Battery cell

Abstract

The first laminate (110A) has: a first positive electrode (112A) and a first negative electrode (114A) alternately laminated in a predetermined direction; and a first separator (116A) that at least partially covers the first negative electrode (114A), which is located on the outermost side in the predetermined direction, among the first positive electrode (112A) and the first negative electrode (114A). The second laminate (120A) has: a second positive electrode (122A) and a second negative electrode (124A) which are alternately laminated in a predetermined direction; and a second separator (126A) that at least partially covers the second negative electrode (124A), which is located on the outermost side in the predetermined direction, among the second positive electrode (122A) and the second negative electrode (124A). The positive electrode (130A) is interposed between the outermost first separator (116A) of the first laminate (110A) and the outermost second separator (126A) of the second laminate (120A).

Description

Technical Field

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

[0002] In recent years, various battery cells such as lithium ion secondary batteries have been developed. The battery cell includes battery elements and an exterior member that seals the battery elements. The battery elements include at least one positive electrode and at least one negative electrode that are alternately laminated, and a separator at least a part of which is located between the adjacent positive electrode and negative electrode.

[0003] An example of a battery cell is described in Patent Document 1. This battery cell includes a plurality of stacked unit cells that are overlapped and a folding separation diaphragm interposed between the overlapping portions of the plurality of stacked unit cells.

[0004] An example of a battery cell is described in Patent Document 2. This battery cell includes a plurality of wound battery elements that are overlapped.

[0005] An example of a battery cell is described in Patent Document 3. This battery cell includes an all-solid-state battery laminate. Tabs are led out upward from substantially the upper half of the all-solid-state battery laminate. Tabs are led out downward from substantially the lower half of the all-solid-state battery laminate.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-530513

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2003-234094

[0010] Patent Document 3: Japanese Patent Application Laid-Open No. 2018-129153 Summary of the Invention

[0011] -Problems to be Solved by the Invention-

[0012] In order to increase the energy density of a battery cell, it is sometimes required to laminate a relatively large number of positive electrodes and negative electrodes in a single battery element. However, the larger the number of laminations of the positive electrode and the negative electrode, the more likely it is that the lamination of the positive electrode or the negative electrode will deviate. Therefore, if only the number of laminations of the positive electrode and the negative electrode is increased, it may be difficult to sufficiently increase the energy density of the battery cell.

[0013] An example of the object of the present invention is to simply increase the number of laminations of the positive electrode and the negative electrode in a single battery element. Other objects of the present invention will be apparent from the description of this specification.

[0014] -Means for Solving the Problems-

[0015] One aspect of the present invention is described as follows.

[0016] [1] A battery cell, characterized by comprising: a plurality of laminates, each having a first electrode and a second electrode that are alternately laminated in a given direction and have different first and second polarities respectively, and a separator that covers at least a part of the second electrode located on the outermost side in the given direction among the first electrode and the second electrode; and a sandwiching electrode, located between one outermost separator among the plurality of laminates and the other outermost separator among the plurality of laminates, having the first polarity.

[0017] [2] The battery cell according to [1], wherein the separator is alternately folded back at the side portions in the given direction of the first electrode and the side portions in the given direction of the second electrode.

[0018] [3] The battery cell according to [1] or [2], wherein one of the first electrode, the second electrode, and the separator among the plurality of laminates is integrally held separately from the sandwiching electrode, and the other first electrode, second electrode, and separator among the plurality of laminates are integrally held separately from the sandwiching electrode.

[0019] [4] The battery cell according to [1] or [2], wherein one of the first electrode, the second electrode, and the separator among the plurality of laminates is integrally held together with the sandwiching electrode, and the other first electrode, second electrode, and separator among the plurality of laminates are integrally held separately from the sandwiching electrode.

[0020] -Advantages of the Invention-

[0021] According to the above aspect of the present invention, it is possible to simply increase the number of laminations of the positive electrode and the negative electrode in a single battery element. Description of the Drawings

[0022] Figure 1 is a front perspective view of the battery cell according to Embodiment 1.

[0023] Figure 2 is a front enlarged perspective view of a part of the battery cell according to Embodiment 1.

[0024] Figure 3 is a right side view of the battery cell according to Embodiment 1.

[0025] Figure 4 is Figure 3 a schematic cross-sectional view taken along line A-A of

[0026] Figure 5 It is a cross-sectional schematic view of the battery cell according to Embodiment 2. Specific Embodiment

[0027] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are assigned to the same structural elements, and the description will be appropriately omitted.

[0028] Figure 1 It is a front perspective view of the battery cell 10A according to Embodiment 1. Figure 2 It is a front enlarged perspective view of a part of the battery cell 10A according to Embodiment 1. Figure 3 It is a right side view of the battery cell 10A according to Embodiment 1. In Figure 3 For the sake of convenience of explanation, it is illustrated in a state where the outer packaging film 400 is transparent.

[0029] In each figure, for the sake of explanation, the X direction, the Y direction, and the Z direction are marked. The X direction represents the front-rear direction of the battery cell 10A. The Y direction is orthogonal to the X direction. The Y direction represents the left-right direction of the battery cell 10A. The Z direction is orthogonal to both the X direction and the Y direction. The Z direction represents the up-down direction of the battery cell 10A. The direction indicated by the arrow representing the X direction, the direction indicated by the arrow representing the Y direction, and the direction indicated by the arrow representing the Z direction are the rear direction, the left direction, and the up direction, respectively. However, the relationships of the X direction, the Y direction, the Z direction, the front-rear direction, the left-right direction, and the up-down direction of the battery cell 10A are not limited to this example. In addition, the white circle with X representing the X direction, the Y direction, or the Z direction indicates that the direction from the front of the paper to the inside is the direction indicated by the arrow representing that direction.

[0030] Hereinafter, as needed, the side indicated by the arrow representing the X direction will be referred to as the +X side. Hereinafter, as needed, the opposite side of the side indicated by the arrow representing the X direction will be referred to as the -X side. Hereinafter, as needed, the side indicated by the arrow representing the Y direction will be referred to as the +Y side. Hereinafter, as needed, the opposite side of the side indicated by the arrow representing the Y direction will be referred to as the -Y side. Hereinafter, as needed, the side indicated by the arrow representing the Z direction will be referred to as the +Z side. Hereinafter, as needed, the opposite side of the side indicated by the arrow representing the Z direction will be referred to as the -Z side.

[0031] Hereinafter, as needed, the plane perpendicular to the X direction will be referred to as the YZ plane. Hereinafter, as needed, the plane perpendicular to the Y direction will be referred to as the ZX plane. Hereinafter, as needed, the plane perpendicular to the Z direction will be referred to as the XY plane.

[0032] The battery cell 10A includes a battery element 100A, a front cover 210, a rear cover 220, a positive electrode tab 310, a negative electrode tab 320, and an exterior film 400. The exterior film 400 has a winding portion 402 and a lead-out portion 404.

[0033] The battery element 100A is substantially rectangular parallelepiped in shape. The long side direction of the battery element 100A is substantially parallel to the X direction. The short side direction of the battery element 100A is substantially parallel to the Z direction. The thickness direction of the battery element 100A is substantially parallel to the Y direction.

[0034] The front cover 210 covers the front end portion of the battery element 100A. The front cover 210 contains a resin such as polypropylene, for example. When viewed from the front, the front cover 210 is substantially rectangular in shape. When viewed from the front, the long side direction of the front cover 210 is substantially parallel to the Z direction, and the width direction of the front cover 210 is substantially parallel to the Y direction.

[0035] The rear cover 220 covers the rear end portion of the battery element 100A. The rear cover 220 contains a resin such as polypropylene, for example. When viewed from the rear, the rear cover 220 is substantially rectangular in shape. When viewed from the rear, the long side direction of the rear cover 220 is substantially parallel to the Z direction, and the width direction of the rear cover 220 is substantially parallel to the Y direction.

[0036] The positive electrode tab 310 protrudes forward from the front cover 210. The positive electrode tab 310 is electrically connected to a positive electrode current collector 102 led out forward from a first positive electrode 112A and a second positive electrode 122A of the battery element 100A described later. Therefore, the positive electrode tab 310 is electrically connected to the first positive electrode 112A and the second positive electrode 122A of the battery element 100A.

[0037] The negative electrode tab 320 protrudes rearward from the rear cover 220. The negative electrode tab 320 is electrically connected to a negative electrode current collector 104 led out rearward from a first negative electrode 114A and a second negative electrode 124A of the battery element 100A described later. Therefore, the negative electrode tab 320 is electrically connected to the first negative electrode 114A and the second negative electrode 124A of the battery element 100A.

[0038] As Figure 1 and Figure 2As shown, the winding portion 402 has a substantially cylindrical shape that is open at both the front and the rear. A front cover member 210 is disposed inside the opening at the front of the winding portion 402. A rear cover member 220 is disposed inside the opening at the rear of the winding portion 402. The winding portion 402 is wound one turn around the battery element 100A, the front cover member 210, and the rear cover member 220 in the X direction. As a result, the front cover member 210, the rear cover member 220, and the winding portion 402 form a housing space 500 for housing the battery element 100A. In the housing space 500, an electrolyte (not shown) is housed together with the battery element 100A. In addition, the winding manner of the battery element 100A in the winding portion 402 is not limited to the above example.

[0039] In Figure 1 and Figure 2 In the example shown, at least a part of the periphery of the positive electrode tab 310 on the front surface of the front cover member 210 is exposed from the outer packaging film 400. However, the outer packaging film 400 may also cover the periphery of the positive electrode tab 310 on the front surface of the front cover member 210. Similarly, at least a part of the periphery of the negative electrode tab 320 on the rear surface of the rear cover member 220 is exposed from the outer packaging film 400. However, the outer packaging film 400 may also cover the periphery of the negative electrode tab 320 on the rear surface of the rear cover member 220.

[0040] The outer peripheral surface of the front cover member 210 around the X direction and the inner peripheral surface of the opening at the front of the winding portion 402 around the X direction are joined to each other, for example, by heat welding. As a result, a front sealing portion 510 is formed. The outer peripheral surface of the rear cover member 220 around the X direction and the inner peripheral surface of the opening at the rear of the winding portion 402 around the X direction are joined to each other, for example, by heat welding. As a result, a rear sealing portion 520 is formed.

[0041] As Figure 1 and Figure 2 shown, when viewed from the front, the lead-out portion 404 is led out from the upper left corner of the battery element 100A of the winding portion 402. Specifically, as Figure 2 shown, the lead-out portion 404 includes a first lead-out portion 404a and a second lead-out portion 404b. The first lead-out portion 404a is led out from one of the circumferential ends of the winding portion 402 around the X direction. The second lead-out portion 404b is led out from the other of the circumferential ends of the winding portion 402 around the X direction. The first lead-out portion 404a and the second lead-out portion 404b are joined to each other, for example, by heat welding. As a result, a side sealing portion 530 is formed. The lead-out portion 404 is bent along the upper surface of the battery element 100A. However, the lead-out portion 404 may not be bent. In addition, the bent shape of the lead-out portion 404 is not limited to the shape according to Embodiment 1.

[0042] In Embodiment 1, the front end portion and the rear end portion of the battery element 100A are covered by two cover members. However, for example, when both the positive electrode tab 310 and the negative electrode tab 320 are led out from the front end portion of the battery element 100A, the rear end portion of the battery element 100A may not be covered by the cover member while the front end portion of the battery element 100A is covered by the cover member. That is, only the side from which the positive electrode tab 310 and the negative electrode tab 320 of the battery element 100A are led out may be covered by the cover member. In this case, on the side of the battery element 100A opposite to the cover member, the exterior film 400 may be sealed and folded along the battery element 100A.

[0043] Figure 4 is Figure 3 A-A sectional schematic view of.

[0044] The battery element 100A according to Embodiment 1 includes a first laminate 110A, a second laminate 120A, and a sandwiched positive electrode 130A. The first laminate 110A and the second laminate 120A are laminated on each other in the Y direction. The sandwiched positive electrode 130A is located between the first laminate 110A and the second laminate 120A in the Y direction. The first laminate 110A has a plurality of first positive electrodes 112A, a plurality of first negative electrodes 114A, and a first separator 116A. The second laminate 120A has a plurality of second positive electrodes 122A, a plurality of second negative electrodes 124A, and a second separator 126A.

[0045] The first laminate 110A will be described. Hereinafter, matters described for the first laminate 110A will be the same for the second laminate 120A as long as there is no special description.

[0046] The plurality of first positive electrodes 112A and the plurality of first negative electrodes 114A are alternately laminated in the Y direction. Each of the first positive electrodes 112A and each of the first negative electrodes 114A have different polarities from each other. The area of each first negative electrode 114A perpendicular to the Y direction is larger than the area of each first positive electrode 112A perpendicular to the Y direction. When viewed from the X direction, the length of each first negative electrode 114A in the Z direction is longer than the length of each first positive electrode 112A in the Z direction. In Figure 4 the example shown, the first negative electrode 114A is located on the outermost sides in the Y direction among the plurality of first positive electrodes 112A and the plurality of first negative electrodes 114A.

[0047] When viewed from the X direction, the first separator 116A has a substantially zigzag shape from the outermost side on the +Y side to the outermost side on the -Y side of the first laminate 110A. Therefore, from the outermost side on the +Y side to the outermost side on the -Y side of the first laminate 110A, the first separator 116A alternately folds back at the side portions in the Y direction of the first positive electrode 112A and the side portions in the Y direction of the first negative electrode 114A. Specifically, from the outermost side on the +Y side to the outermost side on the -Y side of the first laminate 110A, the first separator 116A alternately folds back at the side portion on the +Z side of the first positive electrode 112A and the side portion on the -Z side of the first negative electrode 114A. Therefore, the first separator 116A passes through the region between the first positive electrode 112A and the first negative electrode 114A adjacent to each other in the Y direction between the side portion on the +Z side of the first positive electrode 112A and the side portion on the -Z side of the first negative electrode 114A. Therefore, at least a part of the first separator 116A is located between the first positive electrode 112A and the first negative electrode 114A adjacent to each other in the Y direction.

[0048] In Figure 4 In the example shown, when viewed from the X direction, the base end portion of the substantially zigzag shape of the first separator 116A and the front end portion of the remaining length portion of the substantially zigzag shape of the first separator 116A are fixed to each other by the first fixing member 118A at the end portion on the +Y side of the first laminate 110A. Therefore, the plurality of first positive electrodes 112A, the plurality of first negative electrodes 114A, and the first separator 116A are integrally held by the first fixing member 118A. Specifically, when viewed from the X direction, the remaining length portion of the first separator 116A extends from the outermost side on the -Y side of the first laminate 110A toward the +Z side of the first laminate 110A. When viewed from the X direction, the remaining length portion of the first separator 116A bends toward the +Y side at the side of the +Z side of the battery element 100A. When viewed from the X direction, the front end portion of the remaining length portion of the first separator 116A bends toward the -Z side at the end portion on the +Y side of the battery element 100A. When viewed from the X direction, at the outermost side on the +Y side of the first laminate 110A, the front end portion of the remaining length portion of the first separator 116A and the base end portion of the first separator 116A overlap each other in the Y direction and are fixed to each other by the first fixing member 118A. The first fixing member 118A is, for example, a tape.

[0049] Next, the relationship among the first laminate 110A, the second laminate 120A, and the interposed positive electrode 130A will be described. Hereinafter, as needed, the outermost first negative electrode 114A on the -Y side among the plurality of first positive electrodes 112A and the plurality of first negative electrodes 114A of the first laminate 110A is referred to as the first outermost negative electrode 114aA. Hereinafter, as needed, the outermost second negative electrode 124A on the +Y side among the plurality of second positive electrodes 122A and the plurality of second negative electrodes 124A of the second laminate 120A is referred to as the second outermost negative electrode 124aA.

[0050] The first laminate 110A is located on the +Y side with respect to the interposed positive electrode 130A. The first separator 116A covers the -Y side surface of the first outermost negative electrode 114aA on the outermost side of the -Y side of the first laminate 110A. Therefore, the +Y side surface of the interposed positive electrode 130A and the -Y side surface of the first outermost negative electrode 114aA are separated from each other by the portion of the first separator 116A that covers the -Y side surface of the first outermost negative electrode 114aA. Therefore, an electrochemical reaction capable of charging and discharging the battery element 100A can occur between the +Y side surface of the interposed positive electrode 130A and the -Y side surface of the first outermost negative electrode 114aA.

[0051] The second laminate 120A is located on the -Y side with respect to the interposed positive electrode 130A. The second separator 126A covers the +Y side surface of the second outermost negative electrode 124aA on the outermost side of the +Y side of the first laminate 110B. Therefore, the -Y side surface of the interposed positive electrode 130A and the +Y side surface of the second outermost negative electrode 124aA are separated from each other by the portion of the second separator 126A that covers the +Y side surface of the second outermost negative electrode 124aA. Therefore, an electrochemical reaction capable of charging and discharging the battery element 100A can occur between the -Y side surface of the interposed positive electrode 130A and the +Y side surface of the second outermost negative electrode 124aA.

[0052] In Embodiment 1, the first laminate 110A and the second laminate 120A are separate laminates. That is, the first laminate 110A can operate alone as a battery element. The second laminate 120A can also operate alone as a battery element. However, as described above, in Embodiment 1, an electrochemical reaction capable of charging and discharging the battery element 100A can occur both between the interposed positive electrode 130A and the first outermost negative electrode 114aA, and between the interposed positive electrode 130A and the second outermost negative electrode 124aA. Therefore, the first laminate 110A, the second laminate 120A, and the interposed positive electrode 130A can operate integrally as a single battery element 100A.

[0053] In Embodiment 1, the first positive electrode 112A, the first negative electrode 114A, and the first separator 116A of the first laminate 110A are integrally held separately from the interposed positive electrode 130A. The second positive electrode 122A, the second negative electrode 124A, and the second separator 126A of the second laminate 120A are integrally held separately from the interposed positive electrode 130A. The total number of the first positive electrode 112A and the first negative electrode 114A included in the first laminate 110A is less than the total number of the positive electrodes and the negative electrodes included in the battery element 100A. Therefore, compared with the case where all the positive electrodes and the negative electrodes included in the battery element 100A are simply alternately laminated only in the Y direction, the first positive electrode 112A and the first negative electrode 114A can be alternately laminated in the Y direction in the first laminate 110A more easily. Similarly, the total number of the second positive electrode 122A and the second negative electrode 124A included in the second laminate 120A is less than the total number of the positive electrodes and the negative electrodes included in the battery element 100A. Therefore, compared with the case where all the positive electrodes and the negative electrodes included in the battery element 100A are simply alternately laminated only in the Y direction, the second positive electrode 122A and the second negative electrode 124A can be alternately laminated in the Y direction in the second laminate 120A more easily. Therefore, compared with the case where all the positive electrodes and the negative electrodes included in the battery element 100A are simply alternately laminated in the Y direction, the number of laminations of the positive electrodes and the negative electrodes in a single battery element 100A can be simply increased.

[0054] In Embodiment 1, the side portions in the Z direction of the interposed positive electrode 130A are not covered by the separator. That is, in the embodiment, a single interposed positive electrode 130A is disposed between the first laminate 110A and the second laminate 120A instead of other laminates, thereby forming the battery element 100A. Therefore, compared with the case where other laminates are disposed between the first laminate 110A and the second laminate 120A, the battery element 100A can be formed more easily.

[0055] In Embodiment 1, the first fixing member 118A is not disposed between the first stacked body 110A and the sandwiching positive electrode 130A in the Y direction. Specifically, the first fixing member 118A is disposed on the +Y side of the first stacked body 110A. Assuming that the first fixing member 118A is disposed between the first stacked body 110A and the sandwiching positive electrode 130A in the Y direction, the first fixing member 118A may affect the electrochemical reaction between the sandwiching positive electrode 130A and the first outermost negative electrode 114aA. In contrast, when the first fixing member 118A is not disposed between the first stacked body 110A and the sandwiching positive electrode 130A in the Y direction, the influence of the first fixing member 118A on the electrochemical reaction can be suppressed. The first fixing member 118A may be disposed on the +Z side or the -Z side of the first stacked body 110A instead of the +Y side. In this case, the influence of the first fixing member 118A on the above electrochemical reaction can also be suppressed. The same applies to the second fixing member 128A.

[0056] In Embodiment 1, when viewed from the X direction, the first partition member 116A of the first stacked body 110A is alternately folded back at the side portions on the +Z side of the first positive electrode 112A and the side portions on the -Z side of the first negative electrode 114A. However, instead of the first partition member 116A according to Embodiment 1SU, the first stacked body 110A may have a plurality of first partition members 116A having substantially sheet shapes and separated from each other. The plurality of first partition members 116A are respectively located between the first positive electrode 112A and the first negative electrode 114A adjacent to each other in the Y direction. The same applies to the second partition member 126A of the second stacked body 120A.

[0057] In Embodiment 1, a positive electrode 130A is present as a sandwiched electrode between a first separator 116A on the outermost -Y side of the first laminate 110A and a second separator 126A on the outermost +Y side of the second laminate 120A. However, it is also possible that a negative electrode is present as a sandwiched electrode between the first separator 116A on the outermost -Y side of the first laminate 110A and the second separator 126A on the outermost +Y side of the second laminate 120A. In this example, the first separator 116A covers the -Y side surface of the first positive electrode 112A located on the outermost -Y side among the plurality of first positive electrodes 112A and the plurality of first negative electrodes 114A on the outermost -Y side of the first laminate 110A. Therefore, the polarity of the sandwiched negative electrode is different from the polarity of the electrode located on the outermost -Y side of the first laminate 110A. The second separator 126A covers the +Y side surface of the second positive electrode 122A located on the outermost +Y side among the plurality of second positive electrodes 122A and the plurality of second negative electrodes 124A on the outermost +Y side of the second laminate 120A. Therefore, the polarity of the sandwiched negative electrode is different from the polarity of the electrode located on the outermost +Y side of the second laminate 120A. In this example, for the same reasons as those described in the embodiment, the first laminate 110A, the second laminate 120A, and the sandwiched positive electrode 130A can operate integrally as a single first laminate 110A.

[0058] In Embodiment 1, the battery cell 10A includes two laminates, namely, a first laminate 110A and a second laminate 120A, and one sandwiched positive electrode 130A. However, the battery cell 10A may also include three or more laminates and two or more sandwiched electrodes. In this example, each sandwiched electrode is located between two laminates stacked in the Y direction.

[0059] Next, an example of the manufacturing method of the battery element 100A will be described.

[0060] First, the first laminate 110A is formed. For example, when viewed from the X direction, a plurality of first positive electrodes 112A and a plurality of first negative electrodes 114A are alternately arranged in the Y direction on a first separator 116A bent into a substantially zigzag shape. Next, the plurality of first positive electrodes 112A, the plurality of first negative electrodes 114A, and the first separator 116A are integrally held by a first fixing member 118A. However, the formation method of the first laminate 110A is not limited to this example.

[0061] Simultaneously with or before or after the formation of the first laminate 110A, the second laminate 120A is formed in the same manner as the first laminate 110A.

[0062] Next, with the positive electrode 130A interposed therebetween, the first laminate 110A and the second laminate 120A are stacked on each other in the Y direction. Thus, the battery element 100A is manufactured.

[0063] Figure 5 It is a cross-sectional schematic view of the battery cell 10B according to the second embodiment. The battery cell 10B according to the second embodiment is the same as the battery cell 10A according to the first embodiment except for the following points.

[0064] The battery element 100B according to the second embodiment includes a first laminate 110B, a second laminate 120B, and a sandwiched positive electrode 130B. The first laminate 110B includes a plurality of first positive electrodes 112B, a plurality of first negative electrodes 114B, and a first separator 116B. The second laminate 120B includes a plurality of second positive electrodes 122B, a plurality of second negative electrodes 124B, and a second separator 126B.

[0065] The plurality of first positive electrodes 112B, the plurality of first negative electrodes 114B, and the first separator 116B are integrally held together with the sandwiched positive electrode 130B by a pair of first fixing members 118B. The pair of first fixing members 118B are provided on both sides in the Z direction of the first laminate 110B and the sandwiched positive electrode 130B. Each first fixing member 118B is, for example, a belt.

[0066] The plurality of second positive electrodes 122B, the plurality of second negative electrodes 124B, and the first separator 116B are held together separately by a pair of second fixing members 128B. The pair of second fixing members 128B are provided on both sides in the Z direction of the second laminate 120B. Each second fixing member 128B is, for example, a belt.

[0067] In the second embodiment, the surface on the +Y side of the sandwiched positive electrode 130B and the surface on the -Y side of the first outermost negative electrode 114aB are also separated from each other by the portion of the first separator 116B that covers the surface on the -Y side of the first outermost negative electrode 114aB. The surface on the -Y side of the sandwiched positive electrode 130B and the surface on the +Y side of the second outermost negative electrode 124aB are separated from each other by the portion of the second separator 126B that covers the surface on the +Y side of the second outermost negative electrode 124aB. Thus, similarly to the first embodiment, compared with the case where all the positive electrodes and negative electrodes included in the battery element 100B are simply alternately stacked in the Y direction, the number of stacked positive electrodes and negative electrodes in a single battery element 100B can be easily increased.

[0068] As described above, the embodiments of the present invention have been described with reference to the drawings, but these are examples of the present invention, and various structures other than the above can also be adopted.

[0069] This application claims priority based on Japanese Patent Application No. 2022-201916 filed on December 19, 2022, and incorporates the entire disclosure thereof herein.

[0070] -Description of Reference Numerals-

[0071] 10A, 10B: Battery cells, 100A, 100B: Battery elements, 102: Positive current collector, 104: Negative current collector, 110A, 110B: First laminate, 112A, 112B: First positive electrode, 114A, 114B: First negative electrode, 114aA, 114aB: First outermost negative electrode, 116A, 116B: First separator, 118A, 118B: First fixing member, 120A, 120B: Second laminate, 122A, 122B: Second positive electrode, 124A, 124B: Second negative electrode, 124aA, 124aB: Second outermost negative electrode, 126A, 126B: Second separator, 128A, 128B: Second fixing member, 130A, 130B: Clamped positive electrode, 210: Front cover member, 220: Rear cover member, 310: Positive electrode tab, 320: Negative electrode tab, 400: Outer packaging film, 402: Winding portion, 404: Lead-out portion, 404a: First lead-out portion, 404b: Second lead-out portion, 500: Accommodation space, 510: Front sealing portion, 520: Rear sealing portion, 530: Side sealing portion.

Claims

1. A battery cell, characterized in that, Comprising: Multiple laminates, each having a first electrode and a second electrode that are alternately laminated in a given direction and have different first and second polarities respectively, and a separator that covers at least a part of the second electrode located on the outermost side in the given direction among the first electrode and the second electrode; And A sandwich electrode, located between one outermost separator of the multiple laminates and the other outermost separator of the multiple laminates, having the first polarity.

2. The battery cell according to claim 1, wherein The separator is alternately folded back at the side portions in the given direction of the first electrode and the side portions in the given direction of the second electrode.

3. The battery cell according to claim 1 or 2, wherein One of the first electrode, the second electrode, and the separator in the multiple laminates is integrally held separately from the sandwich electrode, The other first electrode, the second electrode, and the separator in the multiple laminates are integrally held separately from the sandwich electrode.

4. The battery cell according to claim 1 or 2, wherein One of the first electrode, the second electrode, and the separator in the multiple laminates is integrally held together with the sandwich electrode, The other first electrode, the second electrode, and the separator in the multiple laminates are integrally held separately from the sandwich electrode.

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