Battery cell

Abstract

To achieve both suppression of misalignment of a laminate and improvement in energy density of a battery cell.SOLUTION: A battery cell 10A includes: a first laminate 110A having a first positive electrode 112A, a first negative electrode 114A, and a first separator 116A; a second laminate 120A having a second positive electrode 122A, a second negative electrode 124A, and a second separator 126A; and an intervening positive electrode 130A located between the first laminate 110A and the second laminate 120A. At least one of the surfaces of at least one of the first laminate 110A and the second laminate 120A and the intervening positive electrode 130A in contact with each other is subjected to an anti-slip treatment.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] In recent years, various types of battery cells have been developed, each of which has a battery element including a positive electrode, a negative electrode, and a separator.

[0003] Patent Document 1 describes an example of a battery cell. This battery cell includes two electrode bodies and an adhesive layer interposed between the two electrode bodies to bond the two electrode bodies to each other.

[0004] Patent Document 2 describes an example of a battery cell. This battery cell includes multiple laminate units stacked on top of each other. Each laminate unit has a positive electrode plate, a negative electrode plate, and a separator positioned between the positive and negative electrode plates. Concave and concave portions are provided on the opposing surfaces of the stacked laminate units to position the stacked laminate units relative to each other. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-51907 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-248465 Summary of the Invention [Problem to be solved by the invention]

[0006] For example, as described in Patent Document 1, a plurality of laminates, each having a positive electrode, a negative electrode, and a separator, may be stacked on top of each other. When a plurality of laminates are stacked on top of each other, an adhesive layer may be provided between the laminates to prevent the laminates from shifting. However, when an adhesive layer is provided between the laminates, the volume of the battery cell increases depending on the thickness of the adhesive layer, which may make it difficult to improve the energy density of the battery cell.

[0007] An example of an object of the present invention is to simultaneously suppress misalignment of the laminate and improve the energy density of the battery cell. Other objects of the present invention will become apparent from the description of this specification. [Means for solving the problem]

[0008] One aspect of the present invention is as follows. 1. A plurality of laminates each having a positive electrode, a negative electrode, and a separator; an intervening electrode located between the laminates; Equipped with A battery cell, wherein at least one of the surfaces of the intervening electrode and at least one of the laminates located on both sides of the intervening electrode that come into contact with each other is treated with an anti-slip treatment. 2. The battery cell according to claim 1, wherein the anti-slip treatment includes at least one of a roughening treatment and the addition of an adhesive compound. 3. The battery cell according to 1. or 2., wherein the laminate has a plurality of the positive electrodes and a plurality of the negative electrodes stacked alternately, and the separator is folded back alternately at one side of each positive electrode and at the side opposite to the one side of each negative electrode. 4. The battery cell described in 3., wherein the intervening electrode has a polarity different from that of either the positive electrode or the negative electrode located at the outermost position on the side where the intervening electrode is located among the multiple positive electrodes and multiple negative electrodes of the laminate located on one side of the intervening electrode, or the positive electrode or the negative electrode located at the outermost position on the side where the intervening electrode is located among the multiple positive electrodes and multiple negative electrodes of the laminate located on the other side of the intervening electrode. 5. A battery comprising a plurality of laminates, each having a positive electrode, a negative electrode, and a separator; At least one of the surfaces of the laminated bodies that come into contact with each other is treated with an anti-slip coating. 6. The battery cell according to claim 5, wherein the anti-slip treatment includes at least one of a roughening treatment and the addition of an adhesive compound. 7. The battery cell according to claim 5 or 6, wherein each laminate includes a plurality of the positive electrodes and a plurality of the negative electrodes stacked alternately, and the separator is folded back alternately at one side portion of each positive electrode and at the other side portion of each negative electrode opposite the one side portion. [Effects of the Invention]

[0009] According to the above aspect of the present invention, it is possible to suppress misalignment of the laminate and improve the energy density of the battery cell at the same time. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a front perspective view of a battery cell according to the first embodiment. [Figure 2] 1 is an enlarged front perspective view of a portion of a battery cell according to Embodiment 1. FIG. [Figure 3] FIG. 2 is a right side view of the battery cell according to the first embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view of FIG. 3 taken along the line AA. [Figure 5] FIG. 10 is a cross-sectional view of a battery cell according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, similar components are designated by similar reference numerals, and the description thereof will be omitted as appropriate.

[0012] Fig. 1 is a front perspective view of a battery cell 10A according to Embodiment 1. Fig. 2 is an enlarged front perspective view of a portion of the battery cell 10A according to Embodiment 1. Fig. 3 is a right side view of the battery cell 10A according to Embodiment 1. For the sake of explanation, Fig. 3 shows an exterior film 400 in a see-through state.

[0013] For ease of explanation, each figure is labeled with an X, Y, and Z direction. The X direction indicates the front-to-rear direction of the battery cell 10A. The Y direction is perpendicular to the X direction. The Y direction indicates the left-to-right direction of the battery cell 10A. The Z direction is perpendicular to both the X and Y directions. The Z direction indicates the up-to-down direction of the battery cell 10A. The directions indicated by the arrow indicating the X direction, the arrow indicating the Y direction, and the arrow indicating the Z direction are the rearward, leftward, and upward directions, respectively. However, the relationships between the X direction, Y direction, Z direction, front-to-rear direction, left-to-right direction, and up-to-down direction of the battery cell 10A are not limited to this example. Note that a white circle with an X indicating the X direction, Y direction, or Z direction indicates that the direction from the front to the back of the page is the direction indicated by the arrow indicating that direction.

[0014] Hereinafter, where necessary, the side indicated by the arrow indicating the X direction will be referred to as the +X side. Hereinafter, where necessary, the side opposite the side indicated by the arrow indicating the X direction will be referred to as the -X side. Hereinafter, where necessary, the side indicated by the arrow indicating the Y direction will be referred to as the +Y side. Hereinafter, where necessary, the side opposite the side indicated by the arrow indicating the Y direction will be referred to as the -Y side. Hereinafter, where necessary, the side indicated by the arrow indicating the Z direction will be referred to as the +Z side. Hereinafter, where necessary, the side opposite the side indicated by the arrow indicating the Z direction will be referred to as the -Z side.

[0015] Hereinafter, where necessary, a plane perpendicular to the X direction will be referred to as the YZ plane. Hereinafter, where necessary, a plane perpendicular to the Y direction will be referred to as the ZX plane. Hereinafter, where necessary, a plane perpendicular to the Z direction will be referred to as the XY plane.

[0016] The battery cell 10A includes a battery element 100A, a front cover member 210, a rear cover member 220, a positive electrode tab 310, a negative electrode tab 320, and an exterior film 400. The exterior film 400 has a wound portion 402 and a pulled-out portion 404.

[0017] The battery element 100A has a substantially rectangular parallelepiped shape. The longitudinal direction of the battery element 100A is substantially parallel to the X direction. The lateral 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.

[0018] The front cover member 210 covers the front end portion of the battery element 100A. The front cover member 210 is made of a resin such as polypropylene. When viewed from the front, the front cover member 210 has a substantially rectangular shape. When viewed from the front, the longitudinal direction of the front cover member 210 is substantially parallel to the Z direction, and the lateral direction of the front cover member 210 is substantially parallel to the Y direction.

[0019] The rear lid member 220 covers the rear end of the battery element 100A. The rear lid member 220 is made of a resin such as polypropylene. When viewed from the rear, the rear lid member 220 has a substantially rectangular shape. When viewed from the rear, the longitudinal direction of the rear lid member 220 is substantially parallel to the Z direction, and the lateral direction of the rear lid member 220 is substantially parallel to the Y direction.

[0020] The positive electrode tab 310 protrudes forward from the front cover member 210. The positive electrode tab 310 is electrically connected to a positive electrode current collector 102 that is drawn forward from a first positive electrode 112A and a second positive electrode 122A (described later) of the battery element 100A. Thus, 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.

[0021] The negative electrode tab 320 protrudes rearward from the rear cover member 220. The negative electrode tab 320 is electrically connected to a negative electrode current collector 104 that is drawn rearward from a first negative electrode 114A and a second negative electrode 124A (described later) of the battery element 100A. Thus, 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.

[0022] As shown in FIGS. 1 and 2 , the wound portion 402 has a generally cylindrical shape that is open both front and rear. The front cover member 210 is disposed inside the front opening of the wound portion 402. The rear cover member 220 is disposed inside the rear opening of the wound portion 402. The wound portion 402 is wound around the battery element 100A, the front cover member 210, and the rear cover member 220 in the X direction by one turn. As a result, the front cover member 210, the rear cover member 220, and the wound portion 402 form a storage space 500 that stores the battery element 100A. The storage space 500 stores the battery element 100A as well as an electrolyte (not shown). The manner in which the wound portion 402 wraps around the battery element 100A is not limited to the example described above.

[0023] 1 and 2 , at least a portion of the periphery of the positive electrode tab 310 on the front surface of the front cover member 210 is exposed from the exterior film 400. However, the exterior film 400 may cover the periphery of the positive electrode tab 310 on the front surface of the front cover member 210. Similarly, at least a portion of the periphery of the negative electrode tab 320 on the rear surface of the rear cover member 220 is exposed from the exterior film 400. However, the exterior film 400 may cover the periphery of the negative electrode tab 320 on the rear surface of the rear cover member 220.

[0024] The outer peripheral surface of the front lid member 210 in the X direction and the inner peripheral surface of the front opening of the wound portion 402 in the X direction are joined to each other by, for example, heat fusion. This forms the front sealed portion 510. The outer peripheral surface of the rear lid member 220 in the X direction and the inner peripheral surface of the rear opening of the wound portion 402 in the X direction are joined to each other by, for example, heat fusion. This forms the rear sealed portion 520.

[0025] As shown in FIGS. 1 and 2, when viewed from the front, the drawn-out portion 404 is drawn out from the upper left corner of the wound portion 402 of the battery element 100A. Specifically, as shown in FIG. 2, the drawn-out portion 404 includes a first drawn-out portion 404a and a second drawn-out portion 404b. The first drawn-out portion 404a is drawn out from one of both ends of the wound portion 402 in the circumferential direction around the X direction. The second drawn-out portion 404b is drawn out from the other end of the wound portion 402 in the circumferential direction around the X direction. The first drawn-out portion 404a and the second drawn-out portion 404b are joined to each other by, for example, thermal fusion. This forms a side sealing portion 530. The drawn-out portion 404 is bent along the top surface of the battery element 100A. However, the drawn-out portion 404 does not have to be bent. The folded shape of the drawn-out portion 404 is not limited to the shape according to the first embodiment.

[0026] In the first embodiment, the front and rear ends of the battery element 100A are covered with two lid materials. However, for example, when both the positive electrode tab 310 and the negative electrode tab 320 are pulled out from the front end of the battery element 100A, the front end of the battery element 100A may be covered with the lid material, without the rear end of the battery element 100A being covered with the lid material. That is, only the side of the battery element 100A from which the positive electrode tab 310 and the negative electrode tab 320 are pulled out may be covered with the lid material. In this case, an exterior film 400 may be sealed on the side of the battery element 100A opposite the lid material and folded along the battery element 100A.

[0027] FIG. 4 is a schematic cross-sectional view taken along the line AA in FIG.

[0028] The battery element 100A according to the first embodiment includes a first laminate 110A, a second laminate 120A, and an intervening positive electrode 130A. The first laminate 110A and the second laminate 120A are stacked on top of each other in the Y direction. The intervening positive electrode 130A is located between the first laminate 110A and the second laminate 120A in the Y direction. The first laminate 110A includes a plurality of first positive electrodes 112A, a plurality of first negative electrodes 114A, and a first separator 116A. The second laminate 120A includes a plurality of second positive electrodes 122A, a plurality of second negative electrodes 124A, and a second separator 126A.

[0029] The first stacked body 110A will be described below. Unless otherwise specified, the matters described below regarding the first stacked body 110A also apply to the second stacked body 120A.

[0030] The multiple first positive electrodes 112A and the multiple first negative electrodes 114A are alternately stacked in the Y direction. The first positive electrodes 112A and the first negative electrodes 114A have polarities different from each other. The area perpendicular to the Y direction of each first negative electrode 114A is larger than the area perpendicular to the Y direction of each first positive electrode 112A. When viewed from the X direction, the length in the Z direction of each first negative electrode 114A is longer than the length in the Z direction of each first positive electrode 112A. In the example shown in FIG. 4, the first negative electrodes 114A are located on the outermost sides of both sides in the Y direction of the multiple first positive electrodes 112A and the multiple first negative electrodes 114A.

[0031] When viewed from the X direction, the first separator 116A has a generally zigzag shape from the outermost side on the +Y side of the first laminate 110A to the outermost side on the -Y side. Therefore, the first separator 116A is folded back alternately at the Y-direction side portion of the first positive electrode 112A and the Y-direction side portion of the first negative electrode 114A from the outermost side on the +Y side of the first laminate 110A to the outermost side on the -Y side. Specifically, the first separator 116A is folded back alternately at the +Z-side side portion of the first positive electrode 112A and the -Z-side side portion of the first negative electrode 114A from the outermost side on the +Y side of the first laminate 110A to the outermost side on the -Y side. Therefore, the first separator 116A passes through the region between the first positive electrode 112A and the first negative electrode 114A that are adjacent in the Y direction, between the +Z side portion of the first positive electrode 112A and the -Z side portion of the first negative electrode 114A. Therefore, at least a portion of the first separator 116A is located between the first positive electrode 112A and the first negative electrode 114A that are adjacent in the Y direction.

[0032] In the example shown in FIG. 4 , as viewed from the X direction, the base end of the first separator 116A having the above-described generally zigzag shape and the tip end of the above-described generally zigzag shape excess portion of the first separator 116A are fixed to each other by a first fixing material 118A at the end of the +Y side of the first stack 110A. Thus, the multiple first positive electrodes 112A, the multiple first negative electrodes 114A, and the first separator 116A are integrally held by the first fixing material 118A. Specifically, as viewed from the X direction, this excess portion of the first separator 116A is pulled out from the outermost side on the −Y side of the first stack 110A to the +Z side of the first stack 110A. As viewed from the X direction, this excess portion of the first separator 116A is bent toward the +Y side at the side of the +Z side of the battery element 100A. When viewed from the X direction, the tip of this excess portion of the first separator 116A is bent toward the -Z side at the end 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 tip of this excess portion of the first separator 116A and the base end of the first separator 116A overlap each other in the Y direction and are fixed to each other by a first fixing material 118A. The first fixing material 118A is, for example, a tape.

[0033] Next, the relationship between the first stack 110A, the second stack 120A, and the interposed positive electrode 130A will be described. Hereinafter, as needed, the first negative electrode 114A located outermost on the -Y side among the multiple first positive electrodes 112A and multiple first negative electrodes 114A of the first stack 110A will be referred to as the first outermost negative electrode 114aA. Hereinafter, as needed, the portion of the first separator 116A covering the -Y side surface of the first outermost negative electrode 114aA will be referred to as the first outermost separator portion 116aA. Hereinafter, as needed, the second negative electrode 124A located outermost on the +Y side among the multiple second positive electrodes 122A and multiple second negative electrodes 124A of the second stack 120A will be referred to as the second outermost negative electrode 124aA. Hereinafter, the portion of the second separator 126A that covers the surface on the +Y side of the second outermost negative electrode 124aA will be referred to as the second outermost separator portion 126aA, as necessary.

[0034] The first laminate 110A is located on the +Y side of the intervening positive electrode 130A. The first separator 116A covers the -Y side surface of the first outermost negative electrode 114aA at the outermost -Y side of the first laminate 110A. Therefore, the +Y side surface of the intervening positive electrode 130A and the -Y side surface of the first outermost negative electrode 114aA are separated from each other by the first outermost separator portion 116aA. This allows electrochemical reactions for charging and discharging the battery element 100A to occur between the +Y side surface of the intervening positive electrode 130A and the -Y side surface of the first outermost negative electrode 114aA.

[0035] 4, a gap is schematically illustrated between the −Y side surface of the first outermost separator portion 116aA and the +Y side surface of the interposed positive electrode 130A. However, in reality, the −Y side surface of the first outermost separator portion 116aA and the +Y side surface of the interposed positive electrode 130A are in contact with each other without a gap therebetween.

[0036] At least one of the -Y side surface of the first outermost separator portion 116aA and the +Y side surface of the interposed positive electrode 130A is treated with an anti-slip coating. The -Y side surface of the first outermost separator portion 116aA and the +Y side surface of the interposed positive electrode 130A are in contact with each other. Therefore, compared to when the anti-slip coating is not applied, it is possible to suppress the displacement of the first stack 110A and the interposed positive electrode 130A in the Z direction. In addition, in the first embodiment, it is not necessary to provide an adhesive layer between the -Y side surface of the first outermost separator portion 116aA and the +Y side surface of the interposed positive electrode 130A to suppress the displacement of the first stack 110A and the interposed positive electrode 130A in the Z direction. Therefore, it is possible to suppress the increase in the volume of the battery cell 10A compared to when an adhesive layer is provided. Therefore, according to embodiment 1, it is possible to suppress the Z-direction shift of the first stack 110A relative to the interposed positive electrode 130A and improve the energy density of the battery cell 10A, compared to when no anti-slip treatment is applied.

[0037] As an example of the anti-slip treatment, at least one of the −Y side surface of the first outermost separator portion 116aA and the +Y side surface of the interposed positive electrode 130A may be roughened. For example, at least one of the +Y side surface of the interposed positive electrode 130A and the −Y side surface of the first outermost separator portion 116aA may be coated with a resin layer or a resin layer in which ceramic particles are dispersed.

[0038] As another example of the anti-slip treatment, an adhesive compound may be added to at least one of the −Y side surface of the first outermost separator portion 116aA and the +Y side surface of the interposed positive electrode 130A. For example, at least one of the +Y side surface of the interposed positive electrode 130A and the −Y side surface of the first outermost separator portion 116aA may be coated with an adhesive layer containing an adhesive component such as polyvinylidene fluoride (PVDF).

[0039] The examples of the anti-slip treatment are not limited to the examples described above, and the anti-slip treatment may be any one of the above examples alone or a combination of the above examples.

[0040] The second stack 120A is located on the -Y side of the intervening positive electrode 130A. The second separator 126A, located on the outermost +Y side of the first stack 110A, covers the +Y side surface of the second outermost negative electrode 124aA. Therefore, the -Y side surface of the intervening positive electrode 130A and the +Y side surface of the second outermost negative electrode 124aA are separated from each other by the second outermost separator portion 126aA. This allows electrochemical reactions for charging and discharging the battery element 100A to occur between the -Y side surface of the intervening positive electrode 130A and the +Y side surface of the second outermost negative electrode 124aA.

[0041] 4, a gap is schematically illustrated between the +Y side surface of the second outermost separator portion 126aA and the −Y side surface of the interposed positive electrode 130A. However, in reality, the +Y side surface of the second outermost separator portion 126aA and the −Y side surface of the interposed positive electrode 130A are in contact with each other without a gap therebetween.

[0042] At least one of the +Y side surface of the second outermost separator portion 126aA and the −Y side surface of the interposed positive electrode 130A is treated with an anti-slip coating. The +Y side surface of the second outermost separator portion 126aA and the −Y side surface of the interposed positive electrode 130A are in contact with each other. Therefore, compared to when the anti-slip coating is not applied, it is possible to suppress the displacement of the second stack 120A and the interposed positive electrode 130A in the Z direction. In addition, in the first embodiment, it is not necessary to provide an adhesive layer between the +Y side surface of the second outermost separator portion 126aA and the −Y side surface of the interposed positive electrode 130A to suppress the displacement of the second stack 120A and the interposed positive electrode 130A in the Z direction. Therefore, it is possible to suppress the increase in the volume of the battery cell 10A compared to when an adhesive layer is provided. Therefore, according to embodiment 1, it is possible to suppress the Z-direction shift of the first stack 110A relative to the interposed positive electrode 130A and improve the energy density of the battery cell 10A, compared to when no anti-slip treatment is applied.

[0043] Examples of the anti-slip treatment applied to at least one of the +Y side surface of the second outermost separator portion 126aA and the -Y side surface of the interposed positive electrode 130A include the same examples as the anti-slip treatment applied to at least one of the -Y side surface of the first outermost separator portion 116aA and the +Y side surface of the interposed positive electrode 130A.

[0044] In the first embodiment, the first stack 110A and the second stack 120A are separate stacks. That is, the first stack 110A can function independently as a battery element. The second stack 120A can also function independently as a battery element. However, as described above, in the first embodiment, electrochemical reactions for charging and discharging the battery element 100A can occur both between the intervening positive electrode 130A and the first outermost negative electrode 114aA and between the intervening positive electrode 130A and the second outermost negative electrode 124aA. Therefore, the first stack 110A, the second stack 120A, and the intervening positive electrode 130A can operate together as a single battery element 100A.

[0045] In the first embodiment, 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 first positive electrodes 112A and first negative electrodes 114A included in the first laminate 110A is smaller than the total number of positive electrodes and negative electrodes included in the battery element 100A. Therefore, compared to simply stacking all the positive electrodes and negative electrodes included in the battery element 100A alternately in the Y direction, the first positive electrodes 112A and first negative electrodes 114A can be easily stacked alternately in the Y direction in the first laminate 110A. Similarly, the total number of second positive electrodes 122A and second negative electrodes 124A included in the second laminate 120A is smaller than the total number of positive electrodes and negative electrodes included in the battery element 100A. Therefore, compared to a case where all of the positive electrodes and negative electrodes included in the battery element 100A are simply stacked alternately in the Y direction, the second positive electrodes 122A and second negative electrodes 124A can be easily stacked alternately in the Y direction in the second laminate 120A. Therefore, compared to a case where all of the positive electrodes and negative electrodes included in the battery element 100A are simply stacked alternately in the Y direction, the number of stacked positive electrodes and negative electrodes in a single battery element 100A can be easily increased.

[0046] In the first embodiment, both side portions in the Z direction of the interposed positive electrode 130A are not covered with a separator. That is, in the embodiment, the battery element 100A is formed by disposing a single interposed positive electrode 130A without disposing another laminate between the first laminate 110A and the second laminate 120A. Therefore, the battery element 100A can be formed more easily than when another laminate is disposed between the first laminate 110A and the second laminate 120A.

[0047] In the first embodiment, the first fixing material 118A is not disposed between the first stack 110A and the intervening positive electrode 130A in the Y direction. Specifically, the first fixing material 118A is disposed on the +Y side of the first stack 110A. If the first fixing material 118A were disposed between the first stack 110A and the intervening positive electrode 130A in the Y direction, the first fixing material 118A could affect the electrochemical reaction between the intervening positive electrode 130A and the first outermost negative electrode 114aA. In contrast, if the first fixing material 118A is not disposed between the first stack 110A and the intervening positive electrode 130A in the Y direction, the effect of the first fixing material 118A on the electrochemical reaction can be suppressed. The first fixing material 118A may be disposed on the +Z side or the −Z side of the first stack 110A instead of the +Y side of the first stack 110A. In this case as well, the influence of the first fixing material 118A on the above-mentioned electrochemical reaction can be suppressed. The same applies to the second fixing material 128A.

[0048] In the first embodiment, when viewed from the X direction, the first separator 116A of the first stack 110A is folded back alternately at the +Z side portion of the first positive electrode 112A and the -Z side portion of the first negative electrode 114A. However, instead of the first separator 116A according to the first embodiment, the first stack 110A may have a plurality of substantially sheet-shaped first separators 116A that are separated from one another. Each of the plurality of first separators 116A is located between the first positive electrode 112A and the first negative electrode 114A that are adjacent in the Y direction. The same applies to the second separator 126A of the second stack 120A.

[0049] In the first embodiment, an intervening positive electrode 130A is positioned as an intervening electrode between the outermost first separator 116A on the -Y side of the first stack 110A and the outermost second separator 126A on the +Y side of the second stack 120A. However, an intervening negative electrode may be positioned as an intervening electrode between the outermost first separator 116A on the -Y side of the first stack 110A and the outermost second separator 126A on the +Y side of the second stack 120A. In this example, the first separator 116A covers the -Y side surface of the first positive electrode 112A, which is positioned outermost on the -Y side among the plurality of first positive electrodes 112A and the plurality of first negative electrodes 114A, at the outermost side on the -Y side of the first stack 110A. Therefore, the polarity of the intervening negative electrode is different from the polarity of the electrode located at the outermost position on the -Y side of the first stack 110A. The second separator 126A covers the +Y side surface of the second positive electrode 122A located at the outermost position on the +Y side of the second stack 120A among the plurality of second positive electrodes 122A and the plurality of second negative electrodes 124A. Therefore, the polarity of the intervening negative electrode is different from the polarity of the electrode located at the outermost position on the +Y side of the second stack 120A. In this example, the first stack 110A, the second stack 120A, and the intervening positive electrode 130A can operate together as a single first stack 110A for the same reasons as those described in the embodiment.

[0050] In the first embodiment, the battery cell 10A includes two laminates, a first laminate 110A and a second laminate 120A, and one intervening electrode, an intervening positive electrode 130A. However, the battery cell 10A may include three or more laminates and two or more intervening electrodes. In this example, each intervening electrode is located between two laminates stacked in the Y direction.

[0051] Next, an example of a method for manufacturing the battery element 100A will be described.

[0052] First, a first stack 110A is formed. For example, a plurality of first positive electrodes 112A and a plurality of first negative electrodes 114A are arranged alternately in the Y direction on a first separator 116A that is folded into a generally zigzag shape when viewed from the X direction. 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 material 118A. However, the method for forming the first stack 110A is not limited to this example.

[0053] Simultaneously with the formation of the first stack 110A, or before or after that, the second stack 120A is formed in the same manner as the first stack 110A.

[0054] Next, the interposed positive electrode 130A is prepared.

[0055] Next, anti-slip treatment is applied to at least one of the -Y side surface of the first outermost separator portion 116aA and the +Y side surface of the interposed positive electrode 130A. Similarly, anti-slip treatment is applied to at least one of the +Y side surface of the second outermost separator portion 126aA and the -Y side surface of the interposed positive electrode 130A.

[0056] Next, the first laminate 110A and the second laminate 120A are stacked together in the Y direction with the interposed positive electrode 130A disposed between them in the Y direction, thereby producing the battery element 100A.

[0057] The structure of the battery cell 10A is not limited to the structure according to the first embodiment.

[0058] 5 is a schematic cross-sectional view of a battery cell 10B according to embodiment 2. The battery cell 10B according to embodiment 2 is similar to the battery cell 10A according to embodiment 1 except for the following points.

[0059] The battery element 100B according to the second embodiment includes a first laminate 110A and a second laminate 120A. However, the battery element 100B according to the second embodiment does not include an electrode corresponding to the interposed positive electrode 130A according to the first embodiment.

[0060] 5, a gap is schematically illustrated between the -Y side surface of the first outermost separator portion 116aA and the +Y side surface of the second outermost separator portion 126aA. However, in reality, the -Y side surface of the first outermost separator portion 116aA and the +Y side surface of the second outermost separator portion 126aA are in contact with each other without a gap therebetween.

[0061] At least one of the -Y side surface of the first outermost separator portion 116aA and the +Y side surface of the second outermost separator portion 126aA is treated with an anti-slip coating. The -Y side surface of the first outermost separator portion 116aA and the +Y side surface of the second outermost separator portion 126aA are in contact with each other. Therefore, compared to a case where the anti-slip coating is not applied, it is possible to suppress misalignment of the first stacked body 110A and the second stacked body 120A in the Z direction. In addition, in the second embodiment, it is not necessary to provide an adhesive layer between the -Y side surface of the first outermost separator portion 116aA and the +Y side surface of the second outermost separator portion 126aA to suppress misalignment of the first stacked body 110A and the second stacked body 120A in the Z direction. Therefore, it is possible to suppress an increase in the volume of the battery cell 10B compared to a case where an adhesive layer is provided. Therefore, according to the second embodiment, it is possible to suppress the Z-direction shift of the first stack 110A and the second stack 120A and to improve the energy density of the battery cell 10B, compared to when no anti-slip treatment is applied.

[0062] Examples of the anti-slip treatment applied to at least one of the -Y side surface of the first outermost separator portion 116aA and the +Y side surface of the second outermost separator portion 126aA include the same examples as the anti-slip treatment applied to at least one of the -Y side surface of the first outermost separator portion 116aA and the +Y side surface of the interposed positive electrode 130A in embodiment 1.

[0063] The structure of the battery cell 10B is not limited to the structure according to the second embodiment.

[0064] In one example, the −Y side surface of the first outermost negative electrode 114aA and the +Y side surface of the second outermost negative electrode 124aA may be in contact with each other without the first outermost separator portion 116aA and the second outermost separator portion 126aA being provided between the −Y side surface of the first outermost negative electrode 114aA and the +Y side surface of the second outermost negative electrode 124aA, and an anti-slip treatment may be applied to at least one of the −Y side surface of the first outermost negative electrode 114aA and the +Y side surface of the second outermost negative electrode 124aA. An example of the anti-slip treatment is a coating with a layer having ion conductivity similar to that of the first separator 116A or the second separator 126A. In this example, it is possible to both suppress misalignment in the Z direction of the first stack 110A and the second stack 120A and improve the energy density of the battery cell 10A, compared to a case where the anti-slip treatment is not applied.

[0065] Although the embodiments of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various other configurations can also be adopted. [Explanation of symbols]

[0066] 10A, 10B Battery cell, 100A, 100B Battery element, 102 Positive electrode current collector, 104 Negative electrode current collector, 110A First laminate, 112A First positive electrode, 114A First negative electrode, 114aA First outermost negative electrode, 116A First separator, 116aA First outermost separator portion, 118A First fixing material, 120A Second laminate, 122A Second positive electrode, 124A Second negative electrode, 124aA Second outermost negative electrode, 126A Second separator, 126aA Second outermost separator portion, 128A Second fixing material, 130A Interposed positive electrode, 210 Front cover material, 220 Rear cover material, 310 Positive electrode tab, 320 Negative electrode tab, 400 Outer packaging film, 402 Wrapping portion, 404, drawer portion, 404a, first drawer portion, 404b, second drawer portion, 500, storage space, 510, front sealing portion, 520, rear sealing portion, 530, side sealing portion

Claims

1. a plurality of laminates each having a positive electrode, a negative electrode, and a separator; an intervening electrode located between the laminates; Equipped with A battery cell, wherein at least one of the surfaces of the intervening electrode and at least one of the laminates located on both sides of the intervening electrode that come into contact with each other is treated with an anti-slip treatment.

2. The battery cell of claim 1 , wherein the anti-slip treatment includes at least one of a surface roughening treatment and the addition of an adhesive compound.

3. 3. The battery cell according to claim 1, wherein the stack includes a plurality of the positive electrodes and a plurality of the negative electrodes stacked alternately, and the separators are folded back alternately at a side portion on one side of each positive electrode and a side portion on the opposite side of each negative electrode.

4. 4. The battery cell according to claim 3, wherein the intervening electrode has a polarity different from that of either the positive electrode or the negative electrode located at the outermost position on the side where the intervening electrode is located among the plurality of positive electrodes and the plurality of negative electrodes of the laminate located on one side of the intervening electrode, or the positive electrode or the negative electrode located at the outermost position on the side where the intervening electrode is located among the plurality of positive electrodes and the plurality of negative electrodes of the laminate located on the other side of the intervening electrode.

5. a plurality of laminates each having a positive electrode, a negative electrode, and a separator; At least one of the surfaces of the laminated bodies that come into contact with each other is treated with an anti-slip coating.

6. The battery cell of claim 5 , wherein the anti-slip treatment includes at least one of a surface roughening treatment and the addition of an adhesive compound.

7. 7. The battery cell according to claim 5, wherein each stack includes a plurality of the positive electrodes and a plurality of the negative electrodes stacked alternately, and the separators are folded back alternately at one side portion of each positive electrode and at the other side portion of each negative electrode opposite to the one side portion.

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