Energy storage cell

Abstract

To improve an impregnation speed of an electrolyte.SOLUTION: A power storage cell includes a case, an electrode body, an insulator film, and an electrolyte. The case stores the electrode body, the insulator film and the electrolyte therein. The electrode body includes a top face, a bottom face and a peripheral face. In the case, a liquid injection hole is provided on a face opposed to the top face. The peripheral face connects the top face and the bottom face. The peripheral face includes a first region and a second region. The first region is covered by the insulator film. The second region is not covered by the insulator film. The second region extends from the top face to the bottom face. The second region has a smaller area in relative to the first region.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a storage cell.

Background Art

[0002] JP-A-2016-100270 discloses an insulating tape joined to the outermost circumference of an electrode body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The storage cell includes a case and an electrode body. The case houses the electrode body. After the electrode body is housed, an electrolytic solution is injected into the case. From the viewpoint of the energy density of the storage cell, it is required to reduce the clearance between the case and the electrode body. As the clearance becomes smaller, the flow path of the electrolytic solution around the electrode body may decrease. Therefore, it tends to take a long time for the electrolytic solution to spread over the entire electrode body. That is, there is room for improvement in the impregnation rate of the electrolytic solution.

[0005] An object of the present disclosure is to increase the impregnation rate of the electrolytic solution.

Means for Solving the Problems

[0006] Hereinafter, the technical configuration and operational effects of the present disclosure will be described. However, the mechanism of action includes assumptions. The mechanism of action does not limit the technical scope of the present disclosure.

[0007] 1. The energy storage cell includes a case, an electrode body, an insulating film, and an electrolyte. The case houses the electrode body, the insulating film, and the electrolyte. The electrode body has a top surface, a bottom surface, and a circumferential surface. In the case, an electrolyte injection hole is provided on the surface facing the top surface. The circumferential surface connects the top surface and the bottom surface. The circumferential surface includes a first region and a second region. The first region is covered with an insulating film. The second region is not covered with an insulating film. The second region extends from the top surface to the bottom surface. The second region has a smaller area than the first region.

[0008] The electrolyte injected through the injection hole is supplied to the upper surface of the electrode body. Depending on the thickness of the insulating film, a gap may be formed between the second region and the case. This gap becomes a pathway for the electrolyte, allowing the electrolyte to be rapidly supplied from the top surface to the bottom surface. Therefore, an improvement in the impregnation rate can be expected.

[0009] 2. The energy storage cell described in "1" above may include, for example, the following configuration: The energy storage cell further includes an insulating member. In the case, the insulating member is positioned opposite the second region.

[0010] The insulating material can electrically insulate the second region from the case.

[0011] 3. The energy storage cell described in "1" or "2" above may include, for example, the following configuration: The second region is located below the injection port.

[0012] By positioning the second region below the injection hole, an improvement in the impregnation rate is expected.

[0013] 4. The energy storage cell described in any one of items "1" to "3" above may include, for example, the following configuration: The energy storage cell further includes an insulating tape. In the circumferential direction of the circumferential surface, the second region is sandwiched between the first regions. The insulating tape extends across the second region, bridging the first regions together.

[0014] The insulating tape can electrically insulate the second area from the case.

[0015] 5. The energy storage cell described in any one of items "1" through "4" above may include, for example, the following configuration: The insulating film is in the form of a strip.

[0016] The strip-shaped insulating film is suitable for application to peripheral surfaces. The strip-shaped nature of the insulating film offers advantages such as improved productivity.

[0017] 6. The energy storage cell described in any one of items "1" through "5" above may include, for example, the following configuration: The insulating film is wrapped around the periphery.

[0018] 7. The energy storage cell described in any one of items "1" through "6" above may include, for example, the following configuration: The insulating film has a length direction and a width direction. The width direction is perpendicular to the length direction. The length dimension is shorter than the perimeter of the side surface.

[0019] Because the length of the insulating film is shorter than the perimeter of the surface, when the insulating film is wrapped around the surface, a gap may be formed between the insulating film and the start and end ends. In other words, a second region may be formed.

[0020] 8. The energy storage cell described in any one of items "1" through "7" above may include, for example, the following configuration: The electrode body has a cubic shape. The electrode body is of a stacked type.

[0021] 9. The energy storage cell described in any one of items "1" through "8" above may include, for example, the following configuration: The circumferential surface consists of a first region and a second region.

[0022] Hereinafter, embodiments of the present disclosure (hereinafter may be abbreviated as "the present embodiments") will be described. However, the present embodiments do not limit the technical scope of the present disclosure. The present embodiments are illustrative in all respects. The present embodiments are non-limiting. The technical scope of the present disclosure includes all modifications within the meaning and scope equivalent to the description of the claims. For example, any configurations are extracted from the present embodiments, and their arbitrary combinations are also initially planned.

Brief Description of the Drawings

[0023] [Figure 1] It is a schematic perspective view showing an example of the storage cell in the present embodiment. [Figure 2] It is a first schematic cross-sectional view showing an example of the storage cell in the present embodiment. [Figure 3] It is a schematic view showing an example of the electrode body in the present embodiment. [Figure 4] It is a second schematic cross-sectional view showing an example of the storage cell in the present embodiment. [Figure 5] It is a schematic cross-sectional view showing an example of the electrode body in the present embodiment.

Modes for Carrying Out the Invention

[0025] Geometric terms should not be interpreted strictly. Examples of geometric terms include "parallel," "perpendicular," and "orthogonal." For example, "parallel" may deviate slightly from its strict meaning. Geometric terms may include tolerances and errors in design, operation, and manufacturing. Dimensional relationships in each diagram may not match actual dimensions. Dimensional relationships in each diagram may be altered to aid the reader's understanding. For example, length, width, and thickness may be changed. Furthermore, some components may be omitted.

[0026] Numerical ranges such as "m to n%" include upper and lower limits unless otherwise specified. That is, "m to n%" indicates a numerical range of "m% or more and n% or less". Also, "m% or more and n% or less" includes "greater than m% and less than n%". "Greater than or equal to" and "less than or equal to" are represented by the equals sign inequality sign "≦". "Greater than" and "less than" are represented by the equals sign without an equals sign "<". A number arbitrarily selected from within the numerical range may be used as a new upper or lower limit. For example, a new numerical range may be set by arbitrarily combining a number within the numerical range with a number listed in another part of this specification, in a table, in a figure, etc.

[0027] All numerical values ​​are modified by the term "approximately." The term "approximately" may mean, for example, ±5%, ±3%, ±1%, etc. All numerical values ​​may be approximations that vary depending on how the disclosed technology is used. All numerical values ​​may be expressed with significant figures. Unless otherwise specified, measured values ​​may be the average of multiple measurements. The number of measurements may be three or more, five or more, or ten or more. Generally, the reliability of the average value is expected to improve with a larger number of measurements. Measured values ​​may be rounded to the nearest significant figure. Measured values ​​may include errors such as those associated with the detection limit of the measuring device.

[0028] 2. Energy storage cells Figure 1 is a schematic perspective view showing an example of a storage cell in this embodiment. The storage cell 1 may have, for example, a height direction, a width direction, and a thickness direction. The height direction, width direction, and thickness direction are orthogonal to each other. The "height direction" is the H direction in Figure 1, etc. The "width direction" is the W direction in Figure 1, etc. The "thickness direction" is the D direction in Figure 1, etc. The height direction may be, for example, parallel to the vertical direction. The width direction and thickness direction may be, for example, parallel to the horizontal direction. "Height" indicates the dimension in the height direction. "Width" indicates the dimension in the width direction. "Thickness" indicates the dimension in the thickness direction, or the thickness of the object.

[0029] Figure 2 is a first schematic cross-sectional view showing an example of a storage cell in this embodiment. Figure 2 shows a cross-section perpendicular to the thickness direction. The storage cell 1 includes a case 200, an electrode body 100, an insulating film 101, and an electrolyte (not shown). The electrolyte is a liquid electrolyte. The electrolyte may include, for example, an organic solvent and a lithium salt.

[0030] 3. Electrode body, insulating film The electrode body 100 may have, for example, a cubic shape. The electrode body 100 may have, for example, a rectangular parallelepiped shape. The electrode body 100 may have, for example, a flattened rectangular parallelepiped shape.

[0031] The "first aspect ratio" indicates the ratio of width to height in the electrode body 100. The first aspect ratio may be, for example, 1 or more, 1.5 or more, 2 or more, 2.5 or more, 3 or more, 5 or more, or 10 or more. The first aspect ratio may be, for example, 10 or less, 5 or less, 3 or less, 2.5 or less, 2 or less, or 1.5 or less. The "second aspect ratio" indicates the ratio of thickness to height in the electrode body 100. The second aspect ratio may be, for example, 0.1 or more, 0.2 or more, 0.3 or more, 0.5 or more, or 1 or more. The second aspect ratio may be, for example, 1 or less, 0.5 or less, 0.3 or less, or 0.2 or less.

[0032] Figure 3 is a schematic diagram showing an example of an electrode body in this embodiment. The electrode body 100 has an upper surface 100a, a lower surface 100b, and a circumferential surface 100c. The upper surface 100a, the lower surface 100b, and the circumferential surface 100c may be flat or uneven. The upper surface 100a may be parallel to the lower surface 100b. The circumferential surface 100c connects the upper surface 100a and the lower surface 100b. The circumferential surface 100c may include four planes. Each plane may be a rectangle.

[0033] Figure 4 is a second schematic cross-sectional view showing an example of a storage cell in this embodiment. Figure 4 shows a cross-section perpendicular to the height direction. The circumferential surface 100c includes a first region R1 and a second region R2. The circumferential surface 100c may consist of the first region R1 and the second region R2.

[0034] The first region R1 is covered with an insulating film 101. The insulating film 101 may be attached to the first region R1. The insulating film 101 may be bonded to the first region R1. For example, the insulating film 101 may be bonded to the first region R1 with an adhesive. The first region R1 may be a continuous region. The first region R1 may be divided into multiple parts.

[0035] The second region R2 is not covered by the insulating film 101. The second region R2 may be a continuous region. The second region R2 may be divided into multiple parts. The second region R2 is sandwiched between the first region R1. In the circumferential direction of the circumferential surface 100c, the second region R2 may be sandwiched, for example, between the starting end and the ending end of the first region R1. The second region R2 extends in the height direction. The second region R2 extends from the upper surface 100a to the lower surface 100b.

[0036] The second region R2 has a smaller area than the first region R1. The ratio of the area of ​​the second region R2 to the area of ​​the first region R1 may be, for example, 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, 0.1 or less, 0.05 or less, 0.03 or less, or 0.01 or less. The ratio of the area of ​​the second region R2 to the area of ​​the first region R1 may be, for example, 0.001 or more, 0.005 or more, 0.01 or more, 0.05 or more, or 0.1 or more.

[0037] If the first region R1 is divided into multiple parts, the sum of the areas of all parts is considered to be the area of ​​the first region R1. The same applies to the second region R2.

[0038] The insulating film 101 has a length direction and a width direction. The width direction is perpendicular to the length direction. The width direction of the insulating film 101 is parallel to the height direction. The insulating film 101 may be, for example, in the shape of a strip. The length dimension of the insulating film 101 may be shorter than the perimeter of the circumferential surface 100c. A continuous first region R1 can be formed by wrapping an insulating film 101 shorter than the perimeter around the circumferential surface 100c.

[0039] The thickness of the insulating film 101 may be, for example, 1 μm or more, 5 μm or more, 10 μm or more, 50 μm or more, 100 μm or more, 500 μm or more, or 1 mm or more. The thickness of the insulating film 101 may be, for example, 2 mm or less, 1 mm or less, 500 μm or less, 100 μm or less, 50 μm or less, 10 μm or less, or 5 μm or less. The thickness of the insulating film 101 may be uniform or locally different. The insulating film 101 may be used individually. Multiple insulating films 101 may be used. For example, multiple insulating films 101 may be laminated together. For example, multiple insulating films 101 may be spliced ​​together.

[0040] The insulating film 101 has electrical insulating properties. As long as it has electrical insulating properties, the insulating film 101 may contain any material. The insulating film 101 may be made of resin, for example. The insulating film 101 may contain at least one selected from the group consisting of polypropylene (PP), polyimide (PI), polyethylene (PE), polyethylene terephthalate (PET), and polyphenylene sulfide (PPS).

[0041] The energy storage cell 1 may further include a first insulating member 102. The first insulating member 102 may have a larger area than the second region R2. The ratio of the area of ​​the first insulating member 102 to the area of ​​the second region R2 may be, for example, 1.01 or more, 1.1 or more, 1.2 or more, 1.5 or more, or 2 or more. The ratio of the area of ​​the first insulating member 102 to the area of ​​the second region R2 may be, for example, 2.5 or less, 2.0 or less, or 1.5 or less.

[0042] The first insulating member 102 may be disposed on the surface of the case 200, for example. For example, the first insulating member 102 may be disposed in the case 200 at a position facing the second region R2. The first insulating member 102 may include, for example, an insulating coating. For example, the insulating coating may be applied to the case 200 at a position facing the second region R2. The insulating coating may include, for example, ceramic powder, resin powder, resin film, etc.

[0043] The first insulating member 102 may include, for example, an insulating tape. The insulating tape may extend, for example, across the second region R2 to bridge the first regions R1 together. The insulating tape may extend, for example, to connect the starting end of the first region R1 to the ending end of the first region R1. The insulating tape may be attached to the insulating film 101 or to the case 200. The insulating tape may be thinner than the insulating film 101, for example. The ratio of the thickness of the insulating tape to the thickness of the insulating film 101 may be, for example, 1 or less, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, or 0.5 or less. The ratio of the thickness of the insulating tape to the thickness of the insulating film 101 may be, for example, 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, or 0.5 or more.

[0044] The insulating tape may include, for example, a base layer and an adhesive layer. The adhesive layer is laminated to the base layer. The base layer may include, for example, a material similar to that of the insulating film 101. The base layer may have a thickness of, for example, 1 to 100 μm. The adhesive layer may include, for example, at least one selected from the group consisting of acrylic adhesives, silicone adhesives, urethane adhesives, and rubber adhesives.

[0045] 4.Laminated structure The electrode body may have any stacked structure. The electrode body may be, for example, a wound type. The electrode body may be, for example, a stacked type.

[0046] Figure 5 is a schematic cross-sectional view showing an example of an electrode body in this embodiment. The electrode body 100 in Figure 5 is of the stacked type. The electrode body 100 includes one or more first electrodes 110, one or more second electrodes 120, and one or more separators 130. In the thickness direction, the first electrodes 110 and the second electrodes 120 are stacked alternately. That is, the thickness direction of the energy storage cell 1 is parallel to the stacking direction of the first electrodes 110 and the second electrodes 120. The number of first electrodes 110 and second electrodes 120 may be 2 or more, 5 or more, 10 or more, 50 or more, or 100 or more, respectively. The number of first electrodes 110 and second electrodes 120 may be 200 or less, 100 or less, 50 or less, 10 or less, or 5 or less, respectively.

[0047] The second electrode 120 has a different polarity from the first electrode 110. For example, the first electrode 110 may be the positive electrode and the second electrode 120 may be the negative electrode.

[0048] The first electrode 110 may include, for example, a first current collector 112 and a first active material layer 114. The first current collector 112 may include, for example, a metal foil. The metal foil may include, for example, Al, Cu, Ni, Ti, Fe, etc. The first active material layer 114 is disposed on the surface of the first current collector 112. The first active material layer 114 may be disposed on only one side of the first current collector 112. The first active material layer 114 may be disposed on both sides of the first current collector 112. The first active material layer 114 includes a positive electrode active material or a negative electrode active material. The positive electrode active material may include, for example, a lithium nickel composite oxide. The negative electrode active material may include, for example, graphite, SiO, Si, etc.

[0049] The second electrode 120 may include, for example, a second current collector 122 and a second active material layer 124. The second current collector 122 may include, for example, a metal foil. The second active material layer 124 is disposed on the surface of the second current collector 122. The second active material layer 124 may be disposed on only one side of the second current collector 122. The second active material layer 124 may be disposed on both sides of the second current collector 122. The second active material layer 124 includes a positive electrode active material or a negative electrode active material. The second active material layer 124 may have the same area as the first active material layer 114, or it may have a different area. For example, the area of ​​the second active material layer 124 may be larger than the area of ​​the first active material layer 114. The ratio of the area of ​​the second active material layer 124 to the area of ​​the first active material layer 114 may be, for example, 1.01 or more, 1.05 or more, or 1.1 or more. The ratio of the area of ​​the second active material layer 124 to the area of ​​the first active material layer 114 may be, for example, 1.1 or less, 1.05 or less, or 1.01 or less.

[0050] The separator 130 has electrical insulating properties. The separator 130 is porous. The separator 130 may include, for example, a microporous membrane made of polyolefin. The thickness of the separator 130 may be, for example, 5 to 50 μm, 5 to 30 μm, or 5 to 15 μm. The separator 130 separates the first electrode 110 from the second electrode 120. There may be, for example, two or more separators 130. For example, one separator 130 may be inserted between the first electrode 110 and the second electrode 120.

[0051] The separator 130 may be, for example, a single sheet. For example, the separator 130 may include a zigzag section 135. In the zigzag section 135, the separator 130 is folded in a zigzag pattern. The zigzag pattern can also be described as, for example, "bellows-like" or "accordion-like."

[0052] The zigzag section 135 includes a flat section 131 and a folded section 132. In the flat section 131, the separator 130 extends in a planar manner. In the folded section 132, the separator 130 is folded back. The folded sections 132 are located at both ends in the height direction. The separator 130 is folded back so as to alternately sandwich the first electrode 110 or the second electrode 120. The flat section 131 sandwiches the first electrode 110 or the second electrode 120. The separator 130 may further include, for example, an outer peripheral section 136. The outer peripheral section 136 may be wound around to wrap the zigzag section 135. The zigzag section may also be formed by folding back the separator 130 at both ends in the width direction.

[0053] 5. Case Case 200 houses the electrolyte and electrode body 100. Case 200 may be sealed. Case 200 may include, for example, a can 210 and a lid 220. Can 210 has an opening. The opening is in the height direction. The opening may be, for example, vertically upward. Can 210 may be made of, for example, metal. Can 210 may contain, for example, Al. Can 210 may include, for example, a bottom wall 212 and a peripheral wall 214. The bottom wall 212 may be, for example, flat. The planar shape of the bottom wall 212 may be, for example, rectangular. The peripheral wall 214 rises from the bottom wall 212. The peripheral wall 214 may be, for example, rectangular tubular. The width of the peripheral wall 214 may be greater than the thickness of the peripheral wall 214. The height of the peripheral wall 214 may be greater than the thickness of the peripheral wall 214. Here, "thickness of the peripheral wall 214" refers to the external dimension of the case 200 in the thickness direction.

[0054] The lid 220 seals the opening of the can 210. The lid 220 may be welded to the peripheral wall 214. The lid 220 may be, for example, a flat plate. The lid 220 may be, for example, made of metal. The lid 220 may contain, for example, Al. The lid 220 may include, for example, a pressure relief valve 222 and a sealing member 224.

[0055] The pressure relief valve 222 may be located, for example, near the center of the lid 220. The pressure relief valve 222 releases the internal pressure of the case 200. When the internal pressure exceeds a set value, the pressure relief valve 222 may be opened. The sealing member 224 seals the injection hole 221. Electrolyte can be injected through the injection hole 221.

[0056] The inner surface of the lid 220 faces the upper surface 100a of the electrode body 100. That is, in the case 200, an injection hole 221 is provided on the surface facing the upper surface 100a. The injection hole 221 may have a specific positional relationship with the second region R2. The second region R2 may be located below the injection hole 221. For example, the angle between the line connecting the second region R2 and the injection hole 221 and the height direction may be 60° or less. This angle may be, for example, 45° or less, 30° or less, 15° or less, 5° or less, 3° or less, or 1° or less. The second region R2 may be located directly below the injection hole 221. For example, in the width direction, the position of the injection hole 221 and the position of the second region R2 may coincide.

[0057] A pair of external terminals 300 are fixed to the cover 220. The external terminals 300 are connected to the first electrode 110 or the second electrode 120. The external terminals 300 may be made of, for example, metal. The external terminals may contain Al, Cu, Ni, etc. The external terminals 300 may have, for example, a rectangular parallelepiped shape. The external terminals 300 may be connected to a busbar (not shown).

[0058] A pair of connecting members 400 connect the electrode tabs to the external terminals 300. The electrode tabs refer to the first electrode tab 116 or the second electrode tab 126. The two connecting members 400 may have substantially the same structure.

[0059] The connecting member 400 may include, for example, a current collector tab 410, a sub-tab 420, and a connecting pin 430. The current collector tab 410 includes a lateral portion 412 and an upper portion 414. The lateral portion 412 is located laterally to the electrode body 100 in the width direction. The upper portion 414 is located above the electrode body 100. The upper portion 414 extends inward in the width direction from the upper end of the lateral portion 412.

[0060] The sub-tab 420 connects multiple electrode tabs to the current collection tab 410. The sub-tab 420 may include a first end 422 and a second end 424. The first end 422 is connected to the multiple electrode tabs. The second end 424 is connected to the lateral portion 412.

[0061] The connecting pin 430 connects the current collection tab 410 to the external terminal 300. The connecting pin 430 also connects the upper portion 414 to the external terminal 300. For example, the lower end of the connecting pin 430 may be inserted through a through hole provided in the upper portion 414.

[0062] The second insulating member 500 insulates the case 200 from the connecting member 400. The second insulating member 500 may include, for example, a first part 510, a second part 520, a third part 530, and a fourth part 540.

[0063] Part 1 510 is fixed to the upper surface of the lid 220. Part 1 510 is positioned between the lid 220 and the external terminal 300. Part 2 520 is fixed to the lower surface of the lid 220. Part 2 520 is positioned between the lid 220 and the upper part 414. Part 2 520 is positioned between the lid 220 and the lower part of the connecting pin 430. Part 3 530 is positioned between the connecting pin 430 and the lid 220. Part 3 530 is cylindrical. Part 3 530 surrounds the connecting pin 430. Parts 1 510, 2 520, and 3 530 are provided with through holes. The connecting pin 430 is inserted through the through holes.

[0064] The fourth part 540 is plate-shaped. It is fixed to the lower surface of the upper part 414. The fourth part 540 is positioned above the electrode body 100. A through hole is provided in the fourth part 540 below the pressure relief valve 222. A through hole is also provided in the fourth part 540 below the liquid injection hole 221. [Explanation of Symbols]

[0065] 1 Energy storage cell, 100 Electrode body, 100a Top surface, 100b Bottom surface, 100c Peripheral surface, 101 Insulating film, 102 First insulating member, 110 First electrode, 112 First current collector, 114 First active material layer, 116 First electrode tab, 120 Second electrode, 122 Second current collector, 124 Second active material layer, 126 Second electrode tab, 130 Separator, 131 Flat part, 132 Folded part, 135 Zigzag part, 136 Outer circumference, 200 Case, 210 Can, 212 Bottom wall, 214 Peripheral wall, 220 Lid, 221 Liquid injection hole, 222 Pressure relief valve, 224 Sealing member, 300 External terminal, 400 Connecting member, 410 Current collector tab, 412 Side part, 414 Upper section, 420 sub-tab, 422 first end, 424 second end, 430 connecting pin, 500 second insulating member, 510 first part, 520 second part, 530 third part, 540 fourth part, R1 first region, R2 second region.

Claims

1. Includes case, electrode body, insulating film and electrolyte, The case houses the electrode body, the insulating film, and the electrolyte. The electrode body has an upper surface, a lower surface, and a circumferential surface. In the above case, an injection hole is provided on the surface facing the upper surface, The aforementioned circumferential surface connects the aforementioned upper surface and the aforementioned lower surface, The circumferential surface includes a first region and a second region, The first region is covered by the insulating film, The second region is not covered by the insulating film, The second region extends from the upper surface to the lower surface, and The second region has a smaller area compared to the first region. It further includes an insulating member, and Within the case, the insulating member is positioned opposite the entirety of the second region. Energy storage cell.

2. The second region is located below the injection hole, The energy storage cell according to claim 1.

3. Further includes insulating tape, In the circumferential direction of the circumferential surface, the second region is sandwiched between the first region, and The insulating tape extends across the second region and bridges the first regions together. The energy storage cell according to claim 1.

4. The insulating film is in the shape of a strip. The energy storage cell according to claim 1.

5. The insulating film is wrapped around the circumferential surface, The energy storage cell according to claim 1.

6. The insulating film has a length direction and a width direction, The width direction is perpendicular to the length direction, and The aforementioned lengthwise dimension is shorter than the perimeter of the circumferential surface. The energy storage cell according to claim 1.

7. The electrode body has a cubic shape, and The electrode body is of the stacked type. The energy storage cell according to claim 1.

8. The circumferential surface consists of the first region and the second region. A storage cell according to any one of claims 1 to 7.

9. The electrode body has a height direction, a width direction, and a thickness direction that are orthogonal to each other, The aforementioned height direction is the direction from the upper surface to the lower surface. In the aforementioned thickness direction, electrodes are stacked, and Current collection tabs are provided on both sides in the width direction. A storage cell according to any one of claims 1 to 7.

10. The insulating member includes an insulating paint, The insulating paint is applied to the inner surface of the case. A storage cell according to any one of claims 1 to 7.

11. The insulating member includes an insulating tape, The insulating tape is attached to the inner surface of the case. The energy storage cell according to claim 1 or claim 2.

12. The ratio of the area of ​​the insulating member to the area of ​​the second region is greater than 1 and less than or equal to 2.

5. The energy storage cell according to claim 1.

13. The ratio of the area of ​​the insulating member to the area of ​​the second region is 1.01 or more and 1.5 or less. The energy storage cell according to claim 12.

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