Battery manufacturing method, battery, electrode plate

Abstract

To provide a battery manufacturing method, a battery, and an electrode plate that improve the yield of current collector foil. [Solution] In the manufacturing method of the battery 1, a bypass slit X is formed in the main body portion 110 of the current collector foil 100 of the positive electrode plate 30 before the positive electrode tab 120 is provided. The bypass slit X is continuous from the first end P1 to the second end P2, and the intermediate portion XA between them is a bypass slit that moves away from the main body end 111 of the main body portion 110. Both the first end P1 and the second end P2 are located away from the main body end 111 of the main body portion 110. Then, folded portions 130 and 140 are provided in the area located between the first end P1 and the second end P2, which are cut off from the main body portion 110 by the bypass slit X, and which are folded back toward the main body end 111 side. As a result, the current collector foil 100 is provided with a positive electrode tab 120 that protrudes beyond the main body end 111.

Description

Technical Field

[0001] The disclosed technology relates to a method for manufacturing a battery, a battery, and an electrode plate that use, as a current collector foil, one having tabs protruding from an end portion of a main body portion.

Background Art

[0002] An electrode plate of a battery such as a lithium-ion secondary battery generally has a current collector foil. Further, the current collector foil may have tabs provided so as to protrude from the main body portion at a location where it is connected to a current collecting member. For example, Patent Document 1 discloses a battery having a structure in which an electrode plate provided with a lead portion as a tab is connected to a current collecting terminal as a current collecting member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, conventionally, as the material of a current collector foil having tabs, one larger than the area actually used as the current collector foil has been required. Specifically, as the material of the current collector foil, on the side where the tabs are provided rather than the main body portion of the current collector foil, one larger by the height of protrusion of the tabs from the main body portion is prepared, and portions other than the portion to be the main body portion and the portion to be the tabs are cut away from the material to form the current collector foil. For this reason, conventionally, there have been many wasted portions in the material of the current collector foil.

[0005] The disclosed technology aims to provide a method for manufacturing a battery, a battery, and an electrode plate that improve the yield of the current collector foil.

Means for Solving the Problems

[0006] One aspect of the disclosed technology is a method for manufacturing a battery in which an electrode plate having a main body and tabs protruding from the ends of the main body is used as the current collecting foil, a current collecting member is connected to the tabs, and the electrode plate to which the current collecting member is connected is housed inside a battery case. The method involves forming a bypass slit in the main body before the tabs are provided, which is a slit that is continuous from a first end to a second end located away from the ends of the main body, with the intermediate portion between the first end and the second end bypassing the main body end, and providing a folded portion that is folded back toward the main body end in the area located between the first end and the second end that is cut from the main body by the bypass slits, thereby providing a tab that protrudes from the ends of the main body.

[0007] In the battery manufacturing method according to the above embodiment, a tab can be created by making the portion of the current collector foil that was located inside the outer edge of the main body protrude beyond the end of the main body. Therefore, the material of the current collector foil does not need to be as large as conventional materials in order to create the tab. Thus, the yield of the current collector foil is improved.

[0008] Another aspect of the disclosed technology is a battery having an electrode plate housed inside a battery case and a current collector connected to the current collector foil of the electrode plate inside the battery case, wherein the current collector foil has a main body and a tab that protrudes from the end of the main body and is connected to the current collector, and the main body has a bypass slit formed therein which is a slit that is continuous from a first end to a second end located away from the end of the main body, with the intermediate part between the first end and the second end bypassing away from the end of the main body, and the tab has a folded portion that is folded back toward the end of the main body in the area located between the first end and the second end which is cut from the main body by the bypass slit, so that the battery protrudes from the end of the main body.

[0009] Another aspect of the disclosed technology is an electrode plate that protrudes from the body end, wherein the current collector foil has a main body and a tab that protrudes from the end of the main body, the main body has a bypass slit which is a slit that is continuous from a first end to a second end located away from the end of the main body, and the intermediate portion between the first end and the second end bypasses away from the end of the main body, and the tab has a folded portion which is folded back toward the end of the main body in the area located between the first end and the second end that is cut from the main body by the bypass slit, and the tab is an electrode plate that protrudes from the end of the main body. [Effects of the Invention]

[0010] According to the disclosed technology, a method for manufacturing a battery, a battery, and an electrode plate are provided that improve the yield of current collector foil. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram of the battery according to the embodiment. [Figure 2] This is a perspective view of the electrode body of the battery according to the embodiment. [Figure 3] This figure shows the positive electrode plate according to the first embodiment. [Figure 4] This is a cross-sectional view of the current collector foil of the positive electrode plate according to the first embodiment, at the position of the positive electrode tab. [Figure 5] This figure shows the shape of the slit formed in the main body to provide the positive electrode tab according to the first embodiment. [Figure 6] This is a diagram showing a slit forming unit according to the first embodiment. [Figure 7] This figure illustrates the details of the first and second rollers of the slit forming unit according to the first embodiment. [Figure 8] This is a diagram showing the protruding unit according to the first embodiment. [Figure 9] This is a cross-sectional view of the first roller and the second roller in the axial direction of the ejection unit according to the first embodiment. [Figure 10] This is a diagram showing a folding portion forming unit according to the first embodiment. [Figure 11] It is a cross-sectional view of the folding part forming unit according to the first embodiment in a direction intersecting the axial direction of the inclined roller. [Figure 12] It is a diagram showing a positive electrode plate according to the second embodiment. [Figure 13] It is a cross-sectional view of the current collector foil of the positive electrode plate according to the second embodiment at the position of the positive electrode tab. [Figure 14] It is a diagram showing the shape of the slit formed in the main body part to provide the positive electrode tab according to the second embodiment. [Figure 15] It is a diagram showing a tab pulling-out unit according to the second embodiment. [Figure 16] It is a diagram showing a modified example of the shape of the slit according to the second embodiment. [Figure 17] It is a diagram showing a modified example in which a reinforcing member is provided in the main body end region of the current collector foil. [Figure 18] It is a diagram showing a modified example in which a folded reinforcing part is provided in the main body end region of the current collector foil. [Figure 19] It is a diagram showing a modified example of the bypass slit.

Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments embodying the disclosed technology will be described in detail with reference to the accompanying drawings.

[0013] [First Embodiment] FIG. 1 shows a battery 1 according to the first embodiment. The battery 1 is a lithium-ion secondary battery in this embodiment. The battery 1 houses an electrode body 20 inside a battery case 10. The electrode body 20 is formed by laminating a positive electrode plate 30 and a negative electrode plate 40. The positive electrode plate 30 is a positive electrode plate, and the negative electrode plate 40 is a negative electrode plate. A separator 50 is sandwiched between the positive electrode plate 30 and the negative electrode plate 40 in the electrode body 20.

[0014] The battery case 10 consists of a battery case body 11 and a lid 12. An opening is formed at the top of the battery case body 11 for housing the electrode body 20 inside the battery case body 11, and this opening is closed by the lid 12. An electrolyte 60 is also housed inside the battery case 10.

[0015] The battery 1 in this embodiment has a flat, rectangular shape overall. Positive terminals 5 and negative terminals 6 are provided near both ends in the longitudinal direction of the lid 12. A positive electrode current collector 3 is provided on the inside of the battery case 10 for the positive electrode terminal 5. The positive electrode current collector 3 connects the positive electrode terminal 5 to the positive electrode tab 120 of the positive electrode plate 30. The positive electrode current collector 3 is connected to the positive electrode tab 120 inside the battery case 10. A negative electrode current collector 4 is provided on the inside of the battery case 10 for the negative electrode terminal 6. The negative electrode current collector 4 connects the negative electrode terminal 6 to the negative electrode tab 220 of the negative electrode plate 40. The negative electrode current collector 4 is connected to the negative electrode tab 220 inside the battery case 10. The connection between the positive electrode current collector 3 and the positive electrode tab 120, and the connection between the negative electrode current collector 4 and the negative electrode tab 220 can be made, for example, by welding. The battery 1 can then be charged or discharged via the positive terminal 5 and the negative terminal 6.

[0016] Figure 2 shows a perspective view of the electrode body 20. The electrode body 20 is a flattened shape formed by winding together a sheet-like positive electrode plate 30, a negative electrode plate 40, and a separator 50. The electrode body 20 has a laminated portion 21. The laminated portion 21 is the part in which the positive electrode plate 30 and the negative electrode plate 40 are laminated with the separator 50 sandwiched between them. The positive electrode tab 120 and the negative electrode tab 220 are provided so as to protrude from the upper surface 22 of the laminated portion 21.

[0017] Figure 3 shows the positive electrode plate 30. Figure 3 shows the positive electrode plate 30 in its state before winding to form the electrode body 20. The positive electrode plate 30 has a current collector foil 100 and an active material layer 31 formed on its surface. For example, aluminum foil can be used for the current collector foil 100 of the positive electrode plate 30. The current collector foil 100 has a main body portion 110 and a positive electrode tab 120.

[0018] The main body portion 110 is a strip-shaped part with its longitudinal direction in the left-right direction in Figure 3. The positive electrode tab 120 is the portion that protrudes from the main body end portion 111, which is the upper end of the main body portion 110 in Figure 3. The main body end portion 111 is the portion that constitutes the upper surface 22 of the laminated portion 21 in the electrode body 20. A through hole 112 is formed at the location of the positive electrode tab 120 in the longitudinal direction of the main body portion 110. In this embodiment, the positive electrode tab 120 is essentially provided by folding back the portion that was located at the location of the through hole 112 in the current collector foil 100 toward the main body end portion 111. This point will be explained later. Furthermore, in this embodiment in which the electrode body 20 is of the wound type, multiple positive electrode tabs 120 are provided in the longitudinal direction of the main body portion 110.

[0019] The active material layer 31 is formed on the front and back surfaces of the main body portion 110 of the current collector foil 100. The active material layer 31 is not formed on the positive electrode tab 120. Therefore, the current collector foil 100 is exposed at the location of the positive electrode tab 120. The active material layer 31 is a layer containing at least active material. The active material is a material that contributes to charging and discharging, and in lithium-ion secondary batteries, it intercalates and releases lithium ions. In addition to the active material, the active material layer 31 appropriately contains materials such as binders and conductive materials. The binder is a material that binds the materials constituting the active material layer 31 to the surface of the current collector foil 100. The conductive material is a material that can increase the conductivity within the active material layer 31.

[0020] Furthermore, the negative electrode plate 40 can also adopt the same shape as the positive electrode plate 30 shown in Figure 3, except for differences in the number and type of materials used. The electrode body 20 shown in Figure 2 can be manufactured by stacking the positive electrode plate 30, the negative electrode plate 40, and the separator 50 to form a flattened wound body. In this process, multiple positive electrode tabs 120 and multiple negative electrode tabs 220 are made to protrude from the upper surface 22 of the laminated portion 21. In addition, multiple positive electrode tabs 120 and multiple negative electrode tabs 220 are stacked on top of each other. This results in the electrode body 20 with the shape shown in Figure 2.

[0021] Figure 4 is a cross-sectional view of the current collector foil 100 at the location of the positive electrode tab 120. As shown in Figure 4, the current collector foil 100 has a folded portion 130 at the location of the positive electrode tab 120. The folded portion 130 is formed by folding back the portion that was located inside the outer shape of the through hole 112 toward the main body end 111. Therefore, at the base of the folded portion 130, there is a bent portion 135 which is a fold that is bent toward the main body 110 and connects to the main body 110. The positive electrode tab 120 is provided on the tip side of the folded portion 130, as the tip side of the folded portion 130 protrudes above the main body end 111.

[0022] Figure 5 shows the current collector foil 100 before the folded portion 130 is formed and the positive electrode tab 120 is provided. As shown in Figure 5, a bypass slit X is formed in the main body portion 110 at the location that will become the positive electrode tab 120. The bypass slit X is a continuous slit from the first end P1 to the second end P2. Both the first end P1 and the second end P2 are located away from the main body end 111. Figure 5 shows the main body end region 113, which is the area of ​​the main body portion 110 on the side of the main body end 111. In this embodiment, the main body end region 113 is the area on the side of the main body end 111 that is closer to the main body end 111 than the first end P1 and the second end P2.

[0023] Furthermore, the bypass slit X has an intermediate section XA. The intermediate section XA is shaped to bypass away from the main body end 111. In this embodiment, the bypass slit X is almost entirely an intermediate section XA that bypasses away from the main body end 111, except for the first end P1 and the second end P2. In this embodiment, the bypass slit X is composed of three linear first bypass slits X1, second bypass slit X2, and third bypass slit X3. The first bypass slit X1 is a slit that extends from the first end P1 in a direction away from the main body end 111. The second bypass slit X2 is a slit that extends from the second end P2 in a direction away from the main body end 111. The third bypass slit X3 is a slit that extends from the end of the first bypass slit X1 opposite to the first end P1 to the end of the second bypass slit X2 opposite to the second end P2.

[0024] The area enclosed by the intermediate portion XA of the bypass slit X is the planned folding portion 130A, which will become the folding portion 130. The planned folding portion 130A is folded back toward the main body end portion 111, overlapping with the main body end region 113. This forms the folding portion 130. Furthermore, the portion of the planned folding portion 130A furthest from the main body end portion 111 is the planned positive electrode tab portion 120A, which will become the positive electrode tab 120.

[0025] Thus, in this embodiment, a positive electrode tab 120 is provided by creating a folded portion 130 that is folded back toward the main body end 111 side in the area from the first end P1 to the second end P2, which is cut off from the main body portion 110 by the bypass slit X. Therefore, as a material for the current collector foil 100, there is no need for waste material that is cut off and discarded in the area outside the main body end 111. Thus, the positive electrode plate 30 has a good yield for the current collector foil 100. The same applies to the negative electrode plate 40. The same also applies to the battery 1 using these positive electrode plates 30 and negative electrode plates 40.

[0026] Next, the manufacturing method of the battery 1 will be described. First, an example of the procedure for providing a positive electrode tab 120 to the current collector foil 100 used for the positive electrode plate 30 of the battery 1 will be described in detail. The current collector foil 100 can be prepared by providing a positive electrode tab 120 to a long strip of aluminum foil.

[0027] The positive electrode tab 120 of the current collector foil 100 can be provided by performing the following steps on a strip of aluminum foil in this order: "slit formation," "protrusion of the planned folding portion," and "formation of the folding portion." Each step can be performed on the aluminum foil being transported while the strip of aluminum foil is being transported in its longitudinal direction.

[0028] Figure 6 shows a slit forming unit 300 that performs "slit formation". The slit forming unit 300 has a first roller 310 and a second roller 320 that are positioned opposite each other. Between the first roller 310 and the second roller 320, an aluminum foil 100A, which will become the current collector foil 100, is conveyed in the direction of arrow D. Both the first roller 310 and the second roller 320 are positioned so that their axial directions are perpendicular to the conveying direction D. The aluminum foil 100A is the current collector foil 100 before the positive electrode tab 120 is attached. The aluminum foil 100A is also the main body portion 110 of the current collector foil 100 before the positive electrode tab 120 is attached.

[0029] The first roller 310 is provided with a first blade 311. The second roller 320 is provided with a second blade 321. Figure 7 is a magnified view of the first blade 311 and the second blade 321, separated vertically. As shown in Figure 7, the first blade 311 is provided protruding toward the second roller 320. The second blade 321 is a portion of the second roller 320 that is recessed from the outer surface that contacts the aluminum foil 100A. The first blade 311 is shaped to enter the inside of the second blade 321 when it rotates to the opposite position of the second roller 320. Both the first blade 311 and the second blade 321 are shaped to correspond to the bypass slit X.

[0030] The first roller 310 and the second roller 320 each rotate such that the direction of movement of their outer surfaces facing the aluminum foil 100A is the same as the direction of movement of the conveyed aluminum foil 100A. As a result, the slit forming unit 300 can pass the aluminum foil 100A to the opposing positions of the first roller 310 and the second roller 320, while the first blade 311 and the second blade 321 form bypass slits X at a predetermined pitch.

[0031] Furthermore, if the pitch of the bypass slits X, which are provided in multiple locations along the longitudinal direction of the current collector foil 100, is not at a constant interval, the bypass slits X can be formed in an arrangement corresponding to the pitch of the bypass slits X. In other words, in this embodiment, multiple positive electrode tabs 120 provided along the longitudinal direction of the current collector foil 100 are laminated by winding. For this reason, the pitch of the positive electrode tabs 120 is narrower in the portion of the current collector foil 100 located on the inside of the winding. This is because the pitch of the positive electrode tabs 120 has different lengths in the inner portion of the current collector foil 100 and the outer portion of the current collector foil 100, depending on the difference in circumference. Therefore, for example, the first blade 311 and the second blade 321 can be provided, respectively, in the circumferential direction of the first roller 310 and the second roller 320, at intervals corresponding to the pitch of the positive electrode tabs 120, which have a length that changes according to the length of the circumference inside and outside the winding.

[0032] Figure 8 shows an ejection unit 400 that performs "extrusion of the portion to be folded back". The ejection unit 400 has a first roller 410 and a second roller 420 that are positioned opposite each other. Aluminum foil 100A is transported between the first roller 410 and the second roller 420 in the direction of transport direction D. Both the first roller 410 and the second roller 420 are positioned so that their axial directions are perpendicular to the transport direction D.

[0033] The first roller 410 is provided with a protruding portion 411. The second roller 420 is provided with a recess 421. Figure 9 is a cross-sectional view of the first roller 410 and the second roller 420 in the axial direction. As shown in Figure 9, the protruding portion 411 is provided projecting toward the second roller 420. The protruding portion 411 is a projection with a shape corresponding to the shape of the planned folding portion 130A, and is provided on the first roller 410 in an arrangement corresponding to the conveyed planned folding portion 130A. The recess 421 is a portion of the second roller 420 that is recessed from the outer circumferential surface that contacts the aluminum foil 100A. The recess 421 is provided continuously in the circumferential direction of the second roller 420. Note that the recess 421 may be provided only in the location corresponding to the planned folding portion 130A.

[0034] When the protruding portion 411 rotates to a position facing the second roller 420, it enters the recess 421. As a result, the protruding portion 411 extends the portion 130A intended to be folded back, formed by the bypass slit X, toward the second roller 420. This causes the protruding portion 411 to fold the portion 130A intended to be folded back toward the second roller 420.

[0035] The first roller 410 and the second roller 420 each rotate so that the direction of movement of their outer surfaces facing the aluminum foil 100A is the same as the direction of movement of the conveyed aluminum foil 100A. As a result, the ejection unit 400 can push out the folded portion 130A, which is formed at a predetermined pitch, while passing the aluminum foil 100A to the opposing positions of the first roller 410 and the second roller 420. This causes the folded portion 130A to be folded relative to the main body 110.

[0036] Furthermore, if the pitch of the multiple bypass slits X provided along the longitudinal direction of the current collector foil 100 is not at a constant interval, it is sufficient if the protrusion by the protruding portion 411 can be performed in an arrangement corresponding to the pitch of the bypass slits X. That is, for example, in this embodiment, the protruding portion 411 can be provided in the circumferential direction of the first roller 410 at intervals corresponding to the pitch of the positive electrode tab 120.

[0037] Figure 10 shows a folding portion forming unit 500 that performs "formation of a folded portion". The folding portion forming unit 500 has a pressing portion 510 and an inclined roller 520. Aluminum foil 100A is conveyed between the pressing portion 510 and the inclined roller 520 in the direction of the conveying direction D. The inclined roller 520 is provided with its axial direction aligned with the conveying direction D. The inclined roller 520 is positioned on the surface of the aluminum foil 100A on the side from which the portion to be folded 130A protrudes. The pressing portion 510 is positioned on the surface of the aluminum foil 100A on the side opposite to the inclined roller 520.

[0038] The pressing portion 510 is provided along the surface of the aluminum foil 100A being conveyed. This prevents the aluminum foil 100A from deviating from the conveying path toward the pressing portion 510. The inclined roller 520 is a roller having an inclined outer surface, which is an inclined outer surface 521. The inclined outer surface 521 is inclined in a direction that moves closer to the aluminum foil 100A as it moves downstream in the conveying direction D.

[0039] Figure 11 is a cross-sectional view of the inclined roller 520 in a direction intersecting the axial direction. Figure 11 shows cross-sections at the downstream position in the conveying direction D, in the order of (a), (b), and (c). As shown in Figure 11, the inclined roller 520 rotates in a direction that folds back the portion 130A intended to be folded, which is in contact with the inclined outer surface 521, toward the main body end 111. As a result, the inclined outer surface 521 of the inclined roller 520 folds back the portion 130A intended to be folded, which is being conveyed and has come into contact with it, toward the main body end 111. This allows the folding portion forming unit 500 to fold back the portion 130A intended to be folded, forming the folding portion 130, while passing the aluminum foil 100A between the pressing portion 510 and the inclined roller 520. Furthermore, by providing the folding portion 130, the positive electrode tab 120 can be provided.

[0040] As described above, by conveying the aluminum foil 100A and performing "slit formation," "protrusion of the planned folding portion," and "formation of the folding portion" in this order, the folding portion 130 and the positive electrode tab 120 can be provided. The current collector foil 100 can be manufactured by cutting the aluminum foil 100A, which has the folding portion 130 provided, to a predetermined length in its longitudinal direction.

[0041] The positive electrode plate 30 can be manufactured by forming an active material layer 31 on both sides of the processed current collector foil 100, as described above. The active material layer 31 may be formed on the aluminum foil 100A beforehand. In this case, the active material layer 31 should be formed in the area excluding the area that will become the positive electrode tab 120. The negative electrode plate 40 can be manufactured by the same process as the positive electrode plate 30. The manufactured positive electrode plate 30 and negative electrode plate 40 can be rolled together with the separator 50 to form a flat-shaped wound body to manufacture the electrode body 20. Furthermore, the positive electrode tab 120 and negative electrode tab 220 of the electrode body 20 are connected to the positive electrode current collector 3 and negative electrode current collector 4 provided on the lid 12, respectively, and the electrode body 20 is housed inside the battery case body 11 to manufacture the battery 1.

[0042] [Second Embodiment] In the second embodiment, a method for providing a positive electrode tab by forming a slit that is different overall from that of the above embodiment will be described. In this embodiment, in addition to the bypass slit, the current collector foil is further slit to provide multiple folded portions. This provides multiple folded portions for one tab. The tab is then provided by sliding the portion between the multiple folded portions outward from the end of the main body of the current collector foil. In the second embodiment, the configuration that is not specifically described can be the same as in the above embodiment.

[0043] Figure 12 shows the positive electrode plate 30 according to this embodiment. The positive electrode plate 30 shown in Figure 12 is in the state before winding to form the electrode body 20. The positive electrode plate 30 in this embodiment also has a current collector foil 100 and an active material layer 31 formed on its surface. The positive electrode tab 120 in this embodiment also protrudes from the main body end 111 of the main body portion 110. In addition, in the positive electrode plate 30 in this embodiment, a through hole 114 is formed at the location of the positive electrode tab 120 in the longitudinal direction of the main body portion 110. In short, the positive electrode tab 120 in this embodiment is provided by folding back a part of the portion of the current collector foil 100 that was located at the location of the through hole 114 toward the main body end 111, while sliding the remaining portion outward from the main body end 111.

[0044] In this embodiment, the positive electrode plate 30 has two folded portions 140 for each positive electrode tab 120. Specifically, the folded portions 140 consist of a first folded portion 141 and a second folded portion 142. The first folded portion 141 and the second folded portion 142 are located at positions separated from each other in the longitudinal direction of the main body portion 110. The positive electrode tab 120 is located between the first folded portion 141 and the second folded portion 142.

[0045] Figure 13 is a cross-sectional view of the current collector foil 100 at the position of the positive electrode tab 120. In this embodiment, the folded portion 140 is also formed by folding back the portion that was inside the through hole 114 toward the main body end 111. Therefore, at the base of the folded portion 140, there is a bent portion 145 which connects to the main body 110 and is bent relative to the main body 110. In this embodiment, on the opposite side of the bent portion 145 of the folded portion 140, there is a bent portion 146 which connects to the positive electrode tab 120 and is a fold that is bent relative to the folded portion 140. As shown in Figures 12 and 13, the positive electrode tab 120 is provided by having the portion between the first folded portion 141 and the second folded portion 142 protrude above the main body end 111.

[0046] Figure 14 shows the current collector foil 100 before the folded portion 140 is formed and the positive electrode tab 120 is provided. As shown in Figure 14, in this embodiment as well, a bypass slit X is formed at the location of the positive electrode tab 120 in the main body portion 110. Furthermore, in this embodiment, in addition to the bypass slit X, a pair of main body end slits Y are formed. That is, the pair of main body end slits Y are provided within the range between the first end P1 and the second end P2 of the bypass slit X in the longitudinal direction of the main body portion 110.

[0047] The main body end slit Y is composed of a first main body end slit Y1 located on the first end P1 side and a second main body end slit Y2 located on the second end P2 side. The main body end slit Y extends from the main body end 111 towards the area enclosed by the intermediate portion XA of the bypass slit X. The main body end slit Y on the main body end 111 side reaches the main body end 111. On the other hand, the main body end slit Y on the opposite side from the main body end 111 side does not reach the bypass slit X. In other words, the main body end slit Y and the bypass slit X in the main body portion 110 are not separated but connected.

[0048] Furthermore, the area extending away from the main body end 111 between the first main body end slit Y1 and the first bypass slit X1 of the bypass slit X is the first planned folding portion 141A, which will become the first folded portion 141. Also, the area extending away from the main body end 111 between the second main body end slit Y2 and the second bypass slit X2 of the bypass slit X is the second planned folding portion 142A, which will become the second folded portion 142. In addition, the portion between the first planned folding portion 141A and the second planned folding portion 142A, and between the first main body end slit Y1 and the second main body end slit Y2, is the planned positive electrode tab portion 120A, which will become the positive electrode tab 120. Both the first planned folding portion 141A and the second planned folding portion 142A are folded back toward the main body end 111, overlapping with the main body end region 113. This forms the first folded portion 141 and the second folded portion 142.

[0049] Thus, in this embodiment as well, the bypass slit X provides a first folded portion 141 and a second folded portion 142 that are folded back toward the main body end 111 side in the area from the first end P1 to the second end P2 cut from the main body portion 110. This provides the positive electrode tab 120. Therefore, in this embodiment as well, there is no need for any waste material to be cut off and discarded in the area outside the main body end 111 of the current collector foil 100. Thus, in this embodiment as well, the positive electrode plate 30 has a good yield of current collector foil 100. In this embodiment as well, the negative electrode plate 40 can adopt the same shape as the positive electrode plate 30, except that the materials are different.

[0050] Next, an example of the procedure for providing a positive electrode tab 120 to the current collector foil 100 will be described. In this embodiment as well, the current collector foil 100 can be prepared by providing a positive electrode tab 120 to a long strip of aluminum foil. In this embodiment, the positive electrode tab 120 of the current collector foil 100 can be provided to the strip of aluminum foil by performing "slit formation" and "tab pulling" in that order. In this embodiment as well, each procedure can be performed on the aluminum foil being transported while the strip of aluminum foil is being transported in its longitudinal direction.

[0051] "Slit formation" can be performed using a slit forming unit similar to that of the above embodiment. However, unlike the slit forming unit 300 described in the above embodiment, the first and second blades used in this embodiment have shapes corresponding to the combined shape of the bypass slit X and the pair of main body end slits Y. This makes it possible to form the bypass slit X and the pair of main body end slits Y.

[0052] Figure 15 shows a tab dispensing unit 600 that performs "tab dispensing". The tab dispensing unit 600 has a first cam 610 and a second cam 620. Aluminum foil 100A is transported between the first cam 610 and the second cam 620. In Figure 15, the transport direction of the aluminum foil 100A is the depth direction with respect to the paper surface.

[0053] As shown in Figure 15, the first cam 610 and the second cam 620, as the positive electrode tab portion 120A passes between their opposing positions, clamp the positive electrode tab portion 120A in the thickness direction and slide it to the outside of the main body end 111. This provides the positive electrode tab 120. Also, as the positive electrode tab portion 120A slides outward from the main body end 111, both the first folded portion 141A and the second folded portion 142A are folded back toward the main body end 111. This allows the first folded portion 141A and the second folded portion 142A to be folded back toward the main body end 111, becoming the first folded portion 141 and the second folded portion 142, respectively.

[0054] As described above, by conveying the aluminum foil 100A and performing "slit formation" and "tab pulling" in this order, the positive electrode plate 30 can be manufactured with the folded portion 140 and the positive electrode tab 120. The negative electrode plate 40 can also be manufactured using the same process as the positive electrode plate 30. In this embodiment as well, the manufactured positive electrode plate 30 and negative electrode plate 40 can be used to manufacture the battery 1 in the same manner as in the embodiment described above.

[0055] As described in detail above, in the manufacturing method of the battery 1 according to the above embodiment, a bypass slit X is formed in the main body portion 110 of the positive electrode plate 30 before the positive electrode tab 120 is provided on the current collector foil 100. The bypass slit X is continuous from the first end P1 to the second end P2, and the intermediate portion XA between the first end P1 and the second end P2 is a slit that bypasses away from the main body end 111 of the main body portion 110. The first end P1 and the second end P2 are both located away from the main body end 111 of the main body portion 110. Then, folded portions 130 and 140 are provided in the area located between the first end P1 and the second end P2, which are cut off from the main body portion 110 by the bypass slit X, and which are folded back toward the main body end 111 side. As a result, the current collector foil 100 is provided with a positive electrode tab 120 that protrudes beyond the main body end 111. In other words, the positive electrode tab 120 can be provided by making the portion of the current collector foil 100 that was located inside the outer edge of the main body portion 110 protrude beyond the main body end portion 111 of the main body portion 110. Therefore, in order to provide the positive electrode tab 120, the material of the current collector foil 100 does not need to be as large as conventional materials. Thus, the yield of the current collector foil 100 is improved. Similarly, the yield of the current collector foil 100 is also improved in the battery 1 manufactured in this way. The same applies to the positive electrode plate 30.

[0056] The embodiments described above are merely illustrative and do not limit the disclosed technology in any way. Therefore, the disclosed technology can naturally be improved and modified in various ways without departing from its essence.

[0057] For example, the procedures and apparatus for realizing a method of providing a positive electrode tab 120 while providing folded portions 130 and 140 on the current collector foil 100 may differ from the above embodiment as appropriate. Specifically, for example, slits such as bypass slits X may be formed in stages using multiple slit forming units. Also, for example, in the second embodiment, a robot may be used to grip the planned positive electrode tab portion 120A and slide it outward from the main body end portion 111. Also, for example, in the second embodiment, after providing the positive electrode tab 120 with the tab pulling unit 600, a compression process may be performed to compress the area around the folded portion 140 in the thickness direction of the current collector foil 100 in order to form the bent portion 145 and the bent portion 146.

[0058] Furthermore, for example, the method of providing tabs on the current collector foil as described in the above embodiment may be applied to at least one of the positive electrode plate 30 and the negative electrode plate 40. That is, for example, the tab according to the first embodiment may be applied to one of the positive and negative electrode plates, and the tab on the other may be provided in a different manner than in the above embodiment. Alternatively, for example, the tab according to the first embodiment may be applied to one of the positive and negative electrode plates, and the tab according to the second embodiment may be applied to the other.

[0059] Furthermore, in the second embodiment described above, in addition to the bypass slit X and the pair of main body end slits Y, an inner slit group Z may be provided, as shown in Figure 16. The inner slit group Z consists of a first inner slit Z11, a second inner slit Z12, a third inner slit Z21, and a fourth inner slit Z22. All of the inner slit group Z is provided in a range located between one of the pair of main body end slits Y and the other. The first inner slit Z11 and the third inner slit Z21 both reach the bypass slit X but do not reach the main body end 111. On the other hand, the second inner slit Z12 and the fourth inner slit Z22 both reach the main body end 111 but do not reach the bypass slit X. Furthermore, the first inner slit Z11 is provided between the first main body end slit Y1 and the second inner slit Z12. The third inner slit Z21 is provided between the second main body end slit Y2 and the fourth inner slit Z22. By forming such an inner slit group Z and sliding the planned positive electrode tab portion 120A outward from the main body end portion 111, the positive electrode tab 120 can be slid further outward compared to the slit configuration described in the second embodiment. Therefore, the amount of protrusion of the positive electrode tab 120 from the main body end portion 111 can be increased. Furthermore, by providing an additional inner slit group Z between the second inner slit Z12 and the fourth inner slit Z22 of the inner slit group Z, the positive electrode tab 120 can be slid even further outward. In other words, the more inner slit groups Z are added, the greater the amount of protrusion of the positive electrode tab 120 from the main body end portion 111 can be.

[0060] For example, as shown in Figures 17 and 18, the reinforcing portion is provided in the body end region 113 of the main body portion 110 of the current collector foil 100, and the folding portion 130 and 140 is provided in this state. Figure 17 shows an example in which a reinforcing member 190, separate from the current collector foil 100, is provided as a reinforcing portion in the body end region 113. The reinforcing member 190 can be made of the same material as the current collector foil 100. It is preferable to fix the reinforcing member 190 to the body end region 113 of the current collector foil 100 in advance by welding or the like. Specific examples of the reinforcing member 190 include a sheet made of the same material as the current collector foil 100, or a wire made of the same material as the current collector foil 100.

[0061] Figure 18 shows a folded reinforcement portion 191, which is provided by folding the end of the current collector foil 100 inward to reinforce the main body end region 113. Specifically, the folded reinforcement portion 191 is provided by folding the outer part 192 of the main body end, which is located outside the main body end region 113, inward and overlapping it with the main body end region 113.

[0062] The current collector foil 100 can be fitted with the reinforcing portion shown in Figure 17 or Figure 18 before the folding process that creates the folded portions 130 and 140, and the folding process that creates the folded portions 130 and 140 can be performed with the reinforcing portion fitted. Specifically, in the first embodiment, the reinforcing member 190 is fitted at the latest before the "formation of the folded portion" is performed. In the second embodiment, the folding reinforcing portion 191 is fitted at the latest before the "extension of the tab" is performed. This prevents the current collector foil 100 from tearing when the folded portions 130 and 140 are fitted, and prevents the bypass slit X from reaching the main body end 111. In the above embodiments, the main body end region 113 was described as the region on the main body end 111 side of the first end P1 and second end P2. However, the main body end region 113 where the reinforcing portion is provided only needs to be on the main body end 111 side of the base of the folded portions 130 and 140, and may, for example, overlap with the first end P1 and the second end P2. Figures 17 and 18 show modified examples of the current collector foil 100 according to the first embodiment, but they can be similarly applied to the second embodiment.

[0063] Furthermore, the bypass slit only needs to have an intermediate section between its first and second ends that detours away from the main body end of the current collector foil. For example, the intermediate section may be semicircular in shape. Alternatively, the bypass slit may have portions on both ends of the bypass slit rather than the intermediate section. Specifically, for example, it may have a shape like that shown in Figure 19. The bypass slit X shown in Figure 19 has a first end section XB1 which is the portion on the first end P1 side of the intermediate section XA, and a second end section XB2 which is the portion on the second end P2 side of the intermediate section XA. Even with a bypass slit X of the shape shown in Figure 19, a folded-back portion 130 can be provided in the area enclosed by the intermediate section XA.

[0064] Furthermore, both the first end section XB1 and the second end section XB2 of the bypass slit X shown in Figure 19 have a curved shape that protrudes toward the main body end 111. This shape of the first end section XB1 and the second end section XB2 can suppress stress concentration when folding to create the folded portion 130. Therefore, it is possible to suppress the current collector foil 100 from tearing and the bypass slit X from reaching the main body end 111. Although Figure 19 is a modified example of the current collector foil 100 according to the first embodiment, it can be similarly applied to the second embodiment.

[0065] Furthermore, the configuration of battery 1 shown in the above embodiment is merely one example. That is, the electrode body is not limited to a flat, wound type, but may also be, for example, an electrode plate wound into a cylindrical shape, or an electrode plate stacked flat. Also, for example, there are no particular limitations on the type of battery (types such as nickel-metal hydride batteries and lithium-ion batteries) to which the above embodiment can be applied. Also, for example, the materials etc. shown in the description of the above embodiment are merely examples depending on the type of battery, and can be selected as appropriate.

[0066] Furthermore, the disclosed technology described above includes the following means 1 to means 13. [Means 1] As the current-collecting foil of the electrode plate, a main body portion and a tab protruding from the end of the main body portion are used. A method for manufacturing a battery, comprising connecting a current collector to the tab and housing the electrode plate to which the current collector is connected inside a battery case, The current collector foil includes, Before the tab is provided, a bypass slit is formed in the main body portion, which is a slit that extends continuously from a first end to a second end, both located away from the end of the main body, and whose intermediate portion between the first end and the second end bypasses away from the end of the main body. A method for manufacturing a battery, which provides a tab that protrudes beyond the main body end by providing a folded portion that is folded back toward the main body end side in the range located between the first end and the second end that is cut from the main body by the bypass slit.

[0067] [Means 2] A method for manufacturing a battery as described in means 1, The current collector foil includes, A method for manufacturing a battery in which the tip of the folded portion is provided to protrude beyond the end of the main body, thereby making the tip of the folded portion the tab.

[0068] [Means 3] A method for manufacturing a battery as described in means 1, The current collector foil includes, In addition to the aforementioned bypass slits, a pair of body end slits are further formed within the range between the first end and the second end, which reach the body end but do not reach the bypass slits. A method for manufacturing a battery, wherein the folded portion consists of a first folded portion on the first end and a second folded portion on the second end, which are positioned apart from each other, and the portion between the first folded portion and the second folded portion is slid outward from the end of the main body, thereby forming the sliding portion into the tab.

[0069] [Means 4] A method for manufacturing a battery according to any one of means 1 to means 3, The current collector foil includes, A method for manufacturing a battery, wherein, before the folding that provides the folded portion, a reinforcing portion is provided on the end region of the main body on the end side of the main body portion, and the folding that provides the folded portion is performed with the reinforcing portion provided.

[0070] [Means 5] A method for manufacturing a battery as described in means 4, A method for manufacturing a battery, wherein the reinforcing part is made of the same material as the current collector foil, but is a different component from the current collector foil.

[0071] [Means 6] A method for manufacturing a battery as described in means 4, A method for manufacturing a battery, wherein the portion of the current collector foil located outside the main body end region is folded inward and overlapped with the main body end region to provide the reinforcing portion.

[0072] [Means 7] The electrode plates housed inside the battery case, The battery case has a current collector connected to the current collector foil of the electrode plate inside the battery case, The current collector foil has a main body and a tab that protrudes from the end of the main body and is connected to the current collector member. A bypass slit is formed in the main body portion, which is a slit that extends continuously from a first end to a second end, both located away from the end of the main body, and whose intermediate portion between the first end and the second end bypasses away from the end of the main body. The tab has a folded portion that is folded back toward the end of the main body in the range between the first end and the second end, which is cut from the main body by the bypass slit, so that it protrudes from the end of the main body.

[0073] [Means 8] The battery described in means 7, The aforementioned tab is a battery provided on the tip side of the folded portion, such that the tip side of the folded portion protrudes more than the end of the main body.

[0074] [Means 9] The battery described in means 7, Within the range located between the first end and the second end, a pair of body end slits are formed, which reach the body end but do not reach the bypass slit. The aforementioned folded portion includes a first folded portion at the first end and a second folded portion at the second end, which are provided apart from each other. The tab has a portion that was located between the first folded portion and the second folded portion, which slides outward from the end of the main body, and the battery is provided in that sliding portion.

[0075] [Means 10] A battery according to any of means 7 to means 9, A battery having a reinforcing portion superimposed on the end portion region of the main body on the end portion side of the main body.

[0076] [Means 11] The battery described in means 10, The reinforcing portion is a battery made of the same material as the current collector foil, but a separate component from the current collector foil.

[0077] [Means 12] The battery described in means 10, The reinforcing portion is provided by folding inward the portion of the current collector foil that was located outside the main body end region and overlapping it with the main body end region.

[0078] [Means 13] The current collector foil has a main body and tabs that protrude from the end of the main body. A bypass slit is formed in the main body portion, which is a slit that extends continuously from a first end to a second end, both located away from the end of the main body, and whose intermediate portion between the first end and the second end bypasses away from the end of the main body. The tab has a folded portion that is folded back toward the end of the main body in the area between the first end and the second end, which is cut from the main body by the bypass slit, so that it protrudes from the end of the main body. [Explanation of Symbols]

[0079] 1:Battery 3: Positive electrode current collector 4: Negative electrode current collector 10: Battery case 30: Positive plate 40: Negative electrode plate 100: Current collector foil 110: Main body 111: Main body end 113: Body end area 120: Positive Tab 130: Folded section 140: Folded section 190: Reinforcement member 191: Reinforced section 220: Negative electrode tab P1: 1st end P2: 2nd end X: Bypass slit XA: Middle part Y: Slit at the end of the main body

Claims

1. As the current-collecting foil of the electrode plate, a main body portion and a tab protruding from the end of the main body portion are used. A method for manufacturing a battery, comprising connecting a current collector to the tab and housing the electrode plate to which the current collector is connected inside a battery case, The aforementioned current collector foil includes: Before the tab is provided, a bypass slit is formed in the main body portion, which is a slit that extends continuously from a first end to a second end, both located away from the end of the main body, and whose intermediate portion between the first end and the second end bypasses away from the end of the main body. A method for manufacturing a battery, which provides a tab that protrudes beyond the main body end by providing a folded portion that is folded back toward the main body end side in the range located between the first end and the second end that is cut from the main body by the bypass slit.

2. A method for manufacturing a battery according to claim 1, The aforementioned current collector foil includes: A method for manufacturing a battery in which the tip of the folded portion is provided to protrude beyond the end of the main body, thereby making the tip of the folded portion the tab.

3. A method for manufacturing a battery according to claim 1, The aforementioned current collector foil includes: In addition to the aforementioned bypass slits, a pair of body end slits are further formed within the range between the first end and the second end, which reach the body end but do not reach the bypass slits. A method for manufacturing a battery in which a first folded portion on the first end and a second folded portion on the second end are provided at positions separated from each other, and the portion between the first folded portion and the second folded portion is slid outward from the end of the main body, thereby forming the sliding portion into the tab.

4. A method for manufacturing a battery according to any one of claims 1 to 3, The aforementioned current collector foil includes: A method for manufacturing a battery, wherein, before the folding that provides the folded portion, a reinforcing portion is provided on the end region of the main body on the end side of the main body portion, and the folding that provides the folded portion is performed with the reinforcing portion provided.

5. A method for manufacturing a battery according to claim 4, A method for manufacturing a battery, wherein the reinforcing part is made of the same material as the current collector foil, but is a different component from the current collector foil.

6. A method for manufacturing a battery according to claim 4, A method for manufacturing a battery, wherein the portion of the current collector foil located outside the main body end region is folded inward and overlapped with the main body end region to provide the reinforcing portion.

7. The electrode plates housed inside the battery case, The battery case has a current collector connected to the current collector foil of the electrode plate inside the battery case, The current collector foil has a main body and a tab that protrudes from the end of the main body and is connected to the current collector member. A bypass slit is formed in the main body portion, which is a slit that extends continuously from a first end to a second end, both located away from the end of the main body, and whose intermediate portion between the first end and the second end bypasses away from the end of the main body. The tab has a folded portion that is folded back toward the end of the main body in the range between the first end and the second end, which is cut from the main body by the bypass slit, so that it protrudes from the end of the main body.

8. The battery according to claim 7, The aforementioned tab is a battery provided on the tip side of the folded portion, such that the tip side of the folded portion protrudes more than the end of the main body.

9. The battery according to claim 7, Within the range located between the first end and the second end, a pair of body end slits are formed, which reach the body end but do not reach the bypass slit. The aforementioned folded portion includes a first folded portion at the first end and a second folded portion at the second end, which are provided apart from each other. The tab has a portion that was located between the first folded portion and the second folded portion, which slides outward from the end of the main body, and the battery is provided in that sliding portion.

10. A battery according to any one of claims 7 to 9, A battery having a reinforcing portion superimposed on the end portion region of the main body on the end portion side of the main body.

11. The battery according to claim 10, The reinforcing portion is a battery made of the same material as the current collector foil, but a separate component from the current collector foil.

12. The battery according to claim 10, The reinforcing portion is provided by folding inward the portion of the current collector foil that was located outside the main body end region and overlapping it with the main body end region.

13. The current collector foil has a main body and tabs that protrude from the end of the main body. A bypass slit is formed in the main body portion, which is a slit that extends continuously from a first end to a second end, both located away from the end of the main body, and whose intermediate portion between the first end and the second end bypasses away from the end of the main body. The tab is an electrode plate that protrudes from the end of the main body, with a folded portion provided in the range between the first end and the second end, which are cut from the main body by the bypass slit, and which is folded back toward the end of the main body.

Images