JP2014022325A - Power storage device and secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To laminate a positive electrode and a negative electrode constituting a multilayer electrode assembly so that the lamination position of a positive electrode and a negative electrode is not misaligned, without narrowing a current path in a tub.SOLUTION: A secondary battery 10 has a multilayer electrode assembly 12, and a positive electrode 17 and a negative electrode 19 have bodies 17a, 19a including active material layers 17b, 19b, and tubs 17c projecting from the bodies, respectively. The positive electrode 17 is housed in a bag-shaped separator 21 while projecting the tub 17c from the body, and the separator 21 is formed larger than the bodies 17a, 19a. The separator 21 has two holes 21a at positions closer to the tub 17c side than the position facing the body 17a, and the negative electrode 19 has two holes 19f facing the hole 21a in the active material non-coated portion 19d. The positive electrode 17, negative electrode 19 and separator 21 are configured so that they can be positioned in a state where the a positioning rod is inserted into the holes 21a, 19f when assembling the electrode assembly 12.

Description

  The present invention relates to a power storage device and a secondary battery, and more particularly to a power storage device and a secondary battery having a stacked 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. A stacked secondary battery has an electrode assembly having a structure in which a substantially rectangular positive electrode and negative electrode are alternately stacked with a separator interposed therebetween, and a positive electrode terminal corresponding to each tab of the positive electrode and the negative electrode Or it has the structure connected to the negative electrode terminal. When misalignment occurs between the stacked positive electrode sheet, separator, and negative electrode sheet, the positive electrode sheet and the negative electrode sheet are short-circuited or the performance of the battery is degraded.

  Therefore, in the manufacturing process of the electrode assembly, it is necessary to stack the positive electrode and the negative electrode with high accuracy with the separator interposed therebetween. Lamination is time consuming and expensive. There is also a method of laminating one by one while positioning with a positioning pin or the like that contacts the periphery of the positive electrode, the negative electrode, and the separator. However, in the lithium ion secondary battery, since the positive electrode is smaller than the negative electrode, the positioning pin cannot accurately position. Therefore, a method has been proposed in which even if the positive electrode and the negative electrode are different in size, the misalignment is prevented and the positive electrode and the negative electrode are accurately positioned (see Patent Document 1).

  In the method of Patent Document 1, the positive electrode and the negative electrode have tabs having positioning holes arranged symmetrically with respect to the center line of the positive electrode or the negative electrode. Then, in a state where the positioning hole is inserted through the shaft, the positive electrode and the negative electrode are suspended at the tab portion to perform positioning.

JP 2011-165620 A

  In the method of Patent Document 1, it is necessary to provide tabs at positions symmetrical with respect to the center line of the positive electrode or the negative electrode. In order to prevent the positive and negative electrode tabs from contacting each other, at least one of the positive electrode and the negative electrode Requires two tabs. In addition, in the case where the tab is provided at one place, it is necessary to provide the tab at two places in order to regulate the rotational direction when the positioning is performed by hanging at the hole portion of the tab.

  If a hole is formed in the tab of the metal foil, the strength of the tab becomes weak, and the tab is easily damaged when the positive electrode or the negative electrode is suspended. Further, when the metal foil tab is electrically connected to the positive electrode terminal or the negative electrode terminal, the electric resistance can be reduced by welding, but if the tab has a hole, the current path becomes narrow.

  The present invention has been made in view of the above problems, and the object thereof is to allow lamination so that the lamination positions of the positive electrode and the negative electrode constituting the laminated electrode assembly do not deviate, and the tab. It is an object of the present invention to provide a power storage device and a secondary battery that do not narrow a current path flowing through the battery.

  In order to achieve the above object, an invention according to claim 1 is a power storage device having a stacked electrode assembly in which a positive electrode and a negative electrode are stacked with a separator interposed therebetween. The positive electrode and the negative electrode have a main body portion having an active material layer and a tab protruding from the main body portion, and the separator is formed larger than the main body portion of the positive electrode and the negative electrode, and at least 2 With one hole. The positive electrode and the negative electrode are arranged so that the active material layer of the opposite electrode is opposed through the separator in a state of being wrapped in the separator or in a single state. The positive electrode and the negative electrode have a hole in the body portion at a position facing the hole of the separator, and the positive electrode, the negative electrode, and the separator are inserted into the positioning rod when the electrode assembly is assembled. It is configured so that positioning can be performed in the state. Here, the “single state” refers to a state where the separator is not wrapped. The phrase “wrapped in the separator” is not limited to the state in which the sides excluding the protruding side of the tab are joined and the main body of the positive electrode or the negative electrode is accommodated in the bag-shaped separator. The sheet may be folded and may be accommodated in a separator in which the side opposite to the bent portion of the sheet is joined, or in a separator in which two sheets are joined on two opposite sides.

  In the present invention, as the electrode assembly, both the positive electrode and the negative electrode are encased in the separator, the positive electrode and the negative electrode are encased in the separator, and both the positive electrode and the negative electrode are in the separator. There are four types of unwrapped. Then, when laminating the positive electrode and the negative electrode in a state in which the separator is interposed between them, the hole of the separator and the hole of the main body are laminated for positioning, thereby stacking the electrode assembly. The positive electrode and the negative electrode can be stacked so that the stacked positions do not shift. Specifically, after the positive electrode, the separator, and the negative electrode are suspended with the holes inserted in the positioning rods, they are gathered along the positioning rods to form a laminate. In the state of the power storage device, since the hole is not formed in the tab, the current path flowing through the tab is not narrowed. Accordingly, there are provided a power storage device and a secondary battery that can be stacked so that the stacked positions of the positive electrode and the negative electrode constituting the stacked electrode assembly are not shifted and the current path flowing through the tab is not narrowed. be able to.

  According to a second aspect of the present invention, in the first aspect of the present invention, at least one of the positive electrode and the negative electrode is wrapped in the separator with the tab protruding from the separator. When neither the positive electrode nor the negative electrode is wrapped with the separator, it is necessary to perform the work of inserting the number of the positive electrode, the negative electrode, and the separator into the positioning rod. However, when at least one of the positive electrode and the negative electrode is wrapped in the separator, the number of times of inserting them through the positioning rod is about 2/3, and the man-hour is reduced.

According to a third aspect of the present invention, in the first or second aspect of the present invention, a notch is formed in the main body portion having the separator and the hole so that the tab is positioned therebetween. In the configuration in which positioning is performed at the time of stacking using the holes of the separator and the main body, in the configuration where the positive electrode or the negative electrode is wrapped in the separator, the tab protrudes because the separator covers the base end of the tab. When a hole is formed on the side, the main body and the separator become longer on the protruding side of the tab by at least the space for providing the hole. Therefore, in the configuration in which the electrode assembly is accommodated in the case of the power storage device, the corresponding dead space is required in the case. However, when the cut is formed, by bending the part where the hole is formed,
It is no longer necessary to provide a dead space. At that time, the tabs do not need to be bent, and the tabs are overlapped to be electrically joined to the conductive member without causing any trouble.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the number of the holes is two. When the number of holes is two, the number of man-hours during manufacturing can be reduced as compared with the case where three or more holes are provided.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein only the positive electrode is encased in the separator. In lithium ion secondary batteries, the negative electrode is often formed larger than the positive electrode in order to suppress precipitation of lithium needles called dendrites. In that case, when the negative electrode is wrapped with a separator, if the separator is the same size, the negative electrode is smaller than when the separator is not wrapped, and if the size of the electrode assembly is the same, the capacity of the battery is reduced. That is, it is advantageous in terms of capacity that the positive electrode is wrapped with the separator.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the positive electrode and the negative electrode have the tab protruding on the same side of the electrode assembly, and the hole is the The tab is formed on the protruding side. The separator has a margin for avoiding a short circuit between the positive electrode and the negative electrode, and is formed larger than the positive electrode and the negative electrode. There is also a side where no hole is formed. Therefore, if the hole is formed on the side where the tab protrudes, a part of the substitute space is used as the space for forming the hole, thereby contributing to the miniaturization of the electrode assembly.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the main body portion and the separator have a rectangular shape, and the hole is formed on the short side. When the size of the electrode is the same, the capacity of the secondary battery increases as the area of the active material layer included in the electrode increases. The active material layer formed on the main body generally has a rectangular shape, and the holes are formed in portions where no active material is applied. Therefore, the area of the active material layer is larger when the hole is formed on the short side of the main body with the main body having the same size as compared with the case where the hole is formed on the long side.

  The invention according to claim 8 is a secondary battery including the configuration of the power storage device according to any one of claims 1 to 7. Therefore, the secondary battery of the present invention has the same effect as that of any one of the first to seventh aspects.

  According to the present invention, it is possible to stack the positive electrode and the negative electrode constituting the stacked electrode assembly so that the stacked positions of the positive electrode and the negative electrode do not shift, and the power storage device and the secondary device that do not narrow the current path flowing through the tab A battery can be provided.

(A) is sectional drawing of a secondary battery, (b) is a typical partial expanded sectional view which shows the relationship between the electrically-conductive member cut | disconnected by the BB line of (a), and an electrode assembly. (A) is a front view of the positive electrode wrapped in the separator, (b) is a front view of the negative electrode. (A) is a schematic perspective view which shows a positive electrode, a negative electrode, and the separator lamination | stacking method, (b) is a schematic diagram which shows the relationship between the size of a positioning rod and a hole. The front view of the electrode assembly of another embodiment. The front view of the electrode assembly of another embodiment. Sectional drawing of the secondary battery of another embodiment. The schematic front view which shows the relationship between the tab and hole of the electrode assembly of another embodiment. The schematic perspective view which shows the relationship between the positive electrode of another embodiment, a negative electrode, and a separator.

Hereinafter, an embodiment in which the present invention is embodied in a secondary battery as a power storage device will be described with reference to FIGS.
As shown in FIG. 1A, a secondary battery 10 as a power storage device includes a stacked electrode assembly 12 housed in a case 11 constituted by a case body 11a and a lid 11b. A positive electrode terminal 13 and a negative electrode terminal 14 are fixed to the lid 11 b via an insulating ring 15. The positive electrode terminal 13 and the negative electrode terminal 14 have male screw portions 13a and 14a, and are fastened and fixed to the lid 11b by nuts 16 screwed into the male screw portions 13a and 14a protruding from the lid 11b. An insulating member (not shown) is interposed between the nut 16 and the lid 11b.

  In the electrode assembly 12, the laminate 17 p of the positive electrode tab 17 c is electrically connected to the positive electrode terminal 13 through the positive electrode conductive member 18, and the laminate 19 n of the negative electrode tab 19 c is electrically connected to the negative electrode. It is electrically connected to the negative electrode terminal 14 through 20. The laminated body 17p is welded to the conductive member 18, and the laminated body 19n is welded to the conductive member 20. As shown in FIG. 1B, the laminated body 17 p is welded to the conductive member 18 in a state where the tip end side of each tab 17 c extends in parallel with the end face of the electrode assembly 12. Similarly, the laminated body 19n is welded to the conductive member 20 so that the tip side of each tab 19c extends in parallel with the end face of the electrode assembly 12.

  As shown in FIG. 1B, the electrode assembly 12 is laminated with a positive electrode 17 and a negative electrode 19 with a separator 21 interposed therebetween. As shown in FIGS. 1A, 1B, and 2A, the positive electrode 17 has a main body portion 17a having an active material layer 17b on both surfaces of the metal foil 22, and a tab 17c protruding from the main body portion 17a. . As shown in FIGS. 1B and 2B, the negative electrode 19 has a main body portion 19a having an active material layer 19b on both surfaces of a metal foil 22, and a tab 19c protruding from the main body portion 19a. The main body portions 17a and 19a are formed in a rectangular shape, and tabs 17c and 19c protrude from one long side of the rectangle.

  As shown in FIGS. 1A and 2A, the separator 21 is also formed in a rectangular shape, and the separator 21 is formed larger than the main body portions 17 a and 19 a of the positive electrode 17 and the negative electrode 19. The positive electrode 17 is wrapped in the separator 21 with the tab 17 c protruding from the separator 21. In this embodiment, the separator 21 is formed in a bag shape in which the side from which the tab 17c protrudes is opened. That is, in this embodiment, the electrode assembly 12 includes a bag-like separator 21 containing the positive electrode 17 and a negative electrode 19 which are alternately stacked, so that the positive electrode 17 and the negative electrode 19 are interposed between the separator 21 and the negative electrode 19. They are stacked in an intervening state. The separator 21 has a margin 21 d at the periphery for avoiding a short circuit between the positive electrode 17 and the negative electrode 19.

  The separator 21 has two holes 21a. The holes 21a are circular and are formed at both ends on the open side from the position facing the main body portion 17a. The separator 21 is formed with a cut 21b so that the tab 17c of the positive electrode 17 is located therebetween. In addition, a notch 21c is formed so that the tab 19c of the negative electrode 19 is located therebetween. The notches 21b and 21c are formed on the opening side of the separator 21 from the main body portion 17a of the positive electrode 17 accommodated in the separator 21 so as to extend in the protruding direction of the tabs 17c and 19c.

  As shown in FIG. 2B, the negative electrode 19 has a main body portion 19 a having the same size as the separator 21. The active material layer 19b of the negative electrode 19 is formed so that the length of the tab 19c in the protruding direction is the same as the active material layer 17b of the positive electrode 17, and the area of the active material layer 19b is larger than the area of the active material layer 17b of the positive electrode 17. ing. The negative electrode 19 has an active material non-coated portion 19d extending along the side of the active material layer 19b on the protruding side of the tab 19c.

  In the active material non-applied portion 19d of the negative electrode 19, cuts 19e are formed at positions corresponding to the cuts 21b and 21c of the separator 21, respectively. Further, at both ends of the active material non-application portion 19d, holes 19f are provided at positions corresponding to the holes 21a of the separator 21. The hole 19f is circular and has the same size as the hole 21a.

  Next, a method for manufacturing the electrode assembly 12 will be described. The manufacturing method is a conventional stacking process in which the bag-like separator 21 containing the positive electrode 17 and the negative electrode 19 are stacked with the positive electrode 17 and the active material layers 17b, 19b of the negative electrode 19 positioned accurately. Since it is different, the lamination process will be mainly described.

  In the laminating step, as shown in FIG. 3A, a pair of positioning rods 30 that are horizontally arranged in parallel at a predetermined interval are used. The positioning rod 30 has a circular cross section, and the diameter of the positioning rod 30 is smaller than the diameter of the holes 19f and 21a of the negative electrode 19 and the separator 21, as shown in FIG.

  Then, the separator 21 and the negative electrode 19 in which the positive electrode 17 is accommodated, which are manufactured in another process, are alternately suspended from the positioning rod 30 with the holes 21 a and 19 f being inserted into the positioning rod 30. In a state where a predetermined number of separators 21 and negative electrodes 19 are suspended, the separators 21 and the negative electrodes 19 are moved from both sides along the positioning rods 30 and gathered to form a laminate. The laminate is transported to the welding process in a state of being gripped by a jig (not shown). In the welding process, the laminated body 17p of the tab 17c is welded to the conductive member 18 already welded to the positive electrode terminal 13, and the laminated body 19n of the tab 19c is welded to the conductive member 20 welded to the negative electrode terminal 14. The solid 12 is completed.

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. When used as a power source for a motor for traveling, charging / discharging with a large current is required. When the positioning holes for laminating the electrodes and separators are formed in the tab as in the prior art, the path of the current flowing through the tab is narrowed and heat is easily generated. However, in the electrode assembly 12 of this embodiment, the holes 19f and 21a that can be used for positioning when the negative electrode 19 and the separator 21 are stacked are not formed in the tabs 17c and 19c. Since the coating portion 19d and the separator 21 are formed, the path of the current flowing through the tabs 17c and 19c is not narrowed, and heat generation is suppressed. Further, in the electrode assembly 12, since the positive electrode 17 is accommodated in the bag-shaped separator 21, vibration is applied to the secondary battery 10 while the vehicle is running, and the separator 21 and the negative electrode 19 are slightly displaced. However, the occurrence of a short circuit is avoided.

According to this embodiment, the following effects can be obtained.
(1) The secondary battery 10 is a power storage device having a stacked electrode assembly 12 in which a positive electrode 17 and a negative electrode 19 are stacked with a separator 21 interposed therebetween. The positive electrode 17 and the negative electrode 19 have main body portions 17 a and 19 a having active material layers 17 b and 19 b and tabs 17 c and 19 c protruding from the main body portions 17 a and 19 a, and the positive electrode 17 is in a state where the tab 17 c protrudes from the separator 21. It is wrapped in a separator 21. The separator 21 has two holes 21 a at both ends on the open side from the position facing the main body portion 17 a of the positive electrode 17. The negative electrode 19 has a hole 19f at a position facing the hole 21a of the separator 21 in the active material non-application portion 19d of the main body 19a. The positive electrode 17, the negative electrode 19, and the separator 21 are formed in the holes 19f, 21a is configured to be able to be positioned in a state of being inserted through the positioning rod 30. Therefore, the positive electrode 17 and the negative electrode 19 constituting the multilayer electrode assembly 12 can be stacked so that the positions of the positive electrode 17 and the negative electrode 19 do not deviate, and there is no need to form an extra tab, and the current path flows through the tabs 17c and 19c. Is not narrowed. When neither the positive electrode 17 nor the negative electrode 19 is wrapped with the separator 21, the number of the positive electrode 17, the negative electrode 19, and the separator 21 is inserted into the positioning rod 30 in the manufacturing process of the electrode assembly 12. Need to do work. However, since the positive electrode 17 is wrapped in the separator 21, the number of times of inserting the positive electrode 17 through the positioning rod 30 is about 2/3, and the number of man-hours is reduced.

  (2) The positive electrode 17 is wrapped in the separator 21. In a lithium ion secondary battery, the negative electrode 19 is often formed larger than the positive electrode 17 in order to suppress precipitation of lithium needles called dendrites. In that case, when the negative electrode 19 is wrapped with the separator 21, if the separator 21 has the same size, the negative electrode 19 becomes smaller than when not wrapped with the separator 21, and when the size of the electrode assembly 12 is the same, Capacity is reduced. However, in this embodiment, since the positive electrode 17 is wrapped in the separator 21, it is advantageous in terms of capacity.

  (3) The separator 21 is formed with a pair of cuts 21b and 21c so that the tabs 17c and 19c are positioned between them. The active material non-applied portion 19d of the negative electrode 19 corresponds to the cuts 21b and 21c of the separator 21. A cut 19e is formed at each position. The separator 21 is in a state of covering the base ends of the tabs 17c and 19c, and the hole 21a is formed on the side on which the tabs 17c and 19c protrude. Therefore, the separator 21 is a tab at least for the space for providing the hole 21a. It becomes longer on the protruding side of 17c and 19c. In the case where the notches 21b and 21c are not provided, in the configuration in which the electrode assembly 12 is accommodated in the case 11, a corresponding dead space is required in the case 11. However, since the notches 21b and 21c are formed, the portions where the holes 21a are formed are bent without hindering the electrical connection to the conductive members 18 and 20 by overlapping the tabs 17c and 19c. This eliminates the need to provide a dead space.

  (4) The separator 21 and the negative electrode 19 each have two holes 21a and 19f. When the number of holes 21a and 19f is two, the number of man-hours at the time of manufacture can be reduced compared with the case where three or more holes 21a and 19f are provided.

  (5) The positive electrode 17 and the negative electrode 19 have tabs 17c and 19c projecting on the same side of the electrode assembly 12, and the holes 21a and 19f are formed on the side from which the tabs 17c and 19c project. The separator 21 has a margin 21 d for avoiding a short circuit between the positive electrode 17 and the negative electrode 19, and is formed larger than the positive electrode 17 and the negative electrode 19. The margin 21d is also on the side where the hole 21a is not formed. Therefore, if the hole 21a is formed on the side where the tabs 17c and 19c project, a part of the allowance 21d can be used as a space for forming the hole 21a. As a result, the electrode assembly 12 can be reduced in size. Contributes to

  (6) In the method of manufacturing the electrode assembly 12, as a method of laminating the positive electrode 17, the negative electrode 19 and the separator 21 in a state where they are accurately positioned, the negative electrode 19 and the separator 21 are positioned through the holes 19f and 21a. The method of suspending is used. The sectional shape of the positioning rod 30 and the holes 19f and 21a are circular, and the holes 19f and 21a are formed larger than the sectional shape of the positioning rod 30. In the case where the cross-sectional shape of the positioning rod 30 is a polygon and the holes 19f and 21a are polygons having the same size, if the holes 19f and 21a are accurately formed at predetermined positions, positioning is performed with high accuracy. However, even if the center positions of the pair of polygons are accurate, if the polygons are formed with a slight inclination with respect to the target position, the holes 19f and 21a are damaged when the holes 19f and 21a are inserted through the positioning rod 30. . When the holes 19f and 21a are polygonal, the holes 19f formed in the active material non-application portion 19d made of the metal foil 22 are easily cracked at the corners with a slight force. However, in this embodiment, since the hole 19f is circular, it is difficult to crack. Since the positioning rod 30 has a circular shape with a smaller diameter than the holes 19f and 21a, the holes 19f and 21a can be easily inserted into the positioning rod 30 and can be accurately positioned by being suspended.

The embodiment is not limited to the above, and may be embodied as follows, for example.
When the main body portions 17a and 19a and the separator 21 are rectangular, as shown in FIG. 4, holes 19f and 21a may be provided on the short side. When the size of the electrode is the same, the capacity of the secondary battery 10 increases as the area of the active material layer included in the electrode increases. The active material layers 17b and 19b formed in the main body portions 17a and 19a are generally rectangular in shape, and the holes 19f are formed in the active material non-application portion 19d. Therefore, the area of the active material layers 17b and 19b is larger when the hole 19f is formed on the short side of the main body 19a with the main body 19a having the same size as compared with the case where the hole 19f is formed on the long side.

When the main body portions 17a and 19a and the separator 21 are rectangular, the active material non-applied portion 19d may be provided on the short side of the rectangle, and the tabs 17c and 19c may also protrude from the short side.
As shown in FIG. 5, the holes 19f and 21a may be provided on the side opposite to the protruding side of the tabs 17c and 19c. However, when the negative electrode 19 and the separator 21 have the same external shape, it is advantageous from the viewpoint of the capacity of the secondary battery 10 to be provided on the protruding side of the tabs 17c and 19c.

  O Instead of accommodating the positive electrode 17 in the bag-shaped separator 21, the negative electrode 19 may be accommodated in the bag-shaped separator 21. In this case, the positive electrode 17 has an active material non-application part along the active material layer 17b, and a hole is provided in the active material non-application part. On the other hand, the negative electrode 19 does not have the active material layer 19b, and the tab 19c protrudes from the main body 19a.

  The configuration in which the positive electrode 17 or the negative electrode 19 is wrapped in the separator 21 is not limited to the configuration in which the positive electrode 17 or the negative electrode 19 is accommodated in the bag-shaped separator 21. For example, the separator 21 is formed by folding a sheet in two and the side opposite to the folded portion of the sheet is joined, or the two sheets are accommodated in the separator 21 joined at two opposite sides. May be.

  O The positive electrode 17 and the negative electrode 19 may be both enclosed in the separator 21, and the hole 21 a may be provided only in the separator 21. In this case, it is not necessary to form holes in the positive electrode 17 and the negative electrode 19, and it is not necessary to form holes in the metal foil 22.

  The welding of the laminated body 17p of the electrode assembly 12 and the conductive member 18 and the welding of the laminated body 19n and the conductive member 20 are performed by bending the leading end side of the laminated body 17p and the laminated body 19n along the end surface of the electrode assembly 12. As shown in FIG. 6, it may be performed in a state in which the leading ends of the stacked body 17p and the stacked body 19n extend toward the lid 11b.

  As shown in FIG. 7, the tab 17 c of the positive electrode 17 and the tab 19 c of the negative electrode 19 may protrude from different ends of the electrode assembly 12. This configuration is employed in, for example, a laminate type secondary battery.

  Instead of the configuration in which both the positive electrode 17 and the negative electrode 19 are wrapped in the separator 21, the positive electrode 17, the negative electrode 19, and the sheet-like separator 21 may be alternately stacked as illustrated in FIG. 8. The positive electrode 17 and the negative electrode 19 include active material non-applied portions 17d and 19d, respectively, and the active material non-applied portions 17d and 19d have holes 17f and 19f at positions corresponding to the holes 21a of the separator 21, respectively. The positive electrode 17, the negative electrode 19, and the separator 21 have cuts 17e, 19e, 21b, and 21c, respectively. In this case, it is preferable that the hole 21 a of the separator 21 is smaller than the holes 17 f and 19 f of the positive electrode 17 and the negative electrode 19 in order to ensure electrical insulation between the positive electrode 17 and the negative electrode 19.

O The active material non-application parts 17d, 19d and the notches 17e, 19e, 21b, 21c of the separator 21 are not essential and may be omitted.
When holes 17f and 19f are provided in the positive electrode 17 or the negative electrode 19, the holes 17f and 19f may be provided in the active material layers 17b and 19b. In that case, it is easier to ensure electrical insulation between the positive electrode 17 and the negative electrode 19 by the separator 21 if the holes 17 f and 19 f are formed smaller than the hole 21 a of the separator 21.

  In the case where the tabs 17c and 19c protrude on the same side of the electrode assembly 12, the tabs 17c and 19c do not need to be arranged at line-symmetric positions. For example, the tab 17 c may be provided at the center in the width direction of the positive electrode 17, and the tab 19 c may be provided at a position where the negative electrode 19 does not interfere with the tab 17 c in a state where the electrode assembly 12 is configured.

The cross-sectional shape of the positioning rod 30 and the shapes of the holes 19f and 21a are not limited to a circle, and may be a polygon such as a triangle or a rectangle, an ellipse, or the like.
O There are at least two holes 21a, 17f, and 19f provided in the separator 21, the positive electrode 17, or the negative electrode 19, and the number is not limited to two, and three or more holes may be provided. However, two are preferable in terms of manufacturing man-hours and the like.

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.
The following technical idea (invention) can be understood from the embodiment.

(1) A manufacturing method of a stacked electrode assembly in which one of a positive electrode and a negative electrode is wrapped in a separator, and the positive electrode and the negative electrode are alternately stacked,
At least two holes are formed in the separator so as not to overlap one of the positive electrode and the negative electrode enclosed by the separator, and the other of the positive electrode and the negative electrode not enclosed by the separator is provided with a hole of the separator. And an operation of suspending the separator in the at least two holes with respect to a positioning rod arranged in parallel at an interval of the at least two holes, A predetermined number of the separators set in advance and the positive electrode not wrapped in the separator are alternately performed by suspending the other of the positive electrode and the negative electrode not wrapped in the separator in the at least two holes. And the other of the negative electrodes are suspended from the positioning rods in the holes, and the suspended separators are wrapped in the separators. The positive electrode and the negative electrode of the other of the manufacturing method of the positioning rod moved so Intention collect a stacked electrode assembly comprising a laminating step along the no.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery as an electrical storage device, 12 ... Electrode assembly, 17 ... Positive electrode, 17a, 19a ... Main part, 17b, 19b ... Active material layer, 17c, 19c ... Tab, 17e, 19e, 21b, 21c ... Notch 17f, 19f, 21a ... holes, 19 ... negative electrode, 21 ... separator, 30 ... positioning rod.

Claims (8)

A power storage device having a stacked electrode assembly in which a positive electrode and a negative electrode are stacked with a separator interposed therebetween,
The positive electrode and the negative electrode have a main body part having an active material layer and a tab protruding from the main body part,
The separator is formed larger than the main body of the positive electrode and the negative electrode, and has at least two holes,
The positive electrode and the negative electrode are arranged so that the active material layers of the opposite electrode face each other through the separator in a state of being wrapped in the separator or in a single state,
The positive electrode and the negative electrode have a hole in the body portion at a position facing the hole of the separator, and the positive electrode, the negative electrode, and the separator are inserted into the positioning rod when the electrode assembly is assembled. A power storage device, wherein the power storage device is configured so that positioning is possible.   The power storage device according to claim 1, wherein at least one of the positive electrode and the negative electrode is wrapped in the separator with the tab protruding from the separator.   The power storage device according to claim 1, wherein the main body portion having the separator and the hole is formed with a cut so that the tab is positioned therebetween.   The power storage device according to any one of claims 1 to 3, wherein the number of the holes is two.   The power storage device according to any one of claims 1 to 4, wherein only the positive electrode is encased in the separator.   The electricity storage according to any one of claims 1 to 5, wherein the positive electrode and the negative electrode have the tab protruding on the same side of the electrode assembly, and the hole is formed on a side on which the tab protrudes. apparatus.   The power storage device according to any one of claims 1 to 6, wherein the main body portion and the separator are rectangular, and the hole is formed on a short side.   The secondary battery provided with the structure of the electrical storage apparatus as described in any one of Claims 1-7.