Battery cell

Abstract

To improve the functionality of a conductor provided in a lid material formed by a laminate film.SOLUTION: A battery cell 10 includes a battery element 100, a front laminate film 210 that covers a front end surface of the battery element 100, a front conductor 310 electrically connected to the battery element 100, and a side laminate film 400 wound around the battery element 100. The front conductor 310 is located at least partially between the front end surface of the battery element 100 and the front conductor 310.SELECTED DRAWING: Figure 1

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. A battery cell has a battery element having a positive electrode, a negative electrode, and a separator.

[0003] Patent Documents 1 and 2 describe an example of a battery cell. This battery cell includes a battery case that houses a battery element. The battery case has two cup-shaped members made of a laminate film and a strip-shaped member made of a laminate film. The two cup-shaped members made of a laminate film face each other with the battery element interposed therebetween. The strip-shaped member made of a laminate film is wrapped around the battery element. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-153504 A [Patent Document 2] JP 2019-153514 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described in Patent Documents 1 and 2, the end faces of a battery element may be covered with a lid material made of a laminate film. The battery cell needs to have a conductor electrically connected to the battery element. However, it may be difficult to improve the functionality of the conductor simply by providing the conductor on the lid material made of a laminate film.

[0006] One example of an object of the present invention is to improve the functionality of a conductor provided on a cover material made of a laminate film. Other objects of the present invention will become apparent from the description of this specification. [Means for solving the problem]

[0007] One aspect of the present invention is as follows. 1. A battery element; A laminate film covering an end surface of the battery element; a conductor electrically connected to the battery element; Another laminate film wrapped around the battery element; Equipped with The conductor is at least partially located between the end surface of the battery element and the laminate film. 2. The battery cell described in 1., wherein the conductor has a protruding conductor protruding toward the side opposite to the side on which the battery element is located. 3. The battery cell according to claim 1 or 2, wherein the laminate film and the conductor are at least partially joined to each other. 4. The battery cell according to any one of 1. to 3., wherein the laminate film has a recessed structure recessed toward the side where the battery element is located. 5. The battery cell according to any one of 1 to 4, wherein the laminate film has an edge that is at least partially folded toward the side opposite to the side on which the battery element is located. Effect of the Invention

[0008] According to the above aspect of the present invention, it is possible to improve the functionality of the conductor provided in the lid material constituted by the laminate film. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is an exploded perspective view of a battery cell according to an embodiment. [Diagram 2] FIG. 2 is a perspective view of a front laminating film according to a first modified example of the embodiment. [Diagram 3] 3 is a cross-sectional view of a battery cell according to a first modified example of the embodiment, taken at a position corresponding to the AA cross section in FIG. 2. [Figure 4] FIG. 11 is a perspective view of a front laminating film according to a second modified example of the embodiment. [Diagram 5] FIG. 13 is a perspective view of a front laminating film according to a third modified example of the embodiment. [Figure 6] FIG. 13 is a perspective view of a front lamination film and a front conductor according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments and modifications of the present invention will be described with reference to the drawings. In all the drawings, similar components are given similar reference numerals and descriptions thereof will be omitted as appropriate.

[0011] FIG. 1 is an exploded perspective view of a battery cell 10 according to an embodiment.

[0012] For the sake of explanation, an X direction, a Y direction, and a Z direction are indicated in FIG. 1. The X direction indicates the front-rear direction of the battery cell 10. The Y direction is perpendicular to the X direction. The Y direction indicates the left-right direction of the battery cell 10. The Z direction is perpendicular to both the X direction and the Y direction. The Z direction indicates the up-down direction of the battery cell 10. The direction indicated by the arrow indicating the X direction, the direction indicated by the arrow indicating the Y direction, and the direction indicated by the arrow indicating the Z direction are the front direction, the left direction, and the up-down direction, respectively. However, the relationships between 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 10 are not limited to this example.

[0013] The battery cell 10 includes two battery elements 100 , a front laminate film 210 , a rear laminate film 220 , a front conductor 310 , a rear conductor 320 and side laminate films 400 .

[0014] The two battery elements 100 are stacked in the Z direction. Each battery element 100 has a substantially rectangular parallelepiped shape. The dimension of each battery element 100 in the X direction is the dimension in the longitudinal direction of each battery element 100. The dimension of each battery element 100 in the Y direction is the dimension in the lateral direction of each battery element 100. The dimension of each battery element 100 in the Z direction is the dimension in the thickness direction of each battery element 100. However, the shape of the battery element 100 is not limited to this example. The number of battery elements 100 included in the battery cell 10 may be only one or three or more.

[0015] Each battery element 100 has at least one positive electrode (not shown), at least one negative electrode (not shown), and at least one separator (not shown). In one example, a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked in the Z direction. At least a portion of the separator is located between the positive electrodes and the negative electrodes adjacent in the Z direction. Specifically, in one example, each of a plurality of sheet-like separators is located between the positive electrodes and the negative electrodes adjacent in the Z direction. However, one sheet-like separator may be alternately folded back at the left end of the positive electrode and the right end of the negative electrode, or alternately folded back at the right end of the positive electrode and the left end of the negative electrode. Alternatively, the positive electrode, the negative electrode, and the separator may be wound so that the separator is disposed between the positive electrode and the negative electrode. In one example, the positive electrode, the negative electrode, and the separator are wound in a state in which both sides of one of the positive electrode and the negative electrode are covered by the separator. In another example, a laminate including a plurality of unit laminates including a positive electrode, a separator, and a negative electrode in this order may be wound, but the winding structure of the positive electrode, the negative electrode, and the separator is not limited to these examples.

[0016] In the embodiment, the battery cell 10 is a battery cell containing an electrolyte. However, the battery cell 10 may be an all-solid-state battery. In the all-solid-state battery, a solid electrolyte layer is provided in a portion corresponding to a separator. The all-solid-state battery does not contain an electrolyte.

[0017] Unless otherwise specified, hereinafter, each battery element 100 will be described as including a plurality of positive electrodes and a plurality of negative electrodes alternately stacked in the Z direction.

[0018] A plurality of positive electrode current collectors 110 are drawn out from the front end surface of each battery element 100. In Fig. 1, the plurality of positive electrode current collectors 110 drawn out from the front end surface of each battery element 100 are illustrated as one solid. The plurality of positive electrode current collectors 110 are integrated with the plurality of positive electrodes of each battery element 100 and are electrically connected to the plurality of positive electrodes of each battery element 100.

[0019] A plurality of negative electrode current collectors 120 are drawn out from the rear end surface of each battery element 100. In Fig. 1, the plurality of negative electrode current collectors 120 drawn out from the rear end surface of each battery element 100 are illustrated as one solid. The plurality of negative electrode current collectors 120 are integrated with the plurality of negative electrodes of each battery element 100 and are electrically connected to the plurality of negative electrodes of each battery element 100.

[0020] The front laminate film 210 has a metal layer and a sealant layer located on both sides of the metal layer. Examples of metals used for the metal layer include aluminum and stainless steel. The ends of the metal layer are exposed from the ends of the front laminate film 210. Examples of materials used for the sealant layer include polyolefins such as polypropylene (PP), polyethylene (PE), polystyrene (PS), and polyvinyl chloride (PVC). In addition to the metal layer and the sealant layer, the front laminate film 210 may further have a layer made of a thermoplastic resin. Examples of thermoplastic resins include polyamides (PA) such as nylon, polyesters such as polyethylene terephthalate (PET), and polyolefins such as polypropylene (PP), polyethylene (PE), polystyrene (PS), and polyvinyl chloride (PVC).

[0021] The front laminate film 210 constitutes a lid material that covers the front end surface of each battery element 100. The flexibility of the front laminate film 210 is higher than that of the lid material of the resin block or the lid material of the metal block. That is, the front laminate film 210 is more easily deformable than the lid material of the resin block or the lid material of the metal block. Therefore, when the front laminate film 210 is used, it is easier to apply a strong pressure to the battery element 100 by the lid material than when the lid material of the resin block or the lid material of the metal block is used.

[0022] The front laminate film 210 has a front central portion 212 and a front peripheral folded edge 214 .

[0023] The rear surface of the front central portion 212 and the front end surface of the battery element 100 face each other at a predetermined distance in the X direction. When viewed from the front, the front central portion 212 has a substantially rectangular shape having a pair of long sides substantially parallel to the Y direction, a pair of short sides substantially parallel to the Z direction, and four rounded corners. The front central portion 212 defines a front central hole 213 in the center of the front central portion 212 in the Y direction and the Z direction. However, the shape of the front central portion 212 is not limited to this example.

[0024] The front outer periphery folding edge 214 is folded forward at a substantially right angle with respect to the front central portion 212. The folding between the front central portion 212 and the front outer periphery folding edge 214 is formed, for example, by embossing. The end of the metal layer included in the front laminate film 210 may be exposed from the front end of the front outer periphery folding edge 214. Therefore, by folding the front outer periphery folding edge 214 forward with respect to the front central portion 212, the end of the metal layer exposed from the front end of the front outer periphery folding edge 214 can be directed forward. Therefore, compared to a case where the front outer periphery folding edge 214 is not folded with respect to the front central portion 212 or a case where the front outer periphery folding edge 214 is folded backward with respect to the front central portion 212, a short circuit between the end of the metal layer and the battery element 100 can be suppressed.

[0025] The front end of the front outer periphery folded edge 214 may be electrically insulated by a method such as attaching an insulating tape or applying an insulating material. As described above, an end of a metal layer included in the front laminate film 210 may be exposed from the front end of the front outer periphery folded edge 214. By electrically insulating the front end of the front outer periphery folded edge 214, a short circuit between the end of the metal layer and a conductive member near the front end of the front outer periphery folded edge 214 can be suppressed.

[0026] The rear laminating film 220, like the front laminating film 210, has a rear central portion 222 corresponding to the front central portion 212, and a rear peripheral folded edge portion 224 corresponding to the front peripheral folded edge portion 214. The rear central portion 222 defines a rear central hole 223 corresponding to the front central hole 213, like the front central portion 212. The rear laminating film 220 is similar to the front laminating film 210, except that the front laminating film 210 and the rear laminating film 220 are arranged symmetrically to each other.

[0027] The front conductor 310 includes a front barrier conductor 312 and a forward projecting conductor 314 .

[0028] The front barrier conductor 312 is at least partially located between the front end surface of each battery element 100 and the rear surface of the front central portion 212. Therefore, the front surface of the front barrier conductor 312 and the rear surface of the front central portion 212 can be at least partially joined to each other by a joining method such as heat fusion. Therefore, when the front laminate film 210 and the front conductor 310 can be joined to each other, the handleability of the front laminate film 210 and the front conductor 310 can be improved compared to a case where it is difficult to join the front laminate film 210 and the front conductor 310 to each other. Therefore, the functionality of the front conductor 310 can be improved compared to a case where the front conductor 310 does not have a conductor corresponding to the front barrier conductor 312. However, the front surface of the front barrier conductor 312 and the rear surface of the front central portion 212 do not have to be joined to each other.

[0029] The front barrier conductor 312 covers at least a portion of the rear surface of the front central portion 212. The front barrier conductor 312 is, for example, a metal. Therefore, when the front barrier conductor 312 is provided, it is possible to reduce moisture reaching each battery element 100 from the front side of the front central portion 212, compared to when the front barrier conductor 312 is not provided. Therefore, it is possible to improve the functionality of the front conductor 310, compared to when the front conductor 310 does not have a conductor equivalent to the front barrier conductor 312.

[0030] The forward protruding conductor 314 is located at the center of the front surface of the front barrier conductor 312 in the Y direction and the Z direction. The forward protruding conductor 314 and the front barrier conductor 312 are integral. With the front barrier conductor 312 covering at least a part of the rear surface of the front central portion 212, the forward protruding conductor 314 penetrates the front central hole 213. The edge defining the front central hole 213 in the front central portion 212 may be electrically insulated by a method such as attaching an insulating tape or applying an insulating material. An end of a metal layer included in the front laminate film 210 may be exposed from the edge defining the front central hole 213 in the front central portion 212. By electrically insulating the edge defining the front central hole 213 in the front central portion 212, a short circuit between the end of the metal layer and the outer circumferential surface of the forward protruding conductor 314 can be suppressed. Alternatively, the short circuit between the end of the metal layer and the outer surface of the forward-projecting conductor 314 may be suppressed by electrically reducing the thickness of the outer surface of the forward-projecting conductor 314 by applying insulating tape or other methods such as applying an insulating material.

[0031] The rear surface of the front barrier conductor 312 and the front ends of the positive electrode current collectors 110 are joined to each other by a joining method such as laser welding or ultrasonic bonding. Therefore, the forward protruding conductor 314 and the positive electrodes of each battery element 100 are electrically connected to each other via the front barrier conductor 312 and the positive electrode current collectors 110. Thus, the forward protruding conductor 314 serves as a positive electrode terminal of the battery cell 10. However, the electrical connection between the front conductor 310 and each battery element 100 is not limited to the above example. For example, the front conductor 310 and the positive electrode current collectors 110 may be electrically connected to each other via another conductor disposed between the front conductor 310 and the positive electrode current collectors 110.

[0032] In the embodiment, the forward projecting conductor 314 has a solid structure. For example, the forward conductor 310 is formed by joining a conductor plate constituting the forward barrier conductor 312 and a conductor block constituting the forward projecting conductor 314 to each other. Alternatively, the forward conductor 310 may be formed by integrally extruding the forward barrier conductor 312 and the forward projecting conductor 314. When the forward projecting conductor 314 has a solid structure, heat generation of the forward conductor 310 can be suppressed compared to a case where the forward projecting conductor 314 projects toward the forward barrier conductor 312 by embossing and a space recessed toward the forward barrier conductor 312 is present behind the forward projecting conductor 314. Furthermore, when the forward projecting conductor 314 has a solid structure, the degree of freedom of the joint between the forward conductor 310 and the front end of the plurality of positive electrode current collectors 110 can be improved compared to a case where the forward projecting conductor 314 projects toward the forward barrier conductor 312 by embossing and a space recessed toward the forward barrier conductor 312 is present behind the forward projecting conductor 314.

[0033] In the embodiment, the front barrier conductor 312 is provided with one forward protruding conductor 314. However, the front barrier conductor 312 may be provided with a plurality of forward protruding conductors 314.

[0034] The matters described for the front conductor 310 according to the embodiment are also applicable to the rear conductor 320. As shown in FIG. 1, the rear conductor 320 according to the embodiment has a rear barrier conductor 322 corresponding to the front barrier conductor 312 and a rear-projecting conductor (not shown) corresponding to the forward-projecting conductor 314, similar to the front conductor 310 according to the embodiment. The front surface of the rear barrier conductor 322 and the rear ends of the negative electrode current collectors 120 are joined to each other by a joining method such as laser welding or ultrasonic bonding. Therefore, the rear-projecting conductor and the negative electrodes of each battery element 100 are electrically connected to each other via the rear barrier conductor 322 and the negative electrode current collectors 120. Therefore, the rear-projecting conductor serves as a negative electrode terminal of the battery cell 10.

[0035] As shown in FIG. 1, the side laminate film 400 is wrapped around the battery element 100, the front laminate film 210, and the rear laminate film 220 in the X direction. The side laminate film 400 has a generally cylindrical shape that opens both forward and backward. The front laminate film 210 is disposed inside the front opening of the side laminate film 400. The rear laminate film 220 is disposed inside the rear opening of the side laminate film 400. Thus, the front laminate film 210, the rear laminate film 220, and the side laminate film 400 form a storage space that stores the battery element 100, the multiple positive electrode collectors 110, and the multiple negative electrode collectors 120. The storage space stores the battery element 100, the multiple positive electrode collectors 110, and the multiple negative electrode collectors 120, as well as an electrolyte (not shown).

[0036] The outer peripheral surface around the X direction of the front outer peripheral folded edge 214 and the inner peripheral surface around the X direction of the front end of the side laminate film 400 are joined to each other by a joining method such as heat fusion. Therefore, a sealing portion is formed between the outer peripheral surface around the X direction of the front outer peripheral folded edge 214 and the inner peripheral surface around the X direction of the front end of the side laminate film 400. When the front outer peripheral folded edge 214 is folded forward relative to the front central portion 212, the joining area between the front laminate film 210 and the front end of the side laminate film 400 can be made larger than when the front outer peripheral folded edge 214 is not folded relative to the front central portion 212, and the front laminate film 210 and the front end of the side laminate film 400 can be firmly joined.

[0037] The outer peripheral surface around the X direction of the rear outer peripheral folded edge 224 and the inner peripheral surface around the X direction of the rear end of the side laminate film 400 are joined to each other by a joining method such as heat fusion. Therefore, a sealing portion is formed between the outer peripheral portion around the X direction of the rear outer peripheral folded edge 224 and the inner peripheral portion around the X direction of the rear end of the side laminate film 400. When the rear outer peripheral folded edge 224 is folded backward with respect to the rear central portion 222, the joining area between the rear laminate film 220 and the rear end of the side laminate film 400 can be made larger than when the rear outer peripheral folded edge 224 is not folded with respect to the rear central portion 222, and the rear laminate film 220 and the rear end of the side laminate film 400 can be firmly joined.

[0038] In one example, the side laminate film 400 has a wound portion wound around the battery element 100, the front laminate film 210, and the rear laminate film 220 in the X direction, and two drawn-out portions drawn from both ends of the wound portion in the X direction. The two drawn-out portions are joined to each other by, for example, heat fusion. Thus, a sealing portion is formed between the two drawn-out portions.

[0039] Next, an example of a method for manufacturing the battery cell 10 according to this embodiment will be described.

[0040] First, two battery elements 100 are stacked on each other. Each battery element 100 has at least one positive electrode, at least one negative electrode, and at least one separator. A plurality of positive electrode current collectors 110 and a plurality of negative electrode current collectors 120 are led out from the two battery elements 100.

[0041] Next, the front laminate film 210 and the front conductor 310 are prepared. The front laminate film 210 is previously formed with a front central portion 212 and a front outer peripheral folded edge portion 214 by embossing. Next, in a state in which the forward protruding conductor 314 of the front conductor 310 penetrates the front central hole 213 of the front central portion 212, the rear surface of the front central portion 212 and the front surface of the front barrier conductor 312 are joined to each other by thermal fusion. Next, the front ends of the multiple positive electrode current collectors 110 and the rear surface of the front barrier conductor 312 are joined to each other by a joining method such as laser welding or ultrasonic bonding. Similarly, the multiple negative electrode current collectors 120 and the rear conductor 320 are also joined to each other.

[0042] Next, the side laminate film 400 is wrapped around the battery element 100, the front laminate film 210, and the rear laminate film 220 in the X direction. Next, the outer peripheral surface around the X direction of the front outer peripheral folded edge 214 and the inner peripheral surface around the X direction of the front end of the side laminate film 400 are joined together by heat fusion to form a sealing portion between the outer peripheral surface around the X direction of the front outer peripheral folded edge 214 and the inner peripheral surface around the X direction of the opening at the front end of the side laminate film 400. Next, the outer peripheral surface around the X direction of the rear outer peripheral folded edge 224 and the inner peripheral surface around the X direction of the rear end of the side laminate film 400 are joined together by heat fusion to form a sealing portion between the outer peripheral surface around the X direction of the rear outer peripheral folded edge 224 and the inner peripheral surface around the X direction of the rear end of the side laminate film 400. With these sealing portions formed, the front laminate film 210, the rear laminate film 220, and the side laminate film 400 form a storage space that stores the battery element 100, the plurality of positive electrode current collectors 110, and the plurality of negative electrode current collectors 120. The side laminate film 400 has two pull-out portions pulled out from both ends around the X direction of a wound portion that is wound around the battery element 100, the front laminate film 210, and the rear laminate film 220 one turn around the X direction.

[0043] Next, an electrolyte is injected into the storage space through the gap between the two drawn-out portions of the side laminate film 400. Next, the storage space is evacuated through the gap between the two drawn-out portions of the side laminate film 400. Next, the two drawn-out portions of the side laminate film 400 are joined by heat fusion to form a sealing portion, and the storage space is vacuum-sealed.

[0044] In this manner, the battery cell 10 according to the embodiment is manufactured.

[0045] Fig. 2 is a perspective view of a front laminate film 210A1 according to a first modified example of the embodiment. Fig. 3 is a cross-sectional view of a battery cell 10A1 according to a first modified example of the embodiment at a position corresponding to the AA cross section in Fig. 2. In Fig. 3, the white circle with a black dot indicating the Z direction indicates that the direction indicated by the arrow indicating the Z direction is the direction from the back of the page to the front.

[0046] As shown in FIG. 2, the front laminate film 210A1 has a pair of recessed structures 216A1. The pair of recessed structures 216A1 are located on both sides of the front central hole 213 in the Y direction in the front central portion 212. Each recessed structure 216A1 is recessed toward the rear with respect to the front central portion 212. Each recessed structure 216A1 is formed, for example, by embossing. The rear end surface of the recessed structure 216A1 is located rearward of the rear surface of the front central portion 212. When viewed from the X direction, the dimension of each recessed structure 216A1 in the Z direction is the dimension in the longitudinal direction of the recessed structure 216A1, and the dimension of each recessed structure 216A1 in the Y direction is the dimension in the lateral direction of the recessed structure 216A1. However, the shape of each recessed structure 216A1 is not limited to the example shown in FIG. 2.

[0047] As shown in Fig. 3, the rear end surface of each recessed structure 216A1 and the front end surface of the battery element 100 are in contact with each other. However, the rear end surface of each recessed structure 216A1 and the front end surface of the battery element 100 may be opposed to each other in the X direction with a gap therebetween without contacting each other. By making the dimension of the gap in the X direction between the rear end surface of each recessed structure 216A1 and the front end surface of the battery element 100 sufficiently small, or by making the rear end surface of each recessed structure 216A1 and the front end surface of the battery element 100 contact each other, it is possible to restrict the movement of the battery element 100 and the front laminate film 210A1 in a direction approaching each other.

[0048] As shown in FIG. 3, the front conductor 310A1 includes a front barrier conductor 312A1, a forward protruding conductor 314A1, and a pair of surrounding portions 316A1.

[0049] The forward projecting conductor 314A1 is projected from the front barrier conductor 312A1 by embossing. Therefore, a space recessed forward from the front barrier conductor 312A1 exists behind the forward projecting conductor 314A1. Therefore, the weight of the front conductor 310A1 can be reduced compared to the case where the forward projecting conductor 314A1 has a solid structure. However, the forward projecting conductor 314A1 may have a solid structure.

[0050] Each of the pair of surrounding portions 316A1 at least partially surrounds the pair of recessed structures 216A1 in the X direction. The rear end of each surrounding portion 316A1 is open toward the rear. Therefore, the rear end surface of each recessed structure 216A1 is exposed toward the rear from the rear end of each surrounding portion 316A1.

[0051] As shown in FIG. 3, the battery cell 10A1 includes a temperature sensor 500. The temperature sensor 500 is a thermistor. The temperature sensor 500 is provided to detect the temperature of at least one of the battery element 100 and the plurality of positive electrode current collectors 110. The temperature sensor 500 includes a sealant 502 and a Dumet wire 504. The sealant 502 is, for example, glass that seals a chip such as a thermistor chip. The Dumet wire 504 is electrically connected to the chip sealed in the sealant 502. However, the structure of the temperature sensor 500 is not limited to the example shown in FIG. 3.

[0052] 3, the sealing body 502 is disposed at the rear end of the recessed space inside the right recessed structure 216A1. The Dumet wire 504 is drawn from the rear end of the sealing body 502 to the outside of the right recessed structure 216A1 via the front opening of the right recessed structure 216A1. Thus, the right recessed structure 216A1 functions as an accommodation space for accommodating at least a part of the temperature sensor 500. Therefore, the functionality of the front laminate film 210 can be improved compared to a case where the recessed structure 216A1 is not provided.

[0053] At least a part of the temperature sensor 500 may be disposed inside the left recessed structure 216A1 as well. Alternatively, neither the left recessed structure 216A1 nor the right recessed structure 216A1 may be provided with the temperature sensor 500. An element other than the temperature sensor 500 may be disposed inside the recessed structure 216A1.

[0054] FIG. 4 is a perspective view of a front laminating film 210A2 according to a second modified example of the embodiment.

[0055] The front laminate film 210A2 has four recessed structures 216A2. When viewed from the X direction, the four recessed structures 216A2 are located at the four corners of the front central portion 212. In the example shown in FIG. 4, similarly to the example shown in FIG. 2, the functionality of the front laminate film 210A2 can be improved compared to the case where each recessed structure 216A2 is not provided.

[0056] FIG. 5 is a perspective view of a front laminating film 210A3 according to a third modified example of the embodiment.

[0057] The front laminate film 210A3 has only one recessed structure 216A3. The recessed structure 216A3 is located above the front central hole 213 in the front central portion 212. In the example shown in Fig. 5, as in the example shown in Fig. 2, the functionality of the front laminate film 210A3 can be improved compared to the case where the recessed structure 216A3 is not provided.

[0058] FIG. 6 is a perspective view of a front laminate film 210B and a front conductor 310B according to a modified example.

[0059] The front laminate film 210B has a front central portion 212B and a front inner peripheral folded edge 218B.

[0060] The front inner circumferential folded edge 218B is folded forward at a substantially right angle with respect to the front central portion 212B. The fold between the front central portion 212B and the front inner circumferential folded edge 218B is formed, for example, by embossing. A front central hole 213B is provided at the front end of the front inner circumferential folded edge 218B. From the front central hole 213B, the front surface of the forward protruding conductor 314B of the front conductor 310B is exposed forward. From the front end of the front inner circumferential folded edge 218B, an end of a metal layer included in the front laminate film 210B may be exposed. In a modified example, the front inner circumferential folded edge 218B is folded forward with respect to the front central portion 212B, so that the end of the metal layer can be directed forward. Therefore, compared to a case where the front inner circumferential folded edge 218B is not folded, it is possible to suppress a short circuit between the end of the metal layer and the outer peripheral surface of the forward protruding conductor 314B.

[0061] 6, the outer peripheral edge of the front central portion 212B is not bent forward. However, similar to the embodiment, the outer peripheral edge of the front central portion 212B may be bent forward.

[0062] Although the embodiment and modified examples of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations other than those described above can also be adopted.

[0063] In the embodiment and each modified example, the positive electrode terminal and the negative electrode terminal are disposed on opposite sides of the battery element 100 in the X direction. However, both the positive electrode terminal and the negative electrode terminal may be disposed on only one of the front end face side and the rear end face side in the X direction of the battery element 100. When both the positive electrode terminal and the negative electrode terminal are disposed on only one of the front end face side and the rear end face side in the X direction of the battery element 100, the front end face and the rear end face of the battery element 100 are covered, for example, by two laminate films constituting the lid material. Alternatively, only the end face from which the positive electrode terminal and the negative electrode terminal of the battery element 100 are drawn may be covered by the laminate film constituting the lid material. When only the end face from which the positive electrode terminal and the negative electrode terminal of the battery element 100 are drawn is covered by the laminate film constituting the lid material, the side laminate film 400 may be sealed on the opposite side of the laminate film of the battery element 100 and folded along the battery element 100. [Explanation of symbols]

[0064] 10, 10A1 battery cell, 100 battery element, 110 positive electrode current collector, 120 negative electrode current collector, 210, 210A1, 210A2, 210A3, 210B front laminate film, 212, 212B front center portion, 213, 213B front center hole, 214 front outer peripheral folded edge portion, 216A1, 216A2, 216A3 concave structure, 218B front inner peripheral folded edge portion, 220 rear laminate film, 222 rear center portion, 223 rear center hole, 224 rear outer peripheral folded edge portion, 310, 310A1, 310B front conductor, 312, 312A1 front barrier conductor, 314, 314A1, 314B forward protruding conductor, 316A1 Enclosure, 320 rear conductor, 322 rear barrier conductor, 400 side laminate film, 500 temperature sensor, 502 encapsulant, 504 dumet wire

Claims

1. A battery element; A laminate film covering an end surface of the battery element; a conductor electrically connected to the battery element; Another laminate film wrapped around the battery element; Equipped with The conductor is at least partially located between the end surface of the battery element and the laminate film.

2. The battery cell according to claim 1 , wherein the conductor has a protruding conductor protruding toward a side opposite to the side on which the battery element is located.

3. The battery cell of claim 1 or 2, wherein the laminate film and the conductor are at least partially joined to each other.

4. The battery cell according to claim 1 , wherein the laminate film has a recessed structure recessed toward a side where the battery element is located.

5. The battery cell according to claim 1 or 2, wherein the laminate film has an edge that is at least partially folded toward the side opposite to the side on which the battery element is located.

Images