JP2018137066A - Electrode assembly, power storage device and manufacturing method of electrode assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode assembly capable of suppressing dusting at the electrode end well, and to provide a power storage device and a manufacturing method of the electrode assembly.SOLUTION: An electrode assembly 3 includes a laminate 21 where multiple electrodes are laminated in the lamination direction, a thickness adjustment film 23 laminated on one surface side of the laminate 21 in the lamination direction D, a first tape 22 for fixing the lamination state of multiple electrodes of the laminate 21, and a second tape 24 for fixing the lamination state of the laminate 21 and the thickness adjustment film 23. The first tape 22 is provided on the sides 21d, 21e of the laminate 21 formed by lamination of multiple electrodes, so as to protrude to one and the other surfaces of the laminate 21, and the second tape 24 is provided on the sides 21c, 21f of the laminate 21 and the side of the thickness adjustment film 23 so as to protrude to one surface side of the thickness adjustment film 23 in the lamination direction D and the other surface of the laminate 21, and cover the edges E1-E4 of the side of the laminate 21.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrode assembly, a power storage device, and a method for manufacturing the electrode assembly.

  2. Description of the Related Art There are two types of electrode assemblies for power storage devices, a stacked type in which a plurality of sheet-like positive electrodes and negative electrodes are stacked, and a wound type formed by straddling strip-like positive electrodes and negative electrodes. As a manufacturing process of the stacked electrode assembly, there is a process of welding and integrating the electrode tabs (tab welding process). When performing this tab welding process, the jig | tool described, for example in patent document 1 is used. The jig described in Patent Document 1 has a plate on which a laminated body having a substantially rectangular shape in plan view is placed, a positioning guide that is provided on the plate and positions the laminated body, and presses the upper surface of the laminated body And an upper surface pressing body. In the laminated body placed on the plate, the side surface other than the side surface from which the tab protrudes is in contact with the positioning guide.

JP 2000-251882 A

  In the above prior art, the positional deviation between the tabs of the electrodes is suppressed by bringing the laminate into direct contact with the positioning guide. However, when the above jig is used, there are problems described below. Although it is described in the above prior art that the laminated body is positioned with a jig, the laminated body is transported and positioned with the jig after being formed in the laminating process which is the preceding process. Due to the impact when the laminated body comes into contact with the positioning guide, the active material falls off at the electrode ends constituting the side surface of the laminated body, particularly at the edge of the side surface and the periphery thereof (that is, the corner of the laminated body). There is a risk of powder falling). This causes variations in the quality of the electrodes. Moreover, the above-mentioned powder falling is likely to occur not only in the above-described tab welding process but also when the conveyance of the laminated body onto the jig is automated. This is because, unlike the manual operation of the operator, it is extremely difficult to finely control the automated conveyance speed according to the situation.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide an electrode assembly, a power storage device, and a method for manufacturing the electrode assembly that can satisfactorily suppress powder falling of the electrode end.

  An electrode assembly according to an aspect of the present invention includes a laminate in which a plurality of electrodes are laminated along a lamination direction, a thickness adjustment film laminated on one surface side in the lamination direction of the laminate, A first tape for fixing the laminated state of the plurality of electrodes, and a second tape for fixing the laminated state of the laminated body and the thickness adjusting film, wherein the first tape is stretched on one side and the other side of the laminated body. The second tape is provided on the side surface of the laminated body formed by laminating a plurality of electrodes so that the second tape extends to the one surface in the laminating direction of the thickness adjusting film and the other surface of the laminated body, and is laminated. It is provided on the side surface of the laminated body and the side surface of the thickness adjusting film so as to cover the edge of the side surface of the body.

  In this electrode assembly, the first tape is provided on the side surface of the laminated body formed by laminating a plurality of electrodes so as to project on one side and the other side of the laminated body, and the second tape has a thickness of It is provided on the side surface of the laminated body and the side surface of the thickness adjusting film so as to project on one surface in the laminating direction of the thickness adjusting film and the other surface of the laminated body and cover the edge of the side surface of the laminated body. For this reason, at least a part of the side surface of the laminate formed by laminating a plurality of electrodes is covered and protected by the first tape and the second tape. That is, the first tape and the second tape cover a part of the side surface of the laminated body constituted by the electrode end portions. Thereby, it can prevent that the side surface of a laminated body and a guide member etc. contact directly by making a guide member etc. contact the part protected by the 1st tape and the 2nd tape in a laminated body. Thereby, the impact at the time of a laminated body contacting the said guide member etc. can be relieved, and generation | occurrence | production of the powder fall in the electrode edge part which comprises each side surface of a laminated body can be suppressed. Furthermore, since the edge of the side surface of the laminated body that easily collides with the guide member or the like in the laminated body is covered with the second tape, the occurrence of the above-mentioned dust fall off at the electrode end portion constituting the edge is also well suppressed. it can. Therefore, in the electrode assembly, powder falling off at the electrode end can be satisfactorily suppressed.

  Further, the first tape and the second tape may be provided separately from each other. In this case, when the laminate is expanded, the pressure applied from the outside to the laminate in the stacking direction is favorably dispersed, so that rapid deterioration of the electrode assembly due to the expansion can be suppressed.

  Further, on the side surface of the laminate, the side surface of the laminate on which the first tape is provided and the side surface of the laminate on which the second tape is provided may be different from each other. In this case, it can prevent that the pressure added to a laminated body from the outside concentrates on the specific side surface side.

  Moreover, a laminated body has a tab which protrudes from a side surface, and at least one part of a 2nd tape may be located between a side surface and the current collecting plate attached to a tab. In this case, when the tab is deformed and the current collector plate moves toward the side surface, the current collector plate contacts the second tape. Thereby, generation | occurrence | production of the powder fall of the electrode edge part resulting from a contact with a collector plate and a laminated body and a short circuit with a collector plate and a laminated body can be suppressed.

  A power storage device according to another aspect of the present invention may include the electrode assembly and a case that houses the electrode assembly. In such a power storage device, the electrode assembly in which the occurrence of powder fall is suppressed is housed in the case. For this reason, a power storage device having stable quality can be provided.

  The method for manufacturing an electrode assembly according to another aspect of the present invention includes a first step of stacking a plurality of electrodes along a stacking direction to form a stack, and compressing the stack in the stacking direction, then stacking A second step of providing a first tape on a side surface of a laminate formed by laminating a plurality of electrodes so as to project on one side and the other side in the laminating direction of the body, and a lamination state of the plurality of electrodes by the first tape A third step of laminating the thickness adjusting film on one side of the laminated body to which the film is fixed, an overhang on one side in the laminating direction of the thickness adjusting film and the other side of the laminated body, and an edge of the side surface of the laminated body A fourth step of providing a second tape on the side surface of the laminated body and the side surface of the thickness adjusting film so as to cover, and a first step of supporting the side surface of the laminated body by a guide member via the first tape and the second tape. And 5 steps.

  In this manufacturing method, by performing the second to fourth steps, at least a part of the side surface of the laminate formed by laminating a plurality of electrodes is covered and protected by the first tape and the second tape. That is, a part of side surface of the laminated body comprised by an electrode edge part is covered with the 1st tape and the 2nd tape. Thereby, when the side surface of a laminated body contacts a guide member in a 5th process, the 1st tape and the 2nd tape can protect the electrode edge part in the side surface of a laminated body. For this reason, the impact at the time of a laminated body contacting the said guide member etc. can be relieve | moderated, and generation | occurrence | production of the powder fall in an electrode edge part can be suppressed. In particular, since the edge of the side surface of the laminate that is likely to collide with the guide member or the like in the laminate in the fourth step is covered with the second tape, the occurrence of the above-described dust fall of the electrode end portion that constitutes the edge Can be suppressed well. Therefore, in the electrode assembly, powder falling off at the electrode end can be satisfactorily suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the electrode assembly which can suppress powder falling of an electrode edge part favorably, an electrical storage apparatus, and an electrode assembly can be provided.

FIG. 1 is a schematic exploded view of a power storage device including an electrode assembly according to an embodiment. FIG. 2 is a cross-sectional view of the power storage device taken along line II-II in FIG. FIG. 3 is a plan view of the electrical assembly. FIG. 4 is a perspective view of the electrical assembly. FIG. 5A is a diagram showing the positive electrode, and FIG. 5B is a diagram showing the negative electrode. FIG. 6 is a process diagram for explaining a method of manufacturing power storage device 1. FIG. 7 is a diagram illustrating a state where the electrode assembly is supported by the guide member in step S6.

  Hereinafter, preferred embodiments of a power storage device according to one aspect of the present invention and an electrode assembly included in the power storage device will be described in detail with reference to the drawings. In the following description, the same reference numerals are used for the same elements or elements having the same functions, and redundant description is omitted.

  FIG. 1 is a schematic exploded view of a power storage device including an electrode assembly according to an embodiment. FIG. 2 is a cross-sectional view of the power storage device taken along line II-II in FIG. FIG. 3 is a plan view of the electrical assembly, and FIG. 4 is a perspective view of the electrical assembly. FIG. 5A is a diagram showing the positive electrode, and FIG. 5B is a diagram showing the negative electrode.

  In the present embodiment, the power storage device 1 shown in FIGS. 1 and 2 is a lithium ion secondary battery. The power storage device may be another nonaqueous electrolyte secondary battery or an electric double layer capacitor. The power storage device 1 includes a hollow case 2 having a substantially rectangular parallelepiped shape, for example, and an electrode assembly 3 accommodated in the case 2. The case 2 is formed of a metal such as aluminum or an alloy, for example. The case 2 has a main body 2a that is open on one side and a lid 2b that closes the opening of the main body 2a. An insulating film F is disposed between the inner wall of the case 2 and the electrode assembly 3. For example, a non-aqueous (organic solvent) electrolyte is injected into the case 2. The main body 2a has a substantially rectangular parallelepiped shape. The lid 2b is fixed to the main body 2a so as to cover the opening of the main body 2a. The lid 2b is fixed to the main body 2a, for example, by being welded to the main body 2a. A positive electrode terminal 5 and a negative electrode terminal 6 are spaced apart from each other on the lid 2 b of the case 2. The positive electrode terminal 5 is fixed to the case 2 via an insulating ring 7, and the negative electrode terminal 6 is fixed to the case 2 via an insulating ring 8.

  As shown in FIGS. 1 to 4, the electrode assembly 3 includes a laminated body 21, a first tape 22, a thickness adjusting film 23, and a second tape 24.

  The stacked body 21 is a member formed by stacking a plurality of electrodes in the stacking direction D through the separator 13. The stacked body 21 has a substantially rectangular shape when viewed from the stacking direction D, and the first end surface 21a (one surface) in the stacking direction D and the second end surface 21b (the other surface) located on the opposite side of the first end surface 21a. ) And side surfaces 21c to 21f that connect the first end surface 21a and the second end surface 21b. The stacked body 21 includes a plurality of positive electrodes 11 (electrodes), a plurality of negative electrodes 12 (electrodes), and a bag-shaped separator 13 disposed between the positive electrodes 11 and the negative electrodes 12. Therefore, the first end surface 21 a and the second end surface 21 b are formed from the main surface of either the positive electrode 11 or the negative electrode 12, and the side surfaces 21 c to 21 f are formed by stacking the positive electrode 11, the negative electrode 12, and the separator 13. . The stacking direction D corresponds to the vertical direction with respect to the main surface of the electrode.

  As shown in FIG. 5A in addition to FIG. 2, the positive electrode 11 includes a metal foil 14 made of, for example, an aluminum foil, and a positive electrode active material layer 15 formed on both surfaces of the metal foil 14. . The metal foil 14 of the positive electrode 11 includes a rectangular main body 14a and a rectangular tab 14b protruding from one end of the main body 14a.

  The tab 14 b is a portion that connects the main body 14 a and the positive electrode terminal 5. In FIG. 5, the tab 14b extends upward from the upper edge of the main body 14a. In FIG. 1, the tabs 14 b of each positive electrode 11 are bundled together on the side surface 21 c of the stacked body 21. A current collecting plate 16 is attached to the tab 14b. The current collector plate 16 is a member disposed between the tab 14 b and the positive electrode terminal 5. The current collector plate 16 is made of, for example, the same material as the metal foil 14 of the positive electrode 11 and has a rectangular flat plate shape. The plurality of stacked tabs 14b are disposed, for example, between the current collector plate 16 and a protective plate (not shown) along the shape of the tab 14b.

  The positive electrode active material layer 15 is a porous layer containing a positive electrode active material and a binder. For this reason, the electrolyte solution is impregnated in the pores in the positive electrode active material layer 15. The positive electrode active material layer 15 is formed by supporting a positive electrode active material on at least the central portion of the main body 14a on both surfaces of the main body 14a. Examples of the positive electrode active material include composite oxide, metallic lithium, and sulfur. The composition of the composite oxide includes, for example, at least one of manganese, nickel, cobalt, and aluminum and lithium.

  As shown in FIG. 5 (b) in addition to FIG. 2, the negative electrode 12 includes a metal foil 17 made of, for example, copper foil, and a negative electrode active material layer 18 formed on both surfaces of the metal foil 17. . Similar to the metal foil 14 of the positive electrode 11, the metal foil 17 of the negative electrode 12 includes a rectangular main body 17a and a rectangular tab 17b protruding from one end of the main body 17a. From the viewpoint of suppressing lithium deposition in the power storage device 1, the entire negative electrode active material layer 18 covers the positive electrode active material layer 15 as viewed from the stacking direction D. Further, the negative electrode active material layer 18 covers the entire body 17 a of the metal foil 17 in order to satisfy the above-described relationship and increase the capacity as much as possible. For this reason, in this embodiment, the negative electrode active material layer 18 is exposed on the side surfaces 21c to 21f of the multilayer body 21 together with the end side of the main body 17a of the negative electrode 12 (that is, the end portion of the negative electrode 12).

  The tab 17 b is a portion that connects the main body 17 a and the negative electrode terminal 6. In FIG. 5, the tab 17b extends upward from the upper edge of the main body 17a. In FIG. 1, the tabs 17 b of the negative electrodes 12 are bundled together on the side surface 21 c of the stacked body 21. A current collecting plate 19 is attached to the tab 17b. The current collector plate 19 is a member disposed between the tab 17 b and the negative electrode terminal 6. The current collector plate 19 is made of, for example, the same material as the metal foil 17 of the negative electrode 12 and has a rectangular flat plate shape. The plurality of stacked tabs 17b are disposed, for example, between the current collector plate 19 and a protective plate (not shown) along the shape of the tab 17b.

  The negative electrode active material layer 18 is a porous layer containing a negative electrode active material and a binder. For this reason, the electrolyte solution is impregnated in the pores in the negative electrode active material layer 18. The negative electrode active material layer 18 is formed by supporting a negative electrode active material on at least a central portion of the main body 17a on both surfaces of the main body 17a. Examples of the negative electrode active material include carbon such as graphite, highly oriented graphite, mesocarbon microbeads, hard carbon, and soft carbon, alkali metals such as lithium and sodium, metal compounds, SiOx (0.5 ≦ x ≦ 1.5 ) And the like, and boron-added carbon. Here, as an example, the tab 17b does not carry a negative electrode active material. However, an active material may be carried on the base end portion of the tab 17b on the main body 17a side.

  The separator 13 houses the positive electrode 11. For this reason, in this embodiment, the laminated body 21 is formed by laminating | stacking the separator 13 which accommodated the positive electrode 11, and the some negative electrode 12 by turns. The separator 13 has a rectangular shape when viewed from the stacking direction of the positive electrode 11 and the negative electrode 12. The separator 13 is formed in a bag shape by, for example, a pair of rectangular sheet-like separator members being welded to each other at three sides thereof. Examples of the material of the separator 13 include a porous film made of a polyolefin resin such as polyethylene (PE) and polypropylene (PP), a woven fabric or a non-woven fabric made of polypropylene, polyethylene terephthalate (PET), methylcellulose and the like. The separator 13 of this embodiment is a porous film, and the electrolyte solution is impregnated in the pores in the separator 13.

  The first tape 22 is a member that fixes the stacked state of the plurality of electrodes (the positive electrode 11 and the negative electrode 12) and the separator 13 in the stacked body 21, and is attached to the stacked body 21 by one or more. The first tape 22 has, for example, a belt-like base material layer and an adhesive layer provided on one surface of the base material layer. The first tape 22 is provided on at least one of the side surfaces 21c to 21f of the 21 laminated body so as to overhang the first end surface 21a and the second end surface 21b of the laminated body 21. That is, the first tape 22 is attached to the first end surface 21a, at least one of the side surfaces 21c to 21f, and the second end surface 21b.

  In the present embodiment, two first tapes 22 are attached to the laminate 21. One first tape 22 is affixed to the first end surface 21a, the side surface 21d in contact with the side surface 21c, and the second end surface 21b. That is, one first tape 22 is affixed to a part of the end of each electrode constituting the side surface 21d. The other first tape 22 is attached to the first end surface 21a, the side surface 21e that is in contact with the side surface 21c and opposite to the side surface 21d, and the second end surface 21b. That is, the other first tape 22 is affixed to a part of the end portion of each electrode constituting the side surface 21e. One first tape 22 is affixed so as to cover the central part of the side surface 21d, and the other first tape 22 is affixed so as to cover the central part of the side surface 21e.

  When viewed from the stacking direction D, the width of each first tape 22 is not particularly limited. For example, the width of each first tape 22 only needs to be a width that can favorably fix each electrode of the laminate 21 by the first tape 22 while exposing a part of the side surfaces 21d and 21e. Outgassing occurs favorably from the side surfaces 21d and 21e exposed from the first tape 22, and the positional deviation between the electrodes can be suppressed. In addition, the side surfaces 21d and 21e of the laminated body 21 can be satisfactorily protected by the first tape 22, and the cost of using the first tape 22 can be reduced. Note that the gas loss means that gas generated in the stacked body 21 due to a chemical reaction between the positive electrode 11 and the negative electrode 12 is discharged out of the stacked body 21. As an example of outgassing, it corresponds to the discharge of gas generated in the initial charge / discharge and aging processes. Since the initial charging / discharging and aging processes are well-known techniques in the manufacturing process of the lithium ion secondary battery, detailed description thereof is omitted.

  The thickness adjusting film 23 is an insulating film that adjusts the thickness of the electrode assembly 3 along the stacking direction D, and is stacked on the first end face 21 a side of the stacked body 21. By adjusting the thickness of the electrode assembly 3 with the thickness adjusting film 23, the electrode assembly 3 is satisfactorily fixed to the inner surface of the case 2. Thereby, generation | occurrence | production of the damage by the collision with the electrode assembly 3 and case 2 resulting from a vibration etc. is suppressed. The thickness adjusting film 23 may be prepared by preparing a plurality of films having different thicknesses in multiple stages, selecting one of the films according to the thickness of the laminate 21. Alternatively, a film having an equal thickness may be prepared as the thickness adjusting film 23, and adjusted by the number of films according to the thickness of the laminate 21. In this embodiment, the latter method is used, and the constituent material of the film constituting the thickness adjusting film 23 is, for example, PP (polypropylene).

  In this embodiment, as shown in FIG. 2, the thickness adjusting film 23 is composed of four films 23 a, and the first main surface 23 b (one surface) and the second main surface 23 c in the stacking direction D are provided. Have. The first main surface 23 b and the second main surface 23 c are preferably larger than the first end surface 21 a of the stacked body 21. In this case, the contact between the first end surface 21a of the laminated body 21 and the case 2 can be satisfactorily prevented. In addition, when the thickness of the laminated body 21 corresponds to the desired thickness of the electrode assembly 3, the thickness adjusting film 23 may not be provided. In other words, the thickness adjusting film 23 may not be included in the electrode assembly 3.

  The second tape 24 is a member for fixing the laminated state of the laminated body 21 and the thickness adjusting film 23, and one or more of the second tapes 24 are attached to the laminated body 21 and the thickness adjusting film 23. Similar to the first tape 22, the second tape 24 includes, for example, a belt-like base material layer and an adhesive layer provided on one surface of the base material layer. The second tape 24 and the first tape 22 are provided separately from each other. That is, the second tape 24 and the first tape 22 are provided so as not to contact each other and to overlap each other. Thereby, when the electrode assembly 3 is accommodated in the case 2, it is possible to reduce places where pressure is easily applied in the stacked body 21. By reducing the said location, the location where the chemical reaction of the positive electrode 11 and the negative electrode 12 becomes uneven can be reduced.

  The second tape 24 projects over the first main surface 23b of the thickness adjusting film 23 and the second end surface 21b of the laminate 21, and covers at least one of the edges E1 to E4 of the side surfaces 21c to 21f of the laminate 21. As described above, the laminate 21 is provided on at least one of the side surfaces 21 c to 21 f and the side surface of the thickness adjusting film 23. In the present embodiment, four second tapes 24 are attached to the laminated body 21, and each second tape 24 is formed of the laminated body 21 and the thickness adjusting film 23 when viewed from the lamination direction D. It is provided so as to cover the corners C1 to C4. More specifically, each second tape 24 is provided so as to cover one of the edges E1 to E4 of the side surfaces 21c to 21f of the stacked body 21 extending in the stacking direction D. In the present embodiment, in the laminated body 21, the side surface on which the first tape 22 is provided and the side surface on which the second tape 24 is provided are different from each other (details will be described later).

  The first second tape 24 protrudes from the first main surface 23 b of the thickness adjusting film 23 and the second end surface 21 b of the laminate 21. In addition, the first second tape 24 is adjusted in thickness with the side surface 21c of the multilayer body 21 so as to cover the edge E1 of the multilayer body 21 included in the corner portion C1 positioned at the intersection of the side surfaces 21c and 21d. The film 23 is attached to the side surface overlapping the side surface 21c. That is, the 1st 2nd tape 24 is affixed on the part which comprises the edge E1 among the edge parts of each electrode which comprises the side surface 21c. At this time, the first second tape 24 is preferably positioned between the side surface 21 c and the current collector plate 16. The width of the first second tape 24 as viewed from the stacking direction D is not particularly limited as in the case of the first tape 22, but, for example, each electrode of the stacked body 21 is exposed while exposing a part of the side surface 21c. Any width that can be fixed satisfactorily is acceptable. In addition, the width of the first second tape 24 is adjusted so as not to contact the tab 14b. In this case, in the corner portion C1, in addition to each electrode of the laminate 21 being firmly fixed by the first second tape 24, the laminate 21 and the thickness adjusting film 23 are firmly fixed. Is done. Here, the first second tape 24 is not attached to the side surface 21d constituting the corner portion C1. For this reason, in the corner | angular part C1, gas loss generate | occur | produces favorably. Therefore, it is possible to suppress the occurrence of positional deviation of each electrode due to the corner C1, the occurrence of positional deviation between the laminate 21 and the thickness adjusting film 23, and excessive expansion at the corner C1.

  The second second tape 24 protrudes from the first main surface 23 b of the thickness adjusting film 23 and the second end surface 21 b of the laminate 21. Further, the second tape 24 of the second layer is formed on the side surface 21c of the multilayer body 21 and the thickness adjustment so as to cover the edge E2 of the multilayer body 21 included in the corner portion C2 positioned at the intersection of the side surfaces 21c and 21e. The film 23 is attached to the side surface overlapping the side surface 21c. That is, a second second tape 24 is affixed to the portion constituting the edge E2 of the end portions of the electrodes constituting the side surface 21c. At this time, the second second tape 24 is preferably positioned between the side surface 21 c and the current collector plate 19. The width of the second second tape 24 viewed from the stacking direction D is, for example, substantially the same as the width of the first second tape 24 and is adjusted so as not to contact the tab 17b. Further, the second second tape 24 is not attached to the side surface 21e constituting the corner portion C1. For this reason, in the corner portion C2, similarly to the corner portion C1, each electrode of the laminated body 21 is firmly fixed, and the laminated body 21 and the thickness adjusting film 23 are firmly fixed, and the outgassing is good. Occurs.

  The third second tape 24 protrudes from the first main surface 23 b of the thickness adjusting film 23 and the second end surface 21 b of the laminate 21. In addition, the third second tape 24 is positioned on the opposite side of the side surface 21c of the multilayer body 21 so as to cover the edge E3 of the multilayer body 21 included in the corner portion C3 located at the location where the side surfaces 21d, 21f intersect. The side surface 21f is attached to the side surface of the thickness adjusting film 23 that overlaps the side surface 21f. That is, the third second tape 24 is attached to the portion constituting the edge E3 of the end portions of the electrodes constituting the side surface 21f. The width of the third second tape 24 as viewed from the stacking direction D is not particularly limited, as with the first second tape 24. For example, the stacked body 21 is exposed while exposing a part of the side surface 21f. Any width may be used as long as the electrodes can be fixed satisfactorily. Further, the third second tape 24 is not attached to the side surface 21d constituting the corner portion C3. Therefore, in the corner portion C3 as well as the corner portions C1 and C2, each electrode of the laminated body 21 is firmly fixed, and the laminated body 21 and the thickness adjusting film 23 are firmly fixed, and the gas is released. Occurs well.

  The fourth second tape 24 protrudes from the first main surface 23 b of the thickness adjusting film 23 and the second end surface 21 b of the laminate 21. In addition, the fourth second tape 24 has a thickness adjustment with the side surface 21f of the multilayer body 21 so as to cover the edge E4 of the multilayer body 21 included in the corner C4 positioned at the intersection of the side surfaces 21e and 21f. The film 23 is affixed to the side surface overlapping the side surface 21f. That is, the 4th 2nd tape 24 is affixed on the part which comprises the edge E4 among the edge parts of each electrode which comprises the side surface 21f. For example, the width of the fourth second tape 24 viewed from the stacking direction D is substantially the same as the width of the third second tape 24. Further, the fourth second tape 24 is not attached to the side surface 21e constituting the corner portion C4. Therefore, also in the corner portion C4, as in the corner portions C1 to C3, each electrode of the laminate 21 is firmly fixed, and the laminate 21 and the thickness adjusting film 23 are firmly fixed, and Outgassing occurs well.

  As described above, the second tape 24 is attached to the laminate 21 and the thickness adjusting film 23, thereby forming the corners C1 and C3 on the side surface 21d and the corners C2 and C4 on the side surface 21e. The laminated body 21 and the thickness adjusting film 23 can be satisfactorily fixed while exposing the portion. Therefore, the gas escape is favorably generated from the side surfaces 21d and 21e exposed from the second tape 24, and the positional deviation between the laminate 21 and the thickness adjusting film 23 can be satisfactorily suppressed. In addition, the edges E <b> 1 to E <b> 4 of the laminate 21 can be satisfactorily protected by the second tape 24, and the cost due to the use of the second tape 24 can be reduced.

  Hereinafter, an example of a method for manufacturing the power storage device 1 including the electrode assembly 3 described above will be described with reference to FIGS. 6 and 7. FIG. 6 is a process diagram for explaining a method of manufacturing power storage device 1. FIG. 7 is a diagram illustrating a state where the electrode assembly is supported by the guide member in step S6.

  First, a stacked body 21 is formed by stacking a plurality of electrodes along the stacking direction D (step S1, first step). Step S1 is a so-called lamination step. In step S <b> 1, the positive electrode 11 and the negative electrode 12 accommodated in the separator 13 are alternately stacked to form a stacked body 21. The laminate is formed, for example, by a known P & P (Pick and Place) method. Specifically, after the positive electrode 11 and the negative electrode 12 are manufactured on different production lines, the positive electrode 11 and the negative electrode 12 are automatically conveyed to a laminating apparatus by a conveying machine. The positive electrode 11 and the negative electrode 12 conveyed to the laminating apparatus are alternately laminated by a robot arm equipped with a suction pad to form a laminated body 21. Since lamination by the P & P method is well known, further detailed description is omitted.

  Next, after adjusting the thickness of the laminated body 21, the 1st tape 22 is affixed on the laminated body 21 (process S2, 2nd process). The laminate 21 formed in the step S1 is transported to an apparatus for performing the step S2. In step S2, first, the transported stacked body 21 is positioned. And the laminated body 21 is press-compressed along the lamination direction D of the positive electrode 11 and the negative electrode 12 using a pressing apparatus. At this time, the entire laminate 21 is uniformly compressed in the apparatus. Thereby, the gap in the stacked body 21 in the stacking direction D is filled. Subsequently, the side surfaces 21d and 21f of the stacked body 21 formed by stacking a plurality of electrodes (the positive electrode 11 and the negative electrode 12) so as to overhang the first end surface 21a and the second end surface 21b in the stacking direction D of the stacked body 21. A first tape 22 is provided. Thereby, the laminated state of the positive electrode 11 and the negative electrode 12 in the laminated body 21 is fixed, and the laminated body 21 is maintained in a compressed state. That is, the thickness of the compressed laminate 21 is maintained by the first tape 22. In step S2, it is preferable to affix the first tape 22 to the laminated body 21 through a notch or the like provided in the apparatus. Thereby, the 1st tape 22 can be affixed on the laminated body 21 so that the lamination | stacking state of the positive electrode 11 of the laminated body 21 and the negative electrode 12 may be fixed favorably. In addition, the part exposed from the said apparatus in the laminated body 21 can be protected.

  Next, the thickness of the laminated body 21 is measured (step S3). In step S3, the thickness of the laminated body 21 fixed by the first tape 22 is measured, the necessity and the number of films 23a for thickness adjustment are determined, and the film 23a is within an adjustable range. Make sure that When the thickness of the laminated body 21 does not fall within the adjustable range, it is excluded from the production line as a defective product (not shown). When the measurement result is within the adjustable range, but adjustment with the film 23a is required (step S3: YES), the first tape 22 is attached to the first end face 21a side of the laminate 21. The thickness adjusting film 23 is laminated (step S4, third step). In step S <b> 4, the number of films 23 a (for example, any one of 1 to 6) according to the error between the thickness of the stacked body 21 and the inner dimensions of the case is automatically conveyed onto the stacked body 21. For example, 1 to 6 films 23 a are laminated on the laminate 21 in accordance with the error. The appropriate value is not a predetermined value but may be a value within a predetermined range. In addition, when the measurement result does not require adjustment with the film 23a in the above step S3 (step S3: NO), the step S4 is omitted, and a step S5 described later is performed.

  Next, the 2nd tape 24 is affixed (process S5, 4th process). In step S <b> 5, when the thickness adjusting film 23 is stacked on the stacked body 21, the stacked state of the stacked body 21 and the thickness adjusting film 23 is fixed by the second tape 24. Specifically, the thickness adjusting film 23 projects over the first main surface 23b in the stacking direction D and the second end surface 21b of the stacked body 21 and covers the edges E1 to E4 of the side surfaces 21c to 21f of the stacked body 21. The second tape 24 is provided on the side surfaces 21 c and 21 f of the laminate and the corresponding side surface of the thickness adjusting film 23. On the other hand, when the thickness adjusting film 23 is not laminated on the laminated body 21 in step S3, it protrudes to the first end surface 21a and the second end surface 21b of the laminated body 21 and protects the edges E1 to E4. The second tape 24 is provided on the side surfaces 21c and 21f of the laminate. In step S5, as in step S2, the second tape 24 is attached to the laminate 21 and the thickness adjusting film 23 through another notch provided in the apparatus used in step S2. It is preferred that

  Next, the laminate 21 is supported by the support device 50 (fifth step), and then the tabs 14b and 17b provided on the laminate 21 are welded (step S6). In step S <b> 6, as shown in FIG. 7, the laminated body 21 and the thickness adjusting film 23 integrated by the second tape 24 are placed on the base 51 of the support device 50, and the guide member 52 of the support device 50 is placed. The laminated body 21 and the thickness adjusting film 23 integrated by the above are supported. At this time, the guide member 52 supports the laminate 21 and the thickness adjusting film 23 via the first tape 22 and the second tape 24. Thereby, the guide member 52 can be prevented from coming into direct contact with the stacked body 21. Subsequently, the tabs 14 b and 17 b are welded in a state where the laminated body 21 and the thickness adjusting film 23 integrated by the guide member 52 are supported. Thereby, the electrode assembly 3 is formed.

  In addition, when implementing the said process S6, when transferring the laminated body 21 and thickness adjustment film 23 which were integrated on the base 51 of the support apparatus 50, the laminated body 21 and thickness adjustment film 23 which were integrated. May be automatically transferred by a transfer device such as a robot arm or a conveyor. At this time, the guide member of the conveying device may convey the laminated body 21 and the thickness adjusting film 23 integrated with each other via the first tape 22 and the second tape 24. Thereby, it can prevent that a conveying apparatus touches the laminated body 21 directly. That is, when the integrated laminate 21 and the thickness adjusting film 23 are automatically conveyed, it is possible to suppress the occurrence of electrode dusting caused by the conveying device.

  Next, the positive electrode terminal 5 is attached to the tab 14b, and the negative electrode terminal 6 is attached to the tab 17b (step S7). In step S7, the current collector plate 16 provided with the positive electrode terminal 5 is attached to the tab 14b, and the current collector plate 19 provided with the negative electrode terminal 6 is attached to the tab 17b. Also in step S7, the electrode assembly 3 may be supported by the guide device. In this case, the guide device supports the electrode assembly 3 via the first tape 22 and the second tape 24.

  Next, the electrode assembly 3 is accommodated in the case 2 (step S8). Subsequently, the positive electrode terminal 5 is fixed to the lid portion 2b via the insulating ring 7, and the negative electrode terminal 6 is fixed to the lid portion 2b via the insulating ring 8, and then the opening of the case 2 is closed by the lid portion 2b. Further, the power storage device 1 is formed by injecting an electrolytic solution into the case 2. Also in step S8, as in step S6, the electrode assembly 3 may be automatically transferred by the transfer device. At this time, it is preferable that the guide member of the transport device transports the electrode assembly 3 while supporting the electrode assembly 3 via the first tape 22 and the second tape 24 as in step S6.

  According to the electrode assembly 3 manufactured by the manufacturing method according to the present embodiment described above, the first tape 22 of the stacked body 21 is projected so as to protrude from the first end surface 21a and the second end surface 21b of the stacked body 21. Provided on the side surfaces 21d and 21e, the second tape 24 protrudes from the first main surface 23b of the thickness adjusting film 23 and the second end surface 21b of the stacked body 21, and on the side surfaces 21c to 21f of the stacked body 21. It is provided in the side surface 21c, 21f of the laminated body 21, and the corresponding side surface of the thickness adjustment film 23 so that the edge E1-E4 may be covered. For this reason, at least a part of the side surfaces 21 c to 21 f of the stacked body 21 formed by stacking the positive electrode 11 and the negative electrode 12 is covered and protected by the first tape 22 and the second tape 24. That is, the first tape 22 and the second tape 24 cover a part of the side surfaces 21c to 21f of the stacked body 21 constituted by electrode end portions (more specifically, end portions of the negative electrode 12). Thus, the side surfaces 21c to 21f of the laminate 21 and the guide members 52 and the like are brought into contact with the portions protected by the first tape 22 and the second tape 24 on the side surfaces 21c to 21f of the laminate 21. Can be prevented from contacting directly. Thereby, the impact at the time of the laminated body 21 contacting the guide member 52 grade | etc., Can be relieve | moderated, and generation | occurrence | production of the powder fall in the electrode edge part which comprises the side surfaces 21c-21f can be suppressed. Furthermore, when the edges E1 to E4 of the side surfaces 21c to 21f that easily collide with the guide member 52 in the laminated body 21 are covered with the second tape 24, the above-mentioned powder falling of the electrode ends constituting the edges E1 to E4 Can also be suppressed satisfactorily. Therefore, in the electrode assembly 3, powder falling off at the electrode end can be satisfactorily suppressed.

  In addition, in the electrode assembly 3, the laminated state of the laminated body 21 in which the positive electrode 11, the negative electrode 12, and the separator 13 are fixed by the first tape 22 and the thickness adjusting film 23 is fixed by the second tape 24. ing. For this reason, the thickness adjustment film 23 can be laminated | stacked with respect to the laminated body 21 with which the lamination | stacking state of the several electrode was fixed. That is, the thickness adjusting film 23 can be laminated on the laminated body 21 after the handling of the laminated body 21 is facilitated. Thereby, both the lamination | stacking state of the positive electrode 11 and the negative electrode 12 which comprise the laminated body 21, and the lamination | stacking state of the laminated body 21 and the thickness adjustment film 23 can be fixed favorably, and the laminated body 21 and the thickness adjustment film 23 and Can be easily integrated.

  The first tape 22 and the second tape 24 are provided separately from each other. For this reason, when the laminated body 21 expand | swells, the pressure applied to the laminated body 21 from the exterior in the lamination direction D is disperse | distributed favorably. For example, in the power storage device 1 in which the stacked body 21 is expanded, the force applied from the case 2 to the stacked body 21 is well dispersed. For this reason, rapid deterioration of the electrode assembly 3 due to the expansion can be suppressed. In the laminated body 21, the chemical reaction between the positive electrode 11 and the negative electrode 12 may become uneven in a region where excessive pressure is applied and a region other than the region. In this case, metal (for example, lithium) is likely to be deposited in a region where excessive pressure is applied, and the life of the power storage device 1 may be shortened. For this reason, the lifetime reduction of the electrical storage apparatus 1 can be suppressed by providing the 1st tape 22 and the 2nd tape 24 so that it may not mutually overlap.

  In the laminate 21, the side surfaces 21d and 21e of the laminate 21 on which the first tape 22 is provided and the side surfaces 21c and 21f of the laminate 21 on which the second tape 24 is provided are different from each other on the side surfaces 21c to 21f. Yes. For this reason, it can prevent that the pressure added to the laminated body 21 from the outside concentrates on the specific side surface side.

  The laminate 21 has a tab 14b protruding from the side surface 21c, and at least a part of the second tape 24 is located between the side surface 21c and the current collector plate 16 attached to the tab 14b. For this reason, when the tab 14b is deformed and the current collector plate 16 moves toward the side surface 21c, the current collector plate 16 contacts the second tape 24. Thereby, generation | occurrence | production of the powder fall of the electrode edge part resulting from the contact with the current collecting plate 16 and the laminated body 21, and the short circuit with the current collecting plate 16 and the laminated body 21 can be suppressed. Moreover, the laminated body 21 has the tab 17b which protrudes from the side surface 21c, and at least one part of the 2nd tape 24 is located between the side surface 21c and the current collecting plate 19 attached to the tab 17b. . Thereby, generation | occurrence | production of the powder fall of the electrode edge part resulting from the contact with the current collecting plate 19 and the laminated body 21, and the short circuit between the current collecting plate 19 and the laminated body 21 can also be suppressed.

  The power storage device 1 includes an electrode assembly 3 according to this embodiment and a case 2 that houses the electrode assembly 3. In such a power storage device 1, the electrode assembly 3 in which the occurrence of powder fall is suppressed is accommodated in the case 2. For this reason, the electrical storage apparatus 1 which has favorable performance can be provided.

  The electrode assembly and the manufacturing method thereof according to the present invention and the power storage device are not limited to the above embodiment. For example, the number of the 1st tapes 22 is not restricted to the said embodiment. For example, four first tapes 22 may be provided and attached to the side surfaces 21 c to 21 f of the stacked body 21. In this case, both the first tape 22 and the second tape 24 are provided on each of the side surfaces 21c and 21f. Further, a plurality of first tapes 22 may be provided on one side surface of the laminate 21. In other words, the side surface to which each first tape 22 is affixed may be only one side surface unlike the above embodiment.

  In the said embodiment, the number of the 2nd tapes 24 is not restricted to the said embodiment. For example, the number of the second tapes 24 may be three or less. Viewed from the stacking direction D, the second tape 24 may cover at least one of the corners C1 to C4 of the stacked body 21. Further, the second tape 24 may not be provided between the corner portion C1 and the current collector plate 16 or between the corner portion C2 and the current collector plate 19. Further, unlike the above-described embodiment, the plurality of second tapes 24 may protrude from the second end surface 21b of the laminate 21 and the first main surface 23b of the thickness adjusting film 23 through different side surfaces.

  In the said embodiment, the 1st tape 22 and the 2nd tape 24 may be provided so that it may mutually overlap. In this case, the area exposed on the side surfaces 21c to 21f of the stacked body 21 can be increased, and the outgassing of the stacked body 21 is favorably generated.

  In the above embodiment, each of the main body 11a of the positive electrode 11 and the main body 12a of the negative electrode 12 is not limited to a rectangular shape, and may be a polygonal shape. That is, each of the positive electrode 11 and the negative electrode 12 may have a polygonal shape. Even in this case, it is preferable that the edge of the laminated body along the lamination direction D is covered with the second tape.

  In the said embodiment, the separator 13 is not restricted to a bag shape, A sheet form may be sufficient. For example, as a positive electrode with a separator, a united positive electrode in which sheet-like separators are bonded to both surfaces of the positive electrode 11 may be used.

  In the said embodiment, a tab does not necessarily need to be welded by the said process S6. For example, the above steps S6 and S7 may be performed simultaneously. In this case, first, the integrated laminate 21 and the thickness adjusting film 23 are automatically conveyed onto the pedestal 51 of the support device 50 by a conveying device or the like.

  DESCRIPTION OF SYMBOLS 1 ... Power storage device, 2 ... Case, 3 ... Electrode assembly, 5 ... Positive electrode terminal, 6 ... Negative electrode terminal, 11 ... Positive electrode, 12 ... Negative electrode, 13 ... Separator, 14 ... Metal foil, 14a ... Main body, 14b ... Tab, 16 ... current collector plate, 17 ... metal foil, 17a ... main body, 17b ... tab, 19 ... current collector plate, 21 ... laminated body, 21a ... first end surface (one surface), 21b ... second end surface (other surface), 21c to 21f ... side face, 22 ... first tape, 23 ... thickness adjusting film, 23a ... film, 23b ... first main surface (one side), 23c ... second main surface, 24 ... second tape, 51 ... pedestal 52 ... guide member, C1-C4 ... corner, D ... stacking direction, E1-E4 ... edge.

Claims (6)

A stacked body in which a plurality of electrodes are stacked along the stacking direction;
A thickness adjusting film laminated on one side in the laminating direction of the laminate,
A first tape for fixing a laminated state of the plurality of electrodes of the laminated body;
A second tape for fixing the laminated state of the laminate and the thickness adjusting film;
With
The first tape is provided on a side surface of the stacked body formed by stacking the plurality of electrodes so as to protrude from the one surface and the other surface of the stacked body,
The side surface of the laminate is extended so that the second tape projects on one surface of the thickness adjusting film in the laminating direction and the other surface of the laminate, and covers an edge of the side surface of the laminate. And provided on the side surface of the thickness adjusting film,
Electrode assembly.   The electrode assembly according to claim 1, wherein the first tape and the second tape are provided separately from each other.   The side surface of the laminate on which the first tape is provided and the side surface of the laminate on which the second tape is provided are different from each other on the side surface of the laminate. Electrode assembly. The laminate has a tab protruding from the side surface,
The electrode assembly according to any one of claims 1 to 3, wherein at least a part of the second tape is located between the side surface and a current collector plate attached to the tab. The electrode assembly according to any one of claims 1 to 4,
A case for housing the electrode assembly;
A power storage device comprising: A first step of stacking a plurality of electrodes along the stacking direction to form a stacked body;
After compressing the laminated body in the laminating direction, a first tape is formed on a side surface of the laminated body formed by laminating the plurality of electrodes so as to project on one surface and the other surface of the laminated body in the laminating direction. A second step of providing
A third step of laminating a thickness adjusting film on the one surface side of the laminate in which the laminated state of the plurality of electrodes is fixed by the first tape;
The side surface of the laminated body and the thickness adjustment so as to project on one surface of the thickness adjusting film in the laminating direction and the other surface of the laminated body and cover an edge of the side surface of the laminated body A fourth step of providing a second tape on the side of the film;
A fifth step of supporting the side surface of the laminate by a guide member via the first tape and the second tape;
A method for manufacturing an electrode assembly comprising:

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