JP2018166065A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device capable of inhibiting a foreign object from being caught between an electrode assembly and an insulation sheet or between the insulation sheet and a case.SOLUTION: A secondary battery 10 includes: an electrode assembly 12 obtained by laminating a positive electric electrode and negative electric electrode; an insulation film 40 with which the electrode assembly 12 is covered; and a case 11 housing the electrode assembly 12 covered with the insulation film 40. The electrode assembly 12 includes a first superposition area A1 in which a facing part all of the positive electric electrode and negative electric electrode face is projected on a first side surface 12c and second side surface 12d, end surfaces in the lamination direction, and a second superposition area A2 positioned outside the first superposition area A1. The secondary battery 10 includes a regulation tape 50 that is arranged between the first side surface 12c and second side surface 12d and the insulation film 40 with which the electrode assembly 12 is covered and is arranged along a boundary part B between the first superposition area A1 and second superposition area A2 in a side view viewed from the lamination direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a power storage device including an electrode assembly, an insulating sheet that covers the electrode assembly, and a case that houses the electrode assembly covered with the insulating sheet.

  A vehicle such as an EV (Electric Vehicle) or a PHV (Plug-in Hybrid Vehicle) is equipped with a secondary battery as a power storage device that stores power supplied to a traveling motor. The secondary battery includes an electrode assembly in which a positive electrode and a negative electrode are stacked or wound, and a bottomed cylindrical case that houses the electrode assembly and an electrolytic solution. The electrode assembly and the case are insulated by an insulating sheet that covers the electrode assembly (see Patent Document 1).

JP 2014-38736 A

  In such a secondary battery, the case is restrained in the stacking direction by a restraining jig in order to suppress deformation of the case due to expansion of the positive electrode and the negative electrode in the stacking direction during charging and discharging. At this time, for example, foreign matter mixed in the case after the electrode assembly is accommodated, or foreign matter mixed in the case before the electrode assembly is accommodated and floated by the injection of the electrolyte solution, the electrode assembly and the insulating sheet Or between the insulating sheet and the inner surface of the case. The foreign matter may bite into the insulating sheet due to the expansion of the electrode assembly in the stacking direction and break through the insulating sheet. The tearing of the insulating sheet leads to a short circuit between the electrode assembly and the case.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power storage device that can restrict foreign matter from being caught between the electrode assembly and the insulating sheet or between the insulating sheet and the inner surface of the case. Is to provide.

  A power storage device for solving the above problems is a state in which a plurality of sheet-like first electrodes and a plurality of sheet-like second electrodes having different polarities and sizes from the first electrodes are insulated And a case for accommodating the electrode assembly covered with the insulating sheet, the electrode assembly comprising: an electrode assembly that is alternately stacked; an insulating sheet that covers the electrode assembly; and a case that houses the electrode assembly covered with the insulating sheet. The three-dimensional object includes a first region where all the first electrodes and the second electrode are opposed to each other on the end surface in the stacking direction, and a second region located outside the first region. Between the end face and the insulating sheet, or between the insulating sheet facing the end face and the case, and in a side view as viewed from the stacking direction, the first region and the first A restricting member is provided along the boundary between the two regions. The gist of the door.

  When the power storage device is charged and discharged in a state of being constrained in the stacking direction, the first region is in a pressurized state as the electrode assembly expands in the stacking direction, so the end surface of the electrode assembly in the stacking direction and the insulating sheet Intrusion of foreign matter between the insulating sheet facing the gap and the end face and the inner surface of the case is suppressed. On the other hand, since the second region is in a non-pressurized state even when the electrode assembly expands in the stacking direction, the insulating sheet between the end surface and the insulating sheet in the stacking direction of the electrode assembly and the end surface of the case It is easy to create a gap between the inner surface. In a power storage device that does not include a regulating member, foreign matter that has entered through the gap is sandwiched between the end surface in the stacking direction of the electrode assembly and the insulating sheet at the boundary, or between the insulating sheet that faces the end surface and the inner surface of the case. Sometimes. On the other hand, in a power storage device including a regulating member arranged along the boundary, foreign matter can be prevented from being caught between the end face of the electrode assembly and the insulating sheet, or between the insulating sheet and the inner surface of the case.

  In the power storage device, the case includes a bottomed cylindrical case body that houses the electrode assembly covered by the insulating sheet, and a lid that closes an opening of the case body, and the regulation The member is preferably arranged along a portion of the boundary portion located on the lid side in the side view.

  By arranging the regulating member along the portion of the boundary portion located on the lid side, foreign matter mixed in the case after the electrode assembly is accommodated in the case body is insulated from the end surface of the electrode assembly at the boundary portion. It is possible to restrict the sheet from being sandwiched between the sheet or between the insulating sheet facing the end surface and the inner surface of the case body.

Moreover, about the said electrical storage apparatus, it is preferable that the said limitation member is arrange | positioned between the said end surface and the said insulating sheet.
According to this, since the regulating member can be arranged in the vicinity of the electrode assembly, compared with the case where the regulating member is provided between the insulating sheet and the case, it is easy to grasp the position of the boundary portion. Therefore, the restriction member can be easily arranged.

In the power storage device, the restriction member is preferably a tape.
According to this, a regulation member can be easily arranged by sticking a regulation member to an electrode assembly, an insulating sheet, and a case.

  A power storage device for solving the above problems is laminated in a state where a long strip-shaped first electrode and a long strip-shaped second electrode having a different polarity from the first electrode are insulated, and A power storage device comprising: an electrode assembly wound in a flat shape; an insulating sheet that covers the electrode assembly; and a case that houses the electrode assembly covered by the insulating sheet, wherein the electrode The flat surface is disposed between the flat surface of the assembly and the insulating sheet, or between the insulating sheet and the case facing the flat surface and viewed from a direction orthogonal to the flat surface. The gist of the present invention is to provide a regulating member arranged along the edge of each of the above.

  When the power storage device is charged / discharged in a state constrained in a direction orthogonal to the flat surface, the flat surface is in a pressurized state as the electrode assembly expands in the stacking direction during charge / discharge. Intrusion of foreign matter between the flat surface and the insulating sheet or between the insulating sheet facing the flat surface and the inner surface of the case is suppressed. However, in the case of a power storage device that does not include a restricting member at the edge of the uneven plane, a gap is formed between the electrode assembly and the insulating sheet, or between the insulating sheet and the inner surface of the case, so foreign matter may be caught. is there. On the other hand, in a power storage device including a regulating member arranged along an edge, foreign matter is present between the electrode assembly and the insulating sheet or between the insulating sheet and the inner surface of the case at the edge of the uneven plane. It is possible to regulate pinching.

  ADVANTAGE OF THE INVENTION According to this invention, it can control that a foreign material is pinched | interposed between an electrode assembly and an insulating sheet, or between an insulating sheet and the inner surface of a case.

The disassembled perspective view of the secondary battery of 1st Embodiment. The perspective view of the secondary battery restrained by the restraining jig. The disassembled perspective view of the electrode assembly of 1st Embodiment. (A), (b) is sectional drawing of the secondary battery of 1st Embodiment. (A), (b) is sectional drawing of the secondary battery of 2nd Embodiment. Sectional drawing of the secondary battery of another example. Sectional drawing of the secondary battery of another example.

(First embodiment)
Hereinafter, a first 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 and an electrolytic solution (not shown). The case 11 includes a rectangular parallelepiped case main body 13 and a rectangular flat lid 14 that closes the opening 13 a of the case main body 13. Both the case main body 13 and the lid 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 case body 13 includes a bottom surface 13b and first to fourth wall portions 13c to 13f connected to the bottom surface 13b. The case body 13 includes a first wall portion 13c on one of the wall portions connected to the pair of long edges of the bottom surface 13b, and a second wall portion on the other wall portion facing the first wall portion 13c. 13d. Further, the case body 13 includes the third wall portion 13e on one of the wall portions connecting the first wall portion 13c and the second wall portion 13d and connecting to the pair of short edges of the bottom surface 13b, A fourth wall portion 13f is provided on the other wall portion facing the third wall portion 13e.

  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 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 plurality of sheet-like positive electrodes 20 as first electrodes, a plurality of sheet-like negative electrodes 21 as second electrodes, and a plurality of sheet-like electrodes. And a separator 30. The electrode assembly 12 has a structure in which a separator 30 is interposed between the positive electrode 20 and the negative electrode 21 and laminated in a state of being insulated from each other. A direction in which the positive electrode 20, the negative electrode 21, and the separator 30 are stacked is defined as a stacking direction.

  The positive electrode 20 includes a positive metal foil (for example, an aluminum foil) 22 as a rectangular sheet-shaped current collector, and a positive electrode active material layer 23 present on both surfaces of the positive metal foil 22. The positive electrode 20 includes a first edge portion 20a at one edge portion of the edge portions along the pair of long sides. The positive electrode 20 includes a positive electrode tab 24 having a shape protruding from a part of the first edge 20a. The positive electrode tab 24 is configured by the positive electrode metal foil 22 itself without the positive electrode active material layer 23.

  Further, the positive electrode 20 includes a second edge 20b on the other edge which is the opposite side of the first edge 20a among the edges along the pair of long sides. Further, the positive electrode 20 includes a third edge 20c on one edge of a pair of short edges connecting the first edge 20a and the second edge 20b, and the third edge 20c. A fourth edge portion 20d is provided on the other edge portion which is the opposite side.

  The negative electrode 21 includes a negative electrode metal foil (for example, copper foil) 25 as a rectangular sheet-shaped current collector, and negative electrode active material layers 26 present on both surfaces of the negative electrode metal foil 25. The negative electrode 21 includes a first edge portion 21a on one edge portion of the edge portions along the pair of long sides. The negative electrode 21 has a negative electrode tab 27 having a shape protruding from a part of the first edge 21a. The negative electrode tab 27 is configured by the negative electrode metal foil 25 itself without the negative electrode active material layer 26.

  Moreover, the negative electrode 21 is provided with the 2nd edge part 21b in the other edge part used as the opposite side of the 1st edge part 21a among the edge parts along a pair of long side. Furthermore, the negative electrode 21 includes a third edge 21c on one edge of the pair of short edges connecting the first edge 21a and the second edge 21b, and the third edge 21c. A fourth edge portion 21d is provided on the other edge portion which is the opposite side.

  As shown in FIG. 4A, the length of the first edge 21a of the negative electrode 21 is longer than the length of the first edge 20a of the positive electrode 20, and the length of the second edge 21b of the negative electrode 21. Is longer than the length of the second edge 20 b of the positive electrode 20. Further, the length of the third edge 21 c of the negative electrode 21 is longer than the length of the third edge 20 c of the positive electrode 20, and the length of the fourth edge 21 d of the negative electrode 21 is the fourth length of the positive electrode 20. It is longer than the length of the edge 20d. Therefore, the outer shape of the negative electrode 21 is slightly larger than the outer shape of the positive electrode 20. The negative electrode 21 includes a protruding portion 28 extending from the outer shape of the positive electrode 20 along the first to fourth edge portions 21a to 21d in a state where the positive electrode 20 and the negative electrode 21 are laminated.

  As shown in FIG. 1, each positive electrode 20 is stacked such that the respective positive electrode tabs 24 are arranged in a line along the stacking direction of the electrode assembly 12. Similarly, each negative electrode 21 is laminated so that the respective negative electrode tabs 27 are arranged in a line along the lamination direction of the electrode assembly 12 so as not to overlap the positive electrode tab 24. The positive electrode tabs 24 are collected in a range from one end to the other end in the stacking direction of the electrode assembly 12 to form a positive electrode tab group 24a. The positive electrode terminal 15 is electrically joined to the positive electrode tab group 24a. Similarly, the negative electrode tabs 27 are gathered in a range from one end to the other end in the stacking direction of the electrode assembly 12 to form a negative electrode tab group 27a. The negative electrode terminal 16 is electrically connected to the negative electrode tab group 27a.

  The electrode assembly 12 includes a tab-side end surface 12a in which the positive electrode tab group 24a and the negative electrode tab group 27a are present on the end surface facing the lid 14, and includes the bottom-side end surface 12b on the end surface facing the bottom surface 13b of the case body 13. The tab side end surface 12 a is configured by the first edge portion 21 a of the stacked negative electrode 21, and the bottom end surface 12 b is configured by the second edge portion 21 b of the stacked negative electrode 21. In addition, the electrode assembly 12 includes a first side surface 12 c on an end surface facing the first wall portion 13 c of the case main body 13, and a second side surface 12 d on an end surface facing the second wall portion 13 d of the case main body 13. The first side surface 12c is formed by the negative electrode 21 positioned at one end in the stacking direction, and the second side surface 12d is formed by the negative electrode 21 positioned at the other end in the stacking direction. The electrode assembly 12 includes a third side surface 12e on an end surface of the case main body 13 facing the third wall portion 13e, and a fourth side surface 12f on an end surface of the case main body 13 facing the fourth wall portion 13f. The third side surface 12e is constituted by the third edge portion 21c of the laminated negative electrode 21, and the fourth side surface 12f is constituted by the fourth edge portion 21d of the laminated negative electrode 21. The capacity of the secondary battery 10 increases as the volume of the electrode assembly 12 accommodated in the case 11 increases. For this reason, in this embodiment, the volume of the electrode assembly 12 accommodated in the case 11 is increased by increasing the number of the positive electrode 20 and the negative electrode 21 to be stacked as much as possible. Therefore, the distance between the first and second side surfaces 12c and 12d and the inner surface of the case body 13 is shorter than the distance between the bottom end surface 12b or the third and fourth side surfaces 12e and 12f and the inner surface of the case body 13. In the present embodiment, it is considered that there is no stacking deviation in the plane direction of the positive electrode 20 and the negative electrode 21.

  As shown in FIG. 4A and FIG. 4B, the electrode assembly 12 includes a first overlapping region A1 as a first region and a second region as a first region on the first side surface 12c and the second side surface 12d. 2nd superposition | polymerization area | region A2. The first overlapping region A1 is a region where a facing portion where all the positive electrodes 20 and the negative electrodes 21 face each other is projected in a side view when the electrode assembly 12 is viewed from the stacking direction. It is the same size as the part excluding. The second overlapping region A2 is a region existing outside the first overlapping region A1 in a side view when the electrode assembly 12 is viewed from the stacking direction, and is a region where the protruding portion 28 of the negative electrode 21 is projected. . A boundary portion B between the first overlapping region A1 and the second overlapping region A2, that is, an edge portion of the first overlapping region A1, is the first to fourth of the positive electrode 20 in a side view when the electrode assembly 12 is viewed from the stacking direction. It coincides with the edges 20a to 20d.

  The secondary battery 10 includes an insulating film 40 as an insulating sheet that covers the electrode assembly 12. The insulating film 40 insulates the electrode assembly 12 from the metal case body 13. The insulating film 40 is made of, for example, polypropylene (PP). The insulating film 40 is formed in a bag shape by folding and welding one insulating film. The insulating film 40 covers five surfaces (the bottom side end surface 12b and the first to fourth side surfaces 12c to 12d) excluding the tab side end surface 12a of the electrode assembly 12.

  The secondary battery 10 includes a regulation tape 50 as a regulation member that regulates foreign substances from entering between the first side surface 12 c and the second side surface 12 d of the electrode assembly 12 and the insulating film 40 at the boundary portion B. The regulation tape 50 of this embodiment is made of the same polypropylene (PP) as the insulating film 40 and has adhesiveness on one side. The restriction tape 50 is attached to the electrode assembly 12 so as to cover the boundary portion B. The regulation tape 50 is present along the boundary portion B in a side view of the electrode assembly 12 as viewed from the stacking direction. The regulation tape 50 forms a rectangular ring. The inner edge portion 50a of the regulation tape 50 exists in the first overlapping region A1, and the outer edge portion 50b exists in the second overlapping region A2.

  As shown in FIG. 2, such a secondary battery 10 has a stacking direction by a restraining jig 70 in order to suppress deformation of the case 11 due to expansion of the positive electrode 20 and the negative electrode 21 in the stacking direction during charging and discharging. Restrained by For example, the restraining jig 70 includes a pair of restraining plates 71 and 72, a bolt 73 that connects the restraining plates 71 and 72, and a nut 74 that is screwed to the bolt 73. One restraint plate 71 is disposed to face the first wall portion 13c of the case body 13, and the other restraint plate 72 is disposed to face the second wall portion 13d of the case body 13. Then, by screwing the nut 74 into the bolt 73, the first wall 13 c and the second wall 13 d of the case body 13 are loaded from the restraining plates 71 and 72, and the electrode assembly 12 is stacked in the stacking direction. Be bound.

  Since 1st superposition | polymerization area | region A1 is an area | region where all the positive electrode 20 and the negative electrode 21 overlapped, it will be in a pressurized state with the expansion | swelling to the lamination direction of the electrode assembly 12 at the time of charging / discharging. At this time, the regulation tape 50 is in a state of being bitten into the insulating film 40. Therefore, in the first overlapping region A1, the first and second side surfaces 12c, 12d of the electrode assembly 12 and the insulating film 40, the first and second wall portions 13c of the insulating film 40 and the case body 13, Intrusion of foreign matter between the inner surface of 13d is suppressed. On the other hand, the second polymerization region A2 is a region where the protruding portions 28 of the negative electrode 21 are stacked, and there is a gap between the protruding portions 28 by the thickness of the positive electrode 20. Part of the expansion of the protruding portion 28 in the stacking direction is absorbed by this gap. For this reason, 2nd superposition | polymerization area | region A2 is a non-pressurized state. In the second overlapping region A2, the first and second side surfaces 12c, 12d of the electrode assembly 12 and the insulating film 40, and the inner surfaces of the first and second wall portions 13c, 13d of the insulating film 40 and the case body 13 are used. It is easy to make a gap between them. At the boundary B, the regulation tape 50 is in a state of being buried between the first and second side surfaces 12 c and 12 d of the electrode assembly 12 and the insulating film 40.

Next, the effect of 1st Embodiment is described with an effect | action.
(1) When the secondary battery 10 does not include the regulation tape 50, the foreign matter mixed in the case 11 is caused by the inner surfaces of the first and second side surfaces 12c and 12d of the electrode assembly 12 and the insulating film in the second polymerization region A2. 40 may enter between the first and second side surfaces 12c and 12d and the insulating film 40 at the boundary B. On the other hand, in the present embodiment, since the regulation tape 50 is disposed so as to cover the boundary portion B, the first and second side surfaces 12c and 12d of the electrode assembly 12 and the insulating film 40 at the boundary portion B. It is regulated that foreign matter is caught between them.

  (2) The restriction tape 50 is disposed between the first and second side surfaces 12 c and 12 d of the electrode assembly 12 and the insulating film 40. Thereby, since the regulation tape 50 can be arrange | positioned in the electrode assembly 12 vicinity rather than the case where the regulation tape 50 is arrange | positioned between the insulating film 40 and the case main body 13, it is easy to grasp | ascertain the position of the boundary part B. FIG. Therefore, the regulation tape 50 can be easily attached to the boundary portion B of the electrode assembly 12.

(3) Since the regulation tape 50 has adhesiveness on one side, it can be attached to the electrode assembly 12 and the regulation member can be easily arranged.
(Second Embodiment)
Hereinafter, a second embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIG.

  As shown in FIGS. 5A and 5B, the secondary battery 80 includes a case 11. Note that the case 11 has the same configuration as that of the above embodiment, and thus the description thereof is omitted. The secondary battery 80 includes an electrode assembly 82 accommodated in the case 11 and an electrolytic solution (not shown). The electrode assembly 82 of the present embodiment includes a long strip-shaped positive electrode 90 as a first electrode and a long strip-shaped negative electrode 91 as a second electrode. Is a wound electrode assembly that is laminated in an insulated state and wound in a flat shape. The electrode assembly 82 is accommodated in the case 11 so that the winding axis L coincides with the longitudinal direction of the lid 14. The electrode assembly 82 includes a first flat surface 83 as a flat surface on the outer surface facing the inner surface of the first wall portion 13c of the case body 13, and the flat surface on the outer surface facing the inner surface of the second wall portion 13d. As a second flat plane 84. The electrode assembly 82 includes an arcuate surface 85 on the outer surface connecting the first and second flat surfaces 83 and 84. The electrode assembly 82 includes edges 83 a and 84 a along the winding axis L among the edges of the first and second flat surfaces 83 and 84.

  The secondary battery 80 includes an insulating film 86 as an insulating sheet that covers the outer surface of the electrode assembly 82. In addition, the secondary battery 80 includes a gap between the insulating film 86 and the inner surfaces of the first wall portion 13c and the second wall portion 13d of the case body 13 at the edge portions 83a and 84a of the first and second flat surfaces 83 and 84. A restriction tape 87 for restricting foreign matter from being caught between the two is provided. The restriction tape 87 is disposed so as to cover the edges 83 a and 84 a of the first and second flat surfaces 83 and 84 covered with the insulating film 86. The restriction tape 87 exists along the edges 83a and 84a in a side view when the electrode assembly 82 is viewed from a direction orthogonal to the first and second flat surfaces 83 and 84.

  As in the first embodiment, the secondary battery 80 including such a wound electrode assembly 82 is charged and discharged in a state of being restrained by a restraining jig. That is, the first wall portion 13c and the second wall portion 13d of the case 11 are constrained in a direction orthogonal to the first and second flat surfaces 83 and 84.

  Since the first and second flat surfaces 83 and 84 are in a pressurized state as the electrode assembly 82 expands in the stacking direction during charge and discharge, the first and second flat surfaces 83 and 84 and the insulating film 86 are in contact with each other. And the intrusion of foreign matter between the insulating film 86 and the inner surfaces of the first and second wall portions 13c and 13d of the case main body 13 are suppressed. The distance between the insulating film 86 facing the edges 83a and 84a of the first and second flat surfaces 83 and 84 and the inner surfaces of the first and second wall portions 13c and 13d of the case body 13 is the first and second offsets. The distance between the insulating film 86 facing the flat surfaces 83 and 84 and the inner surfaces of the first and second wall portions 13c and 13d of the case body 13 is longer. The restriction tape 87 is buried between the insulating film 86 facing the edges 83 a and 84 a of the first and second flat surfaces 83 and 84 and the inner surfaces of the first and second wall portions 13 c and 13 d of the case body 13. It is in the state.

Next, the effect of 2nd Embodiment is described with an effect | action.
(4) When the secondary battery 80 does not include the regulation tape 87, the foreign matter mixed in the case 11 is separated from the insulating film 86 and the case main body 13 at the edges 83a and 84a of the first and second flat surfaces 83 and 84. Between the first and second wall portions 13c and 13d. In contrast, the secondary battery 80 of the present embodiment is disposed along the edges 83a and 84a in a side view when the electrode assembly 82 is viewed from a direction orthogonal to the first and second flat surfaces 83 and 84. The regulation tape 87 is provided. Accordingly, foreign matter is restricted from being sandwiched between the insulating film 86 and the inner surfaces of the first and second wall portions 13c and 13d of the case body 13 at the edge portions 83a and 84a.

In addition, you may change 1st Embodiment and 2nd Embodiment as follows.
The current collector is not limited to the positive electrode metal foil 22 and the negative electrode metal foil 25 as long as the positive electrode active material layer 23 and the negative electrode active material layer 26 can be formed. For example, a woven or net-like sheet may be used.

  The positive electrode 20 may have a structure in which the positive electrode active material layer 23 exists on one side of the positive electrode metal foil 22. Similarly, the negative electrode 21 may have a configuration in which the negative electrode active material layer 26 exists on one surface of the negative electrode metal foil 25.

  In the first embodiment, the first electrode may be the negative electrode 21 and the second electrode may be the positive electrode 20. In this case, the second overlapping region A2 is a region where the protruding portion of the positive electrode 20 protruding from the outer shape of the negative electrode 21 is projected in a side view when the electrode assembly 12 is viewed from the stacking direction. Similarly, in the second embodiment, the first electrode may be the negative electrode 91 and the second electrode may be the positive electrode 90.

  In the first embodiment, the positive electrode 20 and the negative electrode 21 are described as having no stacking deviation in the plane direction. Therefore, the boundary portion B is a positive electrode in a side view when the electrode assembly 12 is viewed from the stacking direction. 20 first to fourth edge portions 20a to 20d. However, when the positive electrode 20 and the negative electrode 21 have a stacking deviation in the surface direction, the boundary B is the edge of the first overlapping region A1 where the facing portions where all the positive electrodes 20 and the negative electrodes 21 face each other are projected. And does not coincide with the first to fourth edge portions 20 a to 20 d of the positive electrode 20.

The type of the insulating sheet is not limited to the insulating films 40 and 86, and may be a laminated sheet.
The material of the insulating films 40 and 86 is not limited to polypropylene (PP), but may be other materials such as polyphenylene sulfide (PPS).

  ○ The regulation members of the first and second embodiments were regulation tapes 50 and 87 having adhesiveness on one side, but tapes having adhesiveness on both sides may be used, or a sheet-like shape having no adhesiveness It may be a member. Further, the material of the regulation tapes 50 and 87 may be different from the material of the insulating films 40 and 86.

  In the first embodiment, the regulation tape 50 is adhered to the first and second side surfaces 12 c and 12 d of the electrode assembly 12, but may be adhered to the inner surface of the insulating film 40. However, the regulation tape 50 is arranged along the boundary portion B in a side view when the electrode assembly 12 is viewed from the stacking direction.

  As shown in FIG. 6, the regulation tape 50 according to the first embodiment is disposed between the outer surface of the insulating film 40 and the inner surfaces of the first wall portion 13 c and the second wall portion 13 d of the case body 13. Also good. However, it arrange | positions so that the control tape 50 may follow the boundary part B by the side view which looked at the secondary battery 10 from the lamination direction. The regulation tape 50 may be attached to the outer surface of the insulating film 40, or may be attached to the inner surfaces of the first wall portion 13c and the second wall portion 13d of the case body 13.

  (Circle) the control tape 87 of 2nd Embodiment may be arrange | positioned between the outer surface of the electrode assembly 82, and the inner surface of the insulating film 86. FIG. However, the restriction tape 87 extends along the edges 83 a and 84 a of the first and second flat surfaces 83 and 84 in a side view when the secondary battery 80 is viewed from a direction orthogonal to the first and second flat surfaces 83 and 84. Arrange as follows. The regulation tape 87 may be attached to the outer surface of the electrode assembly 82 or may be attached to the inner surface of the insulating film 40.

  (Circle) the regulation tape 50 of 1st Embodiment may exist along a part of boundary part B by the side view seen from the lamination direction. Similarly, the regulation tape 87 of the second embodiment may exist along part of the edge portions 83 a and 84 a of the first and second flat surfaces 83 and 84.

  Foreign matter mixed in the case 11 after the electrode assembly 12 is accommodated in the case main body 13 falls due to gravity, and between the electrode assemblies 12 and 82 and the insulating films 40 and 86, or between the insulating films 40 and 86 and the case. It is easy to get caught between the main body 13. Therefore, it is preferable to arrange the regulating tapes 50 and 87 along the portions located on the lid 14 side of the boundary portion B and the edge portions 83a and 84a.

As shown in FIG. 7, in addition to the boundary portion B, a rectangular regulation tape 50 may be attached so as to cover the entire first overlapping region A1.
The electrode assembly 12 may be covered with a plurality of insulating films 40.

  In the first embodiment, the method of forming the insulating film 40 in a bag shape is not limited to welding. For example, after covering the electrode assembly 12 with the insulating film 40, the portion protruding from the electrode assembly 12 may be overlapped with the portion covering the electrode assembly 12 and attached with tape. As another method, the electrode assembly 12 is accommodated in a bag-like insulating film 40 that is slightly larger than the electrode assembly 12, and then the insulating film 40 is thermally contracted to thereby shrink the electrode assembly 12 and the insulating film. 40 may be brought into close contact with each other.

  Although the restraining jig 70 of the first embodiment restrains one secondary battery 10, a plurality of secondary batteries 10 may be restrained together. Similarly, the restraining jig of the second embodiment may restrain one secondary battery 80 or a plurality of secondary batteries 80.

  The secondary batteries 10 and 80 may be lithium ion secondary batteries or other secondary batteries. 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.

  The power storage device can also be applied to power storage devices other than secondary batteries, such as capacitors.

  DESCRIPTION OF SYMBOLS 10,80 ... Secondary battery as power storage device, 11 ... Case, 12, 82 ... Electrode assembly, 12c ... First side as end face, 12d ... Second side as end face, 13 ... Case body, 13a ... Opening Part, 14 ... lid, 20 ... positive electrode as first electrode, 21 ... negative electrode as second electrode, 40, 86 ... insulating film as insulating sheet, 50, 87 ... regulating tape as regulating member, 83: First flat surface as a flat surface, 84: Second flat surface as a flat surface, 83a, 84a: Edge, A1: First superposition region as a first region, A2: Second as a second region Polymerization region, B ... boundary.

Claims (5)

An electrode assembly in which a plurality of sheet-shaped first electrodes and a plurality of sheet-shaped second electrodes having different polarities and sizes from the first electrodes are alternately stacked; and
An insulating sheet covering the electrode assembly;
A case for accommodating the electrode assembly covered by the insulating sheet;
A power storage device comprising:
The electrode assembly includes: a first region where all the first electrode and the second electrode are opposed to each other on the end surface in the stacking direction; and a first region located outside the first region. Two regions,
A boundary between the first region and the second region, as viewed from the side as viewed from the stacking direction, between the end surface and the insulating sheet, or between the insulating sheet and the case facing the end surface. A power storage device comprising a regulating member disposed along the portion. The case has a bottomed cylindrical case body that accommodates the electrode assembly covered by the insulating sheet, and a lid that closes an opening of the case body,
The power storage device according to claim 1, wherein the regulating member is disposed along a portion of the boundary portion located on the lid side in the side view.   The power storage device according to claim 1, wherein the regulating member is disposed between the end surface and the insulating sheet.   The power storage device according to claim 1, wherein the regulating member is a tape. An electrode assembly in which a long strip-shaped first electrode and a long strip-shaped second electrode having a polarity different from that of the first electrode are laminated and wound in a flat shape; and
An insulating sheet covering the electrode assembly;
A case for accommodating the electrode assembly covered by the insulating sheet;
A power storage device comprising:
Between the flat surface of the electrode assembly and the insulating sheet, or between the insulating sheet facing the flat surface and the case, and in a side view seen from a direction orthogonal to the flat surface, A power storage device comprising a restricting member disposed along an edge of a flat surface.