Battery cell and battery cell laminate

Abstract

The invention relates to a battery cell and a battery cell stack. A battery cell is provided with: an electrode body in which a plurality of laminated structures having a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode are further laminated; and a tape that is wound and affixed around the outer periphery of the electrode body, the tape having an overlapping portion in which one end side and the other end side in the outer peripheral direction overlap, and the tape having a plurality of stacked structures in the electrode body are stacked in a stacking direction and an end surface in the stacking direction of the electrode body is a stacking surface. The overlapping portion is disposed on a surface other than the laminated surface of the electrode body.

Description

Technical Field

[0001] The present disclosure relates to a battery cell and a battery cell stack. Background Art

[0002] A battery cell using an electrode body in which a plurality of positive electrodes, negative electrodes, and separators are stacked is being studied.

[0003] For example, Japanese Patent Application 2016-015212 discloses a secondary battery comprising a stack and a belt for fixing the stack, wherein the stack is a stack in which positive electrodes and negative electrodes are alternately stacked via a separator, and the belt has a pair of planar attachment portions which are arranged at both ends and are respectively attached to the two outermost layers of the stack, and a middle portion which is located between the pair of planar attachment portions and is attached to the side end edges of each layer of the stack, and the planar attachment portion has a pointed shape with an acute angle at the top.

[0004] In addition, Japanese Patent Publication No. 2015-534251 discloses an electrode assembly, wherein the electrode assembly includes a first electrode stack and a second electrode stack, wherein the first electrode stack is an electrode stack in which at least one electrode assembly having a first area is stacked, and the second electrode stack is an electrode stack in which at least one electrode assembly having a second area different from the first area is stacked, wherein the first electrode stack and the second electrode stack are stacked in a direction perpendicular to a plane, wherein the electrode assembly includes a step portion formed due to the difference in area between the first electrode stack and the second electrode stack, wherein the step portion exists on at least one of the four sides of the electrode assembly, and wherein at least one step portion has at least one belt wrapped across the stacking side surface, and the belt has a step difference shape of the step portion. Summary of the invention

[0005] However, in a battery cell, when the adhesive tape is wound around the periphery of the electrode body, an overlapping portion is formed in which one end side and the other end side of the tape overlap in the peripheral direction. The battery cell is used by stacking a plurality of them in the stacking direction together with other battery cells, so when the overlapping portion of the tape is all arranged on the end face (stacking surface) in the stacking direction of the electrode body, the volume in the stacking direction increases due to the overlapping portion of the tape, resulting in a decrease in volume efficiency. That is, in the method of winding the adhesive tape around the periphery of the electrode body and forming an overlapping portion in which one end side and the other end side of the tape overlap, there is room for further improving the volume efficiency.

[0006] The present disclosure has been made in view of the above-mentioned actual situation, and an object of the present disclosure is to provide a battery cell having improved volume efficiency and a battery cell stack having the battery cell.

[0007] Means for solving the above-mentioned problems include the following aspects.

[0008] <1> A battery cell comprising:

[0009] an electrode body in which a plurality of stacked structures are further stacked, the stacked structure having a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode; and

[0010] The tape is wound around the outer circumference of the electrode body.

[0011] The belt has an overlapping portion where one end side and the other end side in the outer circumferential direction overlap each other,

[0012] When a direction in which a plurality of the stacked structures in the electrode body are stacked is defined as a stacking direction and an end surface of the electrode body in the stacking direction is defined as a stacking surface, the overlapping portion is disposed on a surface of the electrode body other than the stacking surface.

[0013] <2> according to <1> The battery unit,

[0014] A plurality of the tapes are wound and attached to the outer circumference of the electrode body.

[0015] The overlapping portions in all the tapes are arranged on a surface other than the stacking surface of the electrode body.

[0016] <3> according to <2> The battery unit,

[0017] The overlapping portions in all the tapes are arranged on one same surface among surfaces of the electrode body other than the stacking surface.

[0018] <4> A battery cell stack having a plurality of cells stacked in the stacking direction <1> ~ <3> A battery cell as described in any one of the above.

[0019] According to the present disclosure, it is possible to provide a battery cell having improved volume efficiency and a battery cell stack having the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention are described below with reference to the accompanying drawings, in which like reference numerals represent like components, and in which:

[0021] Figure 1 is a schematic perspective view illustrating a battery unit according to an embodiment of the present disclosure;

[0022] Figure 2 is a schematic cross-sectional view illustrating another aspect of a battery cell according to an embodiment of the present disclosure;

[0023] Figure 3is a schematic diagram of a battery cell housed in a battery module as viewed from the thickness direction;

[0024] Figure 4 is a schematic plan view showing the main parts of the vehicle;

[0025] Figure 5 This is a schematic perspective view of a battery module.

[0026] Figure 6 This is a plan view of the battery module with the upper cover removed. DETAILED DESCRIPTION

[0027] Battery Cell

[0028] The battery cell involved in the embodiment of the present disclosure has: an electrode body, wherein a plurality of stacked structures are further stacked, wherein the stacked structure has a positive electrode, a negative electrode, and a separator between the positive electrode and the negative electrode; and a tape that is wound and pasted around the periphery of the electrode body. The tape has an overlapping portion that overlaps one end side and the other end side in the peripheral direction. Moreover, when the direction in which the plurality of stacked structures in the electrode body are stacked is taken as the stacking direction and the surface of the electrode body orthogonal to the stacking direction is taken as the stacking surface, the overlapping portion is arranged on a surface other than the stacking surface of the electrode body.

[0029] Hereinafter, one embodiment of a battery cell according to an embodiment of the present disclosure will be described using the drawings.

[0030] Each of the drawings shown below is a schematic diagram, and the size and shape of each part are appropriately exaggerated for easy understanding.

[0031] Figure 1 It is a schematic perspective view illustrating a battery unit according to an embodiment of the present disclosure.

[0032] Figure 1 The battery cell 20A shown in FIG. 1 has an electrode body 5 formed into a substantially rectangular plate shape. Although not shown in the figure, the electrode body 5 is an electrode body in which a stacked structure having a plurality of positive electrodes, negative electrodes and separators interposed therebetween is further stacked in the arrow Y direction (stacking direction).

[0033] Furthermore, in Figure 1In the figure, the thickness direction of the electrode body 5 (i.e., the stacking direction) is set as the arrow Y direction, the length direction of the electrode body 5 is set as the arrow Z direction, and the width direction of the electrode body 5 is set as the arrow X direction. The arrow X direction, the arrow Y direction, and the arrow Z direction are respectively orthogonal to each other. In addition, the two end faces of the electrode body 5 in the stacking direction (arrow Y direction) are set as stacking surfaces 51A and 51B, the two end faces of the electrode body 5 in the length direction (arrow Z direction) are set as length direction side faces 52A and 52B, and the two end faces of the electrode body 5 in the width direction (arrow X direction) are set as width direction side faces 53A and 53B.

[0034] The electrode body 5 has terminals (tabs) 26 on the longitudinal side surfaces 52A and 52B. In the present embodiment, as an example, the terminals 26 are provided at positions offset to one side from the center of the battery cell 20 in the width direction (arrow X direction).

[0035] Five tapes 41 to 45 are attached to the outer periphery of the electrode body 5 in a manner of being wound all around. The tapes 41 to 45 are all wound around the stacking surfaces 51A, 51B and the width direction side surfaces 53A, 53B of the electrode body 5 all around. The electrode body 5 has a stacked structure of a positive electrode, a negative electrode, and a separator, which is bundled by winding the tapes 41 to 45 around the outer periphery. The tapes 41 to 45 are all wound around the electrode body 5 in a manner of overlapping one end side and the other end side in the outer peripheral direction, forming overlapping portions 41A to 45A with overlapping ends. Moreover, the overlapping portions 41A to 45A are all arranged on the surface other than the stacking surfaces 51A, 51B of the electrode body 5, specifically, on the width direction side surface 53A.

[0036] Thus, the battery cell according to the embodiment of the present disclosure has one or more tapes wound around the outer circumference of the electrode body, and the overlapping portion of at least one of the tapes is arranged on a surface other than the stacking surface of the electrode body. The battery cell according to the embodiment of the present disclosure can be further combined with a plurality of battery cells in the stacking direction (e.g. Figure 1 Therefore, by arranging one or more overlapping portions of the tape on a surface other than the stacking surface of the electrode body, the number of overlapping portions arranged on the stacking surface is reduced, and the overlapping portions arranged on the stacking surface are subjected to a higher surface pressure from the stacked battery cells, so that they are easily flattened. As a result, the volume in the stacking direction caused by the overlapping portions of the tape can be reduced, the space in the stacking direction can be effectively used, and the volume efficiency is improved.

[0037] exist Figure 1, the overlapping portions 41A to 45A of the five tapes 41 to 45 are all arranged on the surfaces other than the stacking surfaces 51A and 51B of the electrode body 5, but the present disclosure is not limited to this. When a plurality of tapes are wound around the periphery of the electrode body, it is sufficient as long as the overlapping portion of at least one of the tapes is arranged on the surface other than the stacking surface of the electrode body.

[0038] However, when a plurality of tapes are wound around the periphery of the electrode body, it is preferable to Figure 1 As shown in the embodiment, all overlapping portions of the tapes are arranged on the stacking surface of the electrode body (e.g. Figure 1 By arranging all the overlapping portions of the plurality of tapes on the surfaces other than the stacking surfaces of the electrode body, there is no overlapping portion arranged on the stacking surface, and the volume in the stacking direction caused by the tapes can be further reduced. As a result, the space in the stacking direction can be used more effectively, and the volume efficiency is further improved.

[0039] exist Figure 1 4 shows that the overlapping portions 41A to 45A of the five tapes 41 to 45 are all arranged on the same surface of the electrode body 5 (specifically, on the side surface 53A in the width direction), but the present disclosure is not limited to this. In the case where multiple tapes are wound around the periphery of the electrode body, the overlapping portions of the tapes can also be arranged on different surfaces. For example, Figure 1 In the embodiment shown in , one or more and four or less overlapping portions among the overlapping portions 41A to 45A in the five belts 41 to 45 may be arranged on the width direction side surface 53B instead of on the width direction side surface 53A.

[0040] However, when a plurality of tapes are wound around the periphery of the electrode body, it is preferable to Figure 1 As shown in , all overlapping portions of the tapes are arranged on one of the same surfaces other than the stacking surfaces of the electrode body. By arranging all overlapping portions of the tapes on one of the same surfaces other than the stacking surfaces of the electrode body, there are no overlapping portions arranged on other surfaces other than the stacking surfaces (for example, Figure 1 In the manner shown in , there is no overlapped portion arranged on the widthwise side surface 53B). Thus, the space on the side where there is no overlapped portion of the belt can be effectively utilized. For example, by ensuring space for setting other components such as a cooling material and a buffer material on the side where there is no overlapped portion of the belt, and increasing the volume of the electrode body (for example, Figure 1 By increasing the length of the electrode body 5 in the width direction in the embodiment shown in FIG. 1 , the space can be effectively utilized.

[0041] exist Figure 1, the tapes 41 to 45 are shown to be wound around the stacking surfaces 51A, 51B and the width-direction side surfaces 53A, 53B of the electrode body 5, that is, wound in the width direction (arrow X direction) of the electrode body 5, but the present disclosure is not limited to this. For example, the tapes 41 to 45 may be wound in the length direction (e.g. Figure 1 The tape is wound in the longitudinal direction (arrow Z direction) of the electrode body 5.

[0042] For example, in Figure 1 In the embodiment shown, the tape may be wound around the stacking surfaces 51A, 51B and the longitudinal side surfaces 52A, 52B of the electrode body 5. In this case, there are one or more tapes wound around the outer circumference of the electrode body 5, and the overlapping portion of at least one of the tapes is arranged on the surface other than the stacking surface of the electrode body 5, that is, on the longitudinal side surfaces 52A, 52B.

[0043] In addition, when the electrode has a terminal, it is preferable that, for example, Figure 1 As shown, the terminals are arranged on the surface not wound with the tape.

[0044] Laminated film

[0045] The battery cell according to the embodiment of the present disclosure may be further covered with a laminate film and sealed. Figure 2 To illustrate the Figure 1 The electrode body and tape of the structure shown are further sealed in a laminate film in a battery cell.

[0046] Figure 2 This is a schematic cross-sectional view illustrating a battery cell according to another embodiment of the present disclosure.

[0047] Figure 2 The battery cell 20B shown has: Figure 1 The electrode body 5 and the five strips 41 to 45 (in Figure 2 Only the structure in which the tape 41 is sealed by the laminate film 28 is shown. Regarding the electrode body 5 and the five tapes 41 to 45, Figure 1 Since the configuration is the same, the description is omitted.

[0048] The laminate film 28 is formed by folding and laminating the embossed sheet-shaped laminate film 28 to form a housing for the electrode body 5. The laminate film 28 has a sealing portion 28A formed thereon where one end side and the other end side are laminated and sealed. The laminate film 28 has a single cup embossing structure in which the embossing is performed at one place. Alternatively, a double cup embossing structure in which the embossing is performed at two places may be used.

[0049] Here, the surface of the laminate film 28 on which the sealing portion 28A is formed is referred to as the sealing portion side surface 20X, and the surface on the side facing the sealing portion side surface 20X is referred to as the facing surface 20Y. The overlapping portion 41A of the tape 41 is formed on the facing surface 20Y side of the laminate film 28. Figure 2 The overlapping portions 42A to 45A of the tapes 42 to 45 omitted in the figure are also formed on the facing surface 20Y side of the laminate film 28. That is, the overlapping portions 41A to 45A of the tapes 41 to 45 are not formed on the surface 20X of the laminate film 28 on the sealing portion side.

[0050] like Figure 2 As shown, there is a method as follows, that is, in the battery cell according to the embodiment of the present disclosure, there is one or more tapes wound and pasted around the outer circumference of the electrode body, and there is a sealing portion where the electrode body and the tape are sealed by a laminate film, and one end side and the other end side of the laminate film are bonded and sealed (hereinafter referred to as a "specific method"). In this specific method, as Figure 2 As shown in FIG. 1 , it is preferred that the overlapping portion of the tape is not arranged at a position in contact with the surface of the laminate film on the side where the seal portion is formed. When the seal portion of the laminate film is formed (for example, when the seal portion is formed by welding), if there are irregularities near the area where the seal portion is to be formed, wrinkles may be generated in the seal portion. In this regard, by not having the overlapping portion of the tape at a position in contact with the surface on the side where the seal portion is formed, the generation of wrinkles generated when the seal portion of the laminate film is formed can be suppressed.

[0051] On the other hand, in the above-mentioned specific embodiment, the overlapping portion of the tape may not be arranged on the surface facing the surface of the laminate film on which the sealing portion is formed (for example, on the Figure 2 In this case, the facing surfaces (in Figure 2 Since the distance between the electrode body and the laminate film on the facing surface 20Y) side is shortened, the electrode body has excellent cooling performance.

[0052] exist Figure 2 , the tapes 41 to 45 are wound and attached to the surface of the electrode body 5 and the electrode body 5 and the tapes 41 to 45 are sealed by the laminate film 28, but the present invention is not limited to this. For example, the tapes may be wound on the outer surface of the laminate film. Figure 3 A battery cell in which a tape is wound around the outer surface of a laminate film will be described.

[0053] like Figure 3As shown in FIG. 1 , the battery cell 20 is formed into a substantially rectangular plate shape, and contains an electrode body (not shown) inside, and is sealed by a laminate film 28. Three tapes 47 to 49 are arranged on the outer periphery of the laminate film 28 and are attached in a manner of being wound around the periphery. The tapes 47 to 49 are all attached to the stacking surface ( Figure 3 The tapes 47 to 49 are wound around the surface 281 in the middle and the surface on the back side of the surface 281) and the width direction side surfaces 282A, 282B. The tapes 47 to 49 are wound in a manner that one end side and the other end side in the outer circumferential direction of the laminate film 28 overlap, forming overlapping portions 47A to 49A with overlapping ends. Moreover, the overlapping portions 47A to 49A are all arranged on the surface other than the stacking surface (the surface 281 and the surface on the back side of the surface 281) of the electrode body 5 sealed by the laminate film 28, specifically, on the width direction side surface 282A.

[0054] In a battery cell in which a tape is wound on the outer surface of a laminate film, the overlapping portion is arranged on a surface other than the stacking surface of the electrode body enclosed by the laminate film, so that the space in the stacking direction can be effectively used and the volume efficiency is improved.

[0055] Battery cell stack

[0056] The battery cell involved in the embodiment of the present disclosure is used, for example, in the form of a battery cell stack having a plurality of battery cells stacked in a stacking direction. Furthermore, in the battery cell stack having a plurality of battery cells stacked, the surface of the overlapping portion of the arrangement band in each battery cell only needs to be arranged with at least one overlapping portion on a surface other than the stacking surface of the electrode body.

[0057] However, when a plurality of tapes are wound around the periphery of each electrode body, it is preferred that the overlapping portions of all tapes are arranged on a surface other than the stacking surface of the electrode body. Also, when a plurality of tapes are wound around the periphery of each electrode body, it is preferred that the overlapping portions of all tapes are arranged on one of the same surfaces other than the stacking surface of the electrode body.

[0058] Furthermore, in the battery cell stack, the positions of the overlapping portions of the tapes provided on the respective electrode bodies may be aligned in the stacking direction, or the positions of the overlapping portions may be non-aligned and dispersed in the stacking direction.

[0059] For example, the overlapping portions of the strips provided on each electrode body in the battery cell stack can be staggered in a staggered grid pattern in the stacking direction. By arranging the overlapping portions in a staggered grid pattern, it is difficult to form large recesses between the overlapping portions, and the generation of wrinkles in the laminate film can be suppressed.

[0060] In addition, for example, the overlapping portions of the tapes provided on the electrode bodies in the battery cell stack can be aligned in the stacking direction. By arranging the overlapping portions in the stacking direction, it is easy to form a large recess between the overlapping portions, and when other components (such as wiring, absorbent material, cooling plate, etc.) are arranged on this surface, it becomes easy to install.

[0061] Next, a battery module, a battery pack, and a vehicle including a battery cell according to an embodiment of the present disclosure will be described using the drawings.

[0062] (Overall Configuration of Vehicle 100)

[0063] Figure 4 1 is a schematic plan view showing the main parts of a vehicle 100 to which the battery pack 10 according to the embodiment is applied. Figure 4 As shown, the vehicle 100 is a battery electric vehicle (pure electric vehicle: battery electric vehicle (BEV)) equipped with a battery pack 10 under the floor. In addition, the arrow UP, arrow FR and arrow LH in each figure respectively represent the upper side in the vehicle vertical direction, the front side in the vehicle front-back direction and the left side in the vehicle width direction. When the front-back, left-right, up-down and left-right directions are used for explanation, unless otherwise specified, they represent the front-back direction in the vehicle front-back direction, the left-right direction in the vehicle width direction and the up-down direction in the vehicle vertical direction.

[0064] The vehicle 100 of the present embodiment, as an example, is provided with a DC / DC converter 102, an electric compressor 104, and a positive temperature coefficient (PTC) heater 106 at a position closer to the front side of the vehicle than the battery pack 10. In addition, a motor 108, a gear box 110, an inverter 112, and a charger 114 are provided at a position closer to the rear side of the vehicle than the battery pack 10.

[0065] The DC current output from battery pack 10 is regulated in voltage by DC / DC converter 102 and then supplied to electric compressor 104, PTC heater 106, inverter 112, etc. Furthermore, by supplying power to electric motor 108 via inverter 112, the rear wheels rotate and vehicle 100 travels.

[0066] A charging port 116 is provided on the right side of the rear portion of the vehicle 100 . By connecting a charging plug of an external charging device (not shown) to the charging port 116 , electricity can be stored in the battery pack 10 via the on-vehicle charger 114 .

[0067] Furthermore, the configuration and structure of the various components constituting the vehicle 100 are not limited to the above-mentioned configuration. For example, it can also be applied to a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV) equipped with an engine. In addition, in the present embodiment, the vehicle is a rear-wheel drive vehicle in which the motor 108 is mounted at the rear of the vehicle, but it is not limited to this. It can also be a front-wheel drive vehicle in which the motor 108 is mounted at the front of the vehicle, or a pair of motors 108 can be mounted at the front and rear of the vehicle. In addition, it can also be a vehicle with an in-wheel motor on each wheel.

[0068] Here, the battery pack 10 is composed of a plurality of battery modules 11. In the present embodiment, as an example, 10 battery modules 11 are provided. Specifically, five battery modules 11 are arranged in the vehicle front-rear direction on the right side of the vehicle 100, and five battery modules 11 are arranged in the vehicle front-rear direction on the left side of the vehicle 100. In addition, each battery module 11 is electrically connected.

[0069] Figure 5 1 is a schematic three-dimensional diagram of the battery module 11. Figure 5 As shown, the battery module 11 is formed into a substantially rectangular parallelepiped shape with the vehicle width direction as the length direction. In addition, the outer shell of the battery module 11 is formed of an aluminum alloy. For example, aluminum die castings are joined at both ends of an aluminum alloy extrusion material by laser welding, thereby forming the outer shell of the battery module 11.

[0070] A pair of voltage terminals 12 and a connector 14 are provided at both ends of the battery module 11 in the vehicle width direction. A flexible printed wiring board 22 described later is connected to the connector 14. Bus bars (not shown) are welded to both ends of the battery module 11 in the vehicle width direction.

[0071] The battery module 11 has a length MW in the vehicle width direction of, for example, 350 mm to 600 mm, a length ML in the vehicle front-rear direction of, for example, 150 mm to 250 mm, and a height MH in the vehicle vertical direction of, for example, 80 mm to 110 mm.

[0072] Figure 6 1 is a plan view of the battery module 11 after the upper cover is removed. Figure 6 As shown, a plurality of battery cells 20 are housed in an aligned state inside the battery module 11. In the present embodiment, as an example, 24 battery cells 20 are aligned in the vehicle front-rear direction and are joined to each other.

[0073] A flexible printed circuit (FPC) 22 is disposed on the battery cell 20. The flexible printed circuit 22 is formed in a strip shape with the vehicle width direction as the longitudinal direction, and thermistors 24 are provided at both ends of the flexible printed circuit 22. The thermistor 24 is not bonded to the battery cell 20, but is pressed toward the battery cell 20 by the upper cover of the battery module 11.

[0074] In addition, one or more buffer materials (not shown) are accommodated inside the battery module 11. For example, the buffer material is a thin plate-shaped member that can be elastically deformed, and is arranged between adjacent battery cells 20 with the arrangement direction of the battery cells 20 as the thickness direction. In this embodiment, as an example, buffer materials are respectively arranged at both ends in the longitudinal direction and the central part in the longitudinal direction of the battery module 11.

[0075] Figure 3 2 is a schematic diagram of a battery cell 20 housed in a battery module 11 as viewed from the thickness direction. Figure 3 As shown, the battery cell 20 is formed in a substantially rectangular plate shape, and an electrode body (not shown) is accommodated therein. The electrode body is formed by laminating a positive electrode, a negative electrode, and a separator, and is sealed by a laminate film 28 .

[0076] In this embodiment, as an example, the electrode body receiving portion is formed by folding and laminating the embossed sheet-shaped laminate film 28. Furthermore, both a single cup embossed structure with embossing at one place and a double cup embossed structure with embossing at two places can be adopted, but in this embodiment, a single cup embossed structure with a drawing depth of about 8 mm to 10 mm is adopted.

[0077] The upper ends of both ends of the battery cell 20 in the longitudinal direction are bent, and the corners become the outer shape. In addition, the upper end of the battery cell 20 is bent, and the fixing band 30 is wound around the upper end of the battery cell 20 along the longitudinal direction.

[0078] Here, terminals (tabs) 26 are provided at both ends in the longitudinal direction of the battery cell 20. In the present embodiment, as an example, the terminal 26 is provided at a position offset downward from the center in the vertical direction of the battery cell 20. The terminal 26 is joined to a bus bar (not shown) by laser welding or the like.

[0079] The length CW1 of the battery cell 20 in the vehicle width direction is, for example, 530 mm to 600 mm, the length CW2 of the region containing the electrode body is, for example, 500 mm to 520 mm, and the height CH of the battery cell 20 is, for example, 80 mm to 110 mm. In addition, the thickness of the battery cell 20 is 7.0 mm to 9.0 mm, and the height TH of the terminal 26 is 40 mm to 50 mm.

Claims

1. A battery cell comprising: an electrode body in which a plurality of stacked structures are further stacked, the stacked structure having a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode; and The tape is wound around the outer circumference of the electrode body. The belt has an overlapping portion where one end side and the other end side in the outer circumferential direction overlap each other, When a direction in which a plurality of the stacked structures in the electrode body are stacked is defined as a stacking direction and an end surface of the electrode body in the stacking direction is defined as a stacking surface, the overlapping portion is disposed on a surface of the electrode body other than the stacking surface.

2. The battery cell according to claim 1, A plurality of the tapes are wound and attached to the outer circumference of the electrode body. The overlapping portions in all the tapes are arranged on a surface other than the stacking surface of the electrode body.

3. The battery cell according to claim 2, The overlapping portions in all the tapes are arranged on one same surface among surfaces of the electrode body other than the stacking surface. 4 . A battery cell stack, wherein a plurality of the battery cells according to claim 1 are stacked in the stacking direction.

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