Power storage cell and power storage module including same

Abstract

The invention provides a power storage unit and a power storage module provided with the power storage unit, wherein the capacity of the power storage module provided with the power storage unit can be increased, and the heat dissipation performance of the power storage unit can be improved. A power storage cell according to the present disclosure is provided with a wound electrode body and a cell case. The unit case has an outer peripheral wall portion, a first end portion, a second end portion, and an inner peripheral wall portion. The first end portion has a first hole portion. The second end portion has a second hole portion. The inner peripheral wall portion extends from the first hole portion to the second hole portion. The inner peripheral wall portion is disposed on the inside in the radial direction of the wound electrode body. A portion of the outer peripheral wall portion that is parallel to the wound electrode body in the radial direction has a rectangular tubular shape. A portion of the inner peripheral wall portion that is parallel to the wound electrode body in the radial direction has a rectangular tubular shape.

Description

Technical Field

[0001] The present disclosure relates to an electric storage cell and an electric storage module including the electric storage cell. Background Art

[0002] Japanese Patent Application Laid-Open No. 2001-093566 discloses a cylindrical battery, characterized in that the core material of the cylindrical battery is made into a hollow member so that air can pass through the hollow part of the hollow member. Japanese Patent Application Laid-Open No. 2001-093566 records that the heat dissipation effect can be promoted by the above structure, and the performance degradation of the cylindrical battery can be prevented. Summary of the invention

[0003] In order to increase the capacity of the power storage module, it is required to arrange a plurality of power storage cells as densely as possible in the power storage module.

[0004] Here, it is described that the battery disclosed in Japanese Patent Application Laid-Open No. 2001-093566 is a battery that promotes the heat dissipation effect. However, when multiple storage cells are arranged more densely in a storage module, the heat dissipation effect of the hollow portion described in Japanese Patent Application Laid-Open No. 2001-093566 is not sufficient.

[0005] The present disclosure has been made in view of the above problems, and an object of the present disclosure is to provide an electric storage cell and an electric storage module including the electric storage cell, which can increase the capacity of an electric storage module including the electric storage cell and improve the heat dissipation of the electric storage cell.

[0006] The electric storage cell according to the present disclosure includes a wound electrode body and a cell case.

[0007] The unit case accommodates the wound electrode body.

[0008] The unit case has an outer peripheral wall portion, a first end portion, a second end portion, and an inner peripheral wall portion.

[0009] The outer peripheral wall portion has a cylindrical shape and is disposed radially outside the wound electrode body.

[0010] The first end portion is connected to one side of the outer peripheral wall portion in the axial direction of the wound electrode body.

[0011] The first end portion has a first hole portion penetrating in the axial direction.

[0012] The second end portion is connected to the other side of the outer peripheral wall portion in the axial direction.

[0013] The second end portion has a second hole portion penetrating in the axial direction.

[0014] The inner peripheral wall portion extends from the first hole portion to the second hole portion.

[0015] The inner peripheral wall portion is arranged on the inner side in the radial direction of the wound electrode body.

[0016] A portion of the outer peripheral wall portion that is parallel to the wound electrode body in the radial direction has a rectangular cylindrical outer shape.

[0017] A portion of the inner peripheral wall portion that is parallel to the wound electrode body in the radial direction has a rectangular cylindrical outer shape.

[0018] According to the present disclosure, the capacity of the power storage module including the power storage cell can be increased, and the heat dissipation of the power storage cell can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Features, advantages, and technical and industrial significance of exemplary embodiments of the present disclosure are described below with reference to the accompanying drawings, wherein like numerals denote like elements.

[0020] Figure 1 It is a perspective view of the power storage unit according to the first embodiment of the present disclosure.

[0021] Figure 2 Observe from the direction of the arrow on line II-II Figure 1 A cross-sectional view of a power storage unit.

[0022] Figure 3 This is a cross-sectional view schematically showing the power storage module according to the first embodiment of the present disclosure.

[0023] Figure 4 This is a perspective view showing a plurality of power storage cells included in the power storage module according to the first embodiment of the present disclosure.

[0024] Figure 5 This is a partial cross-sectional view showing a part of the power storage module according to the first embodiment of the present disclosure.

[0025] Figure 6 It is a cross-sectional view showing a power storage module according to Embodiment 2 of the present disclosure. DETAILED DESCRIPTION

[0026] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their description will not be repeated.

[0027] Implementation Method 1

[0028] First, the electric storage unit according to the first embodiment of the present disclosure will be described. The electric storage unit described below is, for example, a lithium-ion battery mounted on a vehicle. In addition, the use and type of the electric storage unit are not limited to the above example.

[0029] Figure 1 It is a perspective view of the power storage unit according to the first embodiment of the present disclosure. Figure 2 Observe from the direction of the arrow on line II-II Figure 1 A cross-sectional view of a power storage unit.

[0030] like Figure 1 and Figure 2 As shown, the storage cell 10 is a rectangular cylindrical battery. In addition, the "rectangle" in this specification may include a square, a rectangle, and a substantially square and substantially rectangular shape with rounded corners. That is, the "rectangle" in this specification may have two sets of sides that are substantially parallel to each other. The storage cell 10 includes a wound electrode body 100 and a cell case 200.

[0031] like Figure 2 As shown, the wound electrode body 100 includes a positive electrode plate 110, a negative electrode plate 120, a separator 130, a positive electrode tab lead 140, and a negative electrode tab lead 150. The separator 130 is provided between the positive electrode plate 110 and the negative electrode plate 120. The separator 130 enables ions (such as lithium ions) to travel between the positive electrode plate 110 (positive electrode active material) and the negative electrode plate 120 (negative electrode active material), and separates the positive electrode plate 110 from the negative electrode plate 120. The wound electrode body 100 is composed of an electrode group in which the positive electrode plate 110 and the negative electrode plate 120 are wound with the separator 130 interposed therebetween.

[0032] The positive electrode plate 110 includes a positive electrode collector and a positive electrode mixture layer. The positive electrode mixture layer is coated on a portion of the positive electrode collector. That is, the positive electrode collector includes a coated portion coated with the positive electrode mixture layer and an uncoated portion not coated with the positive electrode mixture layer.

[0033] The positive electrode current collector uses aluminum, for example. The positive electrode mixture layer is formed by applying the positive electrode slurry to the surface of the positive electrode current collector and drying it. The so-called positive electrode slurry is a slurry prepared by kneading the materials of the positive electrode mixture layer (positive electrode active material and binder, etc.) and a solvent. The positive electrode mixture layer is in close contact with the separator 130. The thickness of the positive electrode mixture layer is, for example, not less than 0.1 μm and not more than 1000 μm.

[0034] The negative electrode plate 120 includes a negative electrode collector and a negative electrode mixture layer. The negative electrode mixture layer is coated on a portion of the negative electrode collector. That is, the negative electrode collector includes a coated portion coated with the negative electrode mixture layer and an uncoated portion not coated with the negative electrode mixture layer.

[0035] The negative electrode current collector uses, for example, copper foil. The negative electrode mixture layer is formed by applying the negative electrode slurry to the surface of the negative electrode current collector and drying it. The so-called negative electrode slurry is a slurry prepared by kneading the materials of the negative electrode mixture layer (negative electrode active material and binder, etc.) and a solvent. The negative electrode mixture layer is in close contact with the separator 130. The thickness of the negative electrode mixture layer is, for example, not less than 0.1 μm and not more than 1000 μm.

[0036] The positive electrode tab lead 140 is provided so as to protrude from the positive electrode current collector of the positive electrode plate 110 toward one side ( Z1 side) in the axial direction Z.

[0037] The negative electrode tab lead 150 is provided so as to protrude from the negative electrode collector of the negative electrode plate 120 toward the other side ( Z2 side) in the axial direction Z.

[0038] The cell case 200 accommodates the wound electrode body 100. The cell case 200 has a substantially rectangular cylindrical outer shape. Therefore, the power storage cell 10 is a rectangular cylindrical battery.

[0039] The unit case 200 includes an outer peripheral wall portion 210 , a first end portion 220 , a second end portion 230 , and an inner peripheral wall portion 240 .

[0040] The outer peripheral wall portion 210 is cylindrical and is arranged outside the radial direction R of the wound electrode body 100. The portion of the outer peripheral wall portion 210 that is parallel to the wound electrode body 100 in the radial direction R has a rectangular cylindrical shape. The outer peripheral wall portion 210 is formed of copper or aluminum. The outer peripheral wall portion 210 is in contact with the negative electrode collector of the negative electrode plate 120 provided on the outermost periphery of the wound electrode body 100.

[0041] The first end portion 220 is connected to one side (Z1 side) of the outer peripheral wall portion 210 in the axial direction Z of the wound electrode body 100. The first end portion 220 is connected to one side (Z1 side) of the outer peripheral wall portion 210 in the axial direction Z of the wound electrode body 100. The first end portion 220 has a first hole portion 221 penetrating in the axial direction Z.

[0042] Specifically, the first end portion 220 includes an external cap 222 , an insulating layer 223 , and a caulked portion 224 .

[0043] The external cap 222 functions as an external terminal by being electrically connected to a bus bar (described later in detail). The external cap 222 is provided with a fragile portion 225 (thin-walled portion). When the internal pressure of the unit housing 200 rises, the external cap 222 is easily damaged starting from the fragile portion 225. As a result, the gas is quickly discharged to the outside of the unit housing 200. The first hole portion 221 is provided in the external cap 222. The external cap 222 is formed of copper, aluminum, or the like.

[0044] The insulating layer 223 is arranged so as to cover the outer peripheral end of the outer cap 222. The insulating layer 223 is provided so as to insulate the outer cap 222 and the caulked portion 224.

[0045] The caulking portion 224 is connected to one side of the outer peripheral wall portion 210 in the axial direction Z of the wound electrode body 100. The caulking portion 224 is formed integrally with the outer peripheral wall portion 210. The caulking portion 224 caulks the outer peripheral edge of the outer cap 222 (and the conductive film 510 described later) via the insulating layer 223. The caulking portion 224 is formed of copper, aluminum, or the like.

[0046] The second end portion 230 is connected to the other side of the outer peripheral wall portion 210 in the axial direction Z. The second end portion 230 has a second hole portion 231 penetrating in the axial direction Z.

[0047] The second end portion 230 has a rectangular plate-like outer shape. The second end portion 230 is formed of copper, aluminum, or the like. The periphery of the second end portion 230 is connected to the outer peripheral wall portion 210. The second end portion 230 is formed integrally with the outer peripheral wall portion.

[0048] The second end portion 230 contacts the negative electrode tab lead 150. Thus, the negative electrode tab lead 150 is electrically connected to the second end portion 230. As a result, the second end portion 230, the outer peripheral wall portion 210 connected to the second end portion 230, and the caulked portion 224 are negatively charged.

[0049] The inner wall 240 extends from the first hole 221 to the second hole 231. The inner wall 240 is arranged inside the wound electrode body 100 in the radial direction R. The portion of the inner wall 240 parallel to the wound electrode body 100 in the radial direction R has a rectangular cylindrical shape.

[0050] The inner peripheral wall portion 240 includes a core portion 241 , a first insulating end portion 242 , and a second insulating end portion 243 .

[0051] The core 241 has a rectangular cylindrical shape. The core 241 is arranged inside the radial direction R of the wound electrode body 100. The core 241 can also be used as a core material when the electrode group is wound to form the wound electrode body 100. From the viewpoint of heat dissipation, the core 241 is preferably formed of a metal such as copper or aluminum.

[0052] The first insulating end portion 242 is disposed on one side (Z1 side) of the core portion 241. The first insulating end portion 242 insulates the core portion 241 from the first end portion 220 (external cap 222). The core portion 241 is connected to the first end portion 220 (external cap 222) via the first insulating end portion 242.

[0053] The second insulating end portion 243 is disposed on the other side (Z2 side) of the core portion 241. The second insulating end portion 243 insulates the core portion 241 from the second end portion 230. The core portion 241 is connected to the second end portion 230 via the second insulating end portion 243.

[0054] The power storage unit 10 further includes a positive-side insulating plate 300 , a negative-side insulating plate 400 , and a current interrupt device (CID) 500 .

[0055] The positive side insulating plate 300 is housed in the cell case 200. The positive side insulating plate 300 is provided to insulate the wound electrode body 100 (negative electrode plate 120 and separator 130) from the cell case 200. The positive side insulating plate 300 is provided to cover the positive electrode plate 110, the negative electrode plate 120, and the separator 130 from one side (Z1 side).

[0056] The positive side insulating plate 300 has a first through hole 310 and a second through hole 320. The positive electrode tab lead 140 is inserted through the first through hole 310 to contact the conductive film 510 described later. Thus, the positive electrode tab lead 140 is electrically connected to the conductive film 510. The inner peripheral wall portion 240 (core portion 241) is inserted through the second through hole 320.

[0057] The negative side insulating plate 400 is housed in the cell case 200. The negative side insulating plate 400 is provided to insulate the wound electrode body 100 (positive electrode plate 110 and separator 130) from the cell case 200. The negative side insulating plate 400 is provided to cover the positive electrode plate 110, the negative electrode plate 120, and the separator 130 from the other side (Z2 side).

[0058] The negative side insulating plate 400 has a through hole 410. The negative electrode tab lead 150 is inserted through the through hole 410. Thus, the negative electrode tab lead 150 is electrically connected to the second end portion 230. The inner peripheral wall portion 240 (core portion 241 and second insulating end portion 243) is also inserted through the through hole 410.

[0059] CID 500 is a device that cuts off the current path by utilizing the increase in cell internal pressure caused by gas generated by overcharging of power storage cell 10. CID 500 is provided to seal the opening on one side (Z1 side) of outer peripheral wall 210. CID 500 includes conductive film 510, gasket 520, and chassis 530.

[0060] The conductive film 510 is provided to seal the opening on one side (Z1 side) of the peripheral wall portion 210. The conductive film 510 is in contact with the positive electrode tab lead 140. Thus, the conductive film 510 is positively charged. In addition, the conductive film 510 is electrically connected to the external cap 222 via a connecting member (not shown). Thus, the external cap 222 is also positively charged.

[0061] The conductive film 510 is provided with a fragile portion 511 (thin-walled portion) similarly to the external cap 222. When the internal pressure of the cell case 200 rises, the conductive film 510 is easily damaged starting from the fragile portion 511. When the conductive film 510 is damaged due to the increase in internal pressure, the contact between the conductive film 510 and the positive electrode tab lead 140 is released. As a result, the positive charge of the conductive film 510 is eliminated, and the positive charge of the external cap 222 is eliminated. As a result, the charging and discharging of the storage cell 10 is stopped.

[0062] The gasket 520 is located on the wound electrode body 100 side of the conductive film 510. The chassis 530 is connected to the conductive film 510 through the gasket 520.

[0063] The core portion 241 and the first insulating end portion 242 of the inner peripheral wall portion 240 penetrate the CID 500. Specifically, the core portion 241 and the first insulating end portion 242 penetrate the conductive film 510, the spacer 520, and the chassis 530.

[0064] Next, the power storage module according to the first embodiment of the present disclosure will be described. Figure 3 This is a cross-sectional view schematically showing the power storage module according to the first embodiment of the present disclosure. Figure 4 This is a perspective view showing a plurality of power storage cells included in the power storage module according to the first embodiment of the present disclosure. Figure 5 FIG. 1 is a partial cross-sectional view showing a part of the power storage module according to the first embodiment of the present disclosure. Figure 3 , a cross-sectional view of the power storage cell 10 is schematically shown.

[0065] like Figure 3 to Figure 5 As shown, the power storage module 1 according to the first embodiment of the present disclosure includes one or more power storage cells 10 and one or more cooling members 20 .

[0066] The storage module 1 of the present embodiment includes a plurality of storage cells 10. The plurality of storage cells 10 are arranged in parallel so that the axial directions Z of the wound electrode bodies 100 in the respective storage cells 10 are parallel to each other. In each of the plurality of storage cells 10, a flat surface portion in the outer peripheral wall portion 210 is opposite to a flat surface portion in the outer peripheral wall portion 210 of another adjacent storage cell 10. The plurality of storage cells 10 are arranged so that these flat surfaces are parallel to each other.

[0067] The plurality of cooling members 20 are each arranged on the inner side of the inner peripheral wall portion 240 relative to each storage battery cell 10 in the radial direction R of the storage battery cell 10. The cooling member 20 is in contact with the inner peripheral wall portion 240 of the storage battery cell 10. The cooling member 20 extends from the inner side of the first hole portion 221 to the inner side of the second hole portion 231 along the axial direction Z of the corresponding storage battery cell 10. The cooling member 20 is arranged so as to penetrate the storage battery cell 10 in the axial direction Z.

[0068] The cooling member 20 includes a metal portion 21 , a first insulating covering portion 22 , and a second insulating covering portion 23 .

[0069] The metal portion 21 is made of a metal such as aluminum or copper. The metal portion 21 extends from the inner side of the first hole portion 221 to the inner side of the second hole portion 231 along the axial direction Z of the corresponding storage battery cell 10. The portion of the metal portion 21 that is parallel to the wound electrode body 100 of the corresponding storage battery cell 10 in the radial direction R constitutes at least a portion of the outer surface of the cooling member 20. The metal portion 21 is in contact only with the core portion 241 in the inner peripheral wall portion 240.

[0070] The first insulating covering 22 covers a portion of the outer surface of the metal portion 21 in the radial direction R. The first insulating covering 22 contacts the first end 220 of the corresponding power storage cell 10. The first end 220 and the metal portion 21 are electrically insulated from each other by the first insulating covering 22.

[0071] The second insulating covering portion 23 covers the other part of the outer surface of the metal portion 21 in the radial direction R. The second insulating covering portion 23 contacts the second end portion 230 of the corresponding power storage cell 10. The second end portion 230 and the metal portion 21 are electrically insulated from each other by the second insulating covering portion 23.

[0072] The power storage module 1 may further include one or more first bus bars 30 and second bus bars 40 . The first bus bar and / or the second bus bar 40 electrically connect the two or more power storage cells 10 .

[0073] One or more first bus bars 30 are electrically connected to the first ends 220 of the plurality of power storage cells 10. One or more second bus bars 40 are electrically connected to the second ends 230 of the plurality of power storage cells 10. When the power storage module 1 includes a plurality of first bus bars 30 and a plurality of second bus bars 40, a first bus bar 30 may be electrically connected to other first bus bars 30. A second bus bar 40 may be electrically connected to other second bus bars 40. A first bus bar 30 may be electrically connected to a second bus bar 40 connected to a power storage cell 10 to which the first bus bar 30 is not connected.

[0074] The power storage module 1 further includes a first heat transfer portion 50 and a second heat transfer portion 60. The first heat transfer portion 50 is connected to one end of each cooling member 20 (metal portion 21). The second heat transfer portion 60 is connected to the other end of each cooling member 20 (metal portion 21). The first heat transfer portion 50 and the second heat transfer portion 60 play a role in helping to dissipate the heat transferred from the power storage unit 10 to each cooling member 20 (metal portion 21) to the outside of the power storage module 1. The first heat transfer portion 50 and the second heat transfer portion 60 may also be made of metal such as aluminum or copper.

[0075] The power storage module 1 may further include a first insulating plate 70 and a second insulating plate 80. The first insulating plate 70 is disposed between the first bus bar 30 and the first heat transfer unit 50 to electrically insulate them. The second insulating plate 80 is disposed between the second bus bar 40 and the second heat transfer unit 60 to electrically insulate them.

[0076] The power storage module 1 further includes a module case 90 . The module case 90 accommodates the plurality of power storage cells 10 , the plurality of cooling members 20 , the first bus bar 30 , the second bus bar 40 , the first heat transfer unit 50 , the second heat transfer unit 60 , the first insulating plate 70 , and the second insulating plate 80 .

[0077] The specific structure of the module housing 90 is not particularly limited. Figure 3 In the example shown, the module case 90 includes a lower case 91 having an opening and an upper case 92 that seals the opening of the lower case 91. However, the module case 90 may not include the upper case 92. In this case, the opening of the lower case 91 may be sealed by the first heat transfer part 50 or the first insulating plate 70.

[0078] As described above, the storage cell 10 of the first embodiment of the present disclosure includes a wound electrode body 100 and a cell case 200. The cell case 200 accommodates the wound electrode body 100. The cell case 200 includes an outer peripheral wall portion 210, a first end portion 220, a second end portion 230, and an inner peripheral wall portion 240. The outer peripheral wall portion 210 is cylindrical and is arranged outside the radial direction R of the wound electrode body 100. The first end portion 220 is connected to one side of the outer peripheral wall portion 210 in the axial direction Z of the wound electrode body 100. The first end portion 220 is connected to one side of the outer peripheral wall portion 210 in the axial direction Z of the wound electrode body 100. The first end portion 220 has a first hole portion 221 that penetrates in the axial direction Z. The second end portion 230 is connected to the other side of the outer peripheral wall portion 210 in the axial direction Z. The second end portion 230 has a second hole portion 231 that penetrates in the axial direction Z. The inner circumferential wall portion 240 extends from the first hole portion 221 to the second hole portion 231. The inner circumferential wall portion 240 is arranged on the inner side of the radial direction R of the wound electrode body 100. The portion of the outer circumferential wall portion 210 that is parallel to the wound electrode body 100 in the radial direction R has a rectangular cylindrical shape. The portion of the inner circumferential wall portion 240 that is parallel to the wound electrode body 100 in the radial direction R has a rectangular cylindrical shape.

[0079] According to the above structure, since the above portion of the outer peripheral wall portion 210 has a rectangular cylindrical shape, a plurality of the storage cells 10 can be densely arranged in the storage module 1 (see Figure 4 ). Since the storage cells 10 can be densely arranged, the space in the cell case 200 of each storage cell 10 can be expanded in the storage module 1. Therefore, in the storage module 1, the size of the wound electrode body 100 of each storage cell 10 can be increased, and the capacity of the storage module 1 as a whole can be increased.

[0080] Furthermore, according to the above configuration, the above portion of the inner peripheral wall portion 240 has a rectangular cylindrical outer shape, so that the wound electrode body 100 can be easily formed into a shape along the outer peripheral wall portion 210. In addition, the above portion of the inner peripheral wall portion 240 has a rectangular cylindrical outer shape, so that the outer surface area of ​​the inner peripheral wall portion 240 is relatively large. Therefore, even when a plurality of storage cells 10 are densely arranged, the heat dissipation from the inner peripheral wall portion 240 can be improved.

[0081] Therefore, the electric storage cell 10 having the above-described structure can increase the capacity of the electric storage module 1 including the electric storage cell 10 and can improve the heat dissipation performance of the electric storage cell 10 .

[0082] In addition, the power storage module 1 of the first embodiment of the present disclosure includes one or more power storage cells 10 and a cooling member 20. The cooling member 20 is arranged on the inner side of the inner peripheral wall portion 240 in the radial direction R of the power storage cell 10. The cooling member 20 has a metal portion 21. The metal portion 21 is made of metal. The metal portion 21 extends from the inner side of the first hole portion 221 to the inner side of the second hole portion 231 along the axial direction Z of the corresponding power storage cell 10. The portion of the metal portion 21 that is parallel to the wound electrode body 100 of the corresponding power storage cell 10 in the radial direction R constitutes at least a portion of the outer surface of the cooling member 20.

[0083] According to the above configuration, the heat generated from the power storage cell 10 can be easily released through the metal portion 21. Therefore, the cooling efficiency of the power storage cell 10 in the power storage module 1 can be further improved.

[0084] Implementation Method 2

[0085] The following describes a power storage module according to a second embodiment of the present disclosure. The power storage module according to the second embodiment of the present disclosure differs from the power storage module 1 according to the first embodiment of the present disclosure mainly in the structure of the cooling member. Therefore, the same structure and effects as those of the power storage module 1 according to the first embodiment of the present disclosure will not be described repeatedly.

[0086] Figure 6 2 is a cross-sectional view showing a power storage module according to a second embodiment of the present disclosure. Figure 6 In the embodiment 1, the power storage module 1 Figure 3 The same cross-sectional view shows the power storage module according to the second embodiment.

[0087] like Figure 6 As shown, in the power storage module 1a of the second embodiment of the present disclosure, the cooling member 20a extends from the inside of the first hole 221 to the inside of the second hole 231 along the axial direction (Z) of the corresponding power storage cell 10. The cooling member 20a is configured to allow the cooling medium C to flow in the axial direction (Z) therein.

[0088] According to the above configuration, the heat generated by the power storage cells 10 is easily released through the cooling member 20a by circulating the cooling medium C in the cooling member 20a. Therefore, the cooling efficiency of the power storage cells 10 in the power storage module 1a can be further improved.

[0089] More specifically, in each cooling member 20a, the metal portion 21a is configured so that the cold medium C can flow therein along the axial direction Z. In addition, the first heat transfer portion 50a and the second heat transfer portion 60a may be configured so that the cold medium C can be accommodated therein. The interior of the first heat transfer portion 50a and the second heat transfer portion 60a and the interior of the cooling member 20a (metal portion 21a) may be configured so that the cold medium C can enter and exit each other. The first heat transfer portion 50a and the second heat transfer portion 60a may also function as a cooler for cooling the cold medium C.

[0090] The embodiments disclosed herein are illustrative in all aspects and should not be construed as restrictive. The scope of the present disclosure is not indicated by the description of the embodiments described above, but by the scope of the claims, and includes all modifications within the scope and equivalent meanings to the scope of the claims.

Claims

1. A power storage unit comprising: A wound electrode body, and a unit case for housing the wound electrode body, The unit housing has: a cylindrical outer peripheral wall portion disposed radially outside the wound electrode body; a first end portion connected to one side of the outer peripheral wall portion in the axial direction of the wound electrode body and having a first hole portion penetrating in the axial direction; a second end portion connected to the other side of the outer peripheral wall portion in the axial direction and having a second hole portion penetrating in the axial direction; and an inner peripheral wall portion extending from the first hole portion to the second hole portion and arranged on the inner side of the wound electrode body in the radial direction, The portion of the outer peripheral wall portion that is parallel to the wound electrode body in the radial direction has a rectangular cylindrical shape. A portion of the inner peripheral wall portion that is parallel to the wound electrode body in the radial direction has a rectangular cylindrical outer shape.

2. A power storage module comprising: One or more power storage units according to claim 1; and a cooling member arranged on the inner side of the inner peripheral wall portion of the power storage unit in the radial direction of the power storage unit, The cooling member has a metal portion made of metal, The metal portion extends from the inside of the first hole portion to the inside of the second hole portion along the axial direction of the corresponding power storage cell. A portion of the metal portion that is aligned with the wound electrode body of the corresponding power storage cell in the radial direction constitutes at least a portion of the outer surface of the cooling member.

3. A power storage module comprising: One or more power storage units according to claim 1; and a cooling member disposed on the inner side of the inner peripheral wall portion in the radial direction of the power storage unit, The cooling member extends from the inside of the first hole portion to the inside of the second hole portion along the axial direction of the corresponding power storage cell, and a cooling medium can flow in the axial direction inside the cooling member.

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