Energy storage cell cooling structure

Abstract

To provide a storage cell cooling structure capable of stably cooling a storage cell without being affected by a change in the thickness of a storage cell due to the change of the storage cell from an unexpanded state to an expanded state.SOLUTION: A storage cell cooling structure includes a plurality of storage cells 5 arranged so as to face each other at a distance from each other, a pair of elastic bodies 50 located between the storage cells 5, and a partition plate 20 located between the elastic bodies 50, having inner surfaces facing each other in contact with each other, and having a groove 30 on the inner surface. In the partition plate 20, there are a first state in which portions other than the groove 30 on the inner side surfaces facing each other are in contact with each other and cooling water flows into the groove 30, and a second state in which the inner surfaces are separated from each other, and the cooling water flows into the groove 30 and the portion other than the groove.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a power storage cell cooling structure. [Background technology]

[0002] Various types of energy storage cell cooling structures have been proposed in the past. The energy storage cell cooling structure described in Patent Document 1 (JP Patent Publication No. 2015-69845) includes a plurality of energy storage cells arranged in one direction and a cooling device for cooling the energy storage cells arranged between the energy storage cells. The cooling device has a circulation pipe through which a refrigerant flows. The refrigerant flowing through the circulation pipe cools the adjacently arranged energy storage cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-69845 A Summary of the Invention [Problem to be solved by the invention]

[0004] It is known that a power storage cell expands to increase its thickness due to aging, usage conditions, etc. In this conventional power storage cell cooling structure, the thickness of the power storage cell differs between the initial state (unexpanded state) and the expanded state of the power storage cell, and this causes a change in the contact state between the cooling device and the power storage cell. In particular, when the power storage cell is in an unexpanded state, the contact pressure between the power storage cell and the cooling device is insufficient, and the power storage cell cannot be stably cooled.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide a storage cell cooling structure that is less affected by changes in thickness of the storage cell caused by the storage cell changing from an unexpanded state to an expanded state, and can stably cool the storage cell. [Means for solving the problem]

[0006] The energy storage cell cooling structure according to the present disclosure includes a plurality of energy storage cells arranged to face each other with a gap therebetween, a pair of elastic bodies located between the energy storage cells, and a partition plate located between the pair of elastic bodies and having inner sides facing each other so as to be able to come into contact with and separate from each other and having a groove on the inner side. The partition plate is in a first state in which the opposing inner sides other than the groove contact each other and cooling water flows in the groove, and in a second state in which the inner sides are separated from each other and cooling water flows in the groove and the parts other than the groove.

[0007] According to the above-mentioned storage cell cooling structure, when the storage cells are expanded, the interval between the storage cells is narrow, and when the storage cells are not expanded, the interval between the storage cells is wide. When the interval between the storage cells is narrow, the partition plate is pressed by the storage cells via the elastic body. At this time, the partition plate is in a first state in which the portions of the opposing inner sides other than the groove contact each other and the cooling water flows into the groove. When the interval between the storage cells is widened, the inner sides are separated from each other by the pressure of the cooling water and the cooling water flows into the groove and the portion other than the groove. In the second state, the inner sides of the partition plate are separated from each other and the thickness of the partition plate is increased, so that the distance between the cooling water and the storage cells is shortened. By the partition plate being in the first state and the second state, the influence of the expansion and non-expansion of the storage cells is mitigated, and the storage cells can be stably cooled. Effect of the Invention

[0008] According to the storage cell cooling structure of the present disclosure, it is possible to provide a storage cell cooling structure that is less affected by changes in thickness of the storage cell caused by the storage cell changing from an unexpanded state to an expanded state, and that can stably cool the storage cell. [Brief description of the drawings]

[0009] [Figure 1] FIG. 11 is a side view that illustrates a schematic diagram of a storage cell cooling structure in a comparative example in which the storage cell is in an unexpanded state. [Diagram 2]10 is a side view illustrating a schematic diagram of a storage cell cooling structure in a comparative example in which the storage cell is in an expanded state. FIG. [Diagram 3] 3 is a side view that illustrates a schematic diagram of a storage cell cooling structure in the present embodiment when the storage cell is in an unexpanded state. FIG. [Figure 4] 3 is a side view that illustrates a schematic diagram of a storage cell cooling structure in the present embodiment when the storage cell is in an expanded state. FIG. [Diagram 5] 1A and 1B are diagrams showing the structure of a partition plate according to the present embodiment. [Figure 6] FIG. 2 is a perspective view showing the structure of an elastic body and a partition plate according to the present embodiment. [Figure 7] 7 is a cross-sectional view taken along line VII-VII in FIG. 6, showing the structure of an elastic body and a partition plate according to the present embodiment. [Figure 8] FIG. 4 is a side view showing a schematic view of the elastic body and the expanded partition plate of the present embodiment. [Figure 9] 7 is a cross-sectional view taken along line VII-VII in FIG. 6, which diagrammatically illustrates the elastic body and the expanded partition plate of the present embodiment. [Figure 10] 6 is a diagram showing the relationship between the expansion of a storage cell and the expansion of a partition plate. FIG. [Figure 11] FIG. 11 is a diagram showing the relationship between the distance between the power storage cell and the coolant and time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The energy storage cell cooling structure according to the present embodiment will be described with reference to Fig. 1 to Fig. 11. Among the components shown in Fig. 1 to Fig. 11, the same or substantially the same components are denoted by the same reference numerals and duplicated description will be omitted.

[0011] 1 and 2 are diagrams showing comparative examples for explaining the problems of the present embodiment, in which Fig. 1 shows a power storage cell in an unexpanded state, and Fig. 2 shows a power storage cell in an expanded state.

[0012] As shown in Figures 1 and 2, the comparative example storage cell cooling structure includes a plurality of storage cells 5 arranged facing each other at a distance, a pair of elastic bodies 150, 150 positioned between the storage cells 5, 5, and a partition plate 120 positioned between the pair of elastic bodies 150, 150.

[0013] 1 and 2, partition plates 120, 120 are shown at the right and left ends, but outside these, the storage cells 5, partition plates 120, and elastic bodies 150 may also be arranged alternately. The partition plates 120 are configured so as not to be misaligned in the thickness direction of the storage cells 5 (the left-right direction in FIGS. 1 and 2).

[0014] Partition plate 120 of the comparative example is provided with a plurality of holes 130. The plurality of holes 130 serve as flow paths for the flow of cooling water that cools power storage cells 5. Partition plate 120 is made of a relatively hard resin molding or the like, and has a constant thickness S2.

[0015] An elastic body 150 is disposed between the partition plate 120 and the storage cells 5. The elastic body 150 is provided so as to be in contact with the storage cells 5 and the partition plate 120. The elastic body 150 is made of a relatively soft resin molded product or the like, and is deformed so as to reduce in thickness when pressed by the storage cells 5 and the partition plate 120.

[0016] As shown in Fig. 1, when the power storage cell 5 is in an initial state (unexpanded state), the thickness T1 of the power storage cell 5 is relatively small. When the power storage cell 5 is in an expanded state as shown in Fig. 2, the thickness T2 of the power storage cell 5 is greater than the thickness T1 in the unexpanded state.

[0017] Since the arranged partition plates 120 do not shift, when the thickness of the storage cells 5 increases from T1 to T2, the increase is absorbed by the elastic body 150 being compressed and decreasing from thickness a1 (FIG. 1) to thickness b1 (FIG. 2). The elastic body 150 restrains the storage cells 5 so that they do not shift.

[0018] 1 and 2, in the state of Fig. 2 in which the energy storage cells 5 are expanded, the elastic body 150 is compressed and the thickness b1 is relatively small. As a result, the distance between the holes 130, which are the cooling water flow paths, and the energy storage cells 5 is relatively small (the thermal resistance between the energy storage cells 5 and the holes 130 is relatively small), and the energy storage cells 5 can be sufficiently cooled by the cooling water.

[0019] 1 in which the energy storage cells 5 are not yet expanded, the thickness a1 of the elastic body 150 is relatively large. As a result, the distance between the holes 130 and the energy storage cells 5 is relatively large (the thermal resistance between the energy storage cells 5 and the holes 130 is relatively large), and the energy storage cells 5 cannot be sufficiently cooled by the cooling water.

[0020] Thus, in the storage cell cooling structure of the comparative example, the storage cells 5 can be sufficiently cooled when the storage cells 5 are in an expanded state, whereas the storage cells 5 cannot be sufficiently cooled when the storage cells 5 are in an unexpanded state, resulting in a problem that the cooling performance varies depending on the state of the storage cells 5. The embodiment described below solves such a problem of the comparative example.

[0021] 3 and 4 are side views that typically show the electricity storage cell cooling structure of the present embodiment, with FIG. 3 showing electricity storage cell 5 in an unexpanded state and FIG. 4 showing electricity storage cell 5 in an expanded state.

[0022] As shown in Figures 3 and 4, the storage cell cooling structure of the present disclosure comprises a plurality of storage cells 5 arranged facing each other with a gap between them, a pair of elastic bodies 50, 50 positioned between the storage cells 5, 5, and a partition plate 20 positioned between the pair of elastic bodies 50, 50, having inner surfaces facing each other so as to be able to move toward and away from each other, and having a groove 30 on its inner surface.

[0023] The partition plate 20 can be in a first state (FIG. 4) in which the portions of the opposing inner sides other than the grooves 30 are in contact with each other and the cooling water flows into the grooves 30, and in a second state (FIG. 3) in which the inner sides are separated from each other and the cooling water flows into the grooves 30 and the portions other than the grooves 30. This storage cell cooling structure will be described in detail below.

[0024] 3 and 4, the energy storage module is made up of two energy storage cells 5, three partition plates 20, and elastic bodies 50 provided between them. The energy storage cells 5 are restrained by being sandwiched between the pair of elastic bodies 50.

[0025] 3 and 4, partition plates 20, 20 are shown at the right and left ends. Outside the partition plate 20, the power storage cells 5, the partition plates 20 and the elastic bodies 50 may be arranged alternately.

[0026] The energy storage cells 5 or partition plates 20 located at both outermost ends may be restrained by restraining members so as not to be misaligned in the thickness direction (the left-right direction in Figs. 3 and 4) of the energy storage cells 5. The energy storage module of the present embodiment is mounted on a vehicle, for example.

[0027] The storage cells 5 have main surfaces facing outward. The main surfaces are formed flat. As an example, the storage cells 5 are generally plate-shaped. Examples of secondary batteries constituting the storage cells 5 include lithium ion batteries and nickel-metal hydride batteries. The multiple storage cells 5 are arranged at intervals from each other so that their main surfaces face each other.

[0028] A pair of elastic bodies 50, 50 and a partition plate 20 sandwiched between the elastic bodies 50, 50 are disposed between the storage cells 5, 5. The partition plate 20 is fixed to the bottom plate 60. This prevents the partition plate 20 from shifting in position in the arrangement direction of the storage cells 5 (the left-right direction in Figs. 3 and 4). The partition plate 20 may be held by another structure without being fixed to the bottom plate 60. For example, the partition plate 20 may be held by restraining the storage module with a restraining member as described above.

[0029] 5A and 5B are diagrams showing the structure of the partition plate 20, where (a) is an exploded view of the partition plate 20 and (b) is a view showing joints of the partition plate 20. The partition plate 20 is made of a resin material that is harder than the elastic body 50.

[0030] As shown in FIG. 5(a), the partition plate 20 is made up of two plate-like members, a partition plate component member 20A and a partition plate component member 20B.

[0031] 5, the left side surface of partition plate component member 20A is configured to be flat, and a plurality of grooves 30 are provided on the right side surface of partition plate component member 20A facing partition plate component member 20B. The right side surface of partition plate component member 20B is configured to be flat, and a plurality of grooves 30 are provided on the left side surface of partition plate component member 20B facing partition plate component member 20A.

[0032] The partition plate constituent members 20A and 20B are attached to each other as shown in Fig. 5(b) so that the partition plate constituent members 20A and 20B come into contact with each other at the joints 22 and the abutting portions 24.

[0033] As shown in Fig. 5(b), partition plate constituent members 20A and 20B are joined at joint points 22. This joining is performed, for example, by welding or adhering the two. In partition plate constituent members 20A and 20B of this embodiment, joint points 22 are provided at the upper and lower ends of the opposing surfaces of these members. Partition plate constituent members 20A and 20B are joined at their upper and lower ends.

[0034] The opposing surfaces of the partition plate components 20A, 20B are not joined apart from the joints 22. Therefore, the bonded partition plate components 20A, 20B can be separated from each other apart from the upper and lower ends. When the partition plate components 20A, 20B are bonded together to form the partition plate 20, the multiple grooves 30 and multiple abutment portions 24 form the inner surface of the partition plate 20. As described above, the opposing inner surfaces can come into contact with and be separated from each other.

[0035] The grooves 30, 30 of the partition plate components 20A, 20B are provided at positions corresponding to each other. When the partition plate components 20A, 20B are bonded together, the grooves 30, 30 are connected to each other to form a hole that serves as a single cooling water flow path. In the partition plate 20, multiple pairs of the grooves 30, 30 form multiple holes.

[0036] In this embodiment, the partition plate 20 is composed of two plate-like members, but the partition plate 20 may be formed by cutting an integral plate-like member at approximately the center in the thickness direction, leaving the upper and lower ends, to have inner surfaces facing each other so that they can be brought into contact with or separated from each other. The partition plate 20 may also be formed by resin molding an integral member having inner surfaces that can be separated from each other, and in which a plurality of holes that serve as cooling water flow paths and slits connecting the holes are formed in advance.

[0037] 6 is a perspective view showing the structure of the elastic body 50 and the partition plate 20 of this embodiment. Plate-shaped elastic bodies 50, 50 are arranged on both main surfaces of the partition plate 20. In this embodiment, the elastic body 50 is arranged in the center of the side surface of the partition plate 20. In other words, the elastic body 50 is not provided on the outer periphery of the main surface of the partition plate 20. The elastic body 50 may be provided on the entire main surface of the partition plate 20 as necessary.

[0038] The elastic body 50 is a resin molded product made of a relatively soft resin material. The resin material constituting the elastic body 50 is softer than the resin material constituting the partition plate 20. The elastic body 50 is deformed by being pressed by the energy storage cells 5 and the partition plate 20 so as to reduce its thickness.

[0039] Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 6, showing the structure of the elastic body and the partition plate of this embodiment. As shown in Fig. 7, the elastic body 50 has a plate-shaped elastic body main body 53 and elastic body legs 55 extending from the elastic body main body 53. The elastic body legs 55 may extend continuously in the width direction of the elastic body 50 (the direction perpendicular to the paper surface in Fig. 7), or may be provided intermittently in the width direction of the elastic body 50. The elastic body main body 53 and the elastic body legs 55 may be molded integrally, or may be molded separately and joined to each other.

[0040] The elastic body 53 and the elastic leg 55 are joined or continuous with each other, and heat is conducted between them. The end of the elastic leg 55 opposite the elastic body 53 is exposed on the inner surface of the partition plate 20.

[0041] Fig. 8 is a side view showing the elastic body and the partition plate of the present embodiment in an expanded state, and Fig. 9 is a cross-sectional view taken along line VII-VII in Fig. 6, showing the elastic body and the partition plate of the present embodiment in an expanded state.

[0042] The partition plate 20 has inner surfaces facing each other so that they can come into contact with and be separated from each other. When the pressure on the partition plate 20 and the elastic bodies 50, 50 is small (when the distance between the power storage cells 5, 5 is large), the inner surfaces of the partition plate 20 are pushed apart by the pressure of the cooling water. As a result, not only the holes formed by the pair of grooves 30, 30 but also the grooves 30 are connected, and the entire space between the facing inner surfaces becomes a cooling water flow path.

[0043] 9, the tips of the elastic body legs 55 exposed on the inner surface are directly cooled by the cooling water. This allows the elastic body 50 to be efficiently cooled by the cooling water via the elastic body legs 55.

[0044] The operation of cooling the power storage cells 5 by the power storage cell cooling structure of the present embodiment will be described with reference to Figs.

[0045] As shown in Fig. 3, when the storage cell 5 is in an initial state (unexpanded state), its thickness T1 is relatively small. When the storage cell 5 is in an expanded state as shown in Fig. 4, its thickness T2 is greater than the thickness T1 in the unexpanded state.

[0046] The partition plates 20 arranged as described above are fixed to the bottom plate 60, and therefore the partition plates 20 do not shift in position. The storage cells 5 also hardly shift in position because they are restrained by the partition plates 20 and the elastic body 50. Therefore, when the thickness of the storage cells 5 increases from T1 to T2, the distance between the storage cells 5, 5 decreases, and the pressure on the partition plates 20 and the elastic body 50 increases.

[0047] In the present embodiment, when the distance between the power storage cells 5, 5 is relatively large (FIG. 3), the partition plate 20 has a relatively large thickness S2, and when the distance between the power storage cells 5, 5 is relatively small, the partition plate 20 has a relatively small thickness S1. This relationship is shown in FIG 10. As shown in FIG 10, the partition plate 20 can expand and contract in response to the change in the expansion state of the power storage cells (the associated change in the distance between the power storage cells 5, 5).

[0048] For example, when the electricity storage cells 5 gradually expand due to aging, the partition plates 20 can contract so as to gradually reduce their thickness from the expanded state.

[0049] Thus, according to the energy storage cell cooling structure of the present embodiment, when the distance between the energy storage cells 5, 5 is narrow, the partition plate 20 is compressed via the elastic body 50. At this time, the partition plates 20 are in a first state in which the portions (contact portions 24) other than the grooves 30 on the opposing inner surfaces come into contact with each other and the cooling water flows only through the grooves 30.

[0050] When the spacing between the power storage cells 5, 5 is widened, the pressure of the cooling water causes the inner sides to separate from each other, resulting in a second state in which the cooling water flows through the grooves 30 and portions other than the grooves 30 (contact portions 24). In the second state, the inner sides of the partition plates 20 separate from each other, increasing the thickness of the partition plates 20.

[0051] As is clear from Fig. 3, the inner surfaces of the partition plates 20 move away from each other and the thickness of the partition plates 20 increases (the partition plates 20 expand), so that the distance between the cooling water and the electricity storage cells 5 becomes closer than in the comparative example shown in Fig. 1, and the thermal resistance between the cooling water and the electricity storage cells 5 becomes smaller. In other words, the thickness a2 of the elastic member in Fig. 3 is smaller than the thickness a1 of the elastic member in Fig. 1. As a result, even when the electricity storage cells 5 are not yet expanded and the distance between the electricity storage cells 5, 5 is relatively large, the electricity storage cells 5 can be effectively cooled by the cooling water.

[0052] When the power storage cell 5 expands and the distance between the power storage cells 5, 5 becomes smaller as shown in Fig. 4, the partition plate 20 contracts more than in the case of Fig. 3. As a result, the thickness a2 of the elastic body 50 in the unexpanded state (thickness T1) of the power storage cell 5 shown in Fig. 3 becomes equal (or approximately equal) to the thickness b2 of the elastic body 50 in the expanded state (thickness T2) of the power storage cell 5 shown in Fig. 4. As a result, the thermal resistance between the power storage cell 5 and the coolant becomes approximately equal between the unexpanded state of the power storage cell 5 shown in Fig. 3 and the expanded state of the power storage cell 5 shown in Fig. 4.

[0053] Thus, in the energy storage cell cooling structure of the present embodiment, the partition plate 20 can take the above-mentioned first and second states, thereby mitigating the effects of expansion and non-expansion of the energy storage cells and enabling the energy storage cells to be cooled stably.

[0054] 11, even if the power storage cell 5 gradually expands (increases in thickness) due to aging, for example, the distance between the power storage cell 5 and the cooling water can be kept constant (the thermal resistance between the power storage cell 5 and the cooling water can be kept constant). This allows the power storage cell 5 to be stably cooled even if the power storage cell 5 gradually changes from an unexpanded state to an expanded state.

[0055] In the above embodiment, the widthwise ends of the partition plate 20 (ends perpendicular to the paper surface in FIG. 3) can be separated in the same manner as the middle part of the partition plate 20, but the widthwise ends of the partition plate 20 may be joined together so as not to be separated. In this case, the thickness of the partition plate 20 does not change at the ends, so that it is easy to connect a cooling water supply chamber that supplies cooling water to the partition plate 20.

[0056] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the scope of the claims, and it is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. [Explanation of symbols]

[0057] 5 storage cell, 20,120 partition plate, 20A,20B partition plate components, 22 joint portion, 24 abutment portion, 30 groove, 50,150 elastic body, 53 elastic body main body, 55 elastic body leg portion, 60 bottom plate, 130 hole.

Claims

[Claim 1] A plurality of storage cells arranged to face each other at intervals; A pair of elastic bodies positioned between the storage cells; a partition plate located between the pair of elastic bodies, having a pair of inner surfaces facing each other so as to be movable toward and away from each other, the pair of inner surfaces having abutment portions facing each other and grooves recessed from the abutment portions facing each other, A storage cell cooling structure in which the partition plate is in a first state in which the mutually opposing abutment portions of the pair of opposing inner surfaces are in contact with each other and cooling water flows into the groove, and in a second state in which the inner surfaces are separated from each other and cooling water flows into the groove and the abutment portions.

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