Energy storage cell

Abstract

The present invention provides a storage cell capable of suppressing damage to the electrode tabs. [Solution] The energy storage cell 100 comprises an electrode body 10 including a first electrode 10A and a second electrode 10B, a first connecting member 50A and a second connecting member 50B positioned opposite the electrode body 10, a first tab 90A that electrically connects the first electrode 10A and the first connecting member 50A, and a foam layer 140. The foam layer 140 supports the first tab 90A by contacting it.

Description

Technical Field

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

Background Art

[0002] Japanese Patent Publication No. 2023-547686 (Patent Document 1) discloses a battery cell including an electrode assembly, an adapter piece, and a tab. The tab extends from the electrode assembly toward the adapter piece and is connected to the adapter piece.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1 described above, as described above, a tab (electrode tab) connects an electrode assembly (electrode body) and an adapter piece (current collector plate). In such a configuration, when the storage battery cell vibrates, the tab may be damaged due to an external force such as a tensile force or a torsional force being applied to the tab.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a storage battery cell capable of suppressing breakage of an electrode tab.

Means for Solving the Problems

[0006] A storage battery cell according to one aspect of the present disclosure includes an electrode body including an electrode sheet, a current collector plate disposed at a position facing the electrode body, at least one electrode tab that electrically connects the electrode sheet and the current collector plate, and a foam layer including a foam. The foam layer supports at least one electrode tab by contacting at least one electrode tab.

Effects of the Invention

[0007] According to this disclosure, it is possible to suppress damage to the electrode tab. [Brief explanation of the drawing]

[0008] [Figure 1] This diagram shows the configuration of a vehicle equipped with an energy storage device. [Figure 2] This is a perspective view showing the configuration of the energy storage device and frame members. [Figure 3] This is a cross-sectional view along line III-III in Figure 2. [Figure 4] This is a perspective view showing the configuration of the energy storage cell according to the first embodiment. [Figure 5] This is an exploded perspective view showing the configuration of the energy storage cell according to the first embodiment. [Figure 6] This is a cross-sectional view taken in the direction of the arrow VI-VI in Figure 4. [Figure 7] This is a cross-sectional view taken in the direction of the line VII-VII in Figure 6. [Figure 8] This is a partially enlarged cross-sectional view showing the configuration of the first electrode and the first tab according to the first embodiment. [Figure 9] This is a partially enlarged cross-sectional view showing the configuration of the second electrode. [Figure 10] This is a schematic cross-sectional view taken in the direction of the arrow XX in Figure 6. [Figure 11] Figure 10 is a magnified view of the area near the foam layer. [Figure 12] This is a schematic cross-sectional view showing the configuration of a storage cell according to the second embodiment. [Figure 13] This is a partially enlarged cross-sectional view showing the configuration of the first electrode and the first tab according to the second embodiment. [Figure 14] This is a schematic plan view showing the first tab and electrode body according to the second embodiment. [Figure 15] This figure shows the state in which the winding of the first electrode has been unwound according to the second embodiment. [Figure 16] This is a cross-sectional view showing a first modified example of the first embodiment. [Figure 17] It is a cross-sectional view showing a first modification of the second embodiment. [Figure 18] It is a cross-sectional view showing a second modification of the first embodiment. [Figure 19] It is a cross-sectional view showing a second modification of the second embodiment. [Figure 20] It is a cross-sectional view showing a third modification of the second embodiment. [Figure 21] It is a cross-sectional view showing a fourth modification of the second embodiment. [Figure 22] It is a cross-sectional view showing a third modification of the first embodiment.

Mode for Carrying Out the Invention

[0009] Embodiments of the present disclosure will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference numerals.

[0010] [First Embodiment] FIG. 1 is a diagram schematically showing a vehicle equipped with a power storage device according to the first embodiment of the present disclosure. As shown in FIG. 1, the vehicle 1 includes a vehicle body 2 and a power storage device 3. Examples of the vehicle 1 include a hybrid electric vehicle, a plug-in hybrid electric vehicle, and a battery electric vehicle. Note that the power storage device 3 may be provided in an electrical device other than an electric vehicle (for example, a stationary power storage device). In the present specification, the X direction, the Y direction, and the Z direction are directions orthogonal to each other. For example, the X direction and the Y direction may be the front-rear direction and the left-right direction, respectively, when the power storage device 3 is mounted on an electric vehicle. Also, the Z direction may be the vertical direction.

[0011] The vehicle body 2 includes a frame member 4. The frame member 4 is located at the bottom of the vehicle body 2. The frame member 4 is formed in a roughly rectangular cylindrical shape that surrounds the energy storage device 3. The energy storage device 3 is attached to the frame member 4.

[0012] Figure 2 is a schematic perspective view showing the energy storage device 3 and the frame member 4. As shown in Figure 2, the energy storage device 3 comprises a plurality of energy storage stacks 5.

[0013] Each energy storage stack 5 is formed in the shape of a rectangular parallelepiped, elongated in the Y direction. Multiple energy storage stacks 5 are arranged in a line along the X direction.

[0014] Figure 3 is a cross-sectional view (cross-sectional view of the energy storage stack 5) taken in the direction of the arrow III-III in Figure 2. Each energy storage stack 5 includes a plurality of energy storage cells 100 arranged in the Y direction. A pressure relief valve SV is formed at the bottom of each energy storage cell 100. The pressure relief valve SV is an example of an "exhaust valve" in this disclosure.

[0015] Figure 4 is a perspective view showing a storage cell 100 according to the first embodiment. As shown in Figure 4, the storage cell 100 is a so-called prismatic battery. The storage cell 100 is a secondary battery configured to be chargeable and dischargeable. The storage cell 100 may be a secondary battery such as a lithium-ion battery or a nickel-metal hydride battery. The storage cell 100 can be used, for example, as a cell included in a storage module mounted on an electric vehicle.

[0016] The energy storage cell 100 comprises an electrode body 10, a case 20, a first external terminal 30A, a second external terminal 30B, a first terminal support portion 40A, and a second terminal support portion 40B. Figure 4 shows a schematic representation of the electrode body 10. Note that the electrode body 10 is an example of the "wound electrode body" of this disclosure.

[0017] Case 20 is conductive. The conductive portion of Case 20 is made of a metal such as aluminum. Case 20 houses the electrode body 10. Case 20 also houses an electrolyte solution, which is not shown in the diagram.

[0018] Case 20 includes a case body 21 and a lid 22. The case body 21 includes a bottom wall 210 and a peripheral wall 211 rising from the bottom wall 210. The pressure relief valve SV (Figure 3) is formed in the bottom wall 210. Note that the bottom wall 210 is an example of a "wall portion" in this disclosure.

[0019] The lid 22 includes a lid body 220 and an insulating cover 221. The lid body 220 is joined to the peripheral wall 211 by welding or the like so as to close the opening in the peripheral wall 211.

[0020] The first external terminal 30A and the second external terminal 30B are provided in the energy storage cell 100 so as to be exposed to the outside. In the first embodiment, the first external terminal 30A is the positive terminal and the second external terminal 30B is the negative terminal. The first external terminal 30A and the second external terminal 30B are aligned in the X direction.

[0021] The first terminal support portion 40A is locked to the lid body 220. The first terminal support portion 40A supports the first external terminal 30A from the outer circumference side of the first external terminal 30A. The second terminal support portion 40B is locked to the lid body 220. The second terminal support portion 40B supports the second external terminal 30B from the outer circumference side of the second external terminal 30B.

[0022] Figure 5 is an exploded perspective view of a power storage cell 100 according to the first embodiment. The power storage cell 100 further comprises a first connecting member 50A, a second connecting member 50B, a first sealing ring 60A, a second sealing ring 60B, an insulating member 70, and a fuse protection unit 80. The first connecting member 50A and the second connecting member 50B are examples of the "current collector plate" of this disclosure.

[0023] The bottom wall 210 includes the bottom body 212, an outer protective film 213, and an inner protective film 214. The peripheral wall 211 rises from the bottom body 212. The pressure relief valve SV is provided on the bottom body 212. The outer protective film 213 covers the pressure relief valve SV from the outside. The inner protective film 214 covers the pressure relief valve SV from the inside. The bottom body 212 and the pressure relief valve SV are made of a metal such as aluminum.

[0024] An opening is formed at the upper end of the peripheral wall 211. The peripheral wall 211 has a substantially rectangular outer shape when viewed from the direction of the opening. The opening and the bottom wall 210 are aligned in the Z direction. The Z direction may be the height direction or vertical direction of the energy storage cell 100. The peripheral wall 211 is made of a metal such as aluminum.

[0025] The lid 22 further includes a sealing plug 222 and a plug cover 223. The lid body 220 has a first connecting hole 224A, a second connecting hole 224B, and an electrolyte injection hole 225. The electrolyte injection hole 225 is a through hole for injecting electrolyte into the case body 21 during the manufacturing process of the energy storage cell 100.

[0026] The sealing plug 222 seals the injection hole 225. The plug cover 223 covers the injection hole 225 and the sealing plug 222. The insulating cover 221 covers the injection hole 225, the sealing plug 222, and the plug cover 223.

[0027] The first connecting member 50A and the second connecting member 50B are conductive. At least a portion of the first connecting member 50A and the second connecting member 50B are located within the case 20. Each of the first connecting member 50A and the second connecting member 50B is positioned opposite the electrode body 10 in the Z direction.

[0028] The first external terminal 30A or the first connecting member 50A is inserted through the first connecting hole 224A. The first external terminal 30A and the first connecting member 50A are joined to each other. The first connecting member 50A is joined to the electrode body 10. As a result, the first external terminal 30A is electrically connected to the electrode body 10.

[0029] The second external terminal 30B or the second connecting member 50B is inserted through the second connecting hole 224B. The second external terminal 30B and the second connecting member 50B are joined to each other. The second connecting member 50B is joined to the electrode body 10. As a result, the second external terminal 30B is electrically connected to the electrode body 10.

[0030] The first seal ring 60A is provided along the first connecting hole 224A. The first seal ring 60A is provided in the gap between the lid body 220 and the first external terminal 30A, and seals this gap. The second seal ring 60B is provided along the second connecting hole 224B. The second seal ring 60B is provided in the gap between the lid body 220 and the second external terminal 30B, and seals this gap. The first seal ring 60A and the second seal ring 60B have electrical insulating properties.

[0031] The first terminal support portion 40A includes a first locking ring 41A and a first covering ring 42A. The first locking ring 41A extends in an annular shape to surround the first connecting hole 224A and is directly locked to the lid body 220. The first covering ring 42A covers the first locking ring 41A. The first locking ring 41A supports the first external terminal 30A via the first covering ring 42A. The first covering ring 42A is made of a resin material that is electrically insulating or has relatively weak conductivity.

[0032] The second terminal support portion 40B includes a second locking ring 41B and a second covering ring 42B. The second locking ring 41B extends in an annular shape to surround the second connecting hole 224B and is directly locked to the lid body 220. The second covering ring 42B covers the second locking ring 41B. The second locking ring 41B supports the second external terminal 30B via the second covering ring 42B. The second covering ring 42B is made of an electrically insulating resin material.

[0033] The insulating member 70 has electrical insulating properties. The insulating member 70 is placed between the electrode body 10 and the case 20. The insulating member 70 electrically insulates the electrode body 10 and the case 20 from each other. The insulating member 70 includes an insulating bracket 71, a circumferential insulating portion 72, a bottom insulating portion 73, and adhesive tape 74.

[0034] The insulating bracket 71 is positioned between the electrode body 10 and the lid body 220. The insulating bracket 71 is relatively rigid and is in contact with both the electrode body 10 and the lid body 220. As a result, the electrode body 10 is fixed to the case 20 in the Z direction.

[0035] The circumferential insulating portion 72 is positioned between the electrode body 10 and the circumferential wall 211. The electrode body 10 is made of a film-like material.

[0036] The bottom insulating portion 73 is positioned between the electrode body 10 and the bottom wall 210. The bottom insulating portion 73 is made of a film-like material. The bottom insulating portion 73 is fixed (adhered) to the case 20 (bottom wall 210) by adhesive tape 74.

[0037] As shown in Figure 5, the energy storage cell 100 according to the first embodiment includes a plurality of electrode bodies 10. The energy storage cell 100 of the first embodiment includes two electrode bodies 10. These electrode bodies 10 are aligned in the Y direction. The circumferential insulating portion 72 may integrally cover the plurality of electrode bodies 10 so that these electrode bodies 10 are fixed to each other.

[0038] Each of the multiple electrode bodies 10 is provided with at least one first tab 90A and at least one second tab 90B. In the first embodiment, each of the multiple electrode bodies 10 is provided with multiple first tabs 90A and multiple second tabs 90B. Each first tab 90A electrically connects the first electrode 10A (described later) and the first connecting member 50A. Each second tab 90B electrically connects the second electrode 10B (described later) and the second connecting member 50B. Note that each of the first tab 90A and the second tab 90B is an example of an "electrode tab" as described herein.

[0039] Figure 6 is a cross-sectional view taken in the direction of the arrow VI-VI in Figure 4. As shown in Figure 6, the multiple first tabs 90A are arranged so as to be aligned with each other in the Y direction. The multiple first tabs 90A are joined to each other, for example by ultrasonic welding. The multiple first tabs 90A are joined to the first connecting member 50A, for example by ultrasonic welding. The multiple second tabs 90B are arranged so as to be aligned with each other in the Y direction. The multiple second tabs 90B are joined to each other, for example by ultrasonic welding. The multiple second tabs 90B are joined to the first connecting member 50A, for example by ultrasonic welding.

[0040] Figure 7 is a cross-sectional view of the electrode body of Figure 6, viewed in the direction of the VII-VII arrow. The electrode body 10 includes a first electrode 10A, a second electrode 10B, a separator 10C, and a tape member 10D. The electrode body 10 is wound such that the first electrode 10A, the second electrode 10B, and the separator 10C surround the winding axis α. Thus, in the first embodiment, the electrode body 10 is a so-called wound electrode body, but it may also be a laminated electrode body in which the first electrode 10A, the second electrode 10B, and the separator 10C are stacked in one direction (for example, the Y direction). Note that each of the first electrode 10A and the second electrode 10B is an example of an "electrode sheet" as disclosed herein.

[0041] The first electrode 10A and the second electrode 10B have a sheet-like outer shape. The electrode body 10 is composed of a group of electrode plates in which the first electrode 10A and the second electrode 10B are wound around one or more separators 10C.

[0042] In the first embodiment, the first electrode 10A is the positive electrode and the second electrode 10B is the negative electrode. However, the first electrode 10A may be the negative electrode and the second electrode 10B may be the positive electrode.

[0043] The separator 10C is provided between the first electrode 10A and the second electrode 10B. The separator 10C separates the first electrode 10A and the second electrode 10B while allowing ions to move between them. The ions are, for example, lithium ions. The separator 10C has electrical insulating properties.

[0044] Of the first electrode 10A, the second electrode 10B, and the separator 10C, the separator 10C is located on the innermost side with respect to the winding axis α. Also, of the first electrode 10A, the second electrode 10B, and the separator 10C, the separator 10C is located on the outermost side with respect to the winding axis α. The outer edge of the separator 10C in the winding direction is fixed by a tape member 10D placed on the outer surface of the separator 10C.

[0045] The first electrode 10A includes a first current collector 11A and a first active material layer 12A. The second electrode 10B includes a second current collector 11B and a second active material layer 12B.

[0046] Figure 8 is a cross-sectional view of the first electrode 10A. The first current collector 11A includes a support portion 110, a first conductive layer 111, and a second conductive layer 112. The first electrode 10A further includes a protective portion 13. The first current collector 11A and the first active material layer 12A are examples of the "current collector" and "electrode active material layer" of this disclosure, respectively.

[0047] The support portion 110 is made of an electrically insulating resin composition. For example, the support portion 110 is made of a resin composition containing a polyester resin. The polyester resin is preferably polyethylene terephthalate, for example. This makes it possible to increase the rigidity of the first current collector 11A while maintaining the electrical insulation properties of the support portion 110. Consequently, the support portion 110 can be made relatively thin. The orthogonal direction DO, which is perpendicular to the thickness direction DT of the support portion 110, is approximately parallel to the Z direction.

[0048] The first conductive layer 111 is in contact with the support portion 110 on one side in the thickness direction DT. In the first embodiment, the first conductive layer 111 is located on the winding axis α side when viewed from the support portion 110. Furthermore, the first conductive layer 111 is provided over the entire surface of the coated portion 15a and the uncoated portion 15b, which will be described later, on one side in the thickness direction DT.

[0049] The second conductive layer 112 is in contact with the support portion 110 on the other side in the thickness direction DT. In the first embodiment, the second conductive layer 112 is located on the opposite side from the winding axis α when viewed from the support portion 110. Furthermore, the second conductive layer 112 is provided over the entire surface of the coated portion 15a and the uncoated portion 15b, which will be described later, on the other side in the thickness direction DT.

[0050] Each of the first conductive layer 111 and the second conductive layer 112 is made of a metal layer. In the first embodiment, each of the first conductive layer 111 and the second conductive layer 112 is made of a metal containing aluminum. This allows the first current collector 11A to be suitably used as a positive electrode current collector. The first current collector 11A may also be a negative electrode current collector, and the first conductive layer 111 and the second conductive layer 112 may be made of a metal containing copper.

[0051] Each of the multiple first tabs 90A is joined to the first conductive layer 111 and the second conductive layer 112, for example, by ultrasonic welding. Each of the multiple first tabs 90A extends from the support portion 110 toward Z1.

[0052] The first current collector 11A has surfaces 14a and 14b arranged in the thickness direction DT. Surface 14a is the surface of the first conductive layer 111 opposite to the support portion 110. Surface 14b is the surface of the second conductive layer 112 opposite to the support portion 110. Surfaces 14a and 14b are examples of the "first surface" and "second surface" of this disclosure, respectively.

[0053] The first current collector 11A has a coated portion 15a to which the first active material layer 12A is applied, and an uncoated portion 15b to which the first active material layer 12A is not applied. The first current collector 11A is exposed in at least a portion of the uncoated portion 15b. The uncoated portion 15b is located on the Z1 side (the side of the first connecting member 50A (Figure 5)) than the coated portion 15a. The first active material layer 12A covers the surface 14a and the surface 14b of the coated portion 15a of the first current collector 11A, respectively.

[0054] Each of the multiple first tabs 90A includes a first foil portion 91 and a second foil portion 92. The first foil portion 91 is located on the opposite side of the support portion 110 when viewed from the first conductive layer 111. The first foil portion 91 is bonded to the first conductive layer 111. The first foil portion 91 is bonded to the first connecting member 50A (Figure 5). The second foil portion 92 is located on the opposite side of the support portion 110 when viewed from the second conductive layer 112. The second foil portion 92 is bonded to the second conductive layer 112. The second foil portion 92 is bonded to the second connecting member 50B (Figure 5). Note that the first foil portion 91 and the second foil portion 92 are examples of the "first electrode foil" and "second electrode foil" of this disclosure, respectively.

[0055] The first foil portion 91 is provided on the portion 14c of the surface 14a that corresponds to the uncoated portion 15b. The first foil portion 91 is joined to the portion 14c. The portion 14c is an example of the "first uncoated portion" in this disclosure.

[0056] The second foil portion 92 is provided on the portion 14d of the surface 14b that corresponds to the uncoated portion 15b. The second foil portion 92 is bonded to portion 14d. Portion 14d is provided in the region that overlaps with portion 14c in the Z direction. Portion 14d is an example of the "second uncoated portion" in this disclosure.

[0057] The first foil portion 91 includes a lower portion 91a and an upper portion 91b. The lower portion 91a is positioned on the first electrode 10A. Specifically, the lower portion 91a is joined to portion 14c. The upper portion 91b protrudes from the lower portion 91a (part 14c) toward the Z1 side (the first connecting member 50A (Figure 5) side). The upper portion 91b and the lower portion 91a are examples of the "first protruding portion" and the "sheet side portion" of this disclosure, respectively.

[0058] The second foil portion 92 includes a lower portion 92a and an upper portion 92b. The lower portion 92a is positioned on the first electrode 10A. Specifically, the lower portion 92a is joined to portion 14d. The upper portion 92b protrudes from the lower portion 92a (portion 14d) toward the Z1 side (the first connecting member 50A (Figure 5) side). Note that the upper portion 92b is an example of the "second protruding portion" of this disclosure.

[0059] The upper portion 91b is joined to the upper portion 92b. Specifically, the upper portion 91b and the upper portion 92b are joined at a joint portion 93 on the Z1 side of the first current collector 11A, for example by ultrasonic welding. The joint portion 93 extends in the Z direction by a length L. The length L is greater than, for example, the thickness t in the thickness direction DT of the first current collector 11A.

[0060] The first foil portion 91 (upper portion 91b) extends further toward Z1 than the upper end portion 92c (Z1 side end) of the second foil portion 92 (upper portion 92b). The joint portion 93 is the portion where the upper portion 92b and the Z2 side base portion of the upper portion 91b are joined. The joint portion 93 extends toward Z1 from, for example, the upper end portion 10E of the electrode body 10. The upper end portion 10E of the electrode body 10 is the upper end portion of the separator 10C (Figure 7). The lower end portion of the joint portion 93 may be located, for example, toward Z1 or Z2 than the upper end portion 10E.

[0061] As described above, in the first embodiment, the length of the first foil portion 91 in the orthogonal direction DO (Z direction) perpendicular to the thickness direction DT is longer than the length of the second foil portion 92 in the orthogonal direction DO. The first foil portion 91 is joined to the first connecting member 50A, while the second foil portion 92 is not joined to the first connecting member 50A. However, the configuration of the first tab 90A is not limited to this. The length of the second foil portion 92 in the orthogonal direction DO may be longer than the length of the first foil portion 91 in the orthogonal direction DO. The second foil portion 92 may be joined to the first connecting member 50A, while the first foil portion 91 may not be joined to the first connecting member 50A.

[0062] The first active material layer 12A includes a first inner active material layer 121A and a first outer active material layer 122A. The first inner active material layer 121A is laminated on the first conductive layer 111. The first outer active material layer 122A is laminated on the second conductive layer 112.

[0063] The upper edge of the first active material layer 12A is separated from each of the multiple first tabs 90A. Specifically, the upper edge of the first inner active material layer 121A is separated from each of the first foil portions 91 of the multiple first tabs 90A. The upper edge of the first outer active material layer 122A is separated from each of the second foil portions 92 of the multiple first tabs 90A.

[0064] The separator 10C is laminated on the first active material layer 12A in the radial direction centered on the winding axis α (Figure 7). The separator 10C is laminated on the first inner active material layer 121A in the same radial direction. The separator 10C is also laminated on the first outer active material layer 122A in the same radial direction.

[0065] The protective part 13 has electrical insulating properties and is made of, for example, ceramic. The protective part 13 covers the upper part of the first active material layer 12A. The protective part 13 further covers the first current collector 11A between the first tab 90A and the first active material layer 12A.

[0066] The protective portion 13 includes an inner protective portion 131 and an outer protective portion 132. The inner protective portion 131 covers the upper part of the first inner active material layer 121A. The inner protective portion 131 covers the first conductive layer 111 between the first foil portion 91 and the first inner active material layer 121A. The outer protective portion 132 covers the upper part of the first outer active material layer 122A. The outer protective portion 132 covers the second conductive layer 112 between the second foil portion 92 and the first outer active material layer 122A.

[0067] Figure 9 is a cross-sectional view of the second electrode 10B. The second electrode 10B is laminated in the radial direction on the first active material layer 12A (Figures 7 and 8) via the separator 10C (Figure 7). More specifically, the second electrode 10B is laminated in the radial direction on the first inner active material layer 121A (Figure 8) via the separator 10C, and also on the first outer active material layer 122A (Figure 8) via the separator 10C.

[0068] The second electrode 10B includes a second current collector 11B and a second active material layer 12B. The second current collector 11B includes a conductive support portion 113 and a plurality of second tabs 90B. The conductive support portion 113 extends along the orthogonal direction DO (Z direction). The plurality of second tabs 90B extend from the upper end of the conductive support portion 113. The plurality of second tabs 90B are joined to each other by ultrasonic welding and are also joined to the second connecting member 50B (Figures 5 and 6).

[0069] The multiple second tabs 90B and conductive support portion 113 are made of an integral material, for example, metal foil. In the first embodiment, the multiple second tabs 90B and conductive support portion 113 are made of a metal including copper, for example. This allows the second current collector 11B to be suitably used as a negative electrode current collector. If the first current collector 11A is a negative electrode current collector, the multiple second tabs 90B and conductive support portion 113 may be made of a metal including aluminum.

[0070] The second active material layer 12B is laminated on both sides of the conductive support portion 113 of the second current collector 11B. In the first embodiment, since the second electrode 10B is the negative electrode, the edge of the second active material layer 12B in the Z direction is located ahead of the edge of the first active material layer 12A.

[0071] Figure 10 is a schematic cross-sectional view of the electrode body of Figure 6 as seen in the direction of the XX arrow. Multiple first tabs 90A are arranged in the Y direction. In Figure 10, for simplification, the first tabs 90A provided on each electrode body 10 are shown in a reduced number. Also, in Figure 10, for simplification, the upper portion 92b is omitted from the illustration. Furthermore, in Figure 10 and other figures, an example is schematically shown in which multiple portions 94 are overlapped in the Z direction, but each portion 94 may be in direct contact with the first connecting member 50A by, for example, staggering the arrangement of the portions 94. Note that the Y direction is just one example of the "arrangement direction" in this disclosure.

[0072] The upper portion 91b of each first tab 90A includes a portion 94 positioned on the first connecting member 50A. Each portion 94 extends along the Y direction, and at least a part of it is positioned on the first connecting member 50A. Positioning on the first connecting member 50A includes not only cases where it is directly positioned (in contact) with the first connecting member 50A, but also cases where, for example, another portion 94 is sandwiched between it and the first connecting member 50A. Furthermore, portion 94 is an example of the "current collector plate side portion" of this disclosure.

[0073] Each upper portion 91b of the first tab 90A includes a connecting portion 95 that connects the lower portion 91a (Figure 8) to portion 94. Each connecting portion 95 extends along the Z direction. Each of the multiple portions 94 in each electrode body 10 extends from the upper end of the connecting portion 95 to one side in the Y direction. Specifically, each of the multiple portions 94 in the electrode body 10 on the Y1 side extends from the upper end of the connecting portion 95 to the Y2 side. Each of the multiple portions 94 in the electrode body 10 on the Y2 side extends from the upper end of the connecting portion 95 to the Y1 side. In Figure 10, for clarity, adjacent connecting portions 95 are shown spaced apart, but adjacent connecting portions 95 may be in contact with each other. Also, in Figure 10, the connecting portions 95 are schematically shown extending in the Z direction, but the connecting portions 95 may be curved (bent), for example.

[0074] Multiple first tabs 90A (upper portion 91b) protrude from each electrode body 10 toward the Z1 side. The first connecting member 50A has a one-side connecting portion 51 that connects to the first tab 90A of the electrode body 10 on the Y1 side, and a other-side connecting portion 52 that connects to the first tab 90A of the electrode body 10 on the Y2 side. The one-side connecting portion 51 and the other-side connecting portion 52 are spaced apart in the Y direction.

[0075] In conventional energy storage cells, when the energy storage cell vibrates, external forces such as tensile and torsional forces are applied to the electrode tabs, which can cause the electrode tabs to break.

[0076] Therefore, in the first embodiment, the energy storage cell 100 includes a foam layer 140. The foam layer 140 supports the first tab 90A by contacting it. In other words, the foam layer 140 restricts the movement (vibration) of the first tab.

[0077] In the example shown in Figure 10, the foam layer 140 is positioned adjacent to the first tab 90A located at the end of the multiple first tabs 90A arranged in the Y direction on each electrode body 10. Specifically, the foam layer 140 is adjacent to the first tab 90A located furthest towards Y2 on the Y1 side of the electrode body 10. The foam layer 140 is adjacent to the first tab 90A located furthest towards Y1 on the Y2 side of the electrode body 10. Although Figure 10 shows an example where the foam layer 140 adjacent to the first tab 90A on the Y1 side of the electrode body 10 and the foam layer 140 adjacent to the first tab 90A on the Y2 side of the electrode body 10 are provided separately, a single foam layer 140 may extend in the Y direction so as to be adjacent to the two first tabs 90A mentioned above.

[0078] Since the configuration (arrangement) of the foam layer 140 is the same in both electrode bodies 10, only the foam layer 140 placed on the electrode body 10 on the Y1 side will be described below.

[0079] As shown in Figure 10, the pressure relief valve SV is positioned on the opposite side (Z2 side) from the foam layer 140 relative to the electrode body 10. The foam layer 140 may be formed in a position that overlaps with the pressure relief valve SV in the Z direction.

[0080] As a result, for example, if debris is generated in the electrode body 10 due to smoke generation or the like, the foam layer 140 provided on the opposite side of the pressure relief valve SV will foam further (due to the heat of the smoke, etc.), so that the debris can be pushed out of the pressure relief valve SV and discharged outside the case 20.

[0081] Figure 11 is a magnified view of the vicinity of the foam layer 140 in Figure 10. Note that in Figure 11, only the first tab 90A adjacent to the foam layer 140 is shown in contact with the foam layer 140; however, other portions 94 of the first tab 90A may also be in contact with the foam layer 140. The relationship between the foam layer 140 and the first tab 90A adjacent to the foam layer 140 will be explained below with reference to Figure 11.

[0082] As shown in Figure 11, the foam layer 140 is in contact with portion 94. Specifically, the upper end surface 141 of the foam layer 140 is in surface contact with the lower surface 94a of portion 94. Although not shown in the figure, both the upper end surface 141 and the lower surface 94a extend along the X direction. The portion 94, which is positioned on the first connecting member 50A, is pressed by the foam layer 140 from the side opposite to the first connecting member 50A (the Z2 side).

[0083] As a result, the movement of portion 94 is restricted by the foam layer 140, which prevents portion 94 from shifting away from the first connecting member 50A (disconnection of the joint). Consequently, it is possible to prevent the electrode body 10 and the first connecting member 50A from becoming electrically disconnected.

[0084] The foam layer 140 is separated from the connecting portion 95. In other words, a gap C is formed between the foam layer 140 and the connecting portion 95.

[0085] This prevents the connecting portion 95 from being pressed by the foam layer 140. As a result, it is possible to prevent the connecting portion 95 from being damaged or the joint of the connecting portion 93 (Figure 8), which is formed at the position corresponding to the connecting portion 95, from peeling off due to the pressing force from the foam layer 140.

[0086] The lower surface 142 of the foam layer 140 is in contact with the electrode body 10. Therefore, the foam layer 140 presses the electrode body 10 toward the Z2 side. This allows the electrode body 10 to be stably fixed to a support member (for example, the bottom wall 210 of the case 20) that supports the electrode body 10 from the Z2 side. Although the lower surface 142 of the foam layer 140 is in contact with the upper end portion 10E of the electrode body 10, a portion of the foam layer 140 may extend into the interior of the electrode body 10 (the portion toward the Z2 side of the upper end portion 10E).

[0087] The foamed layer 140 contains thermally expandable microcapsules 140a. The density of the microcapsules 140a is uniform throughout the foamed layer 140. By adjusting the density of the microcapsules 140a in the foamed layer 140, the size (expansion) of the foamed layer 140 can be easily adjusted. Note that the microcapsules 140a are an example of the "foam" described herein.

[0088] The foam layer 140 is insulating. This prevents electrical conductivity between the first electrode 10A and the second electrode 10B even when the foam layer 140 is in contact with the second electrode 10B.

[0089] For example, the foam layer 140 may be composed of an insulating tape containing microcapsules 140a. By performing a heating test of the energy storage cell 100 with the insulating tape attached, for example, to the lower surface 94a of portion 94, the microcapsules 140a may be thermally expanded and the insulating tape may also be expanded. This may form the foam layer 140.

[0090] The microcapsule 140a contains the fire extinguishing gas 140c. Specifically, the microcapsule 140a has a capsule wall 140b. The fire extinguishing gas 140c is filled inside the capsule wall 140b. When the temperature of the microcapsule 140a reaches the maximum foaming temperature, the fire extinguishing gas 140c inside is released from the capsule wall 140b. The fire extinguishing gas 140c may be, for example, carbon dioxide.

[0091] As a result, the fire extinguishing gas 140c released from the microcapsule 140a can prevent (suppress) smoke emission from, for example, the energy storage cell 100.

[0092] As described above, in the first embodiment, the foam layer 140 supports the first tab 90A by contacting it. This allows the foam layer 140 to restrict the movement (displacement) of the first tab 90A. As a result, when the energy storage cell 100 vibrates, it is possible to suppress the application of external forces such as tensile force and torsional force to the first tab 90A. This prevents damage to the first tab 90A.

[0093] Furthermore, by suppressing the movement (misalignment) of the first tab 90A, it is possible to prevent the joints between the first tab 90A and the first connecting member 50A, the joint between the first foil portion 91 and the second foil portion 92, and the joint between the first tab 90A and the first electrode 10A from coming loose.

[0094] [Second Embodiment] A storage cell 200 according to the second embodiment of this disclosure will be described with reference to Figures 12 to 15. Unlike the first embodiment, in which part 94 is in contact with the foam layer 140, the storage cell 200 has a connecting part 95 that is in contact with the foam layer. Components that are the same as in the first embodiment will be denoted by the same reference numerals and will not be described repeatedly.

[0095] As shown in Figure 12, the energy storage cell 200 includes a foamed layer 240. For simplicity, the microcapsules 140a and the upper portion 92b are not shown in Figure 12.

[0096] The foam layer 240 spans both the electrode body 10 on the Y1 side and the electrode body 10 on the Y2 side. In the second embodiment as well, similar to the first embodiment, the foam layer placed on the electrode body 10 on the Y1 side and the foam layer placed on the electrode body 10 on the Y2 side may be provided separately.

[0097] The foam layer 240 is positioned between the first tab 90A closest to Y2 among the multiple first tabs 90A of the electrode body 10 on the Y1 side and the first tab 90A closest to Y1 among the multiple first tabs 90A of the electrode body 10 on the Y2 side. The relationship between the foam layer 240 and the first tab 90A of the electrode body 10 on the Y1 side will be described below, but the relationship between the foam layer 240 and the first tab 90A of the electrode body 10 on the Y2 side is similar.

[0098] In the second embodiment, the foam layer 240 is in contact with the connection portion 95 of the first tab 90A. Specifically, the foam layer 240 is positioned in a location aligned in the Y direction with the joint portion 93 between the first foil portion 91 (connection portion 95) and the second foil portion 92 (not shown). In the second embodiment, it is preferable that the joint portion 93 is provided in a position that is offset (protrudes) from the electrode body 10 toward the Z1 side.

[0099] Figure 13 is a partially enlarged cross-sectional view showing the first electrode 10A, the first tab 90A, and the foam layer 240. The foam layer 240 is in contact with the upper end portion 10E of the electrode body 10. A portion of the foam layer 240 may extend into the interior of the electrode body 10 (the portion on the Z2 side of the upper end portion 10E).

[0100] In the second embodiment, the foam layer 240 supports the joint portion 93. This prevents the joint between the first foil portion 91 and the second foil portion 92 at the joint portion 93 from coming apart.

[0101] Specifically, the foamed layer 240 is in contact with the first tab 90A from the second foil portion 92 (upper portion 92b) side. The foamed layer 240 is in surface contact with the surface 92d of the upper portion 92b that is opposite to the joining portion 93.

[0102] The foamed layer 240 includes a portion 241 that covers the upper portion 92b of the second foil portion 92 from the Z1 side. The lower surface 241a of portion 241 is in surface contact with the upper end portion 92c of the upper portion 92b. Also, the side surface 241b of portion 241 is in surface contact with the first foil portion 91 (upper portion 91b). Note that portion 241 is not required to be provided in the foamed layer 240. For example, the upper end of the foamed layer 240 may be at the same position in the Z direction as the upper end portion 92c of the upper portion 92b, or it may be located on the Z2 side of the upper end portion 92c.

[0103] Figure 14 is a schematic plan view showing multiple first tabs 90A in the electrode body 10.

[0104] In the second embodiment, in each of the plurality of first tabs 90A, the first foil portion 91 is positioned on the opposite side of the foam layer 240 from the second foil portion 92. That is, in each of the plurality of first tabs 90A, the second foil portion 92 is positioned on the foam layer 240 side of the first foil portion 91.

[0105] As a result, even if pressing force is applied to each first tab 90A from the foam layer 240, the positional relationship between the first foil portion 91 and the second foil portion 92 with respect to the direction in which the pressing force is applied is unified. As a result, variations in how the pressing force is applied to the joint portion 93 (Figure 13) in each first tab 90A can be suppressed. As a result, it is possible to suppress the occurrence of joint portions 93 that are locally prone to coming undone among the multiple joint portions 93.

[0106] Specifically, in each of the multiple first tabs 90A on the Y1 side of the winding axis α, and the multiple first tabs 90A on the Y2 side of the winding axis α, the first foil portion 91 is positioned on the opposite side of the foamed layer 240 from the second foil portion 92.

[0107] Although not shown in Figure 14, in the electrode body 10 on the Y1 side, similar to the electrode body 10 on the Y2 side, in each of the multiple first tabs 90A, the second foil portion 92 is positioned on the foam layer 240 side relative to the first foil portion 91.

[0108] Figure 15 shows the first electrode 10A and multiple first tabs 90A in an unwound state. The first electrode 10A has a strip shape extending in direction A. Side A1 is the starting point of the winding. Side A2 is the ending point of the winding. Direction A is just one example of the "winding direction" in this disclosure.

[0109] As shown in Figure 15, multiple first tabs 90A are arranged side by side with spacing in the direction A.

[0110] Here, the direction perpendicular to direction A is defined as direction B. The first foil portion 91 and the second foil portion 92 are arranged side by side (adjacent) in direction B. Direction B corresponds to the Y direction when the first electrode 10A is wound. Therefore, direction B corresponds to the "arrangement direction" in this disclosure.

[0111] The first tab 90A includes tab 901 in which the first foil portion 91 is positioned on the B2 side (back of the paper) of the second foil portion 92, and tab 902 in which the first foil portion 91 is positioned on the B1 side (front of the paper) of the second foil portion 92. In other words, the arrangement of the first foil portion 91 and the second foil portion 92 in tab 902 is the opposite of that in tab 901. Note that the dashed line in Figure 15 indicates that the second foil portion 92 is positioned on the back side of the first foil portion 91. Furthermore, tabs 901 and 902 are examples of the "first electrode tab" and "second electrode tab" of this disclosure, respectively.

[0112] In the second embodiment, tabs 901 and tabs 902 are arranged alternately in direction A. Each of the plurality of tabs 901 is arranged on one side in the Y direction (e.g., Y1 side) relative to the winding axis α. Each of the plurality of tabs 902 is arranged on the other side in the Y direction (e.g., Y2 side) relative to the winding axis α.

[0113] By configuring it in this way, when the first electrode 10A is wound, the positional relationship between the first foil portion 91 and the second foil portion 92 in each of the multiple first tabs 90A can be easily unified.

[0114] The other components are the same as those in the first embodiment described above, so we will not repeat them.

[0115] [Differentiation] In the first and second embodiments described above, examples were shown in which the density of microcapsules 140a in the foamed layer 140 (240) is uniform, but the disclosure is not limited thereto. The density of microcapsules 140a in the foamed layer does not have to be uniform.

[0116] Figure 16 shows a modified example of the first embodiment described above. The foam layer 340 includes portion 341 and portion 342. Portion 341 is located closer to the first tab 90A than portion 342. Near the first tab 90A means near the portion (portion 94 in Figure 16) where the first tab 90A is supported by the foam layer 340. Portion 341 is laminated on portion 342 on the Z1 side of portion 342. Portion 341 supports portion 94 of the first tab 90A by contacting portion 94 of the first tab 90A. Portion 342 is in contact with the electrode body 10. Portion 341 and portion 342 are examples of the "other side portion" and "one side portion" of this disclosure, respectively.

[0117] The density of microcapsules 140a in section 341 is higher than the density of microcapsules 140a in section 342. This allows the expansion of section 341, which is closer to the first tab 90A (section 94), to be greater than that of section 342 when the foamed layer 340 foams. As a result, the expanded section 341 can easily cut through the first tab 90A (section 94). This allows the electrical connection between the electrode body 10 and the first connecting member 50A to be interrupted in the event of thermal runaway of the energy storage cell 100. Furthermore, since the expansion of section 342 can be kept relatively small, excessive pressure from section 342 onto the electrode body 10 can be suppressed.

[0118] In Figure 16, section 341 is provided separately from section 342. The density of microcapsules 140a may be uniform in each of section 341 and section 342. In addition, the density of microcapsules 140a may be higher in the foamed layer in which sections 341 and 342 are integrally formed, closer to section 94.

[0119] A modified example of Figure 16 may be applied to the second embodiment described above. Specifically, as shown in Figure 17, the foam layer 440 includes a foam layer 441 and a foam layer 442. The connecting portion 95 of the first tab 90A is sandwiched in the Y direction by the foam layer 441 and the foam layer 442. The foam layer 441 is in contact with the connecting portion 95 of the first tab 90A (connecting portion 95) from the Y2 side. The foam layer 442 is in contact with the connecting portion 95 from the Y1 side. Note that the foam layer 440 may include only one of the foam layer 441 and the foam layer 442.

[0120] The foamed layer 441 includes portion 441a and portion 441b. Portion 441a is located closer to the first tab 90A (connecting portion 95) than portion 441b. Portions 441a and 441b are adjacent to each other. Portions 441a and 441b are examples of the “other side portion” and “one side portion” of this disclosure, respectively.

[0121] The foamed layer 442 includes portion 442a and portion 442b. Portion 442a is located closer to the first tab 90A (connecting portion 95) than portion 442b. Portions 442a and 442b are adjacent to each other. The upper end portion 92c of the upper portion 92b is covered from the Z1 side by a part of portion 442a. Portions 442a and 442b are examples of the "other side portion" and "one side portion" of this disclosure, respectively.

[0122] The density of microcapsules 140a in section 441a is higher than the density of microcapsules 140a in section 441b. The density of microcapsules 140a in section 442a is higher than the density of microcapsules 140a in section 442b. Note that the density of microcapsules 140a may be uniform in each of sections 441a, 441b, 442a, and 442b.

[0123] Part 441a is provided separately from part 441b, and part 442a is provided separately from part 442b. Alternatively, part 441a and part 441b may be formed integrally, and part 442a and part 442b may be formed integrally. The density of microcapsules 140a may be higher in the integrally formed foam layer closer to the connecting portion 95.

[0124] Figure 18 shows a modified example of the first embodiment described above. The foam layer 540 includes portion 541 and portion 542. Portion 541 is located closer to the first tab 90A than portion 542. Near the first tab 90A means near the portion (portion 94 in Figure 18) where the first tab 90A is supported by the foam layer 540. Portion 541 is laminated on portion 542 on the Z1 side of portion 542. Portion 541 supports portion 94 of the first tab 90A by contacting portion 94 of the first tab 90A. Portion 542 is in contact with the electrode body 10. Portion 541 and portion 542 are examples of the "second direction side portion" and "first direction side portion" of this disclosure, respectively.

[0125] The density of microcapsules 140a in section 542 is higher than the density of microcapsules 140a in section 541. This allows the expansion of section 541, which is closer to the first tab 90A (section 94), to be smaller than the expansion of section 542 when the foamed layer 540 foams. As a result, the first tab 90A can be supported while suppressing the cutting of the first tab 90A (section 94) by the expanded section 541. In addition, since the expansion of section 542 can be made relatively large, the electrode body 10 can be more stably fixed by the pressure from section 542.

[0126] Part 541 is provided separately from part 542. The density of microcapsules 140a may be uniform in each of part 541 and part 542. In addition, the density of microcapsules 140a may be lower in the part of the foamed layer in which part 541 and part 542 are integrally formed, closer to part 94.

[0127] A modified example of Figure 18 may be applied to the second embodiment described above. Specifically, as shown in Figure 19, the foam layer 640 includes a foam layer 641 and a foam layer 642. The connecting portion 95 of the first tab 90A is sandwiched in the Y direction by the foam layer 641 and the foam layer 642. The foam layer 641 is in contact with the connecting portion 95 of the first tab 90A (connecting portion 95) from the Y2 side. The foam layer 642 is in contact with the connecting portion 95 from the Y1 side. Note that the foam layer 640 may include only one of the foam layer 641 and the foam layer 642.

[0128] The foamed layer 641 includes portion 641a and portion 641b. Portion 641a is located closer to the first tab 90A (connecting portion 95) than portion 641b. Portions 641a and 641b are adjacent to each other. The upper end portion 92c of the upper portion 92b is covered from the Z1 side by a part of portion 642a. Portions 641a and 641b are examples of the "second direction side portion" and "first direction side portion" of this disclosure, respectively.

[0129] The foamed layer 642 includes portion 642a and portion 642b. Portion 642a is located closer to the first tab 90A (connecting portion 95) than portion 642b. Portions 642a and 642b are adjacent to each other. Portions 642a and 642b are examples of the “second direction side portion” and “first direction side portion” of the present disclosure, respectively.

[0130] The density of microcapsules 140a in section 641b is higher than the density of microcapsules 140a in section 641a. The density of microcapsules 140a in section 642b is higher than the density of microcapsules 140a in section 642a. Note that the density of microcapsules 140a may be uniform in each of sections 641a, 641b, 642a, and 642b.

[0131] Part 641a is provided separately from part 641b, and part 642a is provided separately from part 642b. Alternatively, part 641a and part 641b may be formed integrally, and part 642a and part 642b may be formed integrally. The density of microcapsules 140a may be lower in the integrally formed foam layer closer to the connecting portion 95.

[0132] In the second embodiment described above, an example was shown in which the foam layer is provided only on one side in the Y direction relative to the first tab 90A. However, the disclosure is not limited thereto, and foam layers may be provided on both sides in the Y direction relative to the first tab 90A.

[0133] Figure 20 shows a modified example of the second embodiment described above. The foamed layer 740 includes a foamed layer 741 and a foamed layer 742. The foamed layer 741 is in contact with the first tab 90A (connecting portion 95) from the Y2 side of the connecting portion 95. The foamed layer 742 is in contact with the connecting portion 95 from the Y1 side of the connecting portion 95. The connecting portion 95 is sandwiched in the Y direction by the foamed layer 741 and the foamed layer 742. The positions of the foamed layers 741 and 742 may be reversed from those described above. Furthermore, the foamed layer 741 and the foamed layer 742 are examples of the "first foamed layer" and "second foamed layer" of this disclosure, respectively.

[0134] As shown in Figure 20, the direction in which each of the foamed layers 741 and 742 extends along the first tab 90A (connecting portion 95) will be defined as the Z direction, and the explanation will proceed accordingly. In this case, the Z direction is an example of the "extension direction" in this disclosure.

[0135] The foamed layer 741 includes portion 741a and portion 741b. Portion 741a is laminated on portion 741b on the Z1 side of portion 741b. Portion 741a and portion 741b are examples of the "second portion" and "first portion" of this disclosure, respectively.

[0136] The foamed layer 742 includes portion 742a and portion 742b. Portion 742a is laminated on portion 742b on the Z1 side of portion 742b. A portion of portion 742a covers the upper end portion 92c of the upper portion 92b from the Z1 side. Portion 742a and portion 742b are examples of the "fourth portion" and "third portion" of this disclosure, respectively.

[0137] Part 741a is located in the same position as part 742a in the Z direction. Part 741b is located in the same position as part 742b in the Z direction. Therefore, part 741b is located in a position offset from part 742a in the Z direction. Part 741b may also be located in a position that does not overlap with part 742a in the Y direction.

[0138] The connecting portion 95 has portions 95a and 95b aligned in the Z direction. Portion 95a is sandwiched in the Y direction by portions 741a and 742a. ​​Portion 95b is sandwiched in the Y direction by portions 741b and 742b.

[0139] The density of microcapsules 140a in portion 741b is higher than the density of microcapsules 140a in portion 741a. The density of microcapsules 140a in portion 742a is higher than the density of microcapsules 140a in portion 742b.

[0140] This allows the expansion of section 741b to be greater than that of section 741a, and the expansion of section 742a to be greater than that of section 742b. This makes it possible to reverse the direction in which force is applied to section 95a of the connecting section 95 and the direction in which force is applied to section 95b of the connecting section 95. As a result, tensile stress can be applied to the connecting section 95, making it easy to cut the connecting section 95.

[0141] The density of microcapsules 140a in portion 742a is higher than the density of microcapsules 140a in portion 741a. The density of microcapsules 140a in portion 741b is higher than the density of microcapsules 140a in portion 742b. Note that the density of microcapsules 140a in portion 741a may be equal to the density of microcapsules 140a in portion 742b. The density of microcapsules 140a in portion 741b may be equal to the density of microcapsules 140a in portion 742a.

[0142] The density of microcapsules 140a in each of the portions 741a, 741b, 742a, and 742b may be uniform.

[0143] Part 741a is provided separately from part 741b, and part 742a is provided separately from part 742b. Part 741a and part 741b may be formed integrally. Part 742a and part 742b may be formed integrally. In a foamed layer in which parts 741a and part 741b are integrally formed, the density of microcapsules 140a may be higher in the portion on the Z2 side. In a foamed layer in which parts 742a and part 742b are integrally formed, the density of microcapsules 140a may be higher in the portion on the Z1 side.

[0144] In the second embodiment described above, an example was shown in which the foam layer 240 is arranged on only one side in the Y direction for each of the multiple first tabs 90A in each electrode body 10, but the disclosure is not limited thereto. The foam layer may be arranged on both sides in the Y direction for each of the multiple first tabs 90A in each electrode body 10.

[0145] In the example shown in Figure 21, a foamed layer 840 is added to the configuration of the second embodiment described above. The foamed layer 840 is positioned between the multiple first tabs 90A in each electrode body 10 and the peripheral wall 211 of the case 20. That is, the foamed layer 840 is sandwiched between the first tab 90A closest to the peripheral wall 211 and the peripheral wall 211.

[0146] In the first embodiment described above, the foam layer 140 is in contact only with portion 94, and in the second embodiment described above, the foam layer 240 is in contact only with the connecting portion 95. However, the disclosure is not limited thereto. The foam layer may be in contact with both portion 94 and the connecting portion 95.

[0147] In the second embodiment described above, an example was shown in which no foam layer is provided between the first tabs 90A arranged in the Y direction in each electrode body 10, but the disclosure is not limited thereto. A foam layer may be provided between the first tabs 90A arranged in the Y direction in each electrode body 10.

[0148] In the second embodiment described above, an example was shown in which tabs 901 and 902 are arranged alternately in the A direction, but the disclosure is not limited thereto. The first tab 90A may include only one of tabs 901 and 902.

[0149] In the first and second embodiments described above, examples were shown in which the fire extinguishing gas 140c contained in the microcapsule 140a is carbon dioxide, but the disclosure is not limited thereto. The microcapsule 140a may contain (contain) a gas other than carbon dioxide that is suitable for fire extinguishing (for example, nitrogen). Furthermore, the fire extinguishing gas, which is a mixture of multiple types of gases (for example, a mixture of carbon dioxide, nitrogen, and argon), may be contained in the microcapsule 140a.

[0150] In the first and second embodiments described above, examples were shown in which a foam layer 140 (240) supporting the first tab 90A of the first electrode 10A is provided, but the disclosure is not limited thereto. A foam layer supporting the second tab 90B of the second electrode 10B may also be provided. Figure 22 shows an example of a foam layer 940 supporting the second tab 90B.

[0151] The configurations of each of the above embodiments and each of the modified examples may be combined with each other.

[0152] It should be noted that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of this disclosure is defined by the claims rather than the description of the embodiments above, and includes all modifications within the meaning and scope equivalent to the claims. [Explanation of symbols]

[0153] 10 Electrode body (winding electrode body), 10A First electrode (electrode sheet), 10B Second electrode (electrode sheet), 11A First current collector (current collector), 12A First active material layer (electrode active material layer), 14a Surface (first surface), 14b Surface (second surface), 14c Part (first uncoated part), 14d Part (second uncoated part), 15a Coated part, 15b Uncoated part, 20 Case, 50A First connecting member (current collector plate), 50B Second connecting member (current collector plate), 90A First tab (electrode tab), 90B Second tab (electrode tab), 91 First foil part (first electrode foil), 91a Lower part (sheet side part), 91b Upper part (first protruding part), 92 Second foil part (second electrode foil), 92b Upper part (second protruding part), 93 Joint part, 94 Part (current collector plate side part), 95 Connection part, 100, 200 Energy storage cell, 140, 240, 340, 440, 540, 640, 740, 840, 940 Foam layer, 140a Microcapsule (foam), 140c Fire extinguishing gas, 210 Bottom wall (wall part), 341, 441a, 442a Part (other side part), 342, 441b, 442b Part (one side part), 541, 641a, 642a Part (second direction side part), 542, 641b, 642b Part (first direction side part), 741 Foam layer (first foam layer), 741a Part (second part), 741b Part (first part), 742 Foam layer (second foam layer), 742a section (fourth section), 742b section (third section), 901 tab (first electrode tab), 902 tab (second electrode tab), SV pressure relief valve (exhaust valve), α winding axis.

Claims

1. An electrode body including an electrode sheet, A current collector plate is positioned opposite the electrode body, At least one electrode tab electrically connects the electrode sheet and the current collector plate, A foamed layer containing foam, The foam layer supports the at least one electrode tab by contacting the at least one electrode tab in the energy storage cell.

2. The at least one electrode tab includes a portion that is positioned on the current collector plate, The energy storage cell according to claim 1, wherein the foam layer is in contact with the current collector plate side portion.

3. The at least one electrode tab is The sheet-side portion that is placed on the electrode sheet, It includes a connecting portion that connects the current collector plate side portion and the sheet side portion, The energy storage cell according to claim 2, wherein the foam layer is spaced apart from the connection portion.

4. The electrode sheet is A current collector having a first surface and a second surface arranged in the direction of arrangement, The current collector includes an electrode active material layer, The aforementioned current collector is The coated portion to which the electrode active material layer is coated, The electrode active material layer is not coated, and there is an uncoated portion located on the current collector plate side of the coated portion. The at least one electrode tab is A first electrode foil is provided on the first uncoated portion of the first surface corresponding to the uncoated portion, The invention includes a second electrode foil provided on the second uncoated portion of the second surface corresponding to the uncoated portion, The first electrode foil has a first protruding portion that protrudes from the first uncoated portion toward the current collector plate, The second electrode foil has a second protruding portion that protrudes from the second uncoated portion toward the current collector plate, The first protruding portion is joined to the second protruding portion, The energy storage cell according to any one of claims 1 to 3, wherein the foamed layer supports the joint portion to which the first protruding portion and the second protruding portion are joined.

5. The aforementioned at least one electrode tab includes a plurality of electrode tabs, The plurality of electrode tabs are arranged in the direction of the arrangement, The energy storage cell according to claim 4, wherein in each of the plurality of electrode tabs, the first electrode foil is positioned on one side of the second electrode foil in the arrangement direction.

6. The electrode body is a wound electrode body in which the electrode sheet is wound around a winding axis, The plurality of electrode tabs are arranged in a line with spacing between them in the winding direction of the wound electrode body. The aforementioned arrangement direction is perpendicular to the winding direction, The aforementioned multiple electrode tabs are First electrode tab and The arrangement of the first electrode foil and the second electrode foil includes a second electrode tab that is opposite to the first electrode tab, The energy storage cell according to claim 5, wherein the first electrode tab and the second electrode tab are arranged alternately in the winding direction.

7. The energy storage cell according to any one of claims 1 to 3, wherein the foam contains a fire extinguishing gas.

8. The aforementioned foam layer is One side portion and Including the other portion which is provided closer to the at least one electrode tab than the one portion, The energy storage cell according to any one of claims 1 to 3, wherein the density of the foam in the other portion is higher than the density of the foam in the one portion.

9. The aforementioned foam layer is The first direction side portion and Including a second direction portion provided closer to at least one electrode tab than the first direction portion, The energy storage cell according to any one of claims 1 to 3, wherein the density of the foam in the first direction portion is higher than the density of the foam in the second direction portion.

10. The foamed layer includes a first foamed layer and a second foamed layer sandwiching the at least one electrode tab, If the direction in which each of the first foam layer and the second foam layer extends along the at least one electrode tab is defined as the stretching direction, The first foam layer is Part 1 and, It has a second portion provided on one side of the first portion in the direction of extension, The aforementioned second foam layer is Part 3 and, It has a fourth portion provided on one side of the extension direction relative to the third portion and positioned offset from the first portion in the extension direction, The density of the foam in the first portion is higher than the density of the foam in the second portion. The energy storage cell according to any one of claims 1 to 3, wherein the density of the foam in the fourth portion is higher than the density of the foam in the third portion.

11. The case further comprises a case for housing the electrode body, An exhaust valve is provided in the wall of the aforementioned case. The energy storage cell according to any one of claims 1 to 3, wherein the exhaust valve is disposed on the opposite side of the electrode body from the foam layer.

12. The energy storage cell according to any one of claims 1 to 3, wherein the foamed layer is insulating.

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