JP2018200841A - Manufacturing method of power storage device, and power storage device - Google Patents

Abstract

To provide a manufacturing method of power storage device capable of reducing the load acting on a tub, and to provide a power storage device.SOLUTION: In a manufacturing method of secondary battery, first tubs T1 and second tubs T2 located at both ends in the lamination directions Y1, Y2 are collected toward the center in the lamination directions Y1, Y2 in a first electrode assembly 121 and a second electrode assembly 122. Tub groups of the positive electrodes of the first electrode assembly 121 and the second electrode assembly 122 are welded to a positive electrode conductive member, and tub groups 19 of the negative electrodes are welded to a negative electrode conductive member 16a. Thereafter, each tub group 19 is bent and the first and second electrode assemblies 121, 122 are arranged side by side in the lamination directions Y1, Y2.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for manufacturing a power storage device including two electrode assemblies, and a power storage device.

  Conventionally, vehicles such as EV (Electric Vehicle) and PHV (Plug in Hybrid Vehicle) are mounted with a lithium ion secondary battery or the like as a power storage device that stores electric power supplied to an electric motor or the like. The secondary battery includes an electrode assembly in which a plurality of positive electrodes and negative electrodes having an active material layer are stacked with a separator interposed therebetween, and a metal case that houses the electrode assembly and an electrolytic solution.

  The secondary battery disclosed in Patent Document 1 includes a laminated electrode body as an electrode assembly, and this laminated electrode body is composed of a first electrode body block and a second electrode body block. In the laminated electrode body, the first electrode body block and the second electrode body block are arranged so that the lamination directions of the positive single plate cell (positive electrode) and the negative single plate cell (negative electrode) coincide with each other. Yes. Further, a positive electrode lead extends from the positive electrode of the single plate cell, and a negative electrode lead extends from the negative electrode. The positive electrode lead and the negative electrode lead are stacked for each electrode body block. The laminated positive electrode lead is connected to the positive electrode terminal for each electrode body block by welding, and the laminated negative electrode lead is connected to the negative electrode terminal for each electrode body block by welding.

WO2017 / 38042

  By the way, in Patent Document 1, it is necessary that all the leads of the stacked positive electrode lead and the positive electrode terminal and the stacked negative electrode lead and the negative electrode terminal are connected to the terminal. For this reason, at the time of welding, the lead is pulled toward the terminal so that all the leads overlap the terminal. Then, a tensile force acts on the base end side of the lead, and a lead having a longer separation distance from the collected one end in the stacking direction has a larger tensile force and may damage the lead. Therefore, it is conceivable to increase the length of the lead so that it overlaps without pulling the lead, but the longer the lead, the higher the material cost, and the free end of the lead existing on the tip side from the welding location It becomes long and it becomes easy to short-circuit with a laminated electrode body, and is not preferable.

  The objective of this invention is providing the manufacturing method of an electrical storage apparatus which can reduce the load which acts on a tab, and an electrical storage apparatus.

  A method of manufacturing a power storage device for solving the above problem is a method in which sheet-like electrodes having tabs protruding from a part of an edge are stacked in a state in which different polarities are insulated, and the edge extends. The first electrode assembly and the second electrode assembly each including a tab group in which the tabs having different polarities are spaced apart from each other along the direction in which the tabs are gathered together in the stacking direction of the electrodes. The first electrode assembly and the second electrode assembly are a method of manufacturing a power storage device including a conductive member that is juxtaposed in a state in which the stacking directions coincide with each other and joined to the tab group, In the one electrode assembly and the second electrode assembly, the tabs located at both ends in the stacking direction are gathered toward the center in the stacking direction, and the first electrode assembly and the second electrode assembly have the same polarity. The tab groups are After welding to the conductive member of one remains were collected state, and summarized in that arranging said second electrode assembly and the first electrode assembly by bending the respective tab group in the stacking direction.

  According to this, in the first electrode assembly and the second electrode assembly, when all the tabs are gathered together at one end in the stacking direction, the tabs having a longer separation distance from the tab at one end in the stacking direction are collected as a tab group. In order to form a superposed portion in which all tabs are overlapped, the tab at the other end in the stacking direction is pulled toward the superposed portion, and the pulling force acts strongly. However, if the tabs at both ends in the stacking direction are gathered together in the center in the stacking direction, the reference tab for the gathering becomes a tab near the center in the stacking direction, and even if the tab is located at the end in the stacking direction, The distance from the tab can be shortened. Therefore, the force pulled for forming the overlapping portion of the tab can be reduced, and the tab can be prevented from being damaged by the pull.

  In addition, the overlapping portion where all the tabs overlap in each tab group is formed on the tip side of the tab in the vicinity of the central portion in the stacking direction, which is a reference for gathering, as compared to the case where all tabs are gathered together at one end in the stacking direction. The overlapping portion can be positioned on the tip side of the tab. As a result, there is no need to increase the protruding length of the tab from the edge of the electrode in order to form the overlapped portion, and the electrode assembly caused by the increased material cost and the longer free end Short circuit with the tab can be suppressed.

Moreover, about the manufacturing method of an electrical storage apparatus, when welding the said tab group of the same polarity to the said electrically-conductive member, you may face the front-end | tips between the said tab groups of the same polarity.
According to this, since the overlapping portion where all the tabs overlap in each tab group is close to the tip of the tab near the center in the stacking direction as a reference for gathering, when the laser is irradiated to the tip of the tab group of the same polarity Two tab groups can be welded to the conductive member simultaneously. Therefore, compared with the case where the same polarity tab group is separately welded to the conductive member, welding can be performed easily.

  In a power storage device for solving the above problem, sheet-like electrodes having tabs protruding from a part of the edge are stacked in a state of insulating between different polarities, and along the direction in which the edge extends. The tabs having different polarities are spaced apart from each other, and a first electrode assembly and a second electrode assembly each having a tab group in which the tabs are gathered together in the electrode stacking direction are provided in a case, An electrode assembly and the second electrode assembly are arranged in parallel with each other in the stacking direction, and include a conductive member joined to the tab group, and the tabs positioned at both ends in the stacking direction are provided. The gist of the invention is to provide a welded portion in which the group of tabs gathered toward the center in the stacking direction and the conductive member are welded.

  According to this, in the first electrode assembly and the second electrode assembly, when all the tabs are gathered and welded to one end in the stacking direction, the tabs having a longer distance from the tab at the one end in the stacking direction are tab groups. As a result, the length of the tabs gathered together becomes shorter, and the tab at the other end in the stacking direction is pulled toward the overlapping portion in order to form the overlapping portion where all the tabs are overlapped. However, if the tabs at both ends in the stacking direction are gathered together in the center in the stacking direction, the reference tab for the gathering becomes a tab near the center in the stacking direction, and even if the tab is located at the end in the stacking direction, The distance from the tab can be shortened. Therefore, the force pulled for forming the overlapping portion of the tab can be reduced, and the tab can be prevented from being damaged by the pull.

  In addition, the overlapping portion where all the tabs overlap in each tab group is formed on the tip side of the tab in the vicinity of the central portion in the stacking direction, which is a reference for gathering, as compared to the case where all tabs are gathered together at one end in the stacking direction. It can be located on the tip side of the tab. As a result, there is no need to increase the protruding length of the tab from the edge of the electrode in order to form the overlapped portion, and the electrode assembly caused by the increased material cost and the longer free end Short circuit with the tab can be suppressed.

Moreover, about the electrical storage apparatus, the said tab groups of the same polarity may have the front-end | tips of this tab group facing the said lamination direction.
According to this, since the overlapping portion where all the tabs overlap in each tab group is close to the tip of the tab near the center in the stacking direction as a reference for gathering, when the laser is irradiated to the tip of the tab group of the same polarity Two tab groups can be welded to the conductive member simultaneously. Therefore, compared with the case where the same polarity tab group is separately welded to the conductive member, welding can be performed easily. Further, the free end of the tab is eliminated, and the free end can be prevented from coming into contact with the first electrode assembly or the second electrode assembly.

In the power storage device, the conductive member is electrically connected to an electrode terminal that extracts electricity from the first electrode assembly and the second electrode assembly to the outside of the case.
According to this, for example, the structure for taking out electricity from the electrode assembly can be simplified as compared with the case where a portion where one conductor is bent to be joined to the tab group and a portion where electricity is taken out from the case are formed. Can be formed.

  The power storage device is a secondary battery.

  According to the present invention, the load acting on the tab can be reduced.

The disassembled perspective view which shows the secondary battery of embodiment. Sectional drawing which shows a secondary battery. (A) is a side view showing a state in which tab groups are formed and the tab groups face each other, (b) is a side view showing a state in which conductive members are arranged, and (c) is a tab after forming a welded portion. The side view which shows the state which bends a group, (d) is a side view which shows the state which brought together the tab of the other end of the lamination direction on the tab of the lamination direction one end. The top view which shows the state which has arrange | positioned the electrically-conductive member to the 1st and 2nd electrode assembly.

A power storage device manufacturing method, a power storage device manufacturing method of a secondary battery, and an embodiment in which the secondary battery is embodied will be described with reference to FIGS.
As shown in FIG. 1 or 2, the secondary battery 10 as the power storage device includes a case 11. The secondary battery 10 includes a first electrode assembly 121, a second electrode assembly 122, and an electrolytic solution (not shown) accommodated in the case 11. 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 secondary battery 10 includes a positive electrode terminal 15 and a negative electrode terminal 16 for taking out electricity from the first electrode assembly 121 and the second electrode assembly 122. The positive electrode terminal 15 and the negative electrode terminal 16 penetrate the through hole 14 a of the lid 14 and protrude out of the case 11. A ring-shaped insulating ring 17 for insulating from the lid 14 is attached to the positive terminal 15 and the negative terminal 16, respectively.

  The secondary battery 10 includes a positive electrode conductive member 15 a as a rectangular plate-shaped conductive member in the case 11. The secondary battery 10 includes a negative electrode conductive member 16 a as a rectangular plate-shaped conductive member in the case 11. The positive electrode terminal 15 is electrically connected to the positive electrode conductive member 15a, and the negative electrode terminal 16 is electrically connected to the negative electrode conductive member 16a.

  The first electrode assembly 121 and the second electrode assembly 122 include a plurality of sheet-like positive electrodes 30, a plurality of sheet-like negative electrodes 31, and a plurality of sheet-like separators 32. The first electrode assembly 121 and the second electrode assembly 122 have a structure in which a separator 32 is interposed between the positive electrode 30 and the negative electrode 31 and are stacked in a mutually insulated state.

  Assuming that the end face facing the inner surface of the case 11 in the first electrode assembly 121 is one end side in the stacking direction Y1, the negative electrode 31 is located at one end in the stacking direction Y1 of the first electrode assembly 121, and the stacking direction Y2 The positive electrode 30 is located at the other end. When the end surface side of the second electrode assembly 122 facing the inner surface of the case 11 is one end side in the stacking direction Y2 of the second electrode assembly 122, the negative electrode 31 is disposed at one end of the second electrode assembly 122 in the stacking direction Y2. And the negative electrode 31 is positioned at the other end in the stacking direction Y2.

  The first electrode assembly 121 and the second electrode assembly 122 are stacked such that the separator 32 is interposed between the positive electrode 30 of the first electrode assembly 121 and the negative electrode 31 of the second electrode assembly 122. Yes. The first electrode assembly 121 and the second electrode assembly 122 are arranged side by side so that the stacking direction Y1 and the stacking direction Y2 coincide.

  The positive electrode 30 includes a rectangular sheet-like positive electrode metal foil (for example, an aluminum foil) 33 and a positive electrode active material layer 34 as an active material layer present on both surfaces of the positive electrode metal foil 33. The positive electrode 30 has a positive electrode tab 35 as a tab protruding from a part of the edge 30a along the long side which is one side. The positive electrode tab 35 is composed of the positive electrode metal foil 33 itself without the positive electrode active material layer 34. The direction in which the positive electrode tab 35 protrudes from the edge 30 a of the positive electrode 30 is defined as the protruding direction of the positive electrode tab 35.

  The negative electrode 31 has a rectangular sheet-like negative electrode metal foil (for example, copper foil) 36 and a negative electrode active material layer 37 as an active material layer present on both surfaces of the negative electrode metal foil 36. The negative electrode 31 has a negative electrode tab 38 as a tab protruding from a part of the edge 31a along the long side which is one side. The negative electrode tab 38 is composed of the negative electrode metal foil 36 itself without the negative electrode active material layer 37. The direction in which the negative electrode tab 38 protrudes from the edge 31 a of the negative electrode 31 is defined as the protruding direction of the negative electrode tab 38. The protruding direction of the negative electrode tab 38 coincides with the protruding direction of the positive electrode tab 35. In the present embodiment, the outer shape of the negative electrode 31 viewed from the stacking directions Y1 and Y2 is also slightly larger than the outer shape of the positive electrode 30 viewed from the stacking directions Y1 and Y2.

  The separator 32 is made of polypropylene (PP). The separator 32 has a fine pore structure so that the lithium ion (ion) of the positive electrode active material can pass along with charge / discharge of the secondary battery 10. In the present embodiment, the outer shape of the separator 32 viewed from the stacking directions Y1 and Y2 is the same size as that of the negative electrode 31 viewed from the stacking directions Y1 and Y2, and is slightly more than the outer shape of the negative electrode 31. large.

  As shown in FIG. 1, in the first and second electrode assemblies 121 and 122, the plurality of positive electrodes 30 are arranged such that the respective positive electrode tabs 35 are arranged in a row along the respective stacking directions Y1 and Y2. Laminated. Similarly, in the first and second electrode assemblies 121 and 122, the plurality of negative electrodes 31 are arranged in a row along the respective stacking directions Y1 and Y2 at positions where the respective negative electrode tabs 38 do not overlap with the positive electrode tabs 35. Laminated to be arranged. Therefore, in each electrode assembly 121, 122, the positive electrode tab 35 and the negative electrode tab 38 are separated from each other along the extending direction of the respective edge portions 30a, 31a.

  The first electrode assembly 121 and the second electrode assembly 122 include a positive electrode tab group 18 in which the positive electrode tabs 35 are gathered in the stacking direction Y1, Y2, and the negative electrode tab 38 is gathered in the stacking direction Y1, Y2. A negative electrode tab group 19 is provided.

  In the tab groups 18 and 19 of each polarity, a tab positioned at one end in the stacking direction Y1, Y2 is described as a first tab T1, and a tab positioned at the other end of the stacking direction Y1, Y2 is described as a second tab T2. . The tab closest to the center in the stacking direction Y1, Y2 is defined as a center tab T3. In the tab groups 18 and 19 of each polarity, the first tab T1 and the second tab T2 are gathered together toward the central tab T3. Therefore, the central tab T3 in the vicinity of the center in the stacking direction Y1, Y2 serves as a tab serving as a reference for gathering. However, as shown in FIG. 2, the tab groups 18 and 19 are arranged in a bent state in the case 11, so that the other tabs 35 and 38 are separated from the central tab T3 which is a reference for gathering. It will be in the state.

  As shown in FIG. 1, in the positive electrode tab group 18, an overlapped portion H in which all the positive electrode tabs 35 are overlapped is formed at the tip of the central tab T <b> 3, and in the negative electrode tab group 19, An overlapped portion H is formed by overlapping all the negative electrode tabs 38 at the tip. As shown in FIG. 3A, the tabs closer to the ends of the stacking directions Y1 and Y2 from the center tab T3 have shorter lengths at the portions aggregated as the tab groups 18 and 19.

  In the positive electrode tab groups 18, the tips of the positive electrode tabs 35 face each other in the stacking directions Y1 and Y2, and in the negative electrode tab groups 19, the tips of the negative electrode tabs 38 in the stacking directions Y1 and Y2. Facing each other. As shown in FIG. 2, in the tab groups 18 and 19 of each polarity, a welded portion W is formed at a portion where all the tabs 35 and 38 and the conductive members 15a and 16a overlap. The welded portion W is formed in a portion where the overlapping portion H and the conductive members 15a and 16a in the tab groups 18 and 19 overlap. The welding part W is formed including the front-end | tip part of 1st tab T1, 2nd tab T2, and center tab T3. Accordingly, each tab group 18, 19 does not include a portion where the tabs 35, 38 are free ends on the tip side from the welded portion W.

  As shown in the comparative example of FIG. 3D, in the tab groups 18 and 19 of each polarity, one end of the stacking directions Y1 and Y2 (FIG. 3D) so that the second tab T2 approaches the first tab T1. It is assumed that tabs 35 and 38 are gathered together at the upper end). In this case, in the stacking directions Y1 and Y2, the tabs 35 and 38 gathered as the tab groups 18 and 19 become shorter as the tab is separated from the first tab T1 that is a reference for gathering.

  For this reason, in each tab group 18, 19, the overlapping portion H (welded portion W) where all the tabs 35, 38 are overlapped is provided in the overlapping portion with the other tabs 35, 38 in the second tab T2, It is located on the base side of the tabs 35 and 38 from the position of the overlapping portion H in the embodiment. Therefore, in the tab groups 18 and 19, all the tabs 35 and 38 are free ends on the front end side of the overlapping portion H (welded portion W).

  On the other hand, in this embodiment, as shown in FIG. 3C, in each tab group 18, 19, the overlapping portion H (welded portion W) has the first tab T1, the second tab T2, and the central tab T3. It is formed in the vicinity of their tips, including no free ends.

  As shown in FIG. 1, the 1st electrode assembly 121 is equipped with the tab side end surface 121a in the end surface in which the positive electrode tab group 18 and the negative electrode tab group 19 exist. The second electrode assembly 122 includes a tab-side end surface 122a on an end surface where the positive electrode tab group 18 and the negative electrode tab group 19 are present.

Next, the manufacturing method of the secondary battery 10 is demonstrated with an effect | action.
First, as shown in FIG. 3A, the first electrode assembly 121 and the second electrode assembly 122 are manufactured. Next, in the first electrode assembly 121 and the second electrode assembly 122, the first tab T1 and the second tab T2 at both ends in the stacking direction Y1, Y2 of the positive electrode tab 35 and the negative electrode tab 38 are respectively directed to the central tab T3. The tab groups 18 and 19 are manufactured. Then, in each tab group 18 and 19, the overlap portion H is formed in the vicinity of the tip portion of the central tab T3.

  Next, the first electrode assembly 121 and the second electrode assembly 122 are disposed so that the tab side end surface 121a of the first electrode assembly 121 and the tab side end surface 122a of the second electrode assembly 122 are opposed to each other. To do. At this time, one end surfaces of the first electrode assembly 121 and the second electrode assembly 122 in the stacking directions Y1 and Y2 are upper end surfaces, and the other end surfaces of the stacking directions Y1 and Y2 are supported by a work table (not shown).

  Next, as shown in FIG. 3B or FIG. 4, the positive electrode conductive member 15 a is stacked on the first tab T 1 of the two positive electrode tab groups 18, and the negative electrode is applied to the first tab T 1 of the two negative electrode tab groups 19. The conductive members 16a are stacked. At this time, the first electrode assembly 121 and the second electrode assembly 122 are arranged so that the tips of the two tab groups 18 and the two tab groups 19 face each other. Moreover, although the front-end | tip of each positive electrode tab 35 has faced in the tab groups 18 of positive electrode, the two tab groups 18 do not overlap in the up-down direction. Similarly, although the negative electrode tab groups 19 face each other, the tips of the negative electrode tabs 38 face each other, but the two tab groups 19 do not overlap in the vertical direction.

  Next, as shown in FIG. 3B, the laser L is irradiated toward the overlapping portion H of the tab group 18 of the positive electrode. Then, the overlapping portion H of both tab groups 18 is welded to the positive electrode conductive member 15a at the same time, the two tab groups 18 are joined to the positive electrode conductive member 15a, and a welded portion W is formed. Further, the laser L is irradiated toward the overlapping portion H of the negative electrode tab group 19. Then, as shown in FIG. 3C, the overlapped portion H of both tab groups 19 is simultaneously welded to the negative electrode conductive member 16a, the two tab groups 19 are joined to the negative electrode conductive member 16a, and the welded portion W is It is formed.

  As shown in the comparative example of FIG. 3D, in each of the tab groups 18 and 19 of each polarity, the tabs 35 and 18 are arranged on one end side in the stacking direction Y1 and Y2 so that the second tab T2 approaches the first tab T1. When welding 38 together, the welding location is set according to the second tab T2, and the welded portion W to be formed is far away from the tip of the first tab T1. And in order to form the superposition | polymerization part H, it is pulled so that the tab close | similar to 2nd tab T2 may approach 1st tab T1, and a big load acts on the base end side of 2nd tab T2. However, the load acting on the second tab T2 can be reduced by gathering the first tab T1 and the second tab T2 together with the central tab T3 as in the present embodiment.

  Next, as shown in FIG. 3C, the tab groups 18 and 19 of the first electrode assembly 121 and the tab groups 18 and 19 of the second electrode assembly 122 are bent, and the first electrode assembly 121 and the second electrode assembly 121 are bent. The electrode assemblies 122 are arranged in the stacking directions Y1 and Y2.

  Thereafter, the positive electrode terminal 15 is connected to the positive electrode conductive member 15a, and the negative electrode terminal 16 is connected to the negative electrode conductive member 16a. The first electrode assembly 121 and the second electrode assembly 122 are accommodated in the case main body 13, and the positive electrode terminal 15 and the negative electrode terminal 16 are fixed to the lid 14. Finally, the case main body 13 and the lid 14 are joined, and the opening 14 a of the case main body 13 is closed by the lid 14.

Next, the effect of this embodiment will be described together with the action.
(1) The first tab T1 and the second tab T2 are gathered together in the central tab T3 to form the overlapping portion H in which all the positive electrode tabs 35 are overlapped, and the overlapping portion H in which all the negative electrode tabs 38 are overlapped. In order to form, the first tab T1 and the second tab T2 were gathered together in the central tab T3. For this reason, the load which acts on 2nd tab T2 can be reduced compared with the case where all the tabs 35 and 38 are gathered together in 1st tab T1, for example, and the superimposition part H is formed.

  (2) All of the positive electrode tabs 35 of the secondary battery 10 are divided into the tab group 18 of the first electrode assembly 121 and the tab group 18 of the second electrode assembly 122 and are welded to the positive electrode conductive member 15a. 38 are divided into the tab group 19 of the first electrode assembly 121 and the tab group 19 of the second electrode assembly 122 and are welded to the negative electrode conductive member 16a. Therefore, the number of the positive electrode tabs 35 or the negative electrode tabs 38 to be welded at a time is reduced as compared with the case where all of the positive electrode tabs 35 or the negative electrode tabs 38 are collectively welded to the conductive members 15a and 16a. Therefore, the energy required for one-time welding can be reduced, and for example, an increase in size of the welding apparatus is suppressed.

  (3) The tab group 18 of the first electrode assembly 121 and the tab group 18 of the second electrode assembly 122 are welded with their tips facing each other, and the tab group 19 and the second electrode assembly of the first electrode assembly 121 are welded. The tab group 19 of the solid body 122 is welded with the tips facing each other. Therefore, two tab groups 18 and two tab groups 19 can be welded at one place, and the number of weldings can be reduced as compared with the case where the tab groups 18 and 19 are individually welded. .

  (4) Since the tab groups 18 and 19 of the first electrode assembly 121 and the tab groups 18 and 19 of the second electrode assembly 122 are welded with their tips facing each other, the positive electrode tab groups 18 and the negative electrode tabs The welding of the groups 19 can be performed at one place, and the free ends of the positive electrode tab 35 and the negative electrode tab 38 can be eliminated. Therefore, the free end can be prevented from contacting the first electrode assembly 121 or the second electrode assembly 122.

  (5) The positive electrode conductive member 15a and the positive electrode terminal 15 are joined and electrically connected by welding, and the negative electrode conductive member 16a and the negative electrode terminal 16 are joined and electrically connected by welding. For example, a structure for taking out electricity from the electrode assembly can be easily formed as compared with a case where a portion of one conductor is bent to join the tab groups 18 and 19 and a portion to be an electrode terminal.

In addition, you may change the said embodiment as follows.
The positive electrode conductive member 15a and the positive electrode terminal 15 may be integrally formed, and the negative electrode conductive member 16a and the negative electrode terminal 16 may be integrally formed.

  The tab group 18 of the first electrode assembly 121 and the tab group 18 of the second electrode assembly 122 may be welded to the positive electrode conductive member 15a separately, or the tab group 19 of the first electrode assembly 121 The tab group 19 of the two-electrode assembly 122 may be welded to the negative electrode conductive member 16a separately.

  The tab group 18 of the first electrode assembly 121 and the tab group 18 of the second electrode assembly 122 are not opposed to each other and may be in positions shifted in the extending direction of the edges 30a and 31a. Similarly, the tab group 19 of the first electrode assembly 121 and the tab group 19 of the second electrode assembly 122 do not face each other and may be in positions shifted in the extending direction of the edges 30a and 31a.

  The first electrode assembly 121 and the second electrode assembly 122 may be ones in which the negative electrode 31 is located at both ends in the stacking direction Y1, Y2. In this case, the negative electrode 31 of the first electrode assembly 121 The first electrode assembly 121 and the second electrode assembly 122 are juxtaposed without interposing the separator 32 between the first electrode assembly 122 and the negative electrode 31 of the second electrode assembly 122.

  The positive electrode 30 may have a structure in which the positive electrode active material layer 34 exists on one side of the positive electrode metal foil 33. Similarly, the negative electrode 31 may have a structure in which the negative electrode active material layer 37 exists on one surface of the negative electrode metal foil 36.

  The secondary battery 10 may be a lithium ion secondary battery or another secondary battery. In short, any ion may be used as long as ions move between the active material for the positive electrode and the active material for the negative electrode and charge is transferred.

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

  H ... polymerization part, Y1, Y2 ... stacking direction, 10 ... secondary battery as power storage device, 11 ... case, 15 ... positive electrode terminal as electrode terminal, 15a ... positive electrode conductive member, 16 ... negative electrode terminal as electrode terminal, 16a ... negative electrode conductive member, 18, 19 ... tab group, 30 ... positive electrode, 30a, 31a ... edge, 31 ... negative electrode, 35 ... positive electrode tab, 38 ... negative electrode tab, 121 ... first electrode assembly, 122 ... Electrode assembly, 122 ... second electrode assembly.

Claims (6)

Sheet-like electrodes having tabs protruding from a part of the edge are stacked with insulation between different polarities, and the tabs having different polarities are spaced apart along the extending direction of the edge. In addition, the case includes a first electrode assembly and a second electrode assembly including a tab group in which the tabs are gathered together in the stacking direction of the electrodes,
The first electrode assembly and the second electrode assembly are a method of manufacturing a power storage device including a conductive member that is juxtaposed in a state in which the stacking directions coincide with each other and joined to the tab group,
In the first electrode assembly and the second electrode assembly, the tabs located at both ends in the stacking direction are gathered toward the center in the stacking direction,
After welding the tab groups of the same polarity of the first electrode assembly and the second electrode assembly to the one conductive member in the state of being gathered together,
A method of manufacturing a power storage device, wherein each tab group is bent to arrange the first electrode assembly and the second electrode assembly in the stacking direction.   The method for manufacturing a power storage device according to claim 1, wherein when the tab groups having the same polarity are welded to the conductive member, the tab groups having the same polarity face each other. Sheet-like electrodes having tabs protruding from a part of the edge are stacked with insulation between different polarities, and the tabs having different polarities are spaced apart along the extending direction of the edge. In addition, the case includes a first electrode assembly and a second electrode assembly including a tab group in which the tabs are gathered together in the stacking direction of the electrodes,
The first electrode assembly and the second electrode assembly are arranged in parallel in a state in which the stacking directions coincide with each other and are provided with a conductive member joined to the tab group,
A power storage device comprising: a welded portion that welds a tab group in which the tabs positioned at both ends in the stacking direction are gathered together toward the center in the stacking direction and the conductive member.   The power storage device according to claim 3, wherein the tab groups having the same polarity face each other in the stacking direction.   5. The power storage device according to claim 3, wherein an electrode terminal that extracts electricity from the first electrode assembly and the second electrode assembly to the outside of the case is electrically connected to the conductive member. .   The power storage device according to claim 3, wherein the power storage device is a secondary battery.