Power storage cell

Abstract

To prevent damage and wrinkling of an electrode foil, as well as a short circuit within the electrode body.SOLUTION: A power storage cell includes an electrode body 110 having a strip-shaped electrode tab 114, a laminate film that houses the electrode body 110 such that a portion of the electrode tab 114 is exposed, and an insulating covering portion 170 that is provided on the end face of the electrode body 110 on which the electrode tab 114 is formed and that covers the portion of the end face on which the electrode tab 114 is not formed.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to an energy storage cell. [Background technology]

[0002] For example, JP 2023-502698 A discloses a battery including a plurality of electrode assembly sets and a case for accommodating the plurality of electrode assembly sets. The plurality of electrode assembly sets includes at least one electrode assembly. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2023-502698 Summary of the Invention [Problem to be solved by the invention]

[0004] The electrode body has a coated portion and an electrode tab. The coated portion is a region of the electrode foil on the positive or negative electrode sheet where an active material layer is provided. The electrode tab is a region of the electrode foil on the positive or negative electrode sheet where an active material layer is not provided, i.e., an uncoated portion where the electrode foil is exposed. Generally, a long strip-shaped electrode tab is formed on one side of the short side of the long strip-shaped coated portion. The short side of the coated portion corresponds to the first direction described below. A positive electrode tab is formed at one end of the electrode body in the first direction, and a negative electrode tab is formed at the other end of the electrode body in the first direction. To gather the electrode tabs, the electrode tabs are pressed from both ends of the short side of the end face of the electrode body. The short side of the end face of the electrode body corresponds to the second direction described below. As a result, the electrode foil of the electrode tab is pulled from both ends of the long side of the end face to the center of the long side of the end face. The long side of the end face corresponds to the third direction described below. Pulling the electrode foil can cause it to tear or wrinkle. In addition, the electrode foil of the positive electrode sheet or the negative electrode sheet is located on the end surface of the electrode assembly. Therefore, if foreign matter adheres to the end surface of the electrode assembly, there is a risk of a short circuit within the electrode assembly.

[0005] An object of the present disclosure is to suppress breakage and wrinkling of the electrode foil, as well as to suppress short circuits within the electrode body. [Means for solving the problem]

[0006] A storage cell according to one aspect of the present disclosure includes an electrode body having a strip-shaped electrode tab, a laminate film that houses the electrode body so that a portion of the electrode tab is exposed, and an insulating covering portion that is provided on the end face of the electrode body on which the electrode tab is formed and that covers a portion of the end face on which the electrode tab is not formed.

[0007] Preferably, the electrode body is formed to surround the periphery of the imaginary winding line. The electrode body includes a first end face and a second end face aligned in the direction in which the imaginary winding line extends. The electrode tab protrudes from the first end face in the direction in which the imaginary winding line extends. The electrode tab is bent in a direction intersecting the direction in which the imaginary winding line extends.

[0008] Preferably, the electrode tab is bent at an exposed portion that is exposed from the laminate film in a direction intersecting the direction in which the imaginary winding line extends. The energy storage cell further includes a current collecting terminal connected to a bent tip of the exposed portion.

[0009] Preferably, the electrode tab is bent in a direction intersecting the direction of the imaginary winding line at a portion covered with the laminate film, and the electrode tab is further bent at an exposed portion exposed from the laminate film, and the storage cell further includes a current collecting terminal connected to a bent tip of the exposed portion.

[0010] Preferably, at least one of a portion of the electrode tab in contact with the laminate film and a portion of the laminate film in contact with the electrode tab is roughened. [Effects of the Invention]

[0011] According to the present disclosure, breakage and wrinkling of the electrode foil can be suppressed, and short circuits within the electrode body can also be suppressed. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a side view schematically illustrating a vehicle equipped with an electricity storage device including an electricity storage cell according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a perspective view schematically illustrating a storage cell according to an embodiment of the present disclosure. [Figure 3] FIG. 2 is a front view of a storage cell according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 2 is a perspective view showing a set of electrode assemblies included in each cell unit 100. [Figure 6] 10 is a diagram showing an example of a portion of the electrode tab 114 that comes into contact with the laminate film 160, and an example of a portion of the laminate film 160 that comes into contact with the electrode tab 114. FIG. [Figure 7] FIG. 10 is a cross-sectional view showing a first modified example of a connection portion of two cell units 100 aligned in a first direction. [Figure 8] FIG. 10 is a cross-sectional view showing a second modified example of a connection portion of two cell units 100 aligned in the first direction. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments and modifications according to the present disclosure will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated. Note that the embodiments and modifications described below may be selectively combined as appropriate.

[0014] [Embodiment] An energy storage cell according to an embodiment of the present disclosure will be described with reference to Figures 1 to 6. Figure 1 is a side view that schematically shows a vehicle equipped with an energy storage device including an energy storage cell according to an embodiment of the present disclosure. Figure 2 is a perspective view that schematically shows an energy storage cell according to an embodiment of the present disclosure. Figure 3 is a front view of an energy storage cell according to an embodiment of the present disclosure.

[0015] 1 and 2, a vehicle 10 includes a power storage device 2 and a vehicle frame 3. The power storage device 2 is disposed below a floor panel of the vehicle 10. The power storage device 2 includes a plurality of power storage cells 1. Examples of the vehicle 10 include a hybrid vehicle, a plug-in hybrid vehicle, a fuel cell vehicle, and an electric vehicle.

[0016] 2 and 3, the energy storage cell 1 includes a plurality of cell units 100, a cell case 300, and an external terminal 400.

[0017] In this embodiment, the plurality of cell units 100 includes eight cell units 100. More specifically, four cell units 100 are arranged in the first direction, and two cell units 100 are arranged in the second direction. Note that the number of cell units 100 is not limited to eight.

[0018] The first direction may be the front-to-rear direction of the vehicle 10 (see FIG. 1) or the width direction of the vehicle 10. The second direction corresponds to the thickness direction of the energy storage cell 1. More specifically, the second direction corresponds to the stacking direction in which positive electrode sheets and negative electrode sheets, which will be described later, are stacked on each other. The third direction corresponds to the height direction of the energy storage cell 1. The first direction is perpendicular to both the second direction and the third direction. The second direction is perpendicular to both the first direction and the third direction. The third direction is perpendicular to both the first direction and the second direction. Each cell unit 100 has a shape that is longer in the first direction than in the second direction and that extends longer in the first direction than in the third direction. Each cell unit 100 has a shape that is longer in the third direction than in the second direction.

[0019] For example, a lithium ion battery can be used as each cell unit 100. Each cell unit 100 may be configured as a so-called all-solid-state battery that includes a solid electrolyte.

[0020] The cell case 300 houses a plurality of cell units 100. The cell case 300 is made of, for example, aluminum. The cell case 300 is formed in the shape of a rectangular parallelepiped that is long in the first direction.

[0021] The cell case 300 has a case body 310 and a lid 320. The case body 310 is formed in the shape of a rectangular tube that is long in a first direction. The case body 310 surrounds the multiple cell units 100.

[0022] The lid 320 is connected to the case body 310 by welding or the like so as to close the opening of the case body 310 .

[0023] The external terminal 400 is provided on the lid 320. The external terminal 400 is connected to the electrode tab 114 of the cell unit 100 that is positioned closest to the lid 320 among the multiple cell units 100.

[0024] Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3. Referring to Fig. 4, the plurality of cell units 100 includes a first cell unit 101, a second cell unit 102, a third cell unit 103, and a fourth cell unit 104.

[0025] The first cell unit 101 is connected to the second cell unit 102. The first cell unit 101 and the second cell unit 102 are aligned in a first direction. The third cell unit 103 is connected to the fourth cell unit 104. The third cell unit 103 and the fourth cell unit 104 are aligned in the first direction.

[0026] The first cell unit 101 and the third cell unit 103 are adjacent to each other in the second direction. The second cell unit 102 and the fourth cell unit 104 are adjacent to each other in the second direction.

[0027] Each cell unit 100 includes at least one electrode body 110 and a laminate film 160 .

[0028] Fig. 5 is a perspective view showing a set of electrode assemblies included in each cell unit 100. Referring to Fig. 5, in this embodiment, each cell unit 100 includes two electrode assemblies 110 (electrode assembly 110a and electrode assembly 110b). However, the number of electrode assemblies 110 included in each cell unit 100 is not limited to two.

[0029] Each electrode body 110 is formed by a wound body in which a positive electrode sheet and a negative electrode sheet are wound with a separator interposed therebetween. In the example shown in FIG. 5, each electrode body 110 is formed by winding a positive electrode sheet, a negative electrode sheet, and a separator so as to surround the periphery of a winding imaginary line 118 extending in the first direction. Therefore, each electrode body 110 includes two end faces arranged in the first direction (the direction in which the winding imaginary line 118 extends). The two end faces included in each electrode body 110 and arranged in the first direction are an example of the "first end face and second end face" in the present disclosure. Note that the state in which each sheet is wound in a spiral shape can be visually confirmed from these two end faces. The two electrode bodies 110 are adjacent to each other in the second direction. The second direction corresponds to the stacking direction in which the positive electrode sheet and the negative electrode sheet are stacked on each other. Each electrode body 110 is formed in a shape elongated in the first direction.

[0030] Each electrode body 110 has a coated portion 112 and an electrode tab 114. The coated portion 112 is a region of the electrode foil on the positive electrode sheet or negative electrode sheet where an active material layer is provided. The electrode tab 114 is a region of the electrode foil on the positive electrode sheet or negative electrode sheet where no active material layer is provided, i.e., an uncoated portion where the electrode foil is exposed.

[0031] In each electrode body 110, a rectangular electrode tab 114 is formed on at least one end face (first end face) of two end faces arranged in a first direction. The first direction corresponds to the short-side direction of the coated section 112. The electrode tab 114 protrudes from the first end face in the direction in which the imaginary winding line 118 extends. In this embodiment, a plurality of electrode tabs 114 are formed. For example, in the positive electrode sheet and the negative electrode sheet before winding, a plurality of electrode tabs 114 are formed at intervals in the direction in which each sheet extends. Then, when each sheet is wound, the electrode tabs 114 are arranged in the second direction. However, the number of electrode tabs 114 may be one.

[0032] In the example shown in FIG. 5, the positive electrode tab 114c of the electrode body 110a protrudes in the direction of the imaginary winding line 118a from one of the two end faces of the electrode body 110a arranged in the first direction. Meanwhile, the negative electrode tab 114d of the electrode body 110a protrudes in the direction of the imaginary winding line 118a from the other of the two end faces of the electrode body 110a arranged in the first direction. Similarly, the positive electrode tab 114c of the electrode body 110b protrudes in the direction of the imaginary winding line 118b from one of the two end faces of the electrode body 110b arranged in the first direction. Meanwhile, the negative electrode tab 114d of the electrode body 110b protrudes in the direction of the imaginary winding line 118b from the other of the two end faces of the electrode body 110b arranged in the first direction.

[0033] The positive electrode tabs 114c of the electrode bodies 110a and 110b are gathered together at one end of the electrode bodies 110a and 110b in the first direction, while the negative electrode tabs 114d of the electrode bodies 110a and 110b are gathered together at the other end of the electrode bodies 110a and 110b in the first direction.

[0034] An insulating covering portion 170 is provided on the end face of each electrode assembly 110 on which the electrode tabs 114 are formed. The covering portion 170 covers the portion of the end face of the electrode assembly 110 on which the electrode tabs 114 are formed that does not have the electrode tabs 114. That is, each cell unit 100 (see FIG. 4) includes the electrode assembly 110, a laminate film 160 (see FIG. 4), and the covering portion 170. The covering portion 170 prevents short circuits within the electrode assembly 110.

[0035] Referring again to Fig. 4, in each cell unit 100, the laminate film 160 accommodates the electrode assembly 110 such that a portion of the electrode tab 114 of the electrode assembly 110 is exposed. Referring again to Fig. 5, more specifically, when the electrode assembly 110a and the electrode assembly 110b are accommodated in the laminate film 160 (see Fig. 4), a portion of the positive electrode tab 114c of the electrode assembly 110a and a portion of the positive electrode tab 114c of the electrode assembly 110b are exposed at one end of the electrode assemblies 110a and 110b in the first direction. Furthermore, when the electrode assemblies 110a and 110b are accommodated in the laminate film 160 (see Fig. 4), a portion of the negative electrode tab 114d of the electrode assembly 110a and a portion of the negative electrode tab 114d of the electrode assembly 110b are exposed at the other end of the electrode assemblies 110a and 110b in the first direction.

[0036] Referring again to FIG. 4, two cell units 100 aligned in the first direction are connected by connecting the electrode tabs 114 of the two cell units 100 together.

[0037] More specifically, the exposed portion 116 of the electrode tab 114 of the first cell unit 101 that is exposed from the laminate film 160 of the first cell unit 101 is connected by welding or the like to the exposed portion 116 of the electrode tab 114 of the second cell unit 102 that is exposed from the laminate film 160 of the second cell unit 102. In this way, the first cell unit 101 is connected to the second cell unit 102.

[0038] The exposed portion 116 of the electrode tab 114 of the third cell unit 103 that is exposed from the laminate film 160 of the third cell unit 103 is connected by welding or the like to the exposed portion 116 of the electrode tab 114 of the fourth cell unit 104 that is exposed from the laminate film 160 of the fourth cell unit 104. In this way, the third cell unit 103 is connected to the fourth cell unit 104.

[0039] Fig. 6 is a diagram showing an example of a portion of the electrode tab 114 that comes into contact with the laminate film 160, and an example of a portion of the laminate film 160 that comes into contact with the electrode tab 114. Referring to Fig. 6, a portion 201 of the electrode tab 114 that comes into contact with the laminate film 160, and a portion 202 of the laminate film 160 that comes into contact with the electrode tab 114, are roughened.

[0040] At least one of the portion 201 and the portion 202 may be roughened. Alternatively, neither the portion 201 nor the portion 202 may be roughened. However, if at least one of the portion 201 and the portion 202 is roughened, peeling of the laminate film 160 from the electrode tab 114 can be suppressed.

[0041] As described above, the energy storage cell 1 in this embodiment includes the electrode assembly 110, the laminate film 160, and the covering portion 170. The electrode assembly 110 has a rectangular electrode tab 114. The laminate film 160 houses the electrode assembly 110 so that a portion of the electrode tab 114 is exposed. The covering portion 170 is an insulating member that is provided on the end face of the electrode assembly 110 on which the electrode tab 114 is formed, and that covers a portion of the end face on which the electrode tab 114 is not formed.

[0042] Generally, in an electrode body, a long strip-shaped electrode tab is formed on one side of the long strip-shaped coated portion in the short direction. Therefore, it is necessary to press the electrode tab from both ends of the short direction of the end face of the electrode body to gather the electrode tabs together. By pressing the electrode tab from both ends of the short direction of the end face of the electrode body, the electrode foil of the electrode tab is pulled from both ends of the long direction of the end face to the center of the long direction of the end face, which may cause the electrode foil to tear or wrinkle. The short direction of the coated portion corresponds to the first direction described above. The short direction of the end face corresponds to the second direction described above. The long direction of the end face corresponds to the third direction described above.

[0043] In contrast, in the present embodiment, in each electrode assembly 110, a strip-shaped electrode tab 114 is formed on one side in the short direction (the first direction described above) of the long strip-shaped coated portion 112. That is, the electrode assembly 110 in the present embodiment has strip-shaped electrode tabs 114 instead of long strip-shaped electrode tabs. This makes it possible to prevent the electrode foil of the electrode tabs 114 from being pulled when the electrode tabs 114 are gathered together. Therefore, the energy storage cell 1 in the present embodiment can prevent breakage and wrinkling of the electrode foil.

[0044] Furthermore, electrode foil of a positive electrode sheet or a negative electrode sheet is generally located on the end face of the electrode assembly. Therefore, if foreign matter adheres to the end face of the electrode assembly, there is a risk of a short circuit occurring within the electrode assembly. In contrast, in this embodiment, of the end face of the electrode assembly 110 on which the electrode tab 114 is formed, the portion on which the electrode tab 114 is not formed is covered with an insulating covering portion 170. Therefore, the energy storage cell 1 in this embodiment can suppress a short circuit within the electrode assembly 110.

[0045] Furthermore, in this embodiment, two cell units 100 aligned in the first direction are connected by connecting the electrode tabs 114 of the two cell units 100 together. Therefore, the energy storage cell 1 of this embodiment does not require a current collecting terminal or the like to connect the two cell units 100 aligned in the first direction. Therefore, the energy storage cell 1 of this embodiment can reduce the number of parts required for the energy storage cell 1.

[0046] [First Modification] A first modified example of the connection portion of two cell units 100 aligned in the first direction will be described with reference to Fig. 7. Fig. 7 is a cross-sectional view showing the first modified example of the connection portion of two cell units 100 aligned in the first direction.

[0047] In the first modified example, the electrode tab 114 is bent in a direction intersecting the direction in which the imaginary winding line 118 (see FIG. 5) extends at the exposed portion 116 that is exposed from the laminate film 160. In the example shown in FIG. 7, the electrode tab 114 is bent in a second direction at the exposed portion 116. However, the direction in which the electrode tab 114 is bent at the exposed portion 116 may be any direction intersecting the direction in which the imaginary winding line 118 extends, and is not limited to the second direction.

[0048] In the first modified example, each cell unit 100 includes an electrode assembly 110, a laminate film 160, and a covering portion 170 (see FIG. 5). In the first modified example, each cell unit 100 further includes a current collecting terminal 140. The current collecting terminal 140 is connected to a bent tip portion 117 of the exposed portion 116.

[0049] The current collecting terminal 140 of the first cell unit 101 is connected to the current collecting terminal 140 of the second cell unit 102 by welding or the like. The current collecting terminal 140 of the third cell unit 103 is connected to the current collecting terminal 140 of the fourth cell unit 104 by welding or the like. That is, the first cell unit 101 is connected to the second cell unit 102 by connecting the current collecting terminal 140 of the first cell unit 101 to the current collecting terminal 140 of the second cell unit 102 by welding or the like. Furthermore, the third cell unit 103 is connected to the fourth cell unit 104 by connecting the current collecting terminal 140 of the third cell unit 103 to the current collecting terminal 140 of the fourth cell unit 104 by welding or the like.

[0050] In other respects, the first modified example is similar to the above-described embodiment. As described above, in the first modified example, the electrode tab 114 is bent at the exposed portion 116. As a result, according to the first modified example, the dimension in the first direction required to connect two cell units 100 aligned in the first direction can be shortened. In other words, according to the first modified example, the number of cell units 100 that can be accommodated in the energy storage cell 1 can be increased. Therefore, the energy density of the energy storage cell 1 in the first modified example can be improved.

[0051] Furthermore, in the first modified example, the current collecting terminals 140 of two cell units 100 aligned in the first direction are connected to each other by welding or the like. Generally, electrode foil is easily scattered by heat. Therefore, when connecting the electrode tabs 114 of two cell units 100 aligned in the first direction by welding or the like, the difficulty of connecting the two cell units 100 increases. In contrast, in the first modified example, the current collecting terminals 140 of two cell units 100 aligned in the first direction are connected to each other by welding or the like. Therefore, according to the first modified example, the two cell units 100 can be connected more easily than when connecting the electrode tabs 114 of two cell units 100 aligned in the first direction by welding or the like.

[0052] [Second Modification] A second modified example of the connection portion of two cell units 100 aligned in the first direction will be described with reference to Fig. 8. Fig. 8 is a cross-sectional view showing the second modified example of the connection portion of two cell units 100 aligned in the first direction.

[0053] In the second modified example, the electrode tab 114 is bent in a direction intersecting the extension direction of the imaginary winding line 118 (see FIG. 5 ) at the portion covered with the laminate film 160. More specifically, the end 165 of the laminate film 160 is bent in a direction intersecting the extension direction of the imaginary winding line 118. The electrode tab 114 is bent along the laminate film 160 at the portion covered with the laminate film 160. In the example shown in FIG. 8 , the electrode tab 114 is bent in a second direction at the portion covered with the laminate film 160. However, the direction in which the electrode tab 114 is bent at the portion covered with the laminate film 160 need only be a direction intersecting the extension direction of the imaginary winding line 118, and is not limited to the second direction.

[0054] In the second modified example, the electrode tab 114 is further bent at the exposed portion 116 that is exposed from the laminate film 160. In the example shown in Fig. 8, the electrode tab 114 is bent in a first direction (the direction in which the imaginary winding line 118 extends) at the exposed portion 116. However, the direction in which the electrode tab 114 is bent at the exposed portion 116 need only be a direction that intersects with the direction in which the electrode tab 114 is bent at the portion covered by the laminate film 160, and is not limited to the first direction.

[0055] In the second modified example, each cell unit 100 includes an electrode assembly 110, a laminate film 160, and a covering portion 170 (see FIG. 5). In the second modified example, the energy storage cell 1 further includes at least one current collector terminal 150. The current collector terminal 151 and the current collector terminal 152 are examples of the at least one current collector terminal 150. The current collector terminal 150 is connected to the tip portions 117 of the two cell units 100 aligned in the first direction.

[0056] More specifically, the current collecting terminal 151 is connected by welding or the like to the bent tip 117 of the exposed portion 116 of the first cell unit 101 and the bent tip 117 of the exposed portion 116 of the second cell unit 102. The current collecting terminal 152 is connected by welding or the like to the bent tip 117 of the exposed portion 116 of the third cell unit 103 and the bent tip 117 of the exposed portion 116 of the fourth cell unit 104. In other words, the first cell unit 101 is connected to the second cell unit 102 via the current collecting terminal 151. Furthermore, the third cell unit 103 is connected to the fourth cell unit 104 via the current collecting terminal 152.

[0057] In other respects, the second modified example is similar to the above-described embodiment. As described above, in the second modified example, the electrode tab 114 is bent at the portion covered by the laminate film 160 and at the exposed portion 116. As a result, according to the second modified example, the dimension in the first direction required to connect two cell units 100 aligned in the first direction can be shortened. In other words, according to the second modified example, the number of cell units 100 that can be accommodated in the energy storage cell 1 can be increased. Therefore, the energy density of the energy storage cell 1 in the second modified example can be improved.

[0058] In the second modified example, two cell units 100 aligned in the first direction are connected via a current collecting terminal 150. Therefore, according to the second modified example, the two cell units 100 can be connected more easily than when the electrode tabs 114 of the two cell units 100 aligned in the first direction are connected to each other by welding or the like.

[0059] [Other variations] Each electrode body 110 may be configured as a laminate in which a positive electrode sheet and a negative electrode sheet are stacked with a separator interposed therebetween. As with a wound body, in a laminate, there is a risk of the electrode foil breaking or wrinkling. Furthermore, in a laminate, as with a wound body, the electrode foil of the positive electrode sheet or the negative electrode sheet is located at the end surface of the electrode body. Therefore, if foreign matter adheres to the end surface of the electrode body, there is a risk of a short circuit occurring within the electrode body. Even when each electrode body 110 is configured as a laminate in which a positive electrode sheet and a negative electrode sheet are stacked with a separator interposed therebetween, according to the above embodiment or modified example, breakage and wrinkling of the electrode foil are suppressed, and short circuits within the electrode body are suppressed.

[0060] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0061] 1 storage cell, 2 storage device, 3 vehicle frame, 10 vehicle, 100 cell unit, 101 first cell unit, 102 second cell unit, 103 third cell unit, 104 fourth cell unit, 110, 110a, 110b electrode body, 112 coated portion, 114 electrode tab, 114c positive electrode tab, 114d negative electrode tab, 116 exposed portion, 117 tip portion, 118, 118a, 118b winding virtual line, 140, 150, 151, 152 current collecting terminal, 160 laminate film, 165 end, 170 covering portion, 201, 202 part, 300 cell case, 310 case body, 320 lid, 400 external terminal.

Claims

1. an electrode body having strip-shaped electrode tabs; a laminate film that houses the electrode body so that a portion of the electrode tab is exposed; an insulating covering portion provided on the end surface of the electrode body on which the electrode tab is formed, and covering a portion of the end surface on which the electrode tab is not formed.

2. The electrode body is formed so as to surround the periphery of the imaginary winding line, the electrode body includes a first end surface and a second end surface that are arranged in a direction in which the imaginary winding line extends, the electrode tab protrudes from the first end surface in a direction in which the imaginary winding line extends, The energy storage cell according to claim 1 , wherein the electrode tab is bent in a direction intersecting a direction in which the imaginary winding line extends.

3. the electrode tab is bent at an exposed portion exposed from the laminate film in a direction intersecting with a direction in which the imaginary winding line extends, The energy storage cell according to claim 2 , further comprising a current collecting terminal connected to a bent tip of the exposed portion.

4. the electrode tab is bent in a direction intersecting a direction in which the imaginary winding line extends at a portion covered with the laminate film, the electrode tab is further bent at an exposed portion exposed from the laminate film, The energy storage cell according to claim 2 , further comprising a current collecting terminal connected to a bent tip of the exposed portion.

5. The storage cell according to any one of claims 1 to 4, wherein at least one of a portion of the electrode tab that contacts the laminate film and a portion of the laminate film that contacts the electrode tab is roughened.

Images