Cell holders and storage stacks

Abstract

To provide a cell holder capable of suppressing deterioration of cooling efficiency while positioning a power storage cell.SOLUTION: A cell holder 20 holds a power storage cell 10 having a bottom surface 11b. The cell holder 20 comprises: an upper plate part 21 and a bottom plate part 22 which are opposite to a vertical direction so that the power storage cell 10 is arranged between them; a main wall part; and a pair of lip parts 26 that is provided to both end parts of the bottom plate part 22 in a width direction W of the cell holder 20 orthogonal to a vertical direction. The pair of lip parts 26 is provided so as to enable an elastic energization of the power storage cell 10 toward the upper plate part 21 while being contacted to the bottom surface 11b of the power storage cell 10. The pair of lip parts 26 constructs a cooling path into which a cooling air can be flown with the bottom surface 11b of the power storage cell 10 in the elastic energization state where the power storage cell 10 is elastically energized toward the upper plate part 21.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a cell holder for holding a storage cell and a storage stack including the cell holder. [Background technology]

[0002] As a conventional cell holder, Japanese Patent Laid-Open Publication No. 2008-269985 (Patent Document 1) discloses a cell holder that includes upper and lower plate portions that face each other in the vertical direction and that houses energy storage cells between the upper and lower plate portions. The upper and lower plate portions are connected by a base portion (main wall portion), and a plurality of ribs are provided on the inner surface of the main wall portion that faces the energy storage cells. When the energy storage cells are held in the cell holder, the plurality of ribs abut against the side surfaces of the energy storage cells, thereby forming cooling paths through which cooling air can flow. In this way, an energy storage stack is formed by arranging the energy storage cells held in the cell holder in the arrangement direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-269985 Summary of the Invention [Problem to be solved by the invention]

[0004] The height of the cell holder (more specifically, the distance between the upper and lower plates) may vary depending on the manufacturing process. When the cell holder holds the energy storage cell, a gap may form between the lower plate and the bottom surface of the energy storage cell. In such cases, there is a concern that cooling air may leak through the gap, reducing cooling efficiency. Furthermore, if the distance between the upper and lower plates is greater than the height of the energy storage cell housing, it becomes difficult to position the energy storage cell. If the height of the energy storage cell varies and it becomes difficult to position the energy storage cell, the height positions of the external terminals of the energy storage cell also vary.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and the purpose of the present disclosure is to provide a cell holder that can position storage cells while suppressing a decrease in cooling efficiency, and a storage stack equipped with the cell holder. [Means for solving the problem]

[0006] A cell holder according to the present disclosure holds an energy storage cell having a bottom surface. The cell holder includes an upper plate portion and a bottom plate portion that face each other in the vertical direction so that the energy storage cell is disposed therebetween, a main wall portion connecting the upper plate portion and the bottom plate portion, and a pair of lip portions provided at both ends of the bottom plate portion in a width direction of the cell holder that is perpendicular to the vertical direction. The pair of lip portions are configured to contact the bottom surface of the energy storage cell and elastically bias the energy storage cell toward the upper plate portion. In an elastically biased state in which the energy storage cell is elastically biased toward the upper plate portion, the pair of lip portions, together with the bottom surface of the energy storage cell, form a cooling flow path through which cooling air can flow.

[0007] With the above configuration, when the energy storage cell is held, the pair of lip portions elastically bias the energy storage cell toward the upper plate portion, causing the energy storage cell to abut against the upper plate portion. This makes it easy to determine the position of the energy storage cell. This makes it possible to determine the height position of the external terminals of the energy storage cell at a predetermined position, even if the height of the energy storage cell varies due to manufacturing. Furthermore, when the pair of lip portions elastically bias the energy storage cell, the pair of lip portions come into close contact with the bottom surface of the energy storage cell, thereby preventing cooling air from leaking from the cooling flow path.

[0008] In the cell holder according to the present disclosure, the bottom surface of the energy storage cell may have a curved surface that curves upward toward the main wall portion in a depth direction perpendicular to the up-down direction and the width direction. In this case, the pair of lip portions may be provided with a rib that fits into a gap between the curved surface and the main wall portion in the elastically biased state.

[0009] As in the above configuration, the ribs provided on the pair of lip portions fit into the gap between the curved surface of the storage cell and the main wall portion of the cell holder, thereby preventing cooling air from leaking through the gap.

[0010] In the cell holder according to the present disclosure, the energy storage cell may include a pair of external terminals spaced apart in the width direction. The pair of lip portions may have root portions connected to the bottom plate portion and extend outward in the width direction as they extend upward. In this case, in the elastically biased state, the root portions are preferably located between a center position of the pair of external terminals and a position 5 mm to 20 mm inward in the width direction from the center position.

[0011] With the above configuration, it is possible to ensure an appropriate cooling range and prevent a decrease in cooling efficiency.

[0012] In the cell holder according to the present disclosure, the energy storage cell may include a pair of external terminals spaced apart in the width direction. The pair of lip portions may extend upward and inward in the width direction, and may have tip portions on the inner side in the width direction. In this case, in the elastically biased state, the tip portions are preferably located between a center position of the pair of external terminals and a position 5 mm to 20 mm inward in the width direction from the center position.

[0013] With the above configuration, it is possible to ensure an appropriate cooling range and prevent a decrease in cooling efficiency.

[0014] The power storage stack according to the present disclosure includes the cell holder and a plurality of the power storage cells, each held by the cell holder, arranged in a predetermined direction.

[0015] According to the above configuration, the storage cells positioned by the cell holders are arranged in a predetermined direction, which makes it possible to easily electrically connect the storage cells to each other. [Effects of the Invention]

[0016] According to the present disclosure, it is possible to provide a cell holder that can position a power storage cell while suppressing a decrease in cooling efficiency, and a power storage stack including the cell holder. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a plan view of a power storage stack according to a first embodiment. [Figure 2] 1 is an exploded perspective view showing an electricity storage stack according to a first embodiment. FIG. [Figure 3] 3 is a cross-sectional view showing a state in which the electricity storage stack according to the first embodiment is arranged in a lower case. FIG. [Figure 4] FIG. 2 is a cross-sectional view showing a cell holder according to the first embodiment. [Figure 5] 3 is a cross-sectional view showing a state in which an energy storage cell is held by a cell holder according to the first embodiment. FIG. [Figure 6] 3 is a cross-sectional view showing the positional relationship between the bases of a pair of lip portions and a pair of external terminals in the cell holder according to the first embodiment. FIG. [Figure 7] 2 is a cross-sectional view showing an example of adjacent power storage cells in the power storage stack according to the first embodiment. FIG. [Figure 8] 10 is a cross-sectional view showing a state in which a storage cell is held by a cell holder in a storage stack according to a reference example. FIG. [Figure 9] 10 is a cross-sectional view showing a state in which an energy storage cell is held by a cell holder in an energy storage stack according to a second embodiment. FIG. [Figure 10] 10 is a cross-sectional view showing a state in which an energy storage cell is held by a cell holder according to a third embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference numerals in the drawings, and the description thereof will not be repeated.

[0019] (Embodiment 1) Fig. 1 is a plan view of a power storage stack according to embodiment 1. Fig. 2 is an exploded perspective view showing the power storage stack according to embodiment 1. For convenience, bus bars are omitted from Fig. 2. The power storage stack 1 according to embodiment 1 will be described with reference to Figs. 1 and 2.

[0020] 1 and 2, the energy storage stack 1 includes a plurality of energy storage cells 10, a plurality of cell holders 20, and a plurality of bus bars 30. Each of the plurality of cell holders 20 holds a energy storage cell 10. The energy storage cells 10 held in the cell holders 20 are arranged in a predetermined arrangement direction. The arrangement direction is parallel to a depth direction D of the cell holders 20, which will be described later.

[0021] The power storage cell 10 is, for example, a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The power storage cell 10 may use a liquid electrolyte or a solid electrolyte. The power storage cell 10 may also be a unit capacitor configured to be able to store electricity.

[0022] Each of the multiple storage cells 10 includes a housing 11 having an upper surface 11a, and external terminals 14 and 15. The external terminals 14 and 15 are provided on the upper surface 11a of the housing 11. The housing 11 has a flat, approximately rectangular parallelepiped shape. The multiple storage cells 10 are arranged such that the external terminals 14 and the external terminals 15 are alternately aligned in the arrangement direction. The external terminal 14 is for the positive electrode, and the external terminal 15 is for the negative electrode.

[0023] The bus bars 30 have a generally plate-like shape. The bus bars 30 are made of metal members. The bus bars 30 are arranged to extend along the arrangement direction. The bus bars 30 connect the external terminals 14 and 15 of the storage cells 10 adjacent to each other in the arrangement direction at both ends of the width direction of the storage cells 10, which is perpendicular to the up-down direction. This connects the storage cells 10 in series. The width direction of the storage cells 10 is parallel to the width direction W of the cell holder 20, which will be described later.

[0024] The cell holder 20 holds the energy storage cells 10 and forms a cooling flow path through which cooling air flows together with the energy storage cells 10. The cell holder 20 is made of, for example, an insulating resin material. The cell holder 20 includes an upper plate portion 21, a bottom plate portion 22, a main wall portion 23, and side wall portions 24 and 25.

[0025] The top plate portion 21 and the bottom plate portion 22 face each other in the vertical direction so that the energy storage cell 10 is disposed therebetween. The top plate portion 21 has an opening 21a. The opening 21a is provided so as to extend along the width direction W of the cell holder 20, which is perpendicular to the vertical direction. The opening 21a is provided so that most of the top surface 11a of the housing 11 (specifically, the central portion in the width direction) is exposed. The opening 21a is open from the external terminal 14 to the external terminal 15, and the external terminals 14 and 15 are exposed from the opening 21a.

[0026] The main wall portion 23 connects the upper plate portion 21 and the bottom plate portion 22. Specifically, it connects the ends of the upper plate portion 21 and the bottom plate portion 22 together in the vertical direction and on one side in the depth direction D that is perpendicular to the width direction W. The main wall portion 23 faces the main surface of the housing 11 that has the largest area when the cell holder 20 holds the energy storage cells 10.

[0027] The main wall portion 23 has an outer surface 23a and an inner surface 23b (see FIG. 4). The inner surface 23b is formed to be substantially flat. The inner surface 23b abuts against the main surface of the energy storage cell 10 held by the cell holder 20.

[0028] A plurality of ribs 23p are provided on the outer surface 23a. The plurality of ribs 23p abut against the adjacent energy storage cells 10 on one side in the depth direction D, and together with the energy storage cells 10, form a cooling flow path through which cooling air flows. The plurality of ribs 23p guide the cooling air introduced from below the center of the cell holder 20 in the width direction W toward both sides of the cell holder 20 in the width direction W.

[0029] FIG. 3 is a cross-sectional view showing a state in which the electricity storage stack according to the first embodiment is arranged in a lower case.

[0030] As shown in FIG. 3, when the power storage stack 1 is mounted on a vehicle, it is housed in a housing case. The housing case includes an upper case (not shown) and a lower case 50. The lower case 50 forms the lower part of the housing case. The lower case 50 has a generally box-like shape that is open upward. The lower case 50 includes a bottom 51 and a peripheral wall 53. The peripheral wall 53 is connected to the periphery of the bottom 51.

[0031] The bottom 51 has a recess 52 formed in the center in the width direction W. The electricity storage stack 1 is placed on the bottom 51 so as to straddle the recess 52. Specifically, both end portions of the electricity storage stack 1 in the width direction W are placed on the bottom 51.

[0032] An opening 22a is provided in the bottom plate portion 22 of the cell holder 20. The opening 22a is provided so as to face the recess 52. Like the opening 21a, the opening 22a extends along the width direction W. The opening 22a is provided so as to expose most of the bottom surface 11b of the housing 11 (specifically, the central portion in the width direction). The bottom surface 11b forms the bottom surface of the energy storage cell 10. In this embodiment, the bottom surface 11b is formed to be approximately flat.

[0033] A cooling flow path R1 through which cooling air flows is formed by the bottom surface 11b exposed from the opening 22a and the recess 52. The cooling flow path R1 communicates with a cooling flow path formed by the above-mentioned rib 23p and the energy storage cell 10 adjacent to the rib 23p.

[0034] 4 is a cross-sectional view showing the cell holder according to Embodiment 1. The details of the cell holder 20 will be described with reference to FIG.

[0035] 4, a pair of lip portions 26 are provided at both ends of the bottom plate portion 22 in the width direction W. The pair of lip portions 26 are provided in the width direction W so as to sandwich the opening 22a therebetween.

[0036] The pair of lip portions 26 are provided so as to extend outward in the width direction W as they extend upward. The pair of lip portions 26 are provided so as to be elastically deformable. As a result, when the pair of lip portions 26 deform, an elastic biasing force is exerted. The pair of lip portions 26 may be molded integrally with the bottom wall portion 22, etc., or may be configured as separate bodies from the bottom wall portion 22, etc. The pair of lip portions 26 are formed, for example, from an insulating resin member.

[0037] Each of the pair of lip portions 26 has a first inclined portion 261 , a second inclined portion 262 , and a root portion 263 .

[0038] The first inclined portion 261 constitutes the tip side of the lip portion 26. The first inclined portion 261 inclines so as to extend outward in the width direction W as it extends upward. The root portion 263 is connected to the bottom plate portion 22. The second inclined portion 262 connects the first inclined portion 261 and the root portion 263. The second inclined portion 262 inclines so as to extend outward in the width direction W as it extends upward.

[0039] The inclination angle of the first inclined portion 261 is smaller than the inclination angle of the second inclined portion 262. The inclination angle refers to the smaller of the angles at which the first inclined portion 261 and the second inclined portion 262 intersect with a plane parallel to the width direction W.

[0040] When the cell holder 20 is not holding the storage cell 10, the distance G1 from the upper plate portion 21 to the tip of the lip portion 26 is smaller than the height of the housing 11.

[0041] FIG. 5 is a cross-sectional view showing a state in which an energy storage cell is held by the cell holder according to the first embodiment.

[0042] As shown in Fig. 5, the energy storage cell 10 is held by the cell holder 20 in a state in which the pair of lip portions 26 are elastically deformed so as to bend downward. As a result, the pair of lip portions 26 contact the bottom surface of the energy storage cell 10 (the bottom surface 11b of the housing 11) and elastically bias the energy storage cell 10 toward the upper plate portion 21. In this elastically biased state, the upper surface 11a of the housing 11 abuts against the upper plate portion 21 (specifically, the lower surface of the upper plate portion 21). This makes it easy to determine the position of the energy storage cell 10. At this time, a distance G2 from the upper plate portion 21 to the tip of the lip portion 26 is larger than the distance G1 and is substantially the same as the height of the housing 11.

[0043] In the above-described elastically biased state, the first inclined portion 261 is in close contact with the bottom surface 11b of the housing 11, and the bottom surface 11b of each energy storage cell 10 and the pair of lip portions 26 form part of the cooling flow path R1. The pair of lip portions 26 are in close contact with the bottom surface 11b of the housing 11, thereby preventing cooling air from leaking out of the cooling flow path R1. As a result, a decrease in cooling efficiency can be prevented.

[0044] 6 is a cross-sectional view showing the positional relationship between the base portions of a pair of lip portions and a pair of external terminals in the cell holder according to Embodiment 1. The above positional relationship will be described with reference to FIG.

[0045] As shown in Fig. 6, the energy storage cell 10 accommodates a battery element (electrode body) 40 inside a housing 11. The battery element 40 has a positive electrode core, a negative electrode core, and a separator (none of which are shown), and the positive electrode core and the negative electrode core are wound with the separator interposed between them. The battery element 40 has a positive electrode core exposed portion 41 and a negative electrode core exposed portion 42 on both end sides in the width direction W.

[0046] The positive electrode substrate exposed portion 41 is connected to a positive electrode external terminal 14 by a current collecting member 18. The negative electrode substrate exposed portion 42 is connected to a negative electrode external terminal 15 by a current collecting member 19.

[0047] In the elastically biased state, the base portions 263 of the pair of lip portions 26 are preferably located, for example, in the width direction W, between a center position A1 of the pair of external terminals 14, 15 and a position B1 that is 5 mm inward from the center position A1 in the width direction. Note that the range between the center position A1 and the position B1 includes the center position A1 and the position B1. Furthermore, the position B1 is not limited to a position 5 mm inward from the center position A1 in the width direction, but may be located approximately 5 mm to 20 mm inward from the center position A1 in the width direction.

[0048] When the base portion 263 is located within the above range, cooling air can be applied over a wide area to the portion of the battery element 40 that corresponds to the portion located between the positive electrode substrate exposed portion 41 and the negative electrode substrate exposed portion 42. The portion of the battery element 40 that is located between the positive electrode substrate exposed portion 41 and the negative electrode substrate exposed portion 42 is a portion that greatly affects charge and discharge, and this portion can be cooled effectively. Furthermore, when position B1 is located 5 mm inward in the width direction from the center position A1, this portion can be cooled even more effectively.

[0049] 7 is a cross-sectional view showing an example of adjacent power storage cells in the power storage stack according to Embodiment 1. The adjacent power storage cells will be described with reference to FIG.

[0050] As shown in Fig. 7, the height of the cell holders 20 may vary due to manufacturing variations. In Fig. 7, of two cell holders 20 adjacent to each other in the arrangement direction, the height H1 of the cell holder 20A located on one side in the arrangement direction is greater than the height H2 of the cell holder 20B located on the other side in the arrangement direction.

[0051] Even in such a case, each storage cell 10 held in each cell holder 20A, 20B is elastically biased by the pair of lip portions 26 so as to contact the upper plate portion 21 of each cell holder 20. Therefore, by arranging each cell holder 20 that holds the storage cells 10 so that the upper surfaces of each cell holder 20 are flush, the height positions of the external terminals 14, 15 of each storage cell 10 can be made approximately the same. This makes it easy to attach the bus bar 30 and to electrically connect the storage cells 10 to each other.

[0052] (Reference example) FIG. 8 is a cross-sectional view showing a state in which the energy storage cells are held by the cell holders in the energy storage stack according to the reference example.

[0053] An electricity storage stack 1X according to the reference example will be described with reference to Fig. 8. The electricity storage stack 1X according to the reference example is different from the electricity storage stack 1 according to the first embodiment in the shape of the casing 11.

[0054] In the third embodiment, the bottom surface 11b of the housing 11 has curved surfaces 11c that curve upward toward the main wall portion 23. Specifically, the bottom surface 11b has curved surfaces 11c at both ends in the depth direction D. These curved surfaces 11c curve upward toward the outside in the depth direction D.

[0055] In this case, a gap S1 is formed between the inner surface 23b of the main wall portion 23 of the cell holder 20 and the curved surface 11c. This may cause the cooling air flowing through the cooling flow path R1 to leak out of the cooling flow path R1 through the gap S1.

[0056] (Embodiment 2) FIG. 9 is a cross-sectional view showing a state in which the energy storage cells are held by the cell holders in the energy storage stack according to the second embodiment.

[0057] 9, the energy storage stack 1C according to the second embodiment is different from the energy storage stack 1X according to the reference example in the shape of the cell holder 20 (specifically, the shape of the pair of lip portions 26). The other configurations are substantially the same.

[0058] In the second embodiment, a rib 264 is provided that, in the elastically biased state, fits into the gap S1 (see FIG. 8) between the curved surface 11c and the main wall portion 23. This makes it possible to prevent the cooling air from leaking out of the cooling flow path R1 through the gap S1.

[0059] Even when configured as described above, the cell holder 20C and the power storage stack 1C according to the second embodiment have substantially the same effects as those of the first embodiment.

[0060] (Embodiment 3) Fig. 10 is a cross-sectional view showing a state in which power storage cells are held by cell holders according to embodiment 3. With reference to Fig. 10, a power storage stack 1D according to embodiment 3 will be described.

[0061] 10, the energy storage stack 1D according to the third embodiment differs from the energy storage stack 1 according to the first embodiment in the shape of a pair of lip portions 26 included in a cell holder 20D. The other configurations are substantially the same.

[0062] In the third embodiment, the pair of lip portions 26 extend upward and inward in the width direction W. As in the first embodiment, the pair of lip portions 26 have a first inclined portion 261, a second inclined portion 262, and a base portion 263, but the first inclined portion 261 is located more inward in the width direction W than the base portion 263. The pair of lip portions 26 have tip portions 26a on the inner side in the width direction W.

[0063] In the third embodiment, in the above-described elastically biased state, the tip portion 26a is preferably located, for example, in the width direction W, between a center position A1 of the pair of external terminals 14, 15 and a position B1 that is 5 mm inward from the center position A1 in the width direction W. Furthermore, position B1 is not limited to a position 5 mm inward from the center position A1 in the width direction, and may be located approximately 5 mm to 20 mm inward from the center position A1 in the width direction.

[0064] By positioning the tip portion 26a in the above range, cooling air can be applied over a wide range to the portion of the battery element 40 that corresponds to the portion located between the positive electrode substrate exposed portion 41 and the negative electrode substrate exposed portion 42. This makes it possible to effectively cool the portion that has a significant effect on the charging and discharging of the energy storage cell 10, just like in the first embodiment.

[0065] Even when configured as described above, the cell holder 20D and the power storage stack 1D according to the third embodiment have substantially the same effects as those of the first embodiment.

[0066] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0067] 1, 1C, 1D, 1X Energy storage stack, 10 Energy storage cell, 11 Housing, 11a Top surface, 11b Bottom surface, 11c Curved surface, 14, 15 External terminal, 18, 19 Current collecting member, 20, 20A, 20B, 20C, 20D Cell holder, 21 Top plate portion, 21a Opening, 22 Bottom plate portion, 22a Opening, 23 Main wall portion, 23a Outer surface, 23b Inner surface, 23p Rib, 24, 25 Side wall portion, 26 Lip portion, 26a Tip portion, 30 Bus bar, 40 Battery element, 41 Positive electrode core exposed portion, 42 Negative electrode core exposed portion, 50 Lower case, 51 Bottom portion, 52 Recessed portion, 53 Peripheral wall portion, 261 First inclined portion, 262 Second inclined portion, 263 base, 264 ribs;

Claims

1. A cell holder for holding a storage cell having a bottom surface, an upper plate portion and a bottom plate portion which face each other in a vertical direction so that the storage cell is disposed therebetween; a main wall portion connecting the top plate portion and the bottom plate portion; a pair of lip portions provided at both ends of the bottom plate portion in a width direction of the cell holder perpendicular to the up-down direction; the pair of lip portions are provided to be in contact with the bottom surface of the energy storage cell and to be capable of elastically urging the energy storage cell toward the upper plate portion, the pair of lip portions, together with the bottom surfaces of the energy storage cells, define cooling flow paths through which cooling air can flow in an elastically biased state in which the energy storage cells are elastically biased toward the upper plate portion, The bottom surface of the storage cell has a curved surface that curves upward toward the main wall portion, The pair of lip portions are provided with ribs that fit into the gap between the curved surface and the main wall portion in the elastically biased state.

2. The storage cell includes a pair of external terminals spaced apart in the width direction, The pair of lip portions have root portions connected to the bottom plate portion, and extend upward toward the outside in the width direction, A cell holder as described in claim 1, wherein in the elastically biased state, the root portion is located in the width direction between a center position of the pair of external terminals and a position 5 mm to 20 mm inward in the width direction from the center position.

3. The storage cell includes a pair of external terminals spaced apart in the width direction, The pair of lip portions extend inward in the width direction as they extend upward, and have tip portions on the inner side in the width direction, A cell holder as described in claim 1, wherein in the elastically biased state, the tip portion is located in the width direction between a center position of the pair of external terminals and a position 5 mm to 20 mm inward in the width direction from the center position.

4. A cell holder according to any one of claims 1 to 3; a plurality of the storage cells each held by the cell holder; A storage stack, wherein a plurality of the storage cells are arranged in a predetermined direction.

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