Power storage device

Abstract

To provide a power storage device which can improve the cooling efficiency of a battery by a cooling plate.SOLUTION: A power storage device 100 comprises a battery 10 including: a wound electrode body 11 in which a positive electrode plate 110, a negative electrode plate 111, and a separator are laminated on one another and are wound around a winding axis line α; and a case 12 for storing the wound electrode body 11. The power storage device 100 has a cooling plate 20 for cooling the battery 10. The case 12 includes a side wall 122 provided to surround the wound electrode body 11 from the outer peripheral side of the wound electrode body 11. The side wall 122 has an irregular part 122a (a first irregular part) formed thereon. The cooling plate 20 has an irregular part 21 (a second irregular part) corresponding to the irregular part 122a formed thereon.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to an electricity storage device. [Background technology]

[0002] Japanese Patent Application Laid-Open No. 2017-168285 (Patent Document 1) discloses a battery module in which a plurality of cylindrical batteries are arranged. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-168285 Summary of the Invention [Problem to be solved by the invention]

[0004] Although not explicitly stated in Patent Document 1, the battery may be cooled by placing a cooling plate adjacent to the wall surface of the battery. In this case, it is desirable to improve the cooling efficiency of the battery.

[0005] The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide an electricity storage device that can improve the efficiency of cooling the battery by a cooling plate. [Means for solving the problem]

[0006] An energy storage device according to one aspect of the present disclosure includes a battery including a wound electrode assembly in which an electrode sheet and a separator are stacked on each other and wound around a winding axis, and a case that houses the wound electrode assembly. The energy storage device also includes a cooling plate that cools the battery. The case includes a sidewall that is provided so as to surround the wound electrode assembly from the outer periphery of the wound electrode assembly. A first uneven portion is formed on the sidewall. A second uneven portion corresponding to the first uneven portion is formed on the cooling plate.

[0007] In the energy storage device according to one aspect of the present disclosure, as described above, the cooling plate is formed with second uneven portions corresponding to the first uneven portions. This allows the surface area for heat exchange between the side wall of the case and the cooling plate to be easily increased compared to when heat exchange occurs between flat surfaces. As a result, the cooling efficiency of the battery by the cooling plate can be improved.

[0008] In the electricity storage device according to the above aspect, preferably, the winding axis extends in the axial direction, and the first uneven portion is provided at least from one end to the other end of the range in the axial direction in which the wound electrode body is arranged. With this configuration, the first uneven portion is formed over the entire range in the axial direction in which the wound electrode body is arranged, making it possible to cool the wound electrode body more easily.

[0009] In this case, the first concave-convex portion preferably includes first convex portions and first concave portions arranged alternately in the axial direction. If the distance between the first convex portions arranged in the axial direction is a predetermined distance, the predetermined distance in the center of the range (the range in the axial direction in which the wound electrode body is arranged) is smaller than the predetermined distance at the end of the range. Here, the heat generation amount in the wound electrode body is higher the closer to the center of the range. Therefore, by making the distance between the first convex portions in the center of the range relatively small, the cooling efficiency in the center of the range can be made relatively high. As a result, the temperature of the wound electrode body can be easily uniformed.

[0010] In the electricity storage device according to the above aspect, the first uneven portion preferably includes first protrusions and first recesses arranged alternately in an axial direction along which the winding axis extends. The second uneven portion preferably includes second protrusions and second recesses arranged alternately in the axial direction. The first protrusions are received in the second recesses. The second protrusions are received in the first recesses. With this configuration, it is possible to easily reduce the distance between the first protrusions and the second recesses and the distance between the second protrusions and the first recesses. As a result, heat exchange between the first protrusions and the second recesses and heat exchange between the second protrusions and the first recesses can each be efficiently performed.

[0011] In the electricity storage device according to the above aspect, the first concave-convex portion is preferably provided so as to circumferentially surround the wound electrode body. With this configuration, the first concave-convex portion of the case and the second concave-convex portion of the cooling plate can be easily made to face each other (to exchange heat) regardless of the position of the cooling plate relative to the case. As a result, the case and the cooling plate can be easily positioned to exchange heat with each other. [Effects of the Invention]

[0012] According to the present disclosure, the cooling efficiency of the battery by the cooling plate provided adjacent to the wall surface of the battery can be improved. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a plan view showing an overall configuration of an electricity storage device according to an embodiment. [Figure 2] 1 is a perspective view showing the configuration of a battery according to one embodiment. [Figure 3] FIG. 1 is a schematic perspective view showing the configuration of a wound electrode body according to one embodiment. [Figure 4] FIG. 2 is a plan view of a battery according to an embodiment, viewed from the Z1 side. [Figure 5] FIG. 2 is a cross-sectional view taken along line VV in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0015] FIG. 1 is a plan view showing the overall configuration of an energy storage device 100 according to an embodiment of the present disclosure. The energy storage device 100 includes a battery 10 and a cooling plate 20. A plurality of batteries 10 are provided. Although three batteries 10 are provided in FIG. 1, the number of batteries 10 is not limited to three. For simplification, an uneven portion 122a and an uneven portion 21, which will be described later, are not shown in FIG. 1.

[0016] The cooling plate 20 is provided adjacent to each of the plurality of batteries 10. Note that, although a single cooling plate 20 is provided adjacent to each of the plurality of batteries 10 in Fig. 1, the configuration of the cooling plate 20 is not limited to the above example. For example, the cooling plate may be divided into multiple pieces corresponding to the number of batteries 10.

[0017] The cooling plate 20 cools the battery 10. Specifically, heat is transferred from the battery 10 to the cooling plate 20 through heat exchange between the cooling plate 20 and the battery 10. As a result, the battery 10 is cooled. The cooling plate 20 is made of, for example, copper or aluminum.

[0018] 2 is a perspective view showing the configuration of battery 10. Battery 10 includes a wound electrode body 11 and a case 12 that houses wound electrode body 11. Case 12 has a cylindrical shape. That is, battery 10 is a cylindrical battery. Case 12 is made of, for example, copper or aluminum.

[0019] 3 is a schematic perspective view showing the configuration of the wound electrode body 11. The wound electrode body 11 includes a positive electrode plate 110, a negative electrode plate 111, and a separator 112. The separator 112 is provided between the positive electrode plate 110 and the negative electrode plate 111. That is, the positive electrode plate 110, the separator 112, and the negative electrode plate 111 are stacked one on top of the other. The separator 112 separates the positive electrode plate 110 from the negative electrode plate 111 while allowing ions (e.g., lithium ions) to move between the positive electrode plate 110 (positive electrode active material) and the negative electrode plate 111 (negative electrode active material). The wound electrode body 11 is composed of an electrode plate group in which the positive electrode plate 110 and the negative electrode plate 111 are wound with the separator 112 interposed therebetween. The positive electrode plate 110, the separator 112, and the negative electrode plate 111 are wound around a winding axis α. In this specification, the direction in which the winding axis extends is defined as the Z direction. Each of the positive electrode plate 110 and the negative electrode plate 111 is an example of an "electrode sheet" in the present disclosure. The Z direction is an example of an "axial direction" in the present disclosure.

[0020] 2 again, the case 12 includes a top plate 120, a bottom surface 121, and side walls 122. The top plate 120 is provided so as to cover the wound electrode body 11 from the Z1 side. The bottom surface 121 is provided so as to support the wound electrode body 11 from the Z2 side. The side walls 122 connect the top plate 120 and the bottom surface 121.

[0021] The side wall 122 is provided so as to surround the wound electrode body 11 from the outer periphery of the wound electrode body 11. That is, the side wall 122 has an annular shape centered on the winding axis α (see FIG. 3).

[0022] The side wall 122 is formed with an uneven portion 122a. The uneven portion 122a includes convex portions 122b and concave portions 122c arranged alternately in the Z direction. That is, a plurality of convex portions 122b and a plurality of concave portions 122c are provided. The concave portions 122c are formed between the convex portions 122b arranged in the Z direction. The uneven portion 122a is an example of a "first uneven portion" in the present disclosure. The convex portions 122b and the concave portions 122c are examples of a "first convex portion" and a "first concave portion" in the present disclosure, respectively.

[0023] 4 is a plan view of the battery 10 as seen from the Z1 side. The uneven portion 122a is provided so as to circumferentially surround the wound electrode body 11. In other words, each of the multiple protrusions 122b is formed so as to extend circumferentially and has a circular ring shape.

[0024] Here, when the battery is cooled by placing the wall surface of the battery adjacent to a cooling plate, it is desired to improve the cooling efficiency of the battery by the cooling plate.

[0025] 5, in this embodiment, the cooling plate 20 is formed with an uneven portion 21 corresponding to the uneven portion 122a (see FIG. 2) of the side wall 122. The uneven portion 21 of the cooling plate 20 is provided so as to be adjacent to the uneven portion 122a of the side wall 122 in the radial direction (R direction) of the wound electrode body 11. Note that the uneven portion 21 is provided on the cooling plate 20 regardless of its position in the direction in which the cooling plate 20 extends (direction perpendicular to the Z direction). The uneven portion 21 is also an example of a "second uneven portion" in the present disclosure.

[0026] The uneven portion 21 includes convex portions 22 and concave portions 23 arranged alternately in the Z direction. That is, a plurality of convex portions 22 and a plurality of concave portions 23 are provided. The concave portions 23 are formed between the convex portions 22 arranged in the Z direction. The convex portions 22 and the concave portions 23 are examples of the "second convex portions" and the "second concave portions" of the present disclosure, respectively.

[0027] The protrusions 122b of the sidewall 122 are received in the recesses 23 of the cooling plate 20. The protrusions 22 of the cooling plate 20 are received in the recesses 122c of the sidewall 122. As a result, the protrusions 122b and the protrusions 22 aligned in the Z direction are arranged to face each other in the Z direction. In other words, when viewed along the Z direction, the multiple protrusions 122b and the multiple protrusions 22 overlap each other.

[0028] A thermally conductive resin 30 (thermally conductive grease or the like) is applied between the uneven portion 122a of the side wall 122 and the uneven portion 21 of the cooling plate 20. This allows heat exchange to be easily performed between the case 12 and the cooling plate 20 via the thermally conductive resin 30, even if the uneven portion 122a and the uneven portion 21 are not in direct contact with each other. The thermally conductive resin 30 may contain a thermally conductive filler or the like. The uneven portion 122a and the uneven portion 21 may be in direct contact with each other without the thermally conductive resin 30 interposed therebetween.

[0029] The uneven portion 122a of the side wall 122 is provided at least from one end S1 to the other end S2 of the range S in the Z direction in which the wound electrode body 11 is arranged. That is, the range in the Z direction in which the uneven portion 122a is provided is wider than the range S in which the wound electrode body 11 is arranged. Furthermore, the uneven portion 122a is arranged so as to cover the entire wound electrode body 11 (range S) when viewed along the radial direction (direction R).

[0030] The protrusions 122b aligned in the axial direction are spaced apart by a distance D1. The distance D1 at the center S3 of the range S is smaller than the distance D1 at the ends (S1, S2) of the range S (near the ends). Specifically, the distance D1 becomes smaller as one approaches the center S3 of the range S. In other words, the protrusions 122b become denser as one approaches the center S3 of the range S. Note that the distance D1 between the protrusions 122b refers to the distance between the vertices of the protrusions 122b. The distance D1 is an example of a "predetermined distance" in the present disclosure.

[0031] The protrusions 22 aligned in the axial direction are disposed at a distance D2 from each other. The distance D2 at the center S3 of the range S is smaller than the distance D2 at the ends (S1, S2) of the range S. Specifically, the distance D2 becomes smaller as one approaches the center S3 of the range S. In other words, the protrusions 22 become denser as one approaches the center S3 of the range S. Note that the distance D2 between the protrusions 22 refers to the distance between the vertices of the protrusions 22.

[0032] As described above, the shape of the uneven portion 122a of the case 12 and the shape of the uneven portion 21 of the cooling plate 20 match (correspond) to each other.

[0033] As described above, in this embodiment, the side wall 122 of the case 12 is formed with the uneven portion 122a. The cooling plate 20 is formed with the uneven portion 21 corresponding to the uneven portion 122a. By using uneven portions having corresponding shapes, the surface area where heat exchange occurs can be relatively large, making it easy to ensure heat exchange efficiency. As a result, the cooling plate 20 can cool the battery 10 more efficiently.

[0034] In the above embodiment, an example has been shown in which the uneven portion 122a of the case 12 is formed over the entire range S of the wound electrode body 11, but the present disclosure is not limited to this. For example, the uneven portion 122a may be provided so as to correspond only to the center portion S3 of the range S.

[0035] In the above embodiment, an example was shown in which the distance D1 between the protrusions 122b of the case 12 becomes smaller as it approaches the center S3 of the range S of the wound electrode body 11, but the present disclosure is not limited to this. The distance D1 may be constant regardless of the position in the Z direction.

[0036] In the above embodiment, an example has been shown in which the uneven portion 122a of the case 12 circumferentially surrounds the wound electrode body 11, but the present disclosure is not limited to this. The uneven portion 122a may be provided so as to partially surround the wound electrode body 11. In other words, the protrusion 122b may have an arc shape.

[0037] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0038] 10 battery, 11 wound electrode body, 12 case, 20 cooling plate, 21 uneven portion (second uneven portion), 22 convex portion (second convex portion), 23 concave portion (second concave portion), 100 energy storage device, 110 positive electrode plate (electrode sheet), 111 negative electrode plate (electrode sheet), 112 separator, 122 side wall, 122a uneven portion (first uneven portion), 122b convex portion (first convex portion), 122c concave portion (first concave portion), D1 interval (predetermined interval), S range, S1 one end, S2 other end, S3 center portion, Z direction (axial direction), α winding axis.

Claims

1. a battery including a wound electrode body in which an electrode sheet and a separator that are stacked on each other are wound around a winding axis, and a case that houses the wound electrode body; a cooling plate that cools the battery, the case includes a side wall provided to surround the wound electrode body from an outer periphery side of the wound electrode body, a first concave-convex portion is formed on the side wall, in which first concave portions and first convex portions are alternately arranged in an axial direction, which is a direction in which the winding axis extends; a second concave-convex portion is formed on the cooling plate, in which second concave portions and second convex portions are alternately arranged in the axial direction; the first protrusion is received in the second recess, The second protrusion is received in the first recess.

2. An energy storage device as described in Claim 1, wherein the first uneven portion is provided at least from one end to the other end of the range in the axial direction in which the wound electrode body is arranged.

3. An energy storage device as described in Claim 2, wherein, when the spacing between the first convex portions arranged in the axial direction is a predetermined spacing, the predetermined spacing in the center of the range is smaller than the predetermined spacing on the end sides of the range.

4. 4. The power storage device according to claim 1, wherein the first uneven portion is provided so as to circumferentially surround the wound electrode body.

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