JP2018107021A - Method for manufacturing power storage device - Google Patents

Abstract

A method of manufacturing a power storage device capable of improving the productivity of a power storage device including an electrode assembly having a layered structure is provided.
An insulating film 33 that covers an electrode assembly 12 and insulates the case and the electrode assembly 12 protrudes from surfaces 12a and 12b of the electrode assembly 12 in the width direction Y and is opposed to the stacking direction X. Projecting portions 34 and 36. A pair of protrusion parts 34 and 36 are heat-welded and joined. Heat is applied to the pair of protruding portions 34 and 36 while being pulled outward in the width direction Y, and the pair of protruding portions 34 and 36 are heat-welded.
[Selection] Figure 4

Description

  The present invention relates to a method for manufacturing a power storage device including an insulating sheet that insulates a case and an electrode assembly.

  Power storage devices such as secondary batteries and capacitors are widely used as power sources because they can be recharged and can be used repeatedly. Some secondary batteries include a stacked electrode assembly in which a plurality of rectangular sheet-like positive electrodes and negative electrodes are stacked with a separator interposed therebetween. In some cases, a belt-like positive electrode and a belt-like negative electrode are each provided with a wound-type electrode assembly wound with a belt-like separator in between. That is, the electrode assembly has a layered structure in which a separator is interposed between the positive electrode and the negative electrode. Generally, an electrode assembly is covered with an insulating sheet and insulated from a case that houses the electrode assembly.

  Moreover, in order to prevent the positive electrode, the negative electrode, and the separator from being displaced from each other and the layered structure of the electrode assembly from collapsing, for example, in the power storage device described in Patent Document 1, holding tape is attached to a plurality of locations of the electrode assembly. Yes.

Japanese Patent Laying-Open No. 2015-53220

  However, when the power storage device described in Patent Document 1 is manufactured, a process of attaching and holding a holding tape to the electrode assembly and a process of covering the electrode assembly with an insulating sheet are required, and the productivity of the power storage device is reduced. There was a problem.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method of manufacturing a power storage device that can improve the productivity of a power storage device including an electrode assembly having a layered structure. It is in.

  A method of manufacturing a power storage device for solving the above problems includes an electrode assembly having a layered structure in which electrodes having different polarities are insulated from each other, a metal case housing the electrode assembly, and the electrode assembly. An insulating sheet that covers and insulates the case and the electrode assembly, and the insulating sheet has a pair of protrusions protruding from both sides of the electrode assembly in the stacking direction and facing the stacking direction. A method of manufacturing a power storage device in which the pair of protruding portions is bonded, wherein at least one of the pair of protruding portions is subjected to a bonding step in a state of being pulled in a protruding direction, and the pair of protruding portions are The gist is to join.

  According to this, a pair of protrusion part is joined so that the tension | tensile_strength of the lamination direction may be applied to at least one protrusion part. The tension of the protruding portion becomes a restraining force that restrains the electrode assembly of the insulating sheet in the stacking direction, and the restraining force suppresses the collapse of the layered structure of the electrode assembly. In this case, since the step of restraining the electrode assembly and the step of covering the electrode assembly with the insulating sheet are simultaneously performed, the productivity of the power storage device including the electrode assembly having a layered structure can be improved.

In the method for manufacturing the power storage device, it is preferable to pull the pair of protruding portions together.
According to this, compared with the case where each protrusion part is pulled, the number of apparatuses for pulling the protrusion part can be reduced.

In the method for manufacturing the power storage device, it is preferable that the electrode assembly is a stacked electrode assembly, and the pair of protruding portions are joined at the center in the stacking direction.
According to this, since the tension of the protruding portion can be directed to the center in the stacking direction, the balance of the restraining force in the stacking direction with respect to the electrode assembly of the insulating sheet can be improved.

  In the method of manufacturing the power storage device, it is preferable that at least one of the pair of protruding portions is pulled in the protruding direction with a load applied to the electrode assembly from at least one direction in the stacking direction. .

  According to this, a restoring force (reaction force) in the stacking direction is generated in the electrode assembly, but the electrode assembly is restrained by the insulating sheet as a resistance against the restoring force. Therefore, the restraining force with respect to the electrode assembly of the insulating sheet can be further increased.

  Further, regarding the method for manufacturing the power storage device, the insulating sheet includes the pair of protruding portions on both sides of the electrode assembly, and the pair of protruding portions on both sides of the electrode assembly are pulled in the protruding direction. It is preferable to join in a state.

  According to this, in addition to the pair of protruding portions protruding to one side, the pair of protruding portions protruding to the other side are also joined in a pulled state, so that the balance of the restraining force in the protruding direction of the insulating sheet with respect to the electrode assembly is excellent. Can be.

Moreover, about the manufacturing method of an electrical storage apparatus, it is preferable to cover with the said insulating sheet so that at least one surface of the said electrode assembly may be open | released.
According to this, it can respond to the electrode assembly which has a tab, for example.

  ADVANTAGE OF THE INVENTION According to this invention, productivity of an electrical storage apparatus provided with the electrode assembly which has a layered structure can be improved.

The disassembled perspective view of 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. (A)-(d) is a schematic plan view for demonstrating the manufacturing process of a secondary battery. The disassembled perspective view of the secondary battery of another example.

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 FIGS. 1 and 2, the secondary battery 10 as the power storage device includes a case 11. The secondary battery 10 includes an electrode assembly 12 accommodated in a case 11. The case 11 includes a rectangular parallelepiped main body member 13 and a rectangular flat plate-shaped lid member 14 that closes the opening 13 a of the main body member 13. Both the main body member 13 and the lid member 14 constituting the case 11 are made of metal (for example, stainless steel or aluminum). Further, the secondary battery 10 of the present embodiment is a prismatic battery whose appearance is square. Further, the secondary battery 10 of the present embodiment is a lithium ion battery.

  The secondary battery 10 includes a positive electrode terminal 15 and a negative electrode terminal 16 for taking out electricity from the electrode assembly 12. The positive electrode terminal 15 and the negative electrode terminal 16 are exposed to the outside of the case 11 through a pair of holes 14 a arranged in parallel with the lid member 14 at a predetermined interval. Further, a ring-shaped insulating ring 17 a for insulating from the case 11 is attached to the positive terminal 15 and the negative terminal 16, respectively.

  As shown in FIG. 3, the electrode assembly 12 includes a sheet-like positive electrode 20 and a sheet-like negative electrode 21 as electrodes having different polarities. The positive electrode 20 has a positive electrode metal foil (in this embodiment, an aluminum foil) 22 and a positive electrode active material layer 23 formed by applying a positive electrode active material on both surfaces thereof. The negative electrode 21 has a negative electrode metal foil (copper foil in this embodiment) 24 and a negative electrode active material layer 25 formed by applying a negative electrode active material on both surfaces thereof. The electrode assembly 12 is a laminate having a layered structure in which a separator 26 of a microporous film is interposed between the positive electrode 20 and the negative electrode 21. The electrode assembly 12 is configured, for example, by laminating a plurality of positive electrodes 20 and a plurality of negative electrodes 21 alternately. That is, the electrode assembly 12 includes a plurality of sets each including a positive electrode 20, a negative electrode 21, and a separator 26.

  As shown in FIG. 3, the positive electrode 20 includes a positive electrode current collecting tab 28 made of a positive electrode metal foil 22 at an edge (one end). The positive electrode current collecting tab 28 is formed in the same position and in the same shape in each positive electrode 20 constituting the electrode assembly 12. Further, the negative electrode 21 includes a negative electrode current collecting tab 30 made of a negative electrode metal foil 24 at an edge (one end). The negative electrode current collecting tab 30 is formed in the same shape at the same position in each negative electrode 21 constituting the electrode assembly 12.

  Each positive electrode 20 is stacked such that the respective positive electrode current collecting tabs 28 are arranged in a line along the stacking direction X of the electrode assembly 12. Similarly, each negative electrode 21 is laminated so that the respective negative electrode current collecting tabs 30 are arranged in a line along the lamination direction X of the electrode assembly 12 so as not to overlap the positive electrode current collecting tabs 28. . Then, as shown in FIG. 1, each positive electrode current collecting tab 28 is collected in a range from one end to the other end in the stacking direction X of the electrode assembly 12 to form a positive electrode current collecting group 31. The positive electrode terminal 15 is electrically joined to the positive electrode current collecting group 31. Similarly, each negative electrode current collecting tab 30 is also collected in a range from one end to the other end in the stacking direction X of the electrode assembly 12 to form a negative electrode current collecting group 32. The negative electrode terminal 16 is electrically connected to the negative electrode current collecting group 32.

  The electrode assembly 12 of this embodiment is a rectangular parallelepiped having six surfaces. The six surfaces of the electrode assembly 12 are surfaces 12a and 12b which are both surfaces in the stacking direction X of the electrode assembly 12, and four side surfaces which are connected to the two surfaces and which are orthogonal to the stacking direction X of the electrode assembly 12. 12c, 12d, 12e, and 12f. The side surface 12e is a current collecting side surface from which the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 protrude. The positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 protrude in the same direction from one side surface 12e. The side surface 12f is a bottom side surface as an opposite surface facing the side surface 12e. The side surfaces 12 c and 12 d are side surfaces orthogonal to the side surfaces 12 e and 12 f, respectively, and are surfaces facing the width direction Y orthogonal to the stacking direction X of the electrode assembly 12.

  The electrode assembly 12 is covered with an insulating film 33 as an insulating sheet. The insulating film 33 is an insulating sheet for insulating the electrode assembly 12 from the metal case 11 and is made of, for example, polypropylene (PP). The insulating film 33 is formed in a bag shape by folding and welding one insulating film 33.

Here, the insulating film 33 before welding will be described.
As shown in FIG. 4A, the insulating film 33 includes a rectangular first region 33a larger than the surface 12a of the electrode assembly 12, and a rectangular second region 33b larger than the surface 12b of the electrode assembly 12. And the third region 33c having a rectangular shape larger than the side surface 12f of the electrode assembly 12. The first region 33a is a portion covering the entire surface 12a of the electrode assembly 12, the second region 33b is a portion covering the entire surface 12b of the electrode assembly 12, and the third region 33c is an electrode assembly. This is a part covering the entire side surface 12f of the solid body 12.

  The first region 33 a includes a protruding portion 34 that protrudes from the surface 12 a of the electrode assembly 12 in the width direction Y and an protruding portion 35 that protrudes in the width direction Y. The second region 33b includes a protruding portion 36 that protrudes from the surface 12b of the electrode assembly 12 in the width direction Y and an protruding portion 37 that protrudes in the width direction Y. The third region 33 c includes a protruding portion 38 that protrudes from the side surface 12 f of the electrode assembly 12 in the width direction Y and a protruding portion 39 that protrudes in the width direction Y. The protruding dimensions of the protruding portions 34 and 36 from the surfaces 12 a and 12 b of the electrode assembly 12 and the protruding dimensions of the protruding portions 35 and 37 are shorter than the dimension in the stacking direction X of the electrode assembly 12.

Next, the insulating film 33 covering the electrode assembly 12 will be described.
As shown in FIG. 1, the insulating film 33 has a cover 41 that covers the side surface 12 c of the electrode assembly 12. The cover portion 41 is composed of a root portion 34 a of the protruding portion 34 and a root portion 36 a of the protruding portion 36. The insulating film 33 has a superposed portion 42 that protrudes from the cover portion 41. The overlapping portion 42 includes a surplus portion 34b that is a tip portion of the protruding portion 34, and a surplus portion 36b that is a tip portion of the protruding portion 36 that faces the surplus portion 34b. The insulating film 33 has a welded portion 43 obtained by thermally welding the surplus portion 34 b of the protruding portion 34 and the surplus portion 36 b of the protruding portion 36. The welded portion 43 of the present embodiment is located in the center in the stacking direction X of the electrode assembly 12 and in the vicinity of the side surface 12c.

  As shown in FIG. 4C, the insulating film 33 has a cover portion 44 that covers the side surface 12 d of the electrode assembly 12. The cover portion 44 includes a root portion 35 a of the protruding portion 35 and a root portion 37 a of the protruding portion 37. The insulating film 33 has a superposed portion 45 that protrudes from the cover portion 44. The overlapping portion 45 includes a surplus portion 35b that is a tip portion of the protruding portion 35 and a surplus portion 37b that is a tip portion of the protruding portion 37 that faces the surplus portion 35b. The insulating film 33 has a welded portion 46 obtained by thermally welding the surplus portion 35 b of the protruding portion 35 and the surplus portion 37 b of the protruding portion 37. The welding portion 46 of the present embodiment is located in the center in the stacking direction X of the electrode assembly 12 and in the vicinity of the side surface 12d.

  In the insulating film 33, a tension toward the center in the stacking direction X is generated in the cover portions 41 and 44. Due to this tension, the first region 33 a and the second region 33 b are pulled toward the center in the stacking direction X. The first region 33 a and the second region 33 b are in close contact with the surfaces 12 a and 12 b of the electrode assembly 12.

  As described above, the insulating film 33 covers five surfaces of the electrode assembly 12 except for the side surface 12e. The electrode assembly 12 covered with the insulating film 33 is inserted from the opening 13 a of the main body member 13 and accommodated in the case 11.

Next, a manufacturing process of the secondary battery 10, particularly a procedure for covering the electrode assembly 12 with the insulating film 33 will be described in detail.
First, as shown to Fig.4 (a), the electrode assembly 12 is arrange | positioned between the insulating films 33 bent in the U-shape. At this time, the first region 33a of the insulating film 33 is made to face the surface 12a of the electrode assembly 12, the second region 33b of the insulating film 33 is made to face the surface 12b of the electrode assembly 12, and the third region of the insulating film 33 is made. 33c is opposed to the side surface 12f of the electrode assembly 12. As a result, the entire surfaces 12a and 12b and the side surface 12f of the electrode assembly 12 are covered with the insulating film 33. Further, by arranging the electrode assembly 12 in the center in the width direction Y of the insulating film 33, the protruding portions 34 to 39 of the first to third regions 33 a to 33 c are protruded from the electrode assembly 12.

  Further, a load K is applied to the electrode assembly 12 from both directions of the stacking direction X, the first region 33a of the insulating film 33 is brought into close contact with the surface 12a of the electrode assembly 12, and the second region 33b of the insulating film 33 is attached to the electrode assembly. The solid 12 is brought into close contact with the surface 12b.

  Next, as shown in FIG. 4B, the protruding portions 38 and 39 are bent along the side surfaces 12 c and 12 d of the electrode assembly 12. Thereafter, the clamp 51 is used to hold the tip of the protruding portion 34 and the tip of the protruding portion 36 together as a pair of protruding portions 34, 36, and is pulled outward in the width direction Y as the protruding direction. As a result, the protruding portions 34 and 36 are in a tensioned state. Similarly, the clamp 52 is used to hold the distal end of the protruding portion 35 and the distal end of the protruding portion 37 together as a pair of protruding portions 35 and 37, and pulls outward in the width direction Y as the protruding direction. Thereby, the protrusion parts 35 and 37 will be in the state to which tension was applied. Note that the load K continues to be applied to the electrode assembly 12 when the protruding portions 34 to 37 are pulled.

  As shown in FIG. 4B, heaters 61 and 62 that make a pair in the stacking direction X are disposed on both sides of the pair of protruding portions 34 and 36. Each heater 61, 62 is movable in the stacking direction X at a position near the side surface 12c of the electrode assembly 12. In addition, heaters 63 and 64 that are paired in the stacking direction X are disposed on both sides of the pair of protruding portions 35 and 37. Each heater 63, 64 is movable in the stacking direction X at a position near the side surface 12d of the electrode assembly 12. The power supply of each heater 61-64 is off.

  Next, as shown in FIG. 4C, one heater 61 is moved to the center in the stacking direction X in a state where the pair of protruding portions 34 and 36 are pulled outward in the width direction Y as the protruding direction. The heater 61 is in contact with the protruding portion 34, and the root portion 34 a is bent along the side surface 12 c of the electrode assembly 12. Simultaneously with the movement of one heater 61, the other heater 62 is moved to the center in the stacking direction X. The heater 62 contacts the protruding portion 36, and the root portion 36 a is bent along the side surface 12 c of the electrode assembly 12.

  When the heaters 61 and 62 reach the center in the stacking direction X, the heaters 61 and 62 face each other through the pair of protruding portions 34 and 36. And the cover part 41 is formed by the base parts 34a and 36a of the protrusion parts 34 and 36 which cover the side surface 12c of the electrode assembly 12, and the front-end | tip part which becomes surplus without covering the side surface 12c becomes the surplus parts 34b and 36b. . The pair of surplus portions 34b and 36b are bent away from the side surface 12c to form an overlapped portion 42.

  Thereafter, the heaters 61 and 62 are turned on. Then, the heaters 61 and 62 that are in a high temperature state are pressed against the base portions of the surplus portions 34b and 36b of the protruding portions 34 and 36 so as to be heat-welded to join the pair of surplus portions 34b and 36b. Thereby, the welding part 43 is formed in a pair of surplus parts 34b and 36b. Note that the load K continues to be applied to the electrode assembly 12 even when the heaters 61 and 62 are moved and the protruding portions 34 and 36 are welded. Therefore, the first region 33a of the insulating film 33 is in close contact with the surface 12a of the electrode assembly 12, and the second region 33b of the insulating film 33 is in close contact with the surface 12b of the electrode assembly 12, and the cover 41 and A weld 43 is formed.

  Similarly, one heater 63 is moved to the center in the stacking direction X in a state where the pair of protruding portions 35 and 37 are pulled outward in the width direction Y as the protruding direction. The heater 63 is in contact with the protruding portion 35, and the root portion 35 a is bent along the side surface 12 d of the electrode assembly 12. Simultaneously with the movement of one heater 63, the other heater 64 is moved to the center in the stacking direction X. The heater 64 is in contact with the protruding portion 37, and the root portion 37 a is bent along the side surface 12 d of the electrode assembly 12.

  When the heaters 63 and 64 reach the center in the stacking direction X, the heater 63 and the heater 64 face each other via the pair of protruding portions 35 and 37. And the cover part 44 is formed by the base parts 35a and 37a of the protrusion parts 35 and 37 which cover the side surface 12d of the electrode assembly 12, and the front-end | tip part which becomes surplus without covering the side surface 12d becomes the surplus parts 35b and 37b. . The surplus portions 35b and 36b are bent away from the side surface 12d to form an overlapped portion 45.

  Thereafter, the heaters 63 and 64 are turned on. Then, the heaters 63 and 64 that are in a high temperature state are pressed against the base portions of the surplus portions 35b and 37b of the protruding portions 35 and 37, and heat-welded by heat input to join the pair of surplus portions 35b and 37b. Thereby, the welding part 46 is formed in a pair of surplus parts 35b and 37b.

  Note that the load K continues to be applied to the electrode assembly 12 when the heaters 63 and 64 are moved and when the protruding portions 35 and 37 are welded. Therefore, the first region 33a of the insulating film 33 is in close contact with the surface 12a of the electrode assembly 12, and the second region 33b of the insulating film 33 is in close contact with the surface 12b of the electrode assembly 12, and the covering portion 44 and A weld 46 is formed.

  Thus, when the welding parts 43 and 46 are formed, the insulating film 33 will be a bottomed bag shape. Thereafter, the application of the load K to the electrode assembly 12 and the pulling of the protruding portions 34 to 37 by the clamps 51 and 52 are finished.

  Finally, as shown in FIG. 4D, the overlapping portion 42 (the pair of surplus portions 34 b and 36 b having the welded portion 43) is bent along the side surface 12 c of the electrode assembly 12. In the present embodiment, the surplus portion 36b is bent so as to face the side surface 12c of the electrode assembly 12. Similarly, the overlapping portion 45 (the pair of surplus portions 35 b and 37 b having the weld portion 46) is bent along the side surface 12 d of the electrode assembly 12. In the present embodiment, the surplus portion 37b is bent so as to face the side surface 12d of the electrode assembly 12.

Next, the operation of this embodiment will be described.
Since the pair of protrusions 34 and 36 are heated and joined while being pulled outward in the width direction Y, a tension toward the center in the stacking direction X is generated in the cover 41 that covers the side surface 12c of the electrode assembly 12. Similarly, since the pair of protrusions 35 and 37 are heated and joined while being pulled outward in the width direction Y, the cover 44 covering the side surface 12d of the electrode assembly 12 generates a tension toward the center in the stacking direction X. To do. For this reason, the state in which the first and second regions 33a and 33b of the insulating film 33 are in close contact with the surfaces 12a and 12b of the electrode assembly 12 is maintained.

Next, characteristic effects of the present embodiment will be described.
(1) Since the pair of protrusions 34 and 36 are heated and joined while being pulled outward in the width direction Y, a tension toward the center in the stacking direction X is generated in the cover 41 that covers the side surface 12c of the electrode assembly 12. To do. Since this tension serves as a restraining force that restrains the electrode assemblies 12 in the first region 33a and the second region 33b in the stacking direction X, collapse of the layered structure (lamination misalignment) of the electrode assembly 12 is suppressed.

  Similarly, since the pair of protrusions 35 and 37 are heated and joined while being pulled outward in the width direction Y, the cover 44 covering the side surface 12d of the electrode assembly 12 generates a tension toward the center in the stacking direction X. To do. Since this tension serves as a restraining force that restrains the electrode assemblies 12 in the first region 33a and the second region 33b in the stacking direction X, collapse of the layered structure (lamination misalignment) of the electrode assembly 12 is suppressed.

In this case, since the step of restraining the electrode assembly 12 and the step of covering the electrode assembly 12 with the insulating film 33 are simultaneously performed, the productivity of the secondary battery 10 can be improved.
(2) Since the protruding portion 34 and the protruding portion 36 are collectively pulled outward in the width direction Y, the number of clamps 51 can be reduced as compared with the case where the protruding portions 34 and 36 are pulled separately. Similarly, since the protruding portion 35 and the protruding portion 37 are collectively pulled outward in the width direction Y, the number of the clamps 52 can be reduced as compared with the case where the protruding portions 35 and 37 are pulled separately.

  (3) Since the welding parts 43 and 46 are formed in the center of the stacking direction X, the tension of the protruding parts 34 to 36 can be directed to the center of the stacking direction X. Therefore, the balance of the restraining force of the lamination direction X with respect to the electrode assembly 12 of the insulating film 33 can be made favorable.

  (4) Cover the electrode assembly 12 with the insulating film 33 while applying a load K in the stacking direction X to the electrode assembly 12. Therefore, a restoring force in the stacking direction X is generated in the electrode assembly 12, but the electrode assembly 12 is restrained by the insulating film 33 as a resistance against the restoring force. Therefore, the binding force of the insulating film 33 to the electrode assembly 12 can be further increased.

  (5) Since the pair of protrusions 34 and 36 protruding in one direction in the width direction Y and the pair of protrusions 35 and 37 protruding in the other direction in the width direction Y are heated and joined in a state of being pulled, the electrode set of the insulating film 33 The balance of the restraining force in the width direction Y with respect to the solid 12 can be improved.

  (6) In order to cover the electrode assembly 12 with the insulating film 33 so as to open the side surface 12e of the electrode assembly 12, the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 provided on the side surface 12e are connected to the positive electrode terminal 15 and It can be connected to the negative terminal 16.

  (7) In a state where the cover portions 41 and 44 are along the side surfaces 12c and 12d of the electrode assembly 12, the protruding portions 34 to 37 are heated and joined. Therefore, the insulating film 33 can restrain the electrode assembly 12 in the width direction Y in addition to the stacking direction X.

In addition, you may change the said embodiment as follows.
The electrode assembly 12 may be a wound electrode assembly.
The positive electrode active material layer 23 of the positive electrode 20 is formed on both surfaces of the positive electrode metal foil 22, but may be formed only on one surface. The negative electrode active material layer 25 of the negative electrode 21 is formed on both sides of the negative electrode metal foil 24, but may be formed only on one side.

O The electrode assembly 12 may be covered with a plurality of insulating films 33.
Depending on the shape of the insulating film 33, the surface on which the welded portions 43 and 46 are provided may be only one of the side surface 12c and the side surface 12d.

  (Circle) you may change the dimension of the protrusion parts 34-37 in the range in which the welding parts 43 and 46 can be formed. However, from the viewpoint of suppressing an increase in the size of the secondary battery 10, it is preferable that the dimensions be such that the excess portions 34 b to 37 b do not protrude outward from the end surface in the stacking direction X of the electrode assembly 12. .

  The positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 are provided on the side surface 12e of the electrode assembly 12, but may be provided on the side surfaces 12c, 12d, and 12f. In this case, the electrode assembly 12 is covered with the insulating film 33 so as to open the side surface on which the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 are provided. The welded portions 43 and 46 may be appropriately provided on the side surface where the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 are not provided. For example, when the positive electrode current collecting tab 28 and the negative electrode current collecting tab 30 are provided on the side surface 12c and the welded portions 43 and 46 are provided on the side surfaces 12e and 12f, the protruding portions 34 to 37 are orthogonal to the stacking direction X and the width direction Y. Protrude in the direction. In this manner, the protruding portions 34 to 37 only have to protrude so that the electrode assembly 12 is restrained by the insulating film 33.

A device for pulling the protruding portions 34 to 37 is not limited to the clamps 51 and 52.
(Circle) you may pull the protrusion parts 34-37 in the position which shifted | deviated from the lamination direction X center.

  In the above embodiment, the protruding portions 34 and 36 are pulled in the width direction Y as the protruding direction. However, for example, the protruding portions 34 and 36 may be pulled outward in the width direction Y and on the side surface 12f. That is, as long as the direction includes the protruding direction, the direction in which the protruding portions 34 and 36 are pulled may be appropriately changed.

  In the above embodiment, the protruding portion 34 and the protruding portion 36 are pulled together, and the protruding portion 35 and the protruding portion 37 are pulled together, but they may be pulled separately.

  In the above embodiment, both the protruding portion 34 and the protruding portion 36 are pulled, but only one of them may be pulled. For example, when only the protruding portion 34 is pulled, the heater 61 is moved to the other end side in the stacking direction X (the protruding portion 36 side) while being in contact with the protruding portion 34, so that the pair of protruding portions 34 and 36 are thermally welded. . In this case, the covering portion 41 is configured only by the root portion 34 a of the protruding portion 34. Moreover, the whole protrusion part 36 becomes the surplus part 36b.

  Similarly, in the said embodiment, although both the protrusion part 35 and the protrusion part 37 were pulled, you may pull only any one. For example, when only the protruding portion 37 is pulled, the pair of protruding portions 35 and 37 are thermally welded by moving the heater 64 to one end side (the protruding portion 35 side) in the stacking direction X while being in contact with the protruding portion 37. In this case, the cover portion 44 is configured only by the root portion 37 a of the protruding portion 37. Moreover, the whole protrusion part 35 becomes the surplus part 35b.

  In the above embodiment, the welded portions 43 and 46 are formed at the root portions of the surplus portions 34b to 37b. However, the range in which the welded portions 43 and 46 are formed may be appropriately changed by the surplus portions 34b to 37b. .

O You may form the welding parts 43 and 46 in the position shifted | deviated from the lamination direction X center.
The material of the insulating film 33 is not limited to polypropylene (PP), but may be other materials such as polyphenylene sulfide (PPS).

The method for forming the welding parts 43 and 46 may be other welding methods such as ultrasonic welding instead of heat welding by the heaters 61 to 64.
The method for joining the protruding portions 34 to 37 is not limited to welding, and may be joining using an adhesive or caulking joining using rivets or staples made of an insulating material.

  In the above embodiment, when the electrode assembly 12 is covered with the insulating film 33, the load K is applied to the electrode assembly 12 from both directions of the stacking direction X. However, the load K is applied only from one direction of the stacking direction X. May be added. Further, the load K may not be applied. In this case, the first and second regions 33a and 33b are brought into close contact with the surfaces 12a and 12b of the electrode assembly 12 when the protruding portions 34 to 37 are pulled.

  In the above embodiment, the overlapping portion 42 is bent so that the surplus portion 36b faces the side surface 12c of the electrode assembly 12, and the overlapping portion 45 is bent so that the surplus portion 37b faces the side surface 12d of the electrode assembly 12. However, the processing method of the superposition | polymerization parts 42 and 45 is not limited to this.

  For example, the overlapping portion 42 may be folded so that the surplus portion 34 b faces the side surface 12 c of the electrode assembly 12, or the surplus portion 35 b may be folded in a direction facing the side surface 12 d of the electrode assembly 12. Moreover, you may cut and remove the superposition | polymerization parts 42 and 45 in the position of the width direction Y outer side rather than the welding parts 43 and 46. FIG.

  In the above embodiment, the protruding portions 38 and 39 are bent along the side surfaces 12c and 12d of the electrode assembly 12, and then the protruding portions 34 to 37 are welded. However, after the protruding portions 34 to 37 are welded, The protruding portions 38 and 39 may be bent. In this case, as shown in FIG. 5, when the overlapping portions 42 and 45 are bent, the welded protruding portions 38 and 39 are bent in the same direction as the overlapping direction of the overlapping portions 42 and 45. Thereafter, portions of the protruding portions 38 and 39 that protrude from the side surfaces 12c and 12d of the electrode assembly 12 are bent along the side surfaces 12c and 12d.

The power storage device can also be applied to power storage devices other than secondary batteries, such as capacitors.
The secondary battery 10 may be a lithium ion secondary battery or another secondary battery. In short, any ion may be used as long as ions move between the active material for the positive electrode and the active material for the negative electrode and charge is transferred.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery as power storage device, 11 ... Case, 12 ... Electrode assembly, 12a, 12b ... Surface as surface, 20 ... Positive electrode as electrode, 21 ... Negative electrode as electrode, 33 ... As insulating sheet Insulating film, 34 to 37 ... protruding portion, X ... stacking direction.

Claims (6)

An electrode assembly having a layered structure in which electrodes of different polarities are insulated from each other;
A metal case containing the electrode assembly;
An insulating sheet that covers the electrode assembly and insulates the case and the electrode assembly;
The insulating sheet has a pair of protrusions protruding from both sides in the stacking direction of the electrode assembly and facing the stacking direction, and the method of manufacturing a power storage device in which the pair of protrusions are joined,
A method of manufacturing a power storage device, wherein a joining step is performed on at least one of the pair of protruding portions while being pulled in a protruding direction, and the pair of protruding portions are bonded.   The method for manufacturing a power storage device according to claim 1, wherein the pair of protruding portions are pulled together. The electrode assembly is a stacked electrode assembly,
The method for manufacturing a power storage device according to claim 1, wherein the pair of protruding portions are joined at the center in the stacking direction.   4. The device according to claim 1, wherein a load is applied to the electrode assembly from at least one direction of the stacking direction, and at least one of the pair of protruding portions is pulled in the protruding direction. 5. The manufacturing method of the electrical storage apparatus as described in 2 .. The insulating sheet includes the pair of protruding portions on both sides of the electrode assembly,
The method for manufacturing a power storage device according to any one of claims 1 to 4, wherein the pair of protruding portions on both sides of the electrode assembly are joined while being pulled in a protruding direction. The method for manufacturing a power storage device according to any one of claims 1 to 5, wherein the insulating sheet covers at least one surface of the electrode assembly.

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