JP2019050095A - Power storage device and manufacturing method of power storage device - Google Patents

Abstract

To provide a power storage device capable of suppressing deformation of an anode electrode when moving the anode electrode through contact during manufacture of an electrode assembly, and a manufacturing method of the power storage device.SOLUTION: In a secondary battery 10, an anode electrode 31 and a bag-shaped separator 27 are aligned at first edges 31a and 27a in a height direction. An anode protrusion 35 of the anode electrode 31 comprises a protective layer 34 covering a portion of the anode electrode 31 along the first edge 31a.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power storage device including an electrode assembly in a case, and a method of manufacturing the power storage device.

  2. Description of the Related Art In vehicles such as EV (Electric Vehicle) and PHV (Plug in Hybrid Vehicle), a secondary battery is mounted as a storage device for storing power supplied to a traveling motor. As a secondary battery, a battery provided with a stacked electrode assembly is known. The laminated electrode assembly is configured by laminating a large number of sheet-like positive and negative electrodes in a state in which the both are insulated by a separator. The positive electrode has a positive electrode active material layer on both sides of the metal foil of the positive electrode, and the negative electrode has a negative electrode active material layer on both sides of the metal foil of the negative electrode.

  Further, the positive electrode has an exposed uncoated portion of metal foil for connection to the outside, and typically has a positive electrode tab having a shape protruding from one end of the metal foil, and this positive electrode tab The positive electrode terminal is electrically connected via the conductive member. Similarly, the negative electrode has an exposed uncoated portion of metal foil for connection to the outside, and typically has a negative electrode tab having a shape protruding from one end of the metal foil, and this negative electrode The negative electrode terminal is electrically connected to the tab through the conductive member. The positive electrode terminal and the negative electrode terminal partially protrude through the lid of the case and out of the case.

  Further, in the secondary battery, when a portion where the positive electrode active material layer and the negative electrode active material layer do not face each other is generated between the positive electrode active material layer and the negative electrode active material layer due to positional displacement, etc. Invite. Furthermore, in a lithium ion battery, the area of the negative electrode active material layer is smaller than the area of the positive electrode active material layer in order to suppress the deposition of metallic lithium on the surface of the negative electrode active material layer generated by lithium ion concentration during charging. The For this reason, at the time of manufacture of an electrode assembly, it aligns with respect to a positive electrode active material layer so that a negative electrode active material layer may oppose precisely via a separator.

  By the way, since the laminated structure of the electrode assembly is subjected to a manufacturing process in which the positive electrode, the negative electrode, and the separator are sequentially stacked, the number of stacking processes increases, the tact time of production is long, and the productivity is not good. There was a problem called. Therefore, a method is known in which the positive electrode is housed in advance inside the bag-like separator, and the bag-like separator and the negative electrode are stacked to improve the productivity.

  In addition, as a method of manufacturing an electrode assembly, for example, Patent Document 1 can be cited. In Patent Document 1, the electrode assembly is surrounded while dropping an electrode assembly in which a positive electrode, a separator, and a negative electrode are stacked. Moving the plurality of alignment members towards the electrode assembly. The positive electrode, the separator, and the negative electrode are aligned by pushing the side surface of the electrode assembly with the alignment member.

JP, 2017-76489, A

  However, in the method disclosed in Patent Document 1, when one end edge of the protruding metal foil of the negative electrode tab in the negative electrode is pushed by the alignment member, one end edge of the metal foil is thin in the negative electrode, May be deformed. Such deformation may result in an insufficient amount of movement of the negative electrode, even in the case of temporary bending.

  An object of the present invention is to provide a power storage device and a method of manufacturing a power storage device capable of suppressing deformation of a negative electrode when moving the negative electrode by contact at the time of manufacturing the electrode assembly.

  The power storage device for solving the above problems has a rectangular negative electrode active material layer on the surface of a rectangular sheet-like negative electrode metal foil, and one edge of a pair of edges of the negative electrode active material layer. And a negative electrode having a negative electrode protrusion formed of the negative metal foil and a negative electrode tab protruding from one end edge located at the tip of the negative electrode protrusion from the one edge and protruding from the one edge; A positive electrode active material layer on the surface of the positive metal foil and being contained in a rectangular bag-shaped separator, and having a positive electrode tab protruding from one end of the bag-like separator, the positive electrode active material layer On the other hand, it has a laminated structure in which the negative electrode active material layers are alternately stacked with the bag-like separator facing each other, and has a tab-side end surface on which both the positive electrode tab and the negative electrode tab are present. An electric storage device internally provided with a pole assembly, wherein, with respect to the negative electrode and the bag-like separator, a direction in which a straight line connecting the one end and the other end at the shortest distance with the opposite side of the one end as the other end When the height direction is defined as the height direction, the reinforcing member has a portion where the one end of the negative electrode and the one end of the bag-like separator are aligned in the height direction, and reinforces a portion of the surface of the negative electrode protrusion along the one end. The point is to provide a layer.

  According to this, in the electrode assembly, with respect to the positive electrode active material layer, in a state in which one end edge of the negative electrode protruding portion in the negative electrode and the one end edge of the bag-like separator containing the positive electrode are aligned in the height direction, The negative electrode active material layer faces the bag-like separator. When manufacturing such an electrode assembly, in order to align one end edge of the negative electrode protrusion in the negative electrode and one end edge of the bag-like separator in the height direction, positioning is performed on one end edge of the negative electrode protrusion and one edge of the bag-like separator The members are brought into contact to move the negative electrode and the bag-like separator. At this time, since the negative electrode protrusion is reinforced by the reinforcing layer, the deformation of the negative electrode protrusion when the positioning member comes in contact with one end edge of the negative electrode protrusion is suppressed, and the movement amount is insufficient when moving the negative electrode. It can be suppressed.

  In the power storage device, the negative electrode active material layer and the reinforcing layer coexist on the surface of the negative electrode protrusion, and the reinforcing layer is closer to the one end of the negative electrode protrusion than the negative electrode active material layer. positioned.

  According to this, the negative electrode protruding portion can be further reinforced by the negative electrode active material layer. Further, in the portion where the positioning member abuts, only the reinforcing layer is present, and the negative electrode active material layer is not present. Therefore, the positioning member does not contact the negative electrode active material layer, and a part of the negative electrode active material layer does not come off the negative electrode active material layer due to the contact with the positioning member.

  In the power storage device, assuming that the stacking direction is the stacking direction of the negative electrode and the bag-like separator, the negative electrode protruding portion is at a position not overlapping the positive electrode tab in the stacking direction.

According to this, the contact between the negative electrode protruding portion and the positive electrode tab can be suppressed.
In the power storage device, the electrode assembly is housed in a case, and the case includes a case main body accommodating the electrode assembly, and a lid closing the opening of the case main body, and the negative electrode The negative electrode tab is on one end side in the longitudinal direction of the negative electrode, and the positive electrode tab is on the other end side in the longitudinal direction of the bag-like separator. A negative electrode terminal electrically connected to the negative electrode tab and fixed to the lid at one end side of the negative electrode tab in the longitudinal direction, and electrically connected to the positive electrode tab; A positive electrode terminal fixed to the lid on the other end side of the positive electrode tab in the direction, and the negative electrode projection is negative in the height direction In a position which does not overlap with the terminal and the positive terminal.

  According to this, as one of the manufacturing methods of an electrical storage apparatus, first, a negative electrode terminal and a positive electrode terminal are fixed to a lid, and a lid terminal assembly is manufactured. Next, the negative electrode terminal and the negative electrode tab are electrically connected and the positive electrode terminal and the positive electrode tab are electrically connected to integrate the lid terminal assembly and the electrode assembly. Next, the electrode assembly is housed in the case body, and the lid terminal assembly is further pushed toward the electrode assembly to push the electrode assembly into the case body. At this time, since the negative electrode protrusion is at a position not overlapping with the negative electrode terminal and the positive electrode terminal in the height direction, when the lid terminal assembly is pushed toward the electrode assembly, the negative electrode terminal or the positive electrode terminal is a negative electrode protrusion And the negative electrode protrusion does not deform when the power storage device is manufactured.

  In the method of manufacturing a storage battery for solving the above problems, a rectangular negative electrode active material layer is provided on the surface of a rectangular sheet-like negative electrode metal foil, and one of a pair of edges of the negative electrode active material layer A negative electrode protrusion formed of the negative electrode metal foil protruding from the edge of the negative electrode, and a negative electrode having a negative electrode tab protruding from one end edge located at the tip of the negative electrode protrusion from the one edge A positive electrode active material layer is provided on the surface of a rectangular sheet-like positive metal foil, and the positive electrode is accommodated in a rectangular bag-like separator, and has a positive electrode tab projecting from one end of the bag-like separator; A tab-side end on which both the positive electrode tab and the negative electrode tab are present, having a laminated structure in which the negative electrode active material layers are alternately stacked with the bag-like separator facing the material layer. A manufacturing method of a power storage device including an electrode assembly having the inside, wherein the opposite side of the one end is the other end, and the one end and the other end are the shortest distance for the negative electrode and the bag-like separator. When the extending direction of the connecting straight line is the height direction, the power storage device has a portion where the one end of the negative electrode and the one end of the bag-like separator are aligned in the height direction, and the surface of the negative electrode protrusion And forming a reinforcing layer covering a portion along the one end edge, wherein when the electrode assembly is manufactured by stacking the negative electrode and the bag-like separator, one end edge of the bag-like separator and one end edge of the negative electrode A positioning member is brought into contact with a portion along the reinforcing layer to align the negative electrode and the bag-like separator in the height direction.

  According to this, when manufacturing the electrode assembly, one end edge of the negative electrode protrusion and one end edge of the bag-like separator are aligned in the height direction, so that one end edge of the negative electrode protrusion and one end edge of the bag-like separator The positioning member is brought into contact with the above to move the negative electrode and the bag-like separator. At this time, since the negative electrode protrusion is reinforced by the reinforcing layer, the deformation of the negative electrode protrusion when the positioning member comes in contact with one end edge of the negative electrode protrusion is suppressed, and the movement amount is insufficient when moving the negative electrode. It can be suppressed.

  According to the present invention, when the negative electrode is moved by contact at the time of manufacturing the electrode assembly, deformation of the negative electrode can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS The disassembled perspective view which shows the secondary battery of embodiment. Sectional drawing which shows the secondary battery of embodiment. The disassembled perspective view which shows the component of an electrode assembly. The expanded sectional view which shows negative electrode protrusion part vicinity. (A) shows the state in which the negative electrode is accommodated in the laminating jig, (b) shows the state in which the bag-like separator is accommodated in the laminating jig, and (c) shows the state in which the separator is positioned by the positioning member . The figure which shows a lid terminal assembly and an electrode assembly. The figure which shows the state which pushes in an electrode assembly by the cover terminal assembly. The front view which shows the negative electrode of another example.

Hereinafter, an embodiment in which a power storage device and a method of manufacturing the power storage device are embodied in a secondary battery and a method of manufacturing a secondary battery will be described according to FIGS. 1 to 7.
As shown in FIG. 1 or FIG. 2, the secondary battery 10 is provided with a metal case 11 forming an outer shell. The case 11 includes a bottomed rectangular parallelepiped case main body 12 having an opening 12a on one surface, and a lid 13 for closing the opening 12a. The case 11 accommodates the electrode assembly 14 and an electrolytic solution (not shown) as an electrolyte. The secondary battery 10 is a lithium ion battery.

  As shown in FIG. 3, in the electrode assembly 14, a plurality of positive electrodes 21 and a plurality of negative electrodes 31 are alternately stacked in a state in which a bag-shaped separator 27 made of resin is interposed therebetween. It has a structure. The positive electrode 21 has a positive electrode metal foil (in the embodiment, an aluminum foil) 22 and a rectangular positive electrode active material layer 23 provided on both sides of the positive electrode metal foil 22. The positive electrode metal foil 22 is composed of a rectangular sheet-like positive electrode metal foil main body 22 a and a positive electrode tab 22 b which is formed so that a part thereof extends from the positive electrode metal foil main body 22 a and protrudes. The positive electrode active material layer 23 exists in the same plane shape and the same thickness on both surfaces of the positive electrode metal foil main body 22a, and faces each other with the positive electrode metal foil main body 22a interposed therebetween.

  The positive electrode 21 has a positive electrode uncoated portion 22 d in a portion along one long edge 23 a of a pair of long edges extending in the longitudinal direction of the positive electrode active material layer 23. The positive electrode uncoated portion 22 d is formed of a portion of the positive electrode metal foil main body 22 a where the positive electrode active material layer 23 does not exist, and is formed of the positive electrode metal foil 22 itself.

  The positive electrode 21 has a first end 21a at one end extending in the longitudinal direction, and a second end 21b at the other end opposite to the first end 21a. The first edge 21 a is present in the positive electrode uncoated portion 22 d, and the second edge 21 b is present in the other long edge of the positive electrode active material layer 23. The positive electrode 21 includes a positive electrode tab 22 b protruding from a part of the first end 21 a. In addition, the positive electrode 21 has a third end 21 c at a pair of ends connecting the first end 21 a and the second end 21 b.

  The negative electrode 31 includes a negative electrode metal foil (copper foil in this embodiment) 32, a rectangular negative electrode active material layer 33 provided on both sides of the negative electrode metal foil 32, and a protective layer 34 covering the negative electrode active material layer 33. And. The protective layer 34 has an insulation property to suppress a short circuit between the positive electrode 21 and the negative electrode 31, and a heat resistance higher than that of the bag-like separator 27. The protective layer 34 is composed of insulating particles (ceramic particles in the present embodiment) as a protective coating material having electrical insulation and a binder made of resin.

  The negative electrode metal foil 32 is formed of a rectangular sheet-like negative electrode metal foil main body 32a and a negative electrode protruding portion 35 which is partially extended and protrudes from the negative electrode metal foil main body 32a, which will be described later. It consists of a protruding negative electrode tab 32b.

  The negative electrode active material layer 33 is present on both surfaces of the negative electrode metal foil main body 32a in the same planar shape and the same thickness. The negative electrode 31 has the above-described negative electrode protruding portion 35 in a portion along one long edge portion 33 a of the long edge portions which are a pair of edge portions extending in the longitudinal direction of the negative electrode active material layer 33. The negative electrode protruding portion 35 is formed of a portion of the negative electrode metal foil main body 32 a that protrudes in a rectangular shape from a part along one long edge portion 33 a of the negative electrode active material layer 33.

  The longitudinal direction of the negative electrode protrusion 35 extends in the longitudinal direction of the negative electrode active material layer 33. Assuming that the direction in which the negative electrode protruding portion 35 protrudes from one long edge portion 33 a of the negative electrode active material layer 33 is the protruding direction, the negative electrode 31 has a first end as one end edge at the tip edge in the protruding direction of the negative electrode protruding portion 35 An edge 31a is provided, and a second end 31b is provided at the other end opposite to the first end 31a. The second edge 31 b is present at the other long edge of the pair of long edges of the negative electrode active material layer 33. In addition, the negative electrode 31 includes a third end 31 c at a pair of ends extending in the short direction of the negative electrode active material layer 33.

  The negative electrode 31 includes a negative electrode tab 32 b protruding from the tip end edge of the negative electrode protrusion 35 to be the first end edge 31 a. The negative electrode tab 32 b protrudes from one end side of the negative electrode protruding portion 35 in the longitudinal direction. The negative electrode 31 is provided with a contact edge portion 37 formed of the tip end edge of the negative electrode protruding portion 35 on the other end side in the longitudinal direction of the negative electrode protruding portion 35. Therefore, the negative electrode tab 32 b and the contact edge portion 37 are provided in parallel on the negative electrode protrusion 35.

  As shown in FIG. 4, in the negative electrode protruding portion 35, a part of the negative electrode active material layer 33 exists at the base end side in the protrusion direction, and a protective layer 34 covering the negative electrode active material layer 33 is present. It is a structure. Therefore, the portion along the first edge 31 a of the surface of the negative electrode protrusion 35 is covered by the protective layer 34. The protective layer 34 also covers the base of the negative electrode tab 32 b and covers the negative electrode protrusion 35 and the negative electrode tab 32 b.

  In the negative electrode protruding portion 35, the tip end side in the protruding direction has a single-layer structure of only the protective layer 34. In the negative electrode protruding portion 35, a portion having the negative electrode active material layer 33 and the protective layer 34 and a portion having only the protective layer 34 coexist in the protruding direction. The tip end edge of the negative electrode protruding portion 35 is not covered with the protective layer 34 and the negative electrode active material layer 33, and the metal foil is exposed. The base end side of the negative electrode protrusion 35 is reinforced by the two-layer structure of the negative electrode active material layer 33 and the protective layer 34, and the tip end side of the negative electrode protrusion 35 is reinforced by the one-layer structure of the protective layer 34. . Therefore, a portion of the surface of the negative electrode protruding portion 35 along the contact edge portion 37 is reinforced by the protective layer 34, and the protective layer 34 constitutes a reinforcing layer.

  As shown in FIG. 2, in the positive electrode 21 and the negative electrode 31, the lengths (length in the longitudinal direction and length in the short direction) of two adjacent sides of the negative electrode active material layer 33 are positive electrode active The length is set to be longer than the length (the length in the longitudinal direction and the length in the short direction) of two adjacent sides of the material layer 23. That is, the negative electrode active material layer 33 is set to a size that can cover the entire surface of the positive electrode active material layer 23.

  As shown in FIG. 3, the positive electrode 21 is accommodated in a bag-like separator 27. The bag-like separator 27 is formed by joining a pair of rectangular separator members 28. The pair of separator members 28 face each other, cover both surfaces of the positive electrode 21, and have the same size. The bag-like separator 27 has a storage portion 28 b of the positive electrode 21. The pair of separator members 28 includes the first end edge 21a, the second end edge 21b and the third end edge 21c of the positive electrode 21 in an overlapping state. The bag-like separator 27 is formed by thermally welding the protruding portions 28a along the four end edges of the pair of separator members 28, and the storage portion 28b is provided in a portion surrounded by the protruding portions 28a.

  The bag-like separator 27 has a first end 27 a at one end extending along the first end 21 a of the positive electrode 21, is an opposite side of the first end 27 a, and extends along the second end 21 b of the positive electrode 21. The second end 27b is provided at the other end which extends vertically. In addition, the bag-like separator 27 connects the first end 27a and the second end 27b, and has a third end 27c at an end extending along the third end 21c of the positive electrode 21. The positive electrode tab 22 b of the positive electrode 21 protrudes from a part of the first end 27 a of the bag-like separator 27.

  As shown in FIG. 2, the extending direction of a straight line L connecting the first end 27 a and the second end 27 b of the bag-like separator 27 at the shortest distance is the height direction, and the first end 31 a of the negative electrode 31 ( A direction in which a straight line L connecting the tip end edge of the negative electrode protruding portion 35 and the second end edge 31b at the shortest distance is taken as a height direction. The dimension H1 in the height direction of the bag-like separator 27 and the dimension H2 in the height direction of the negative electrode 31 are the same.

  Further, assuming that the direction along the first edge 27 a of the bag-like separator 27 is the longitudinal direction and the direction along the second edge 31 b of the negative electrode 31 is the longitudinal direction, the dimension in the longitudinal direction of the bag-like separator 27 The dimension in the longitudinal direction of the negative electrode 31 is the same.

  As shown in FIG. 1, the bag-like separator 27 containing the positive electrode 21 and the negative electrode 31 are disposed at positions where the positive tabs 22b are arranged in a row along the stacking direction and do not overlap the positive tabs 22b. The negative electrode tabs 32 b are stacked so as to be arranged in a row along the stacking direction. In the electrode assembly 14, the secondary battery 10 has a portion in which the first end 31 a of the negative electrode 31 and the first end 27 a of the bag-like separator 27 are aligned in the height direction. The two end edges 31 b and the second end edge 27 b of the bag-like separator 27 have portions aligned in the height direction.

  Further, as shown in FIG. 2, in the electrode assembly 14, the third edge 31 c of the negative electrode 31 and the third edge 27 c of the bag-like separator 27 are aligned in the longitudinal direction. Then, in a state where the respective end edges are aligned, the negative electrode active material layer 33 is opposed to the entire surface of the positive electrode active material layer 23 with the separator member 28 of the bag-like separator 27 interposed therebetween.

  The electrode assembly 14 includes a tab-side end surface 14 a formed by gathering the first end 31 a of the negative electrode 31 and the first end 27 a of the bag-like separator 27. Both the positive electrode tab 22b and the negative electrode tab 32b exist in the tab side end surface 14a. The longitudinal direction of the tab side end face 14 a coincides with the longitudinal direction of the negative electrode 31 and the bag-like separator 27. The negative electrode tab 32b is located at one end side of the tab end surface 14a in the longitudinal direction, and the positive electrode tab 22b is located at the other end side of the tab end surface 14a in the longitudinal direction.

  At the tab side end face 14 a, the positive electrode tab 22 b and the negative electrode tab 32 b are bent in a collected (bundled) state in a range from one end to the other end in the stacking direction of the electrode assembly 14. The positive electrode tab 22b is electrically connected by welding the portion where the positive electrode tabs 22b overlap, and the positive electrode conductive member 41a is connected to the positive electrode tab 22b.

  The positive electrode conductive member 41 a is formed by bending a single metal plate, for example, an aluminum plate, and has a crank shape. The positive electrode conductive member 41a has a positive electrode tab welding piece 41b on one side in the longitudinal direction with respect to the curved portion, and the positive electrode tab 22b is joined to the positive electrode tab welding part 41b by welding. Further, the positive electrode conductive member 41a has a terminal-side welding piece 41c on the other side in the longitudinal direction with respect to the curved portion, and the positive electrode terminal 43 is welded to the terminal-side welding piece 41c. The positive electrode terminal 43 welded to the terminal-side welding piece 41c includes a plate-like base 43a and an electrode post 43b protruding from the base 43a. The positive electrode terminal 43 is fixed to the lid 13, and the pole post 43 b penetrates the lid 13 and protrudes outside the case 11.

  Further, in the case 11, the terminal-side welding piece 41 c is formed along the longitudinal direction of the tab-side end surface 14 a in order to release the base 43 a of the positive electrode terminal 43 from the gap between the positive electrode tab 22 b and the lid 13. It is disposed closer to the corner of the bag-like separator 27 than 22 b. Therefore, the positive electrode terminal 43 is on the other end side in the longitudinal direction than the positive electrode tab 22b in the longitudinal direction of the tab side end surface 14a. Further, in order to prevent the base 43a from interfering with the lid 13, the terminal side welding piece 41c is located closer to the tab side end face 14a of the electrode assembly 14 than the positive electrode tab side welding piece 41b in the height direction. It is arranged.

  Similarly, the negative electrode tabs 32b are electrically connected by welding the overlapping portions of the negative electrode tabs 32b, and the negative electrode conductive members 42a for extracting electricity from the electrode assembly 14 to the negative electrode tabs 32b. Is connected. The negative electrode conductive member 42 a is formed by bending a single metal plate, for example, a copper plate, and has a crank shape. The negative electrode conductive member 42a has a negative electrode tab welding piece 42b on one side in the longitudinal direction with respect to the curved portion, and the negative electrode tab 32b is joined to the negative electrode tab welding part 42b by welding.

  Further, the negative electrode conductive member 42a has a terminal-side welding piece 42c on the other side in the longitudinal direction with respect to the curved portion, and the negative electrode terminal 46 is welded to the terminal-side welding piece 42c. The negative electrode terminal 46 welded to the terminal-side welding piece 42c includes a plate-like base 46a and an electrode post 46b protruding from the base 46a. The negative electrode terminal 46 is fixed to the lid 13, and the pole post 46 b protrudes through the lid 13 to the outside of the case 11.

  In order to release the base 46 a of the negative electrode terminal 46 from the gap between the negative electrode tab 32 b and the lid 13, the terminal-side welding piece 42 c has a bag-like separator 27 than the negative electrode tab 32 b along the longitudinal direction of the tab side end surface 14 a. Are placed near the corners of the Therefore, the negative electrode terminal 46 is located on one end side in the longitudinal direction of the negative electrode tab 32 b in the longitudinal direction of the tab side end surface 14 a. Further, in order to prevent the base 46a from interfering with the lid 13, the terminal-side welding piece 42c is disposed at a position closer to the tab-side end surface 14a of the electrode assembly 14 than the negative electrode tab-side welding piece 42b. The positive electrode terminal 43 and the negative electrode terminal 46 are insulated from the lid 13 by the insulating ring 13 b.

Next, a method of manufacturing the secondary battery 10 will be described together with its operation.
First, the electrode assembly 14 is manufactured.
As shown in FIGS. 5A to 5C, the bag-like separator 27 containing the positive electrode 21 and the negative electrode 31 are stacked to manufacture the electrode assembly 14. At this time, the bag-like separator 27 and the negative electrode 31 are manufactured using the positioning jig 60. The positioning jig 60 includes a base 61 having a rectangular shape in plan view. The positioning jig 60 includes a U-shaped guide 62 erected from the upper surface 61 a of the base 61. The guide 62 includes a first guide surface 62 a along the second end 27 b of the bag-like separator 27 and the second end 31 b of the negative electrode 31 at the time of alignment. Further, the guide 62 includes a second guide surface 62 b along the pair of third end edges 27 c of the bag-like separator 27 and the third end edge 31 c of the negative electrode 31 at the time of alignment. The second guide surfaces 62b are at both ends in the longitudinal direction of the first guide surface 62a.

  The first guide surface 62a of the guide 62 restricts the movement of the bag-shaped separator 27 and the negative electrode 31 in the height direction, and the second guide surface 62b moves the bag-shaped separator 27 and the negative electrode 31 in the longitudinal direction. Is regulated.

  As shown in FIG. 5 (a) or FIG. 5 (b), when the bag-like separators 27 are stacked while being positioned using the positioning jig 60, the pair of third edges 27c of the bag-like separators Along the guide surface 62b, the movement of the bag-like separator 27 in the longitudinal direction is restricted. Further, the pair of third end edges 31c of the negative electrode 31 is made to be along the second guide surface 62b, and the movement of the negative electrode 31 in the longitudinal direction is restricted.

  Next, the positioning member 64 is brought into contact with the first end edge 27 a of the bag-like separator 27, and the bag-like separator 27 is pressed by the positioning member 64 toward the first guide surface 62 a. Further, the positioning member 64 is brought into contact with the contact edge portion 37 of the negative electrode 31, and the negative electrode 31 is pressed toward the first guide surface 62 a by the positioning member 64. Then, the bag-like separator 27 and the negative electrode 31 move toward the first guide surface 62a by the contact of the positioning member 64 in a state where the movement in the longitudinal direction is restricted by the second guide surface 62b, and the second end The edges 27b and 31b abut on the first guide surface 62a.

  As a result, as shown in FIG. 5C, the movement of the bag-like separator 27 and the negative electrode 31 in the height direction is restricted, and the second end 27 b of the bag-like separator 27 and the second edge 27 of the negative electrode 31 It aligns in the state which the edge 31b aligns. Further, the first end 27a of the bag-like separator 27 and the first end 31a of the negative electrode 31 are aligned. As a result, four edges of the bag-like separator 27 and the negative electrode 31 are aligned. Then, when a predetermined number of bag-shaped separators 27 and the negative electrode 31 are stacked, a laminate is formed. Then, the laminate is brought into close contact by pressing in the stacking direction, and then the bag-like separator 27 and the negative electrode 31 are fixed with a tape or the like (not shown), whereby the electrode assembly 14 is manufactured.

  Next, as shown in FIG. 6, the positive electrode tab welding piece 41b of the positive electrode conductive member 41a is welded to the positive electrode tab 22b in the electrode assembly 14, and the positive electrode terminal 43 is attached to the terminal welding piece 41c of the positive electrode conductive member 41a. Weld. After welding the negative electrode tab welding piece 42b of the negative electrode conductive member 42a to the negative electrode tab 32b, the negative electrode terminal 46 is welded to the terminal welding part 42c of the negative electrode conductive member 42a. Next, with the insulating ring 13b attached to the positive electrode terminal 43, the positive electrode terminal 43 is fixed to the lid 13, and the negative electrode terminal 46 is fixed to the lid 13 with the insulating ring 13b attached to the negative electrode terminal 46. .

  As a result, the lid 13, the positive electrode conductive member 41a, the negative electrode conductive member 42a, the positive electrode terminal 43, and the negative electrode terminal 46 are integrated to form a lid terminal assembly 53. The lid terminal assembly 53 and the electrode assembly 14 are connected by the positive electrode tab 22 b and the negative electrode tab 32 b.

Next, the electrode assembly 14 is inserted into the case body 12 from the opening 12 a of the case body 12.
At this time, as shown in FIG. 7, the lid 13 is pushed toward the electrode assembly 14 to bend the positive electrode tab 22 b and the negative electrode tab 32 b. At this time, in the lid terminal assembly 53, the base 43 a of the positive electrode terminal 43 and the base 46 a of the negative electrode terminal 46 protrude toward the tab-side end surface 14 a of the electrode assembly 14. The terminal-side welding piece 41 c is joined to the base portion 43 a of the positive electrode terminal 43, and the terminal-side welding piece 42 c is joined to the base portion 46 a of the negative electrode terminal 46.

  As a result, the terminal-side welding pieces 41 c and 42 c are pressed against portions of the first end 27 a of the bag-like separator 27 on both sides in the longitudinal direction. At this time, the negative electrode protrusion 35 is not at a position overlapping the positive electrode terminal 43 and the terminal side welding piece 41c in the height direction, and is not at a position overlapping the negative electrode terminal 46 and the terminal side welding piece 42c in the height direction. For this reason, when the lid 13 is pushed in, the terminal side welding pieces 41c and 42c do not contact the negative electrode protrusion 35.

  Then, the second end 27 b of the bag-like separator 27 located on the bottom side of the electrode assembly 14 and the second end 31 b of the negative electrode 31 abut the inner bottom surface of the case main body 12, and into the case main body 12. The housing of the electrode assembly 14 is completed. Thereafter, when the lid 13 and the case body 12 are joined to close the opening 12 a of the case body 12, the assembly of the secondary battery 10 is completed.

According to the above embodiment, the following effects can be obtained.
(1) The negative electrode 31 is provided with the contact edge portion 37 with which the positioning member 64 abuts on the negative electrode protruding portion 35. On the surface of the negative electrode protrusion 35, a portion along the contact edge 37 is covered by the protective layer 34, and a portion along the contact edge 37 is reinforced. Therefore, it is possible to suppress the deformation of the negative electrode protrusion 35 when the positioning member 64 comes in contact with the contact edge 37 of the negative electrode protrusion 35. Therefore, when the positioning member 64 is moved in contact with the negative electrode 31, the movement amount shortage due to the deformation of the negative electrode 31 can be suppressed. As a result, the first end 31a of the negative electrode 31 and the first end 27a of the bag-like separator 27 can be aligned in the height direction, and the positive electrode active material layer 23 can be precisely used for the negative electrode active material layer 33. The electrode assembly 14 can be manufactured in the opposite state.

  (2) The reinforcing layer of the negative electrode protruding portion 35 is configured of the protective layer 34 that protects the negative electrode active material layer 33. The protective layer 34 has a structure in which the ceramic particles are solidified with a binder, so that the negative electrode protruding portion 35 can be effectively reinforced and the rigidity can be improved.

  (3) The base end side of the negative electrode protruding portion 35 is reinforced by the two-layer structure of the negative electrode active material layer 33 and the protective layer 34. Therefore, when the positioning member 64 is brought into contact with the contact edge portion 37 to move the negative electrode 31, deformation of the negative electrode protrusion 35 from the base end side of the negative electrode protrusion 35 can be suppressed.

  (4) In the negative electrode projecting portion 35, the portion along the contact edge 37 is reinforced by the protective layer 34, and the negative electrode active material layer 33 does not exist in the portion along the contact edge 37. For this reason, when the positioning member 64 is brought into contact with the contact edge portion 37 to move the negative electrode 31, the negative electrode active material does not fall off.

  (5) The negative electrode projecting portion 35 is present at a position not overlapping the positive electrode tab 22 b in the stacking direction. For this reason, the positive electrode 21 and the negative electrode 31 are not in contact with each other through the negative electrode projection 35 and do not short circuit. Therefore, by adjusting the position at which the negative electrode protruding portion 35 protrudes from the negative electrode active material layer 33, the positional alignment between the negative electrode 31 and the bag-like separator 27 is facilitated, and no short circuit occurs between the positive electrode 21 and the negative electrode 31.

  (6) The negative electrode protruding portion 35 is at a position not overlapping the positive electrode terminal 43 and the negative electrode terminal 46 in the height direction. Therefore, when the electrode assembly 14 is pushed into the case main body 12 by the cover terminal assembly 53 when manufacturing the secondary battery 10, the negative electrode protruding portion is formed by the terminal side welding pieces 41c and 42c via the positive electrode terminal 43 and the negative electrode terminal 46. 35 is not pressed, and there is no deformation of the negative electrode protrusion 35.

The above embodiment may be modified as follows.
As shown in FIG. 8, the negative electrode protruding portion 35 may protrude from both sides of the positive electrode tab 22 b at a position along the longitudinal direction of the negative electrode 31. The point is that the negative electrode protrusion 35 may protrude from any position along the long edge portion 33 a of the negative electrode active material layer 33 as long as the negative electrode protrusion 35 does not overlap the positive electrode tab 22 b in the stacking direction. The negative electrode protrusion 35 is covered by the protective layer 34. In this case, the entire surface of the surface of the negative electrode protrusion 35 may be covered by the protective layer 34, or only a portion along the first end 31a may be covered by the protective layer 34.

In the embodiment, the surface of the negative electrode protruding portion 35 may not be covered with the negative electrode active material layer 33, and may be covered with only the protective layer 34, and the reinforcing layer may be configured with only the protective layer 34.
The reinforcing layer may be made of a resin that does not dissolve in an electrolytic solution, such as polypropylene (PP) or polyphenylene sulfide (PPS), instead of ceramic.

  In the embodiment, the three edges of the negative electrode 31 and the bag-like separator 27 are aligned by the U-shaped guide 62, but the three edges of the negative electrode 31 and the bag-like separator 27 are aligned If possible, the shape of the guide 62 may be changed.

  The secondary battery 10 may be a nickel-metal hydride battery or another secondary battery. The point is that the ions move between the active material for the positive electrode and the active material for the negative electrode and transfer of electric charge.

  The positive electrode 21 and the negative electrode 31 have a rectangular shape in which the extending direction of the first edges 21a and 31a is longitudinal, but the rectangular shape in which the extending direction of the third edges 21c and 31c is longitudinal It is also good. In this case, the shape of the case 11 is also changed in accordance with the shapes of the positive electrode 21 and the negative electrode 31.

The storage device may be a laminate cell in which the electrode assembly is wrapped in a laminate film.
The power storage device is also applicable to power storage devices other than secondary batteries, such as capacitors.

  DESCRIPTION OF SYMBOLS 10 Secondary battery as an electrical storage device 11 Case 12 Case main body 12a Opening 13 Lid 14 An electrode assembly 14a Tab end face 21 Positive electrode 22 Positive metal Foil 22b: positive electrode tab 23: positive electrode active material layer 27: bag-shaped separator 27a: first end edge as one end edge 27b: second end edge as the other end edge 31: negative electrode 31a: First edge as one end edge 31b: second end edge as the other end edge 32: negative electrode metal foil 32b: negative electrode tab 33: negative electrode active material layer 33a: long edge as edge portion 34 ... Protective layer as a reinforcing layer, 35 ... Negative electrode protrusion, 43 ... Positive electrode terminal, 46 ... Negative electrode terminal, 64 ... Positioning member.

Claims (5)

A negative electrode formed of the negative electrode metal foil having a rectangular negative electrode active material layer on the surface of a rectangular sheet-like negative electrode metal foil and protruding from one edge of a pair of edges of the negative electrode active material layer A negative electrode having a protrusion and a negative electrode tab protruding from an end edge located at a tip of the negative electrode protrusion in a protruding direction from the one edge;
And a positive electrode having a positive electrode active material layer on the surface of a rectangular sheet-like positive metal foil and being accommodated in a rectangular bag-like separator and having a positive electrode tab protruding from one end of the bag-like separator,
A tab having a laminated structure in which the negative electrode active material layers are alternately stacked in a state of facing the positive electrode active material layer via the bag-like separator, and a tab in which both the positive electrode tab and the negative electrode tab are present A power storage device internally provided with an electrode assembly having side end surfaces, comprising:
In the negative electrode and the bag-like separator, when the opposite side of the one end is the other end, and the extending direction of the straight line connecting the one end and the other end at the shortest distance is the height direction, An electric storage device comprising a reinforcing layer having a portion in which the one end edge of the bag-like separator is aligned in the height direction, and covering a portion along the one end edge of the surface of the negative electrode protrusion.   The negative electrode active material layer and the reinforcing layer coexist on the surface of the negative electrode protrusion, and the reinforcing layer is positioned closer to the one end of the negative electrode protrusion than the negative electrode active material layer. The power storage device according to 1.   3. The power storage device according to claim 1, wherein the negative electrode protruding portion is at a position not overlapping the positive electrode tab in the stacking direction, where a stacking direction is a stacking direction of the negative electrode and the bag-like separator.   The electrode assembly is accommodated in a case, and the case includes a case main body accommodating the electrode assembly, and a lid closing an opening of the case main body. The negative electrode and the bag-like separator Assuming that the direction in which the end edge extends is the longitudinal direction, the negative electrode tab is on one end side in the longitudinal direction of the negative electrode, the positive electrode tab is on the other end side in the longitudinal direction of the bag-like separator, And a negative electrode terminal fixed to the lid at one end side of the negative electrode tab in the longitudinal direction, and electrically connected to the positive electrode tab and from the positive electrode tab in the longitudinal direction The other end side also has a positive electrode terminal fixed to the lid, and the negative electrode protrusion and the negative electrode terminal and the positive electrode terminal in the height direction Power storage device according to any one of claims 1 to claim 3 in the not no position. A negative electrode formed of the negative electrode metal foil having a rectangular negative electrode active material layer on the surface of a rectangular sheet-like negative electrode metal foil and protruding from one edge of a pair of edges of the negative electrode active material layer A negative electrode having a protrusion and a negative electrode tab protruding from an end edge located at a tip of the negative electrode protrusion in a protruding direction from the one edge;
And a positive electrode having a positive electrode active material layer on the surface of a rectangular sheet-like positive metal foil and being accommodated in a rectangular bag-like separator and having a positive electrode tab protruding from one end of the bag-like separator,
A tab having a laminated structure in which the negative electrode active material layers are alternately stacked in a state of facing the positive electrode active material layer via the bag-like separator, and a tab in which both the positive electrode tab and the negative electrode tab are present What is claimed is: 1. A method of manufacturing a power storage device including an electrode assembly having a side end surface therein,
When the opposite side of the one end is the other end of the negative electrode and the bag-like separator, and the extension direction of the straight line connecting the one end and the other end at the shortest distance is the height direction, The reinforcing member has a portion in which the one end of the negative electrode and the one end of the bag-like separator are aligned in the height direction, and a surface of the negative electrode protrusion covers a portion along the one end.
When manufacturing the electrode assembly by stacking the negative electrode and the bag-like separator, a positioning member is brought into contact with a portion along one of the edges of the bag-like separator and one edge of the negative electrode along the reinforcing layer. A method of manufacturing a power storage device, comprising: aligning the negative electrode and the bag-like separator in a height direction.