Battery and battery manufacturing method

Abstract

A battery with a simple structure and increased energy density and a method for manufacturing the battery are provided. [Solution] The battery 20 has an electrode body constructed by laminating a positive electrode current collector, a negative electrode current collector, a positive electrode foil extending from the positive electrode current collector, and a negative electrode foil extending from the negative electrode current collector, a first foil collecting section in which one of the positive electrode foil and the negative electrode foil is collected into one foil, a second foil collecting section in which the other of the positive electrode foil and the negative electrode foil is divided into multiple foils and collected, a first terminal to which the first foil collecting section is joined, and a second terminal to which the second foil collecting section is joined.

Description

[Technical Field]

[0001] The present invention relates to a battery. [Background technology]

[0002] Patent Document 1 discloses a battery in which an electrode group (electrode body) is housed in a battery can (exterior can). In the battery disclosed in Patent Document 1, the exposed metal foil portion of one of the positive and negative electrodes has multiple current collecting leads, and the exposed metal foil portion of the other has a structure that is continuous over a predetermined width. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-060823 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the battery disclosed in Patent Document 1 has a complex structure because multiple current collector leads are individually connected to terminals. On the other hand, a method of collecting metal foils and connecting them to terminals is known, but collecting the foils becomes difficult when there are a large number of metal foils, and there is room for improvement in increasing the energy density.

[0005] In consideration of the above, an object of the present invention is to provide a battery with a simple structure and an increased energy density, and a method for manufacturing the battery. [Means for solving the problem]

[0006] The battery according to claim 1 includes an electrode body formed by laminating a positive electrode current collector, a negative electrode current collector, a positive electrode foil extending from the positive electrode current collector, and a negative electrode foil extending from the negative electrode current collector; a first foil collecting section in which one of the positive electrode foil and the negative electrode foil is collected into a single foil; a second foil collecting section in which the other of the positive electrode foil and the negative electrode foil is divided into multiple pieces and collected; a first terminal to which the first foil collecting section is joined; and a second terminal to which the second foil collecting section is joined.

[0007] In the battery according to claim 1, the electrode body is formed by laminating a positive electrode current collector, a negative electrode current collector, a positive electrode foil extending from the positive electrode current collector, and a negative electrode foil extending from the negative electrode current collector. Furthermore, one of the positive electrode foil and the negative electrode foil is collected together as a first foil collecting portion, and the first foil collecting portion is joined to a first terminal. Collecting one of the positive electrode foil and the negative electrode foil together in this way results in a simpler structure than when the foils are individually joined to the first terminal.

[0008] In addition, the other of the positive and negative foils is divided into multiple pieces and collected as a second foil collecting section, and the second foil collecting section is joined to the second terminal. In this way, the second foil collecting section, which is divided into multiple pieces and collected, can collect the foils without reducing the number of foils even when there are too many foils to collect them into one, such as when the number of positive and negative foils differs. In other words, the energy density can be increased.

[0009] A battery according to claim 2 is the battery according to claim 1, wherein the first terminal is provided on one end side of the electrode body, and the second terminal is provided on the other end side of the electrode body.

[0010] In the battery according to claim 2, the first terminal is provided on one end side of the electrode body, and the second terminal is provided on the other end side of the electrode body, thereby preventing the first foil collecting portion and the second foil collecting portion from being crowded together.

[0011] The battery according to claim 3 is the battery according to claim 2, wherein the distance from the other end of the electrode body to the second terminal is shorter than the distance from one end of the electrode body to the first terminal.

[0012] In the battery according to claim 3, the second foil collecting section, which is formed by collecting foil into multiple parts, can be made shorter than the first foil collecting section. Therefore, by designing the distance on the second foil collecting section side to be shorter, the energy density can be increased.

[0013] A battery according to claim 4 is the battery according to claim 1, wherein the second foil collecting section has a larger number of collected foils than the first foil collecting section.

[0014] In the battery according to claim 4, the second foil collecting section, which has a large number of foils, collects the foils in a plurality of parts, making it easy to collect and join the foils.

[0015] A battery according to claim 5 is the battery according to claim 1, wherein the first foil collecting portion is curved near one corner of the electrode body and joined to the first terminal.

[0016] In the battery according to claim 5, by bending the first foil collecting portion near one corner of the electrode body, gas can be accumulated near the other corner of the electrode body when gas is generated, and thus when the internal pressure of the battery increases, the gas can be leaked from the gas-accumulated portion to the outside of the battery.

[0017] A battery according to claim 6 is the battery of claim 5, wherein the first foil collecting portion is joined to the first terminal at one location, and the second foil collecting portion is joined to the second terminal at multiple locations.

[0018] In the battery according to claim 6, the first foil collecting part is joined to the first terminal at one point, and therefore the unjoined area of ​​the first terminal is larger than that of the second foil collecting part, which is joined at multiple points. This makes the unjoined area weak, making it more likely for gas to leak from the first terminal when the internal pressure of the battery increases.

[0019] The battery of claim 7 is the same as claim 1, and further includes a case that houses the electrode body, a first external terminal that is provided in the case and electrically connected to the first terminal, and a second external terminal that is provided in the case and electrically connected to the second terminal.

[0020] In the battery according to claim 7, the first foil collecting portion is electrically connected to the first external terminal via the first terminal, and the second foil collecting portion is electrically connected to the second external terminal via the second terminal, thereby improving the degree of freedom in designing the first external terminal and the second external terminal.

[0021] The method for manufacturing a battery according to claim 8 is a method for manufacturing a battery including an electrode body constructed by laminating a positive electrode current collector, a negative electrode current collector, a positive electrode foil extending from the positive electrode current collector, and a negative electrode foil extending from the negative electrode current collector, and includes the steps of: gathering one of the positive electrode foil and the negative electrode foil into one foil and joining it to a first terminal arranged on one end side of the electrode body; and dividing the other of the positive electrode foil and the negative electrode foil into multiple pieces, gathering them into multiple pieces, and joining them to a second terminal arranged on the other end side of the electrode body. [Effects of the Invention]

[0022] As described above, the battery and the method for manufacturing the battery according to the present invention can increase the energy density with a simple structure. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a schematic plan view showing a main part of a vehicle to which a battery according to an embodiment is applied; [Figure 2] FIG. 2 is a schematic perspective view of a battery module. [Figure 3] FIG. 2 is a cross-sectional view of a battery cell according to the embodiment, viewed from the stacking direction. [Figure 4] FIG. 2 is a schematic cross-sectional view illustrating a cross section of an electrode body in the embodiment. [Figure 5] FIG. 4 is a cross-sectional view showing a state in which gas is generated from the state shown in FIG. 3. [Figure 6] FIG. 6 is a cross-sectional view showing a state in which gas has leaked from the state shown in FIG. 5. [Figure 7] FIG. 10 is a cross-sectional view of a battery cell according to a first modified example, viewed from the stacking direction. [Figure 8] FIG. 10 is a cross-sectional view of a battery cell according to a second modification, viewed from the stacking direction. DETAILED DESCRIPTION OF THE INVENTION

[0024] (Overall configuration of vehicle 100) Fig. 1 is a schematic plan view showing the main parts of a vehicle 100 to which a battery pack 10 according to this embodiment is applied. As shown in Fig. 1, the vehicle 100 is a battery electric vehicle (BEV) with the battery pack 10 mounted under the floor. Note that the arrows UP, FR, and LH in each figure indicate the upper side in the vehicle vertical direction, the front side in the vehicle longitudinal direction, and the left side in the vehicle width direction, respectively. When describing using the front-rear, left-right, up-down directions, these directions refer to the front and rear in the vehicle longitudinal direction, the left and right in the vehicle width direction, and the up-down in the vehicle vertical direction, unless otherwise specified.

[0025] In the vehicle 100 of this embodiment, for example, a DC / DC converter 102, an electric compressor 104, and a PTC (Positive Temperature Coefficient) heater 106 are arranged on the vehicle front side of the battery pack 10. In addition, a motor 108, a gearbox 110, an inverter 112, and a charger 114 are arranged on the vehicle rear side of the battery pack 10.

[0026] The DC current output from the battery pack 10 has its voltage adjusted by a DC / DC converter 102 and is then supplied to an electric compressor 104, a PTC heater 106, an inverter 112, etc. Furthermore, power is supplied to a motor 108 via the inverter 112, causing the rear wheels to rotate and causing the vehicle 100 to travel.

[0027] A charging port 116 is provided on the right side at the rear of the vehicle 100, and by connecting a charging plug of an external charging facility (not shown) to the charging port 116, power can be stored in the battery pack 10 via the charger 114.

[0028] The arrangement and structure of each component constituting vehicle 100 are not limited to the above-described configuration. For example, the present invention may be applied to a hybrid vehicle (HV) or a plug-in hybrid electric vehicle (PHEV) equipped with an engine. In addition, in this embodiment, the vehicle is a rear-wheel drive vehicle in which motor 108 is mounted at the rear of the vehicle, but the present invention is not limited to this. The vehicle may be a front-wheel drive vehicle in which motor 108 is mounted at the front of the vehicle, or a pair of motors 108 may be mounted at the front and rear of the vehicle. Furthermore, the vehicle may be equipped with in-wheel motors on each wheel.

[0029] Here, the battery pack 10 is configured to include a plurality of battery modules 11. In this embodiment, as an example, ten battery modules 11 are provided. Specifically, five battery modules 11 are arranged on the right side of the vehicle 100 in the vehicle longitudinal direction, and five battery modules 11 are arranged on the left side of the vehicle 100 in the vehicle longitudinal direction. In addition, the respective battery modules 11 are electrically connected to each other.

[0030] Fig. 2 is a schematic perspective view of the battery module 11. As shown in Fig. 2, the battery module 11 is formed in a substantially rectangular parallelepiped shape with the vehicle width direction as the longitudinal direction. The case 13 of the battery module 11 is formed from an aluminum alloy. For example, the case 13 of the battery module 11 is formed by joining aluminum die-casting to both ends of an extruded aluminum alloy material by laser welding or the like.

[0031] A pair of voltage terminals 12 and a connector 14 is provided at each end of the battery module 11 in the vehicle width direction. In addition, bus bars (not shown) are welded to each end of the battery module 11 in the vehicle width direction.

[0032] Here, the battery module 11 contains a plurality of battery cells as batteries.

[0033] 3 is a cross-sectional view of a battery cell 20 according to this embodiment, viewed from the stacking direction. As shown in FIG. 3, the battery cell 20 according to this embodiment includes an exterior can 22 as a case, and an electrode assembly 24.

[0034] The exterior can 22 forms the outer shell of the battery cell 20 and is formed in a substantially rectangular parallelepiped shape. As an example, the exterior can 22 of this embodiment is configured to include a substantially cylindrical peripheral wall portion 22A, a positive electrode side lid portion 22B that closes an opening on one side of the peripheral wall portion 22A, and a negative electrode side lid portion 22C that closes an opening on the other side of the peripheral wall portion 22A.

[0035] The peripheral wall portion 22A is made of metal and is formed in a generally rectangular cylindrical shape with both ends open, and is sized to accommodate the electrode assembly 24. The positive electrode side lid portion 22B is fixed to one opening of the peripheral wall portion 22A by fitting, welding, or other means, and closes the opening on one side of the peripheral wall portion 22A. An opening 22D is formed in the center of the positive electrode side lid portion 22B, and a generally frame-shaped positive electrode side insulator 26 is provided in this opening 22D.

[0036] The negative electrode side lid portion 22C is fixed to the opening on the other side of the peripheral wall portion 22A by fitting, welding, or other means, and closes the opening on the other side of the peripheral wall portion 22A. An opening 22E is formed in the center of the negative electrode side lid portion 22C, and a substantially frame-shaped negative electrode side insulator 28 is provided in this opening 22E.

[0037] A negative electrode tab 32 serving as a first external terminal is disposed inside the negative electrode side insulator 28. A positive electrode tab 30 serving as a second external terminal is disposed inside the positive electrode side insulator 26. The negative electrode tab 32 is electrically connected to a first terminal 33 housed inside the outer can 22, and the positive electrode tab 30 is electrically connected to a second terminal 31 housed inside the outer can 22.

[0038] The first terminal 33 is formed in a substantially rectangular plate shape with an outer shape larger than that of the negative electrode tab 32, and a first current collector portion 34 described later is joined to the first terminal 33. Also, the second terminal 31 is formed in a substantially rectangular plate shape with an outer shape larger than that of the positive electrode tab 30, and a second current collector portion 36 described later is joined to the second terminal 31.

[0039] FIG. 4 is a schematic cross-sectional view schematically depicting a cross-section of the electrode body 24 in the embodiment. Note that FIG. 4 schematically shows only a part of the electrode body 24 and is different from the actual number of stacked layers.

[0040] As shown in FIG. 4, the electrode body 24 is configured by laminating a negative electrode current collector 40, a negative electrode mixture 42, a solid electrolyte 44, a positive electrode mixture 46, and a positive electrode current collector 48. The negative electrode current collector 40 is disposed at the center in the stacking direction and is formed of a metal foil. As the negative electrode current collector 40, a copper foil is preferable.

[0041] The negative electrode mixture 42 is applied to both surfaces of the negative electrode current collector 40. The negative electrode mixture 42 is a mixture of a negative electrode active material, a conductive auxiliary material, a binder, etc. Examples of the negative electrode active material include at least one selected from the group consisting of natural graphite, artificial graphite, hard carbon (non-graphitizable carbon), or soft carbon (graphitizable carbon), Si, SiOx (0 < x < 2), Si-based alloys, Sn, SnOx (0 < x < 2), Li, Li-based alloys, and Li4Ti5O12. Examples of artificial graphite include highly oriented graphite, mesocarbon microbeads, etc. As the negative electrode active material, artificial graphite is preferable.

[0042] A solid electrolyte 44 is laminated on the side of the negative electrode composite 42 opposite the negative electrode current collector 40. A positive electrode composite 46 is laminated on the side of the solid electrolyte 44 opposite the negative electrode composite 42. The positive electrode composite 46 is a mixture of a positive electrode active material, a conductive additive, a binder, and the like, and is applied to a positive electrode current collector 48. The positive electrode active material is not particularly limited, and conventionally known materials can be used as appropriate. Examples of positive electrode active materials include LiCoO2, LiNiO2, LiMnO2, LiMn2O4, Li(NiCoMn)O2, Li(NiCoAl)O2, and LiFePO4. The positive electrode active material particles may be Hi-Nickel (a positive electrode active material with a high Ni content), a Li-Ni-Co-Mn-based composite oxide, or a ternary positive electrode active material.

[0043] The positive electrode current collector 48 is formed of a metal foil, and aluminum foil is preferable as the positive electrode current collector 48. As such, as an example, the electrode body 24 of this embodiment has a structure in which the negative electrode current collector 40 is arranged in the center in the stacking direction and the positive electrode current collectors 48 are arranged on both sides of this negative electrode current collector 40, so that the number of positive electrode current collectors 48 is greater than the number of negative electrode current collectors 40.

[0044] Here, a positive electrode foil (not shown) extends from the end of the positive electrode current collector 48 , and a negative electrode foil (not shown) extends from the end of the negative electrode current collector 40 .

[0045] 3, a first foil collecting portion 34, in which the negative electrode foils of the negative electrode current collector 40 are collected into one foil, is provided at one longitudinal end of the electrode body 24. The first foil collecting portion 34 is curved near one corner of the electrode body 24 (the lower right corner of the drawing) and joined to a first terminal 33.

[0046] Meanwhile, a second foil collecting section 36 is provided at the other longitudinal end of the electrode body 24, in which the positive electrode foil of the positive electrode current collector 48 is divided into multiple pieces and collected. In this embodiment, the second foil collecting section 36 is divided into two, as an example. One of the second foil collecting sections 36 is curved near the upper left corner of the electrode body 24 in the drawing and joined to the second terminal 31. The other second foil collecting section 36 is curved near the lower left corner of the electrode body 24 in the drawing and joined to the second terminal 31. Therefore, the first foil collecting section 34 is joined to the first terminal 33 at one location, and the second foil collecting section 36 is joined to the second terminal 31 at multiple locations.

[0047] Furthermore, because there are more positive electrode current collectors 48 than negative electrode current collectors 40, the second foil collecting section 36 has more collected foil sheets than the first foil collecting section 34. Specifically, the total number of foil sheets in the divided second foil collecting section 36 is greater than the number of foil sheets in the first foil collecting section 34.

[0048] Furthermore, in this embodiment, the distance from the end of the electrode body 24 on the second terminal 31 side to the second terminal 31 is shorter than the distance from the end of the electrode body 24 on the first terminal 33 side to the first terminal 33. In other words, the space between the electrode body 24 and the second terminal 31 is narrower than the space between the electrode body 24 and the first terminal 33.

[0049] The battery cell 20 of this embodiment is formed, for example, by collecting the negative electrode foil extending from the negative electrode current collector 40 and joining it to the first terminal 33, and then collecting the positive electrode foil extending from the electrode body 24 and dividing it into two pieces and joining them to the second terminal 31.

[0050] (action) Next, the operation of the battery cell 20 and the power storage device mounting structure according to this embodiment will be described.

[0051] In the battery cell 20 according to this embodiment, as shown in Fig. 4, the electrode body 24 is configured by laminating a positive electrode current collector 48, a negative electrode current collector 40, a positive electrode foil extending from the positive electrode current collector 48, and a negative electrode foil extending from the negative electrode current collector 40. Also, as shown in Fig. 3, the negative electrode foils are collected into a single foil collecting portion 34, and the first foil collecting portion 34 is joined to the first terminal 33. In this way, by collecting one side of the negative electrode foils into a single foil, the structure is simpler than when multiple negative electrode foils are individually joined to the first terminal 33.

[0052] Additionally, the positive electrode foil is divided into multiple pieces and collected as second foil collecting section 36, and second foil collecting section 36 is joined to second terminal 31. In this way, even when there are too many foils to be collected into one, such as when the number of positive electrode foils and the number of negative electrode foils differ, second foil collecting section 36, which is divided into multiple pieces and collected, allows for collection without reducing the number of foils. In other words, the energy density can be increased.

[0053] In addition, in this embodiment, by providing the first terminal 33 on one end side of the electrode body 24 and the second terminal 31 on the other end side of the electrode body 24, it is possible to prevent the first foil collecting portion 34 and the second foil collecting portion 36 from becoming too close together.

[0054] Furthermore, in this embodiment, second foil collecting section 36, which is formed by dividing and collecting foil into multiple pieces, can be made shorter than first foil collecting section 34, so by designing the distance on the second foil collecting section 36 side to be shorter, the energy density can be increased.

[0055] Furthermore, in this embodiment, the second foil collecting section 36, which has a large number of foils, is divided into multiple pieces to collect the foils, making it easier to collect and join the foils. That is, if the second foil collecting section 36, which has a large number of foils, were to collect the foils into one piece, the foil collecting section would be thick, making it difficult to collect the foils and join them to the terminals. However, by dividing the second foil collecting section 36 into multiple pieces as in this embodiment, it is easier to collect and join the foils.

[0056] In this embodiment, the first foil collecting portion 34 is electrically connected to the negative electrode tab 32 via the first terminal 33, and the second foil collecting portion 36 is electrically connected to the positive electrode tab 30 via the second terminal 31. This improves the design freedom of the negative electrode tab 32 and the positive electrode tab 30.

[0057] Furthermore, in this embodiment, by curving the first foil collecting portion 34 near one corner of the electrode body 24, gas can be accumulated near the other corner of the electrode body 24 when gas is generated. This allows the gas to leak from the gas-accumulating portion to the outside of the battery when the internal pressure of the battery increases. This effect will be explained using FIGS. 5 and 6.

[0058] Fig. 5 is a cross-sectional view showing a state in which gas has been generated from the state shown in Fig. 3, and Fig. 6 is a cross-sectional view showing a state in which gas has leaked from the state shown in Fig. 5. As shown in Fig. 5, repeated charging and discharging of the battery cell 20 generates gas G from the electrode body 24. Furthermore, when an abnormality occurs in the battery cell 20, a large amount of gas G may be generated, causing the internal pressure of the outer can 22 to increase.

[0059] Here, on the negative electrode side of electrode body 24, a gap is provided near the corner on the opposite side to the side where first foil collecting portion 34 is curved, making it easy for gas G to accumulate. Also, because first foil collecting portion 34 is joined to first terminal 33 at one point, the unjoined area of ​​first terminal 33 is larger than that of second foil collecting portion 36, which is joined at multiple points. This makes the unjoined area have a weak structure, and as shown in FIG. 6 , the corner of outer can 22 can break, allowing gas G to leak out of outer can 22.

[0060] In the above embodiment, as shown in FIG. 3, the negative electrode tab 32 is electrically connected to the first terminal 33 housed inside the exterior can 22, and the positive electrode tab 30 is electrically connected to the second terminal 31 housed inside the exterior can 22. However, this is not limiting. For example, the structure of a first modified example shown in FIG. 7 may be adopted. Furthermore, in the above embodiment, the first terminal 33 is provided on one end in the longitudinal direction of the electrode body 24, and the second terminal 31 is provided on the other end. However, this is not limiting. For example, the structure of a second modified example shown in FIG. 8 may be adopted.

[0061] (First Modification) Fig. 7 is a cross-sectional view of a battery cell 50 according to a first modified example, viewed from the stacking direction. As shown in Fig. 7, the battery cell 50 according to this modified example includes a case 52. The case 52 is a laminate film that forms the outer shell of the battery cell 50, and the electrode body 24 is housed in the case 52.

[0062] An annular insulating member 54 is fixed to one end of the case 52, and a first terminal 56 is disposed inside the insulating member 54. Furthermore, an annular insulating member 58 is fixed to the other end of the case 52, and a second terminal 60 is disposed inside the insulating member 58.

[0063] The first foil collecting portion 34 of the electrode body 24 is joined to a first terminal 56 , and the second foil collecting portion 36 is joined to a second terminal 60 .

[0064] The present invention can also be applied to laminated battery cells, as in this modified example.

[0065] (Second Modification) Fig. 8 is a cross-sectional view of a battery cell 70 according to a second modified example, viewed from the stacking direction. As shown in Fig. 8, the battery cell 70 according to this modified example has a terminal orientation that differs from that of the embodiment. Specifically, the battery cell 70 according to this modified example includes an exterior can 72. The exterior can 72 forms the outer shell of the battery cell 70, and the electrode assembly 24 is housed inside the exterior can 72.

[0066] The outer can 72 is formed in a generally rectangular box shape with an open top, and the opening at the top of the outer can 72 is closed by a lid member 74. The lid member 74 is formed in a generally flat plate shape, and two through holes are formed in the lid member 74.

[0067] An insulating member 76 and an insulating member 80 are provided in the through holes of the cover member 74, and a negative electrode tab 78 serving as a first external terminal is fixed to the inside of the insulating member 76. Furthermore, a positive electrode tab 82 serving as a second external terminal is fixed to the inside of the insulating member 80.

[0068] A first terminal 84 is fixed to the negative electrode tab 78, and the first foil collecting portion 34 is joined to the first terminal 84. A second terminal 86 is fixed to the positive electrode tab 82, and the second terminal 86 is joined to the second foil collecting portion 36, which is split into two halves.

[0069] The present invention can also be applied to a battery cell with an upper terminal structure in which a positive electrode tab 82 and a negative electrode tab 78 are provided on the top, as in this modified example.

[0070] The battery cells 20, 50, and 70 according to the embodiments and modifications have been described above, but the present invention is not limited thereto and can be embodied in various forms without departing from the spirit of the present invention. For example, in the above embodiment, as shown in FIG. 3, the negative electrode foils are collected into a single first foil collecting section 34, and the positive electrode foils are divided into multiple pieces and collected into a second foil collecting section 36. However, the present invention is not limited thereto. The negative electrode foils may be collected into multiple pieces, and the positive electrode foil may be collected into a single piece.

[0071] In the above embodiment, the second foil collecting unit 36 ​​is divided into two parts to collect the foil, but this is not limited to this. For example, the second foil collecting unit 36 ​​may be divided into three or more parts to collect the foil. However, it is preferable to divide and collect the foil in the unit with the larger number of foils.

[0072] The following notes are provided regarding the above embodiment.

[0073] (Appendix 1) an electrode assembly formed by laminating a positive electrode current collector, a negative electrode current collector, a positive electrode foil extending from the positive electrode current collector, and a negative electrode foil extending from the negative electrode current collector; a first foil collecting section in which one of the positive electrode foil and the negative electrode foil is collected into one foil; a second foil collecting section in which the other of the positive electrode foil and the negative electrode foil is divided into a plurality of foils and collected; a first terminal to which the first foil collecting portion is joined; a second terminal to which the second foil collecting portion is joined; A battery having (Appendix 2) The first terminal is provided on one end side of the electrode body, 2. The battery according to claim 1, wherein the second terminal is provided on the other end side of the electrode body. (Appendix 3) 3. The battery according to claim 2, wherein the distance from the other end of the electrode body to the second terminal is shorter than the distance from one end of the electrode body to the first terminal. (Appendix 4) 4. The battery according to any one of claims 1 to 3, wherein the second foil collecting section has a greater number of collected foils than the first foil collecting section. (Appendix 5) 5. The battery according to claim 1, wherein the first foil collecting portion is curved near one corner of the electrode body and joined to the first terminal. (Appendix 6) the first foil collecting portion is joined to the first terminal at one point, 6. The battery of claim 5, wherein the second foil collecting portion is joined to the second terminal at multiple locations. (Appendix 7) a case for accommodating the electrode assembly; a first external terminal provided on the case and electrically connected to the first terminal; a second external terminal provided on the case and electrically connected to the second terminal; 7. The battery according to any one of claims 1 to 6, further comprising: (Appendix 8) A method for manufacturing a battery including an electrode assembly configured by laminating a positive electrode current collector, a negative electrode current collector, a positive electrode foil extending from the positive electrode current collector, and a negative electrode foil extending from the negative electrode current collector, a step of collecting one of the positive electrode foil and the negative electrode foil into one foil and joining the foil to a first terminal arranged on one end side of an electrode body; a step of dividing the other of the positive electrode foil and the negative electrode foil into a plurality of pieces, collecting the foil, and joining the collected foil to a second terminal disposed on the other end side of the electrode body; A method for manufacturing a battery having the above structure. [Explanation of symbols]

[0074] 20, 50, 70 battery cells (batteries) 22, 72 outer can (case) 24 Electrode body 30 Positive electrode tab 31 2nd terminal 32 Negative electrode tab 33 1st terminal 34 1st foil collection section 36 2nd collection foil section

Claims

1. an electrode assembly formed by laminating a positive electrode current collector, a negative electrode current collector, a positive electrode foil extending from the positive electrode current collector, and a negative electrode foil extending from the negative electrode current collector; a first foil collecting section in which one of the positive electrode foil and the negative electrode foil is collected into one foil; a second foil collecting section in which the other of the positive electrode foil and the negative electrode foil is divided into a plurality of foils and collected; a first terminal to which the first foil collecting portion is joined; a second terminal to which the second foil collecting portion is joined; A battery having

2. The first terminal is provided on one end side of the electrode body, The battery according to claim 1 , wherein the second terminal is provided on the other end side of the electrode body.

3. The battery according to claim 2 , wherein the distance from the other end of the electrode body to the second terminal is shorter than the distance from one end of the electrode body to the first terminal.

4. The battery according to claim 1 , wherein the second foil collecting section has a greater number of collected foils than the first foil collecting section.

5. The battery according to claim 1 , wherein the first foil collecting portion is curved near one corner of the electrode body and joined to the first terminal.

6. the first foil collecting portion is joined to the first terminal at one location, The battery according to claim 5 , wherein the second foil collecting portion is joined to the second terminal at a plurality of locations.

7. a case for accommodating the electrode assembly; a first external terminal provided on the case and electrically connected to the first terminal; a second external terminal provided on the case and electrically connected to the second terminal; 10. The battery of claim 1 further comprising:

8. A method for manufacturing a battery including an electrode assembly configured by laminating a positive electrode current collector, a negative electrode current collector, a positive electrode foil extending from the positive electrode current collector, and a negative electrode foil extending from the negative electrode current collector, a step of collecting one of the positive electrode foil and the negative electrode foil into one foil and joining the foil to a first terminal arranged on one end side of an electrode body; a step of dividing the other of the positive electrode foil and the negative electrode foil into a plurality of pieces, collecting the foil, and joining the collected foil to a second terminal disposed on the other end side of the electrode body; A method for manufacturing a battery having the above structure.

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