Power storage cell and power storage module including same

Abstract

The utility model 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 a power storage unit and a power storage module including the power storage unit. Background Art

[0002] Japanese Patent Application Laid-Open No. 2001-093566 discloses a cylindrical battery characterized in that a core material of the cylindrical battery is formed as a hollow member so that air can pass through a hollow portion of the hollow member. Japanese Patent Application Laid-Open No. 2001-093566 describes that: by the above structure, heat dissipation effect can be promoted and performance deterioration of the cylindrical battery can be prevented. Summary of the Utility Model

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

[0004] Here, the battery disclosed in Japanese Patent Application Laid-Open No. 2001-093566 is a battery that seeks to promote heat dissipation effect. However, when a plurality of power storage units are arranged more closely in the power storage module, it cannot be said that the heat dissipation effect brought by the hollow portion described in Japanese Patent Application Laid-Open No. 2001-093566 is sufficient.

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

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

[0007] The unit case houses 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 is cylindrical and is disposed on the outer side in the radial direction of 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 above axial direction.

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

[0013] The second end portion has a second hole portion penetrating in the above 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 disposed on the inner side in the radial direction of the wound electrode body.

[0016] A portion of the outer peripheral wall portion that is juxtaposed with the wound electrode body in the above-described radial direction has a rectangular tubular outer shape.

[0017] A portion of the inner peripheral wall portion that is juxtaposed with the wound electrode body in the above-described radial direction has a rectangular tubular outer shape.

[0018] According to the present disclosure, it is possible to increase the capacity of the power storage module including the power storage unit and improve the heat dissipation of the power storage unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Hereinafter, features, advantages, and technical and industrial significance of exemplary embodiments of the present disclosure will be described with reference to the drawings, in which like reference numerals denote like elements.

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

[0021] Figure 2 is a sectional view of the power storage unit viewed from the arrow direction of line II-II Figure 1 of the power storage unit.

[0022] Figure 3 is a sectional view schematically showing the power storage module according to Embodiment 1 of the present disclosure.

[0023] Figure 4 is a perspective view showing a plurality of power storage units included in the power storage module according to Embodiment 1 of the present disclosure.

[0024] Figure 5 is a partial sectional view showing a part of the power storage module according to Embodiment 1 of the present disclosure.

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

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

[0027] Embodiment 1

[0028] First, the power storage unit according to Embodiment 1 of the present disclosure will be described. The power storage unit described below is, for example, a lithium-ion battery mounted on a vehicle. Furthermore, the use and type of the power storage unit are not limited to the above example.

[0029] Figure 1 is a perspective view of the power storage unit according to Embodiment 1 of the present disclosure. Figure 2 is a sectional view of the power storage unit viewed from the arrow direction of line II-II Figure 1 of the power storage unit.

[0030] As Figure 1 and Figure 2 shown, the power storage unit 10 is a rectangular cylindrical battery. Furthermore, "rectangular" in this specification may include a square, a rectangle, and a substantially square or substantially rectangle with rounded corners at each corner, etc. That is, "rectangular" in this specification may have two sets of sides that are substantially parallel to each other. The power storage unit 10 includes a wound electrode body 100 and a unit housing 200.

[0031] As Figure 2 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 move back and forth 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 and the negative electrode plate 120. The wound electrode body 100 is composed of a plate group formed by winding the positive electrode plate 110 and the negative electrode plate 120 with the separator 130 interposed therebetween.

[0032] The positive electrode plate 110 includes a positive electrode current collector and a positive electrode mixture layer. The positive electrode mixture layer is coated on a part of the positive electrode current collector. That is, the positive electrode current 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, for example, aluminum or the like. The positive electrode mixture layer is formed by coating a positive electrode paste on the surface of the positive electrode current collector and drying it. The so-called positive electrode paste is a paste prepared by kneading the materials of the positive electrode mixture layer (positive electrode active material, 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, 0.1 μm or more and 1000 μm or less.

[0034] The negative electrode plate 120 includes a negative electrode current collector and a negative electrode mixture layer. The negative electrode mixture layer is coated on a part of the negative electrode current collector. That is, the negative electrode current 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, a copper foil or the like. The negative electrode mixture layer is formed by coating a negative electrode paste on the surface of the negative electrode current collector and drying it. The so-called negative electrode paste is a paste prepared by kneading the materials of the negative electrode mixture layer (negative electrode active material, 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, 0.1 μm or more and 1000 μm or less.

[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 arranged so as to protrude from the negative electrode current collector of the negative electrode plate 120 to the other side (Z2 side) in the axial direction Z.

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

[0039] The unit case 200 has 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 wound electrode body 100 in the radial direction R. The portion of the outer peripheral wall portion 210 that is juxtaposed with the wound electrode body 100 in the radial direction R has a rectangular cylindrical outer shape. The outer peripheral wall portion 210 is formed of copper, aluminum, or the like. The outer peripheral wall portion 210 is in contact with the negative electrode current 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 that penetrates in the axial direction Z.

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

[0043] The external cap 222 has the function of an external terminal by being electrically connected to a bus bar (details will be described later). A fragile portion 225 (thin wall portion) is provided on the external cap 222. The external cap 222 is likely to be damaged starting from the fragile portion 225 when the internal pressure of the unit case 200 rises. Thereby, gas is rapidly discharged outside the unit case 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 external cap 222. The insulating layer 223 is provided to insulate the external cap 222 from the caulking 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 integrally formed with the outer peripheral wall portion 210. The caulking portion 224 caulks the outer peripheral edge of the external cap 222 (and the conductive film 510 to be described later) with the insulating layer 223 interposed therebetween. 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 peripheral edge of the second end portion 230 is connected to the outer peripheral wall portion 210. The second end portion 230 is integrally formed with the outer peripheral wall portion.

[0048] The second end portion 230 is in contact with 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 caulking portion 224 are negatively charged.

[0049] The inner peripheral wall portion 240 extends from the first hole portion 221 to the second hole portion 231. The inner peripheral wall portion 240 is disposed inside the winding electrode body 100 in the radial direction R. The portion of the inner peripheral wall portion 240 that is juxtaposed with the winding electrode body 100 in the radial direction R has a rectangular cylindrical outer shape.

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

[0051] The core portion 241 has a rectangular cylindrical outer shape. The core portion 241 is disposed inside the winding electrode body 100 in the radial direction R. The core portion 241 can also be used as a core material when winding the above-described electrode plate group to form the winding electrode body 100. From the viewpoint of heat dissipation, the core portion 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 (the outer cap 222). The core portion 241 is connected to the first end portion 220 (the outer cap 222) through 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 through 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 interruption device (CID) 500.

[0055] The positive-side insulating plate 300 is housed in the unit case 200. The positive-side insulating plate 300 is provided to insulate the winding electrode body 100 (the negative electrode plate 120 and the separator 130) from the unit 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 in contact with a conductive film 510 to be described later by being inserted through the first through-hole 310. 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 unit 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 unit 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] The CID 500 is an element that cuts off the current path by the rise in the internal pressure of the unit caused by the gas generated due to overcharging of the power storage unit 10. The CID 500 is provided to seal the opening on one side (Z1 side) of the outer peripheral wall portion 210. The CID 500 has a conductive film 510, a gasket 520, and a chassis 530.

[0060] The conductive film 510 is provided to seal the opening on one side (Z1 side) of the outer 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 through a connecting member (not shown). Thus, the external cap 222 is also positively charged.

[0061] On the conductive film 510, a fragile portion 511 (thin wall portion) is provided in the same manner as the external cap 222. When the internal pressure of the unit case 200 rises, the conductive film 510 is likely to be damaged starting from the fragile portion 511. When the conductive film 510 is damaged due to the rise in the 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 charge and discharge of the power storage unit 10 are stopped.

[0062] The gasket 520 is located on the side of the wound electrode body 100 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 in the inner peripheral wall portion 240 penetrate through the CID500. Specifically, the core portion 241 and the first insulating end portion 242 penetrate through the conductive film 510, the gasket 520, and the chassis 530.

[0064] Next, the power storage module of Embodiment 1 of the present disclosure will be described. Figure 3 It is a cross-sectional view schematically showing the power storage module of Embodiment 1 of the present disclosure. Figure 4 It is a perspective view showing a plurality of power storage units included in the power storage module of Embodiment 1 of the present disclosure. Figure 5 It is a partial cross-sectional view showing a part of the power storage module of Embodiment 1 of the present disclosure. In Figure 3 it, a cross-sectional view of the power storage unit 10 is schematically shown.

[0065] As Figures 3 to 5 shown, the power storage module 1 of Embodiment 1 of the present disclosure includes one or more power storage units 10 and one or more cooling members 20.

[0066] The power storage module 1 of the present embodiment includes a plurality of power storage units 10. The plurality of power storage units 10 are juxtaposed such that the axial directions Z of the wound electrode bodies 100 in each power storage unit 10 are parallel to each other. In each of the plurality of power storage units 10, the planar portions in the outer peripheral wall portion 210 face the planar portions in the outer peripheral wall portion 210 of other adjacent power storage units 10. The plurality of power storage units 10 are arranged such that these planar portions are parallel to each other.

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

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

[0069] The metal portion 21 is made of a metal such as aluminum or copper. The metal portion 21 extends from the inside of the first hole portion 221 to the inside of the second hole portion 231 along the axial direction Z of the corresponding power storage unit 10. The portion of the metal portion 21 juxtaposed with the wound electrode body 100 of the corresponding power storage unit 10 in the radial direction R constitutes at least a part 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 coating portion 22 coats a part of the outer surface of the metal portion 21 in the radial direction R. The first insulating coating portion 22 contacts the first end portion 220 in the corresponding power storage unit 10. The first end portion 220 and the metal portion 21 are electrically insulated from each other by the first insulating coating portion 22.

[0071] The second insulating coating portion 23 coats another part of the outer surface of the metal portion 21 in the radial direction R. The second insulating coating portion 23 contacts the second end portion 230 in the corresponding power storage unit 10. The second end portion 230 and the metal portion 21 are electrically insulated from each other by the second insulating coating 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 two or more power storage units 10.

[0073] One or more first bus bars 30 are electrically connected to the first end portions 220 of a plurality of power storage units 10. One or more second bus bars 40 are electrically connected to the second end portions 230 of a plurality of power storage units 10. When the power storage module 1 includes a plurality of first bus bars 30 and a plurality of second bus bars 40, the first bus bar 30 may also be electrically connected to other first bus bars 30. The second bus bar 40 may also be electrically connected to other second bus bars 40. The first bus bar 30 may also be electrically connected to the second bus bar 40 to which a power storage unit 10 not connected to the first bus bar 30 is 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 function to help 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 a 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 portion 50 and electrically insulates them. The second insulating plate 80 is disposed between the second bus bar 40 and the second heat transfer portion 60 and electrically insulates them.

[0076] The power storage module 1 further includes a module housing 90. The module housing 90 houses a plurality of power storage units 10, a plurality of cooling members 20, a first bus bar 30, a second bus bar 40, a first heat transfer portion 50, a second heat transfer portion 60, a first insulating plate 70, and a second insulating plate 80.

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

[0078] As described above, the power storage unit 10 of Embodiment 1 of the present disclosure includes a wound electrode body 100 and a unit housing 200. The unit housing 200 houses the wound electrode body 100. The unit housing 200 has 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 disposed outside the wound electrode body 100 in the radial direction R. 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 penetrating 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 penetrating in the axial direction Z. The inner peripheral wall portion 240 extends from the first hole portion 221 to the second hole portion 231. The inner peripheral wall portion 240 is disposed inside the wound electrode body 100 in the radial direction R. The portion of the outer peripheral wall portion 210 that is juxtaposed with the wound electrode body 100 in the radial direction R has a rectangular cylindrical outer shape. The portion of the inner peripheral wall portion 240 that is juxtaposed with the wound electrode body 100 in the radial direction R has a rectangular cylindrical outer shape.

[0079] According to the above structure, since the above portion of the outer peripheral wall portion 210 has a rectangular cylindrical outer shape, in the power storage module 1, a plurality of such power storage units 10 can be closely arranged (refer to Figure 4 ). Since the power storage units 10 can be closely arranged, in the power storage module 1, the space inside the unit housing 200 of each power storage unit 10 can be enlarged. Therefore, in the power storage module 1, the size of the wound electrode body 100 of each power storage unit 10 can be increased, and the capacity of the entire power storage module 1 can be increased.

[0080] Moreover, according to the above structure, the above portion of the inner peripheral wall portion 240 has a rectangular cylindrical outer shape, whereby the wound electrode body 100 can easily conform to the shape of the outer peripheral wall portion 210. In addition, since the above portion of the inner peripheral wall portion 240 has a rectangular cylindrical outer shape, the outer surface area of the inner peripheral wall portion 240 is relatively large. Therefore, even when a plurality of power storage units 10 are closely arranged, the heat dissipation performance from the inner peripheral wall portion 240 can be improved.

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

[0082] In addition, the power storage module 1 of Embodiment 1 of the present disclosure includes one or more power storage units 10 and a cooling member 20. The cooling member 20 is disposed on the inner side of the inner peripheral wall portion 240 in the radial direction R of the power storage unit 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 unit 10. The portion of the metal portion 21 juxtaposed with the wound electrode body 100 of the corresponding power storage unit 10 in the radial direction R constitutes at least a part of the outer surface of the cooling member 20.

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

[0084] Embodiment 2

[0085] Hereinafter, the power storage module of Embodiment 2 of the present disclosure will be described. The main difference between the power storage module of Embodiment 2 of the present disclosure and the power storage module 1 of Embodiment 1 of the present disclosure lies in the structure of the cooling member. Therefore, the same structures and their effects as those of the power storage module 1 of Embodiment 1 of the present disclosure will not be repeatedly described.

[0086] Figure 6 is a cross-sectional view showing the power storage module of Embodiment 2 of the present disclosure. In Figure 6 it, the power storage module of Embodiment 2 is shown in the same cross-sectional view as that of the power storage module 1 in Embodiment 1. Figure 3 The power storage module of Embodiment 2 is shown in the same cross-sectional view as that of the power storage module 1 in Embodiment 1.

[0087] As Figure 6 shown, in the power storage module 1a of Embodiment 2 of the present disclosure, the cooling member 20a 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 unit 10. The cooling member 20a is configured such that a cooling medium C can flow therethrough in the axial direction (Z).

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

[0089] More specifically, in each of the cooling members 20a, the metal portion 21a is configured such that a cooling medium C can flow axially in the Z direction inside thereof. In addition, the first heat transfer portion 50a and the second heat transfer portion 60a may also be configured such that the cooling medium C can be accommodated inside them. The interiors 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 also be configured such that the cooling medium C can flow into and out of each other. The first heat transfer portion 50a and the second heat transfer portion 60a may also have a function as a cooler for cooling the cooling medium C.

[0090] The embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The scope of the present disclosure is represented not by the description of the above embodiments but by the scope of the claims for patent, including all modifications within the meaning equivalent to the scope of the claims for patent and within the scope.

Claims

1. A power storage unit, characterized in that: have: 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, characterized in that: have: 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, characterized in that: have: 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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