly ASSY. Becomes smaller.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS.
In the secondary battery 10 of this embodiment, the configuration of the positive electrode conductive member 20 and the negative electrode conductive member 21 is different from that of the first embodiment, and other configurations are the same as those of the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 4 and 5A, 5B, each of the positive electrode conductive member 20 and the negative electrode conductive member 21 has one arm portion 20b, 21b and one weld portion 20c, 21c. The welded portions 20c and 21c are not the outer surface of the electrode assembly 12, but the welded portions 20c and 21c are inserted into the winding center portion of the electrode assembly 12, and the positive electrode uncoated portion on the inner surface side of the electrode assembly 12 15b and the negative electrode uncoated portion 16b are welded.

  The engaging portion 24 has a tip (lower end in FIGS. 4 and 5) formed in a shape that follows the outer shape of the electrode assembly 12, and the protruding direction of the positive terminal 18 and the negative terminal 19. It has the extending part 25 extended in the orthogonal direction. The extending portion 25 is formed in a shape along the outer shape of the electrode assembly 12, has an engagement surface with the same curvature facing the curved surface 12 a of the electrode assembly 12, and the entire engagement surface is the electrode assembly. 12 curved surfaces 12a are engaged.

  In this embodiment, the positive terminal 18 and the negative terminal 19 are fixedly fastened to the lid 11b by male screw portions 18a and 19a passing through the seal member 23 and the lid 11b and screwing into the cap nut 26.

Also in the secondary battery 10 of this embodiment, the following effects can be obtained in addition to the basically same effects as (1) to (5) of the first embodiment.
(6) The engaging portion 24 has an extending portion 25 that extends in a direction orthogonal to the protruding direction of the positive electrode terminal 18 and the negative electrode terminal 19. Therefore, the presence of the extended portion 25 increases the area of engagement with the electrode assembly 12 as compared to the case where the extended portion 25 does not exist, and the positive electrode uncoated portion 15b constituting the positive electrode 15 and the negative electrode 16. And the reduction degree of the load added to the negative electrode uncoated part 16b becomes large. In addition, as compared with a configuration in which the extending portion 25 extends in parallel with the protruding direction of the positive electrode terminal 18 and the negative electrode terminal 19, a load at the time of insertion can be effectively received.

  (7) The extending portion 25 is formed in a shape along the outer shape of the electrode assembly 12 and has an engagement surface having the same curvature facing the curved surface 12 a of the electrode assembly 12. Therefore, the engagement area between the extended portion 25 and the electrode assembly 12 becomes larger, and the degree of reduction of the load applied to the positive electrode uncoated portion 15b and the negative electrode uncoated portion 16b becomes larger.

  (8) Since one arm portion 20b, 21b and one weld portion 20c, 21c are provided, the structure of the positive electrode conductive member 20 and the negative electrode conductive member 21 is simpler than that of the first embodiment in which a pair is provided. become.

The embodiment is not limited to the above, and may be embodied as follows, for example.
As shown in FIG. 6, also in the engaging part 24 provided in the positive electrode conductive member 20 and the negative electrode conductive member 21 of the first embodiment, the curved surface 12a of the electrode assembly 12 as in the second embodiment. An extending portion 25 extending along the line may be provided.

  The present invention is not limited to the wound electrode assembly 12 and may be applied to the secondary battery 10 having the stacked electrode assembly 32. For example, as shown in FIG. 7, in the electrode assembly 32, the positive electrode 15, the negative electrode 16, and the separator 17 are each formed in a rectangular shape, and the positive electrode uncoated portion and the negative electrode uncoated portion (active material uncoated portion). Are formed as tabs 27. The positive electrode conductive member 30 has a positive terminal 18 projecting from one end of a rectangular support 30a and a weld 30c formed at the other end. The welded portion 30c is welded to the tab 27 on the surface opposite to the surface on which the positive electrode terminal 18 protrudes. The welding is performed in a state in which the support portions 30a and 31a of the positive electrode conductive member 30 and the negative electrode conductive member 31 are arranged in parallel with the positive electrode 15, the negative electrode 16, and the separator 17, and the support portions 30a and 31a are the electrode assemblies after the end of welding. The tab 27 is bent so as to be parallel to the end face 32a on the side where the tab 27 protrudes.

  An engaging portion 34 is integrally formed on one end side of the positive electrode conductive member 30. The engaging portion 34 has an extending portion 35 that engages (abuts) over the entire length in the width direction of the end surface 32 a on the protruding side of the tab 27 of the electrode assembly 32. The negative electrode conductive member 31 is also formed in the same manner as the positive electrode conductive member 30, with the negative electrode terminal 19 protruding from one end side of the rectangular support portion 31a and the welded portion 31c formed at the other end side. The welded portion 31c is welded to the tab 27 on the surface opposite to the surface on which the negative electrode terminal 19 protrudes. Also in this embodiment, since the positive electrode conductive member 30 and the negative electrode conductive member 31 each have the engaging portion 34 engaged with the electrode assembly 32, when inserting the lid-electrode assembly ASSY into the case 11, It is possible to reduce the load applied to the tab 27 (active material uncoated portion) constituting the electrodes (the positive electrode 15 and the negative electrode 16) and prevent the active material uncoated portion from being damaged. Moreover, since the engaging part 34 has the extension part 35 engaged (contact | abutted) over the width direction full length of the end surface 32a of the protrusion side of the tab 27 of the electrode assembly 32, the load applied to the tab 27 is reduced. The degree is greater.

  In the secondary battery 10 having the wound electrode assembly 12, as shown in FIG. 8 (a), the electrode assembly 12 has a positive electrode uncoated portion 15b and a negative electrode uncoated portion 16b. The structure formed so that it may be located in the same edge part in the winding axis direction of the solid 12 and as the tab 27 may be sufficient. As shown in FIGS. 8A and 8B, the positive electrode conductive member 20 and the negative electrode conductive member 21 are formed in the same shape, and the engaging portion 24 included in the positive electrode conductive member 20 and the negative electrode conductive member 21 is an electrode assembly. 12 positive electrode uncoated portions 15 b and negative electrode uncoated portions 16 b are formed to engage with the end surface 12 b on the side protruding as the tab 27. The engaging portion 24 has an extending portion that extends in the width direction of the end surface 12b of the electrode assembly 12 and is formed to have the same length as the width of the end surface 12b. Also in this embodiment, since the positive electrode conductive member 20 and the negative electrode conductive member 21 each have the engaging portion 24 engaged with the electrode assembly 12, when inserting the lid-electrode assembly ASSY into the case 11, The load applied to the tab 27 (active material uncoated portion) constituting the electrode can be reduced to prevent the positive electrode uncoated portion 15b and the negative electrode uncoated portion 16b from being damaged. Further, since the engaging portion 24 extends in the width direction of the end surface 12b and has an extended portion having the same length as the width of the end surface 12b, the load applied to the tab 27 is reduced as compared with the case where the extended portion is not provided. The degree is greater.

  ○ The positive electrode terminal 18 and the positive electrode conductive members 20 and 30 or the negative electrode terminal 19 and the negative electrode conductive members 21 and 31 are not limited to being formed integrally, but may be separately formed later by, for example, welding. It may be a fixed configuration. In this case, after the positive electrode conductive members 20, 30 and the positive electrode uncoated portion 15b are welded, and the negative electrode conductive members 21, 31 and the negative electrode uncoated portion 16b are welded, the positive electrode terminal 18 and the positive electrode conductive member 20, 30 or the negative electrode terminal 19 and the negative electrode conductive members 21 and 31 are welded, the positive electrode conductive members 20 and 30 and the negative electrode conductive members 21 and 31 are welded to the positive electrode uncoated portion 15b and the negative electrode uncoated portion 16b. It becomes easy.

  The positive electrode conductive members 20 and 30 and the negative electrode conductive members 21 and 31 only need to have engaging portions 24 and 34 engaged with the electrode assemblies 12 and 32, respectively, and the extended portions 25 and 35 do not exist. May be.

  The engaging portions 24 and 34 may not be formed in a shape along the outer shape of the electrode assemblies 12 and 32. For example, the engaging portion 24 that engages with the curved surface 12a of the wound electrode assembly 12 is formed in a flat shape, or the engaging portion 34 that engages with the stacked electrode assembly 32 is formed in a curved shape. It may be done.

  The engaging portions 24 and 34 and the extending portions 25 and 35 are not limited to the shape extending in the direction intersecting with the protruding direction of the positive electrode terminal 18 and the negative electrode terminal 19, and are parallel to the protruding direction of the positive electrode terminal 18 and the negative electrode terminal 19. The shape may extend. For example, a configuration in which the engaging portion 24 and the extending portion 25 that engage with the wound electrode assembly 12 extend in parallel with the flat portion of the outer peripheral surface of the electrode assembly 12, or a laminated type The engaging portion 34 and the extending portion 35 that engage with the electrode assembly 32 may be engaged with the side surface of the electrode assembly 12 in a state orthogonal to the end surface 32a from which the tab 27 projects.

  The engaging portions 24 and 34 and the extending portions 25 and 35 may be configured to be engaged via an electrical insulating tape or an electrical insulating sheet instead of directly engaging the electrode assemblies 12 and 32. . In this case, even if the engaging portions 24 and 34 and the extending portions 25 and 35 are configured to engage with the end surface of the laminated structure of the electrode assemblies 12 and 32, the metal engaging portions 24 and 34 and the extending portions There is no possibility that the installation portions 25 and 35 are short-circuited with other poles.

  (Circle) the engaging parts 24 and 34 and the extension parts 25 and 35 may contact the positive electrode uncoated part 15b in the electrode assemblies 12 and 32, and the negative electrode uncoated part 16b. In this case, the positive electrode uncoated portion 15b and the negative electrode uncoated portion 16b are increased in width, and the positive electrode uncoated portion 15b and the negative electrode uncoated portion in the engaging portions 24, 34 and the extending portions 25, 35 are provided. The area of the portion in contact with 16b may be made sufficiently large. Even in this case, when the lid-electrode assembly ASSY is inserted into the case 11, the load applied to the positive electrode uncoated portion 15b and the negative electrode uncoated portion 16b constituting the electrode is reduced, and the positive electrode uncoated It is possible to prevent the portion 15b and the negative electrode uncoated portion 16b from being damaged.

(Circle) the secondary battery 10 does not necessarily require electrolyte solution, for example, the separator 17 may be formed with the polymer electrolyte.
The secondary battery 10 is not limited to a lithium ion secondary battery, and may be another secondary battery such as a nickel hydrogen secondary battery or a nickel cadmium secondary battery.

  The power storage device is not limited to the secondary battery 10 and may be a capacitor such as an electric double layer capacitor or a lithium ion capacitor.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery as a power storage device, 11 ... Case, 11a ... Case main body, 11b ... Lid, 12, 32 ... Electrode assembly, 12a ... Curved surface, 15 ... Positive electrode, 15a ... Positive electrode active material layer, 15b ... Positive electrode Uncoated part, 16 ... negative electrode, 16a ... negative electrode active material layer, 16b ... negative electrode uncoated part, 17 ... separator, 18 ... positive electrode terminal, 19 ... negative electrode terminal, 20, 30 ... positive electrode conductive member, 20d ... positive electrode connection 21, 31, negative electrode conductive member, 21 d, negative electrode connection portion, 24, 34, engagement portion, 25, 35, extension portion.

Claims (4)

A positive electrode having a positive electrode active material layer coated with a positive electrode active material, and a positive electrode uncoated portion where the positive electrode active material is not coated;
A negative electrode active material layer coated with a negative electrode active material, and a negative electrode having a negative electrode uncoated portion where the negative electrode active material is not coated,
An electrode assembly having a laminated structure in which a separator is interposed between the positive electrode and the negative electrode is housed in a case constituted by a case main body and a lid, and exchanges electricity with the electrode assembly. A power storage device including a positive electrode terminal and a negative electrode terminal,
The case is provided with the positive terminal and the negative terminal protruding from the lid,
The electrode assembly is a wound type, and the outer shape of the electrode assembly has a curved surface extending along a winding axis, and the positive electrode uncoated portion and the negative electrode uncoated portion are Formed so as to be located at different ends in the winding axis direction of the electrode assembly,
A positive electrode conductive member that electrically connects the positive electrode terminal and the positive electrode uncoated portion; and a negative electrode conductive member that electrically connects the negative electrode terminal and the negative electrode uncoated portion;
The positive electrode conductive member has a positive electrode connecting portion connected to the positive electrode uncoated portion and an engaging portion formed integrally with the positive electrode connecting portion ,
The negative electrode conductive member has a negative electrode connecting portion connected to the negative electrode uncoated portion and an engaging portion formed integrally with the negative electrode connecting portion ,
The electrode assembly has a separator on the outermost periphery,
The engaging portion of the positive electrode conductive member and the engaging portion of the negative electrode conductive member are formed in a shape along the curved surface of the electrode assembly, and are engaged with the electrode assembly by contacting the curved surface. A power storage device characterized by that . The positive terminal and the negative terminal protrude in the same direction,
2. The power storage device according to claim 1 , wherein the electrode assembly is housed in the case in a state in which the winding axis direction is orthogonal to a protruding direction of the positive electrode terminal and the negative electrode terminal. The power storage device according to claim 1 , wherein the engaging portion includes an extending portion that extends in a direction orthogonal to a protruding direction of the positive electrode terminal and the negative electrode terminal. The secondary battery provided with the structure of the electrical storage apparatus as described in any one of Claims 1-3 .