Battery pack

Abstract

To make it possible to suppress displacement of a cell laminate relative to a battery case in a height direction and a horizontal direction of the battery cell while avoiding an increase in the number of components.SOLUTION: A battery pack includes a cell laminate and a battery case. The cell laminate is composed by laminating a plurality of battery cells of almost rectangular parallelepiped shapes. The battery case has an almost rectangular parallelepiped shape and stores the cell laminate. The cell laminate includes a cell side bottom wall opposite a case side bottom wall to be a bottom wall of the battery case. The cell side bottom wall includes one or more claws formed to extend to the case side bottom wall side. The case side bottom wall includes one or more long holes which are formed to hook the one or more claws and are long in the laminate direction of the cell laminate. The one or more claws and one or more long holes hook each other, so that movements of the cell laminate to the battery case both in a height direction of the cell laminate and in a horizontal direction of the cell laminate orthogonal to the laminate direction are restricted.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a battery pack. [Background technology]

[0002] Patent Document 1 discloses a battery fixing structure that fixes a battery assembly made by stacking and restraining multiple batteries to a case. This fixing structure has male threads for fixing the battery assembly to the case. The multiple bolts corresponding to the male threads include a movable bolt and a fixing bolt. The movable bolt is installed on the case side so that it can move in the stacking direction of the batteries. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-070669 Summary of the Invention [Problem to be solved by the invention]

[0004] When a stack of multiple battery cells (cell stack) is inserted into a battery case, the cell stack can become misaligned with the battery case in both the vertical and horizontal directions. It is desirable to suppress such misalignment in a battery pack using a simple structure while avoiding an increase in the number of parts.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a battery pack that can suppress misalignment of the cell stack relative to the battery case in the vertical and horizontal directions of the battery cells with a simple structure while avoiding an increase in the number of parts. [Means for solving the problem]

[0006] A battery pack according to one embodiment of the present disclosure includes a cell stack and a battery case. The cell stack is formed by stacking a plurality of battery cells each having a substantially rectangular parallelepiped shape. The battery case has a substantially rectangular parallelepiped shape and houses the cell stack. The cell stack includes a cell-side bottom wall that faces a case-side bottom wall that is the bottom wall of the battery case. The cell-side bottom wall includes one or more claws formed to extend toward the case-side bottom wall. The case-side bottom wall includes one or more elongated holes that are formed to hook onto the one or more claws and are elongated in the stacking direction of the cell stack. The one or more claws and the one or more elongated holes hook onto each other, thereby restricting movement of the cell stack relative to the battery case in both the height direction of the cell stack and the horizontal direction of the cell stack that is perpendicular to the stacking direction.

[0007] In the above aspect, the one or more claws may be provided at a location closer to the center of the cell stack in the stacking direction than to an end.

[0008] In the above-mentioned embodiment, the one or more claws may include at least one pair of claws formed at positions spaced apart from each other in the horizontal direction.

[0009] In the above aspect, the case-side bottom wall may include a pair of cell-facing portions that face the cell stack at both ends of the case-side bottom wall in the horizontal direction, and a cell cooling air passage formed between the pair of cell-facing portions in the horizontal direction, recessed downward relative to the pair of cell-facing portions, and extending along the stacking direction. The battery case may further include a pair of sealing members that seal between each of the pair of cell-facing portions and the bottom surface of the cell stack. The one or more elongated holes may include at least one pair of elongated holes formed in the pair of cell-facing portions horizontally outward of the pair of sealing members.

[0010] In the above aspect, the cell-side bottom wall may be configured by a plurality of frame members provided on the plurality of battery cells and formed to cover the plurality of battery cells, and the one or more claws may be provided on one or more of the plurality of frame members.

[0011] A battery pack according to another aspect of the present disclosure includes a cell stack and a battery case. The cell stack is formed by stacking multiple battery cells each having a substantially rectangular parallelepiped shape. The battery case has a substantially rectangular parallelepiped shape and houses the cell stack. The battery case includes a metal plate portion made of multiple metal plates that forms a portion of the battery case, and a resin portion that forms another portion of the battery case. The battery case is formed by molding the metal plate portion with the resin portion formed by injection molding. The cell stack includes a pair of cell-side sidewalls that respectively face a pair of case-side sidewalls that are wall portions of the battery case extending along the stacking direction of the cell stack. The pair of cell-side sidewalls include one or more protrusions formed to protrude toward at least one side of the pair of case-side sidewalls. The case-side bottom wall that is the bottom wall of the battery case includes one or more claws formed to hook onto the one or more protrusions. The one or more claws are formed in the resin portion. By having one or more protrusions and one or more claws hook together, movement of the cell stack relative to the battery case is restricted in both the height direction of the cell stack and the horizontal direction of the cell stack, which is perpendicular to the stacking direction.

[0012] In the above other aspect, the one or more claws may be provided at a location closer to the center of the cell stack than to an end in the stacking direction.

[0013] In the above-mentioned other aspect, the one or more claws may include at least one pair of claws arranged to sandwich the cell stack from the outside in the horizontal direction.

[0014] In the above-described other aspect, the pair of cell-side sidewalls may be configured by a plurality of frame members provided on each of the plurality of battery cells and formed to cover the plurality of battery cells, respectively. The one or more protrusions may be a plurality of protrusions. The plurality of protrusions may be provided on each of the plurality of frame members. [Effects of the Invention]

[0015] According to each of the battery packs relating to one aspect and another aspect of the present disclosure, it is possible to suppress the positional deviation of the cell stack relative to the battery case in the vertical and horizontal directions of the battery cells with a simple structure while avoiding an increase in the number of parts. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a perspective view showing the overall configuration of a battery pack according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing a cross section taken along line AA in FIG. [Figure 3] 3 is a view of the cross section shown in FIG. 2 as seen from the direction of arrow B. FIG. [Figure 4] FIG. 4 is an enlarged view of part C in FIG. 3. [Figure 5] FIG. 2 is a perspective view of the battery case shown in FIG. 1, viewed from the bottom wall side. [Figure 6] FIG. 6 is an enlarged view of part D in FIG. 5. [Figure 7] FIG. 10 is a perspective view showing the overall configuration of a battery pack according to a second embodiment. [Figure 8] FIG. 8 is an exploded perspective view showing the configuration of the metal plate portion shown in FIG. [Figure 9] FIG. 8 is a perspective view showing the configuration of a resin part shown in FIG. 7. [Figure 10] FIG. 8 is a perspective view showing a cross section taken along line EE in FIG. [Figure 11] 11 is an enlarged view of part F in FIG. 10. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, each embodiment of the present disclosure will be described with reference to the accompanying drawings. Note that common elements in the drawings will be assigned the same reference numerals, and redundant explanations will be omitted or simplified.

[0018] 1. First Embodiment 1-1. Overall configuration of the battery pack Fig. 1 is a perspective view showing the overall configuration of a battery pack 1 according to embodiment 1. Fig. 2 is a perspective view showing a cross section taken along line AA in Fig. 1. The battery pack 1 includes a cell stack 10 and a battery case 30. The battery pack 1 is mounted on an electric vehicle such as a hybrid electric vehicle (HEV) and supplies power to the electric vehicle.

[0019] The cell stack 10 is formed by stacking a plurality of battery cells 12. Each battery cell 12 has a substantially rectangular parallelepiped shape. More specifically, the cell stack 10 is formed by alternately stacking battery cells 12 and frame members (spacers) 14.

[0020] In the following description, the stacking direction of the cell stack 10 (thickness direction of the battery cells 12) is referred to as the "stacking direction D1." The height direction of the cell stack 10 (battery cells 12) is referred to as the "height direction D2." The horizontal direction of the cell stack 10 (width direction of the battery cells 12) perpendicular to the stacking direction D1 is referred to as the "horizontal direction D3."

[0021] The frame member 14 is made of, for example, an insulating resin, and ensures insulation between adjacent battery cells 12 while also forming a heat dissipation path for the battery cells 12. A plurality of frame members 14 is provided for each of the battery cells 12 that make up the cell stack 10, and is formed to cover each of the battery cells 12. More specifically, as shown in FIG. 2, the frame member 14 covers the bottom surface 12a and a pair of side surfaces 12b and 12c of each battery cell 12. The pair of side surfaces 12b and 12c are located at both ends of the battery cell 12 in the horizontal direction D3. Furthermore, the frame member 14 also covers the side surface of the battery cell 12 that is located opposite the side surface 12d (see FIG. 2) of the battery cell 12 in the stacking direction D1.

[0022] The cell stack 10 having the above-described configuration is inserted under pressure into the battery case 30. More specifically, as shown in Fig. 1, end plates 16 are disposed on both ends of the cell stack 10 in the stacking direction D1. The cell stack 10 is housed in the battery case 30 with a compressive load being applied from the pair of end plates 16 located on both ends.

[0023] The battery case 30 has a substantially rectangular parallelepiped shape. The battery case 30 is, for example, a metal case (for example, a sheet metal case or an aluminum die-cast case). The battery case 30 may also be a resin case.

[0024] The battery case 30 is composed of an upper cover that forms the top wall of the battery case 30, and a lower case that forms the bottom wall (case-side bottom wall) 32 and four side walls 34 to 40 of the battery case 30. Only the lower case is shown as the battery case 30 in Figures 1 and 2. The lower case has a generally rectangular parallelepiped shape with an open top.

[0025] More specifically, the four side walls 34 to 40 are a pair of side walls 34 and 36 and a pair of end walls (side walls) 38 and 40. The pair of side walls 34 and 36 are formed to extend along the stacking direction D1. The pair of end walls 38 and 40 are side walls located at the ends of the stacking direction D1. The pair of end walls 38 and 40 face both ends of the cell stack 10, respectively.

[0026] As an example, the battery case 30 is formed to accommodate two cell stacks 10 in parallel. Only one of the two cell stacks 10 is shown in FIGS. 1 and 2. In the battery case 30, the accommodation space for the two parallel cell stacks 10 is partitioned by a partition wall 42. However, instead of this example, the battery case may be formed to accommodate one or three or more cell stacks 10.

[0027] In addition, the battery pack 1 has a cooling air passage 44 formed between the case-side bottom wall 32 and the cell stack 10. The cooling air passage 44 is a passage through which cooling air flows to cool each battery cell 12. The cooling air is introduced into the battery case 30 from an opening 44a provided on one end wall 38 side.

[0028] Regarding the formation of the cooling air passage 44, the case-side bottom wall 32 includes a pair of cell facing portions 32a and a cell cooling air passage portion 32b (see FIG. 3 described below). The pair of cell facing portions 32a face the cell stack 10 at both ends of the bottom wall 32 in the horizontal direction D3. The cell cooling air passage portion 32b is formed between the pair of cell facing portions 32a in the horizontal direction D3, recessed downward relative to the pair of cell facing portions 32a, and extending along the stacking direction D1. The battery case 30 further includes a pair of sealing members (e.g., sponge members) 46 that seal between each of the pair of cell facing portions 32a and the bottom surface 10a of the cell stack 10.

[0029] 1-2. Misalignment prevention structure Next, the displacement suppression structure of the battery pack 1 will be described with additional reference to Figures 3 to 6 in addition to Figures 1 and 2. Figure 3 is a view of the cross section shown in Figure 2 as seen from the direction of arrow B (stacking direction D1). Figure 4 is an enlarged view of part C in Figure 3. Figure 5 is a perspective view of the battery case 30 shown in Figure 1 as seen from the bottom wall 32 side. Figure 6 is an enlarged view of part D in Figure 5.

[0030] The cell stack 10 includes a bottom wall (cell-side bottom wall) 48 that faces the case-side bottom wall 32 .

[0031] The cell-side bottom wall 48 includes a pair of claws 50. Each of the pair of claws 50 is formed to extend toward the case-side bottom wall 32. As an example, the cell-side bottom wall 48 is made up of a plurality of frame members 14 provided corresponding to each of the plurality of battery cells 12 that make up the cell stack 10. Therefore, the pair of claws 50 are provided on the frame members 14.

[0032] Meanwhile, the case-side bottom wall 32 includes a pair of elongated holes 52. The pair of elongated holes 52 are formed so as to be hooked onto the pair of claws 50. Each of the pair of elongated holes 52 is formed so as to be elongated in the stacking direction D1.

[0033] In the battery pack 1, the pair of claws 50 and the pair of long holes 52 formed as described above are hooked together, thereby restricting movement of the cell stack 10 relative to the battery case 30 in both the height direction D2 and the horizontal direction D3.

[0034] Furthermore, the pair of claws 50 (and the corresponding pair of elongated holes 52) are provided in a position closer to the center of the cell stack 10 than to the ends in the stacking direction D1. As shown in FIG. 5, as an example, the pair of claws 50 (and the corresponding pair of elongated holes 52) are provided in the center position of the cell stack 10 in the stacking direction D1. Note that FIG. 5 shows a pair of claws 50 provided on each of the 12 cell stacks 10.

[0035] 3, the two claws 50 constituting a pair of claws 50 (and the two elongated holes 52 constituting the corresponding pair of elongated holes 52) are formed at positions spaced apart from each other in the horizontal direction D3. More specifically, in the example shown in FIG. 5, the positions of the two claws 50 in the stacking direction D1 are the same. However, the positions do not necessarily have to be the same. Each of the pair of claws 50 includes a hook portion 50a that hooks into the elongated hole 52. As shown in FIG. 3, the hook portion 50a is formed so as to face outward in the horizontal direction D3 with respect to the shaft portion 50b of the claw 50.

[0036] Furthermore, the battery pack 1 of the first embodiment includes a cooling air passage 44 formed by utilizing the shape of the case-side bottom wall 32. In the battery pack 1 including such a cooling air passage 44, the pair of elongated holes 52 are formed in the pair of cell facing portions 32a on the outer side in the horizontal direction D3 (outside the battery case 30) of the pair of sealing members 46, as shown in FIG.

[0037] (Variation) Unlike the above-described example, multiple pairs (e.g., two pairs) of claws 50 may be provided for one cell stack 10. The multiple pairs of claws 50 may be provided, for example, at multiple locations (which may include the central position) closer to the center of the cell stack 10 than the ends in the stacking direction D1. Furthermore, the number of claws 50 provided for one cell stack 10 does not necessarily have to be one or multiple pairs; for example, one or multiple claws may be provided without forming a pair. The long holes 52 may be provided corresponding to the positions of the claws 50 specified in these modified examples.

[0038] 1-3.Effects When the cell stack is inserted into the battery case, the cell stack is misaligned relative to the battery case in the height direction D2 and the horizontal direction D3 of the battery cells. More specifically, this misalignment is more likely to occur in the battery cells located at the center than in the battery cells located at the ends of the stacking direction D1.

[0039] To address the above-described problem, the battery pack 1 according to the first embodiment has a structure in which, when the cell stack 10 is inserted into the battery case 30, a pair of claws 50 provided on the cell-side bottom wall 48 are caught in a pair of elongated holes 52 provided in the case-side bottom wall 32. This restricts movement of the cell stack 10 relative to the battery case 30 in both the height direction D2 and the horizontal direction D3. More specifically, the claws 50 are caught in the elongated holes 52, restricting movement of the cell stack 10 in the height direction D2. Furthermore, the frictional force corresponding to the load acting on the claws 50 due to the claws 50 being caught in the elongated holes 52 restricts movement of the cell stack 10 in the horizontal direction D3. This configuration makes it possible to suppress the above-described misalignment with a simple structure while avoiding an increase in the number of components. Furthermore, since the holes on the case-side bottom wall 32 side are formed as elongated holes 52 that are long in the stacking direction D1, misalignment of the claws 50 due to variations in the thickness tolerance of the cell stack 10 can be absorbed.

[0040] Furthermore, according to the first embodiment, the pair of claws 50 (and the pair of corresponding elongated holes 52) are provided in a location closer to the center of the cell stack 10 than to the ends in the stacking direction D1. This makes it possible to effectively suppress misalignment, which is more likely to occur in battery cells located in the center than in battery cells located at the ends in the stacking direction D1, as described above. In addition, when the cell stack is inserted under pressure into the battery case, the cell stack may vibrate in a bow shape while the vehicle is running. The bow vibration referred to here is a primary bow vibration with both ends of the cell stack as fixed ends and the center as an antinode. By providing the pair of claws 50 (and the pair of corresponding elongated holes 52) in a location closer to the center of the cell stack 10 than to the ends in the stacking direction D1, such bow vibration can be effectively suppressed.

[0041] Furthermore, according to the first embodiment, the two claws 50 constituting a pair of claws 50 (and the two elongated holes 52 constituting the corresponding pair of elongated holes 52) are formed at positions spaced apart from each other in the horizontal direction D3. This makes it possible to effectively suppress misalignment in the horizontal direction D3 compared to an example in which only one claw 50 is provided, which is different from the above embodiment. More specifically, when the pair of claws 50 engage with the pair of elongated holes 52, the pair of claws 50 bend, thereby effectively suppressing misalignment in the horizontal direction D3 due to the load acting on the cell stack 10.

[0042] Furthermore, according to the first embodiment, in the battery pack 1 including the cooling air passage 44 (see FIG. 3 ), the pair of elongated holes 52 are formed in the pair of cell facing portions 32a, respectively, outside the pair of sealing members 46 in the horizontal direction D3 (outside the battery case 30). This allows the pair of claws 50 and the pair of elongated holes 52 to be provided in positions that prevent communication between the pair of elongated holes 52 and the cooling air passage 44. This makes it possible to suppress the above-mentioned misalignment with a simple structure while preventing liquid from entering the cooling air passage 44 from the outside of the battery case 30 through the gap between the claws 50 and the elongated holes 52.

[0043] 2. Second Embodiment 2-1. Overall configuration of the battery pack FIG. 7 is a perspective view showing the overall configuration of a battery pack 2 according to the second embodiment. The battery pack 2 includes a cell stack 60 (see FIG. 10 described later) and a battery case 70. The cell stack 60 is configured similarly to the cell stack 10 shown in FIG. 1, except that the shape of the frame member 62 is different as described later in order to realize a misalignment suppression structure. Although the cell stack 60 is not shown in FIG. 7, like the battery pack 1 according to the first embodiment, the battery pack 2 includes, as an example, two cell stacks 60 arranged in parallel. Furthermore, in the battery pack 2 as well, the cell stack 60 is inserted under pressure into the battery case 70.

[0044] 1, only the lower case of the battery case 70 is shown in FIG. 7, and the upper cover is not shown. The lower case has a generally rectangular parallelepiped shape with an open top. That is, the lower case constitutes the bottom wall (case-side bottom wall) 71 and four side walls 72 to 75 (more specifically, a pair of side walls 72 and 73 and a pair of end walls 74 and 75) of the battery case 70. The lower case also has a partition wall 76 that separates the storage space for the two cell stacks 60 arranged in parallel. Like the battery case 30, the battery case 70 has a cooling air passage 44 and an opening 44a.

[0045] The battery case 30 (lower case) of the first embodiment is made of a single material (for example, metal or resin). In contrast, the battery case 70 (lower case) of the second embodiment is made of a metal plate portion 80 and a resin portion 90. More specifically, the battery case 70 is formed by inserting the metal plate portion 80 into the resin portion 90, which is formed by injection molding. In other words, the battery case 70 is formed by integrally forming the metal plate portion 80 and the resin portion 90.

[0046] FIG. 8 is an exploded perspective view showing the configuration of the metal plate portion 80 shown in FIG. 7. As shown in FIG. 8, the metal plate portion 80 is made of multiple (eight, for example) metal plates (sheet metal members) 81 to 88. The metal plates 81 to 88 are each press-formed and then joined by, for example, welding to form the framework of the battery case 70. More specifically, the metal plates 81 and 82 form the framework of the case-side bottom wall 71, the pair of side walls 72 and 73, and the partition wall 76. The metal plates 83, 84, and 85 form the framework of one end wall 74. The metal plates 86, 87, and 88 form the framework of the other end wall 75. The strength and rigidity of the battery case 70 are ensured by the metal plate portion 80. The material of the metal plates 81 to 88 is not particularly limited, and may be, for example, a steel plate, a zinc-plated steel plate, a nickel-plated steel plate, a stainless steel plate, or an aluminum plate.

[0047] 9 is a perspective view showing the configuration of the resin part 90 shown in FIG. 7 (excluding the claws 92, which will be described later). The resin part 90 is formed by injection molding to realize various shapes that would be difficult to form using only the multiple metal plates (sheet metal members) 81-88. The various shapes referred to here include, for example, the shape of the cooling air passage 44 including the opening 44a, and a shape that ensures the airtightness of the battery case 70. The material of the resin part 90 is not particularly limited, but may be, for example, a thermoplastic resin such as polyamide, a thermosetting resin such as epoxy, or a fiber-reinforced plastic such as glass fiber-reinforced polyamide.

[0048] Additionally, in the example of the metal plate portion 80 shown in Fig. 8, the multiple metal plates 81 to 88 that make up the metal plate portion 80 are joined together by welding or the like before the resin portion 90 is injection molded. However, when a battery case composed of metal plate portions and a resin portion is applied to a battery pack according to the present disclosure, the metal plate portions of the battery case do not necessarily have to be joined together by welding or the like before injection molding, unlike the example shown in Fig. 8. In other words, injection molding may be performed in a state in which the multiple metal plates that make up the metal plate portion are spaced apart from one another, and the resin portion may be formed so as to be interposed between the multiple metal plates and connect the multiple metal plates.

[0049] 2-2. Position shift prevention structure Next, a displacement suppression structure provided in the battery pack 2 will be described with additional reference to Figures 10 and 11 in addition to Figures 7 to 9. Figure 10 is a perspective view showing a cross section taken along line EE in Figure 7. Figure 11 is an enlarged view of part F in Figure 10.

[0050] The cell stack 60 includes a pair of cell-side sidewalls SWs facing a pair of case-side sidewalls SWc. In the example of the battery pack 2, the "pair of cell-side sidewalls SWs" here are configured by a plurality of frame members 62 provided on each of the plurality of battery cells 12 constituting the cell stack 60 and formed to cover the plurality of battery cells 12. The "pair of case-side sidewalls SWc" here corresponds to two of the pair of sidewalls 72 and 73 and the partition wall 76. More specifically, for the cell stack 60 housed in the space on the left side of the battery case 70 in FIG. 7, the sidewall 72 and the partition wall 76 correspond to the "pair of case-side sidewalls SWc." For the cell stack 60 housed in the space on the right side of the battery case 70 in FIG. 7, the partition wall 76 and the sidewall 73 correspond to the "pair of case-side sidewalls SWc."

[0051] The pair of cell-side side walls SWs includes a plurality of protrusions 64. As described above, the pair of cell-side side walls SWs is, for example, configured by a plurality of frame members 62 provided corresponding to each of the plurality of battery cells 12 that make up the cell stack 60. Therefore, in the second embodiment, the plurality of protrusions 64 are provided on each of the plurality of frame members 62. As shown in FIG. 10 , each of the plurality of protrusions 64 is formed so as to protrude toward the pair of case-side side walls SWc. Furthermore, each of the plurality of protrusions 64 protrudes from a lower end of the cell-side side wall SWs in the height direction D2.

[0052] On the other hand, as shown in FIG. 10 , the case-side bottom wall 71 includes a pair of claws 92. The pair of claws 92 are formed in the resin part 90. The pair of claws 92 are formed to hook onto the pair of protrusions 64, respectively. Each of the pair of claws 92 is formed to extend upward from the case-side bottom wall 71 and faces the protrusion 64 in the horizontal direction D3. Each of the pair of claws 92 includes a hook portion 92a that hooks onto the protrusion 64. As shown in FIG. 11 , the hook portion 92a is formed to face inward in the horizontal direction D3 with respect to the shaft portion 92b of the claw 92. Furthermore, as an example, the width of the claw 92 in the stacking direction D1 is equal to the width of the frame member 62 on which the protrusion 64 corresponding to the claw 92 is formed.

[0053] Additionally, in the example of the battery case 70 in which two cell stacks 60 are housed in parallel, a pair of claws 92 is provided for each individual cell stack 60. However, Fig. 7 only shows the pair of claws 92 corresponding to the cell stack 60 housed in the space on the right side of the figure.

[0054] In the battery pack 2, the pair of protrusions 64 and the pair of claws 92 formed as described above are hooked together, thereby restricting movement of the cell stack 60 relative to the battery case 70 in both the height direction D2 and the horizontal direction D3.

[0055] 7, the pair of claws 92 are provided closer to the center than to the ends of the cell stack 60 in the stacking direction D1. More specifically, as an example, the pair of claws 92 are provided at the center position of the cell stack 60 in the stacking direction D1.

[0056] 10, the pair of claws 92 are arranged on the case-side bottom wall 71 so as to sandwich the cell stack 60 from the outside in the horizontal direction D3. In addition, as shown in FIG. 7, the positions of the pair of claws 92 in the stacking direction D1 are the same. However, the positions do not necessarily have to be the same.

[0057] (Variation) Unlike the above-described example, multiple pairs (e.g., two pairs) of claws 92 may be provided on the battery case 70 for one cell stack 60. The multiple pairs of claws 92 may be provided on the battery case 70, for example, at multiple locations (which may include the central position) closer to the center than the ends of the cell stack 60 in the stacking direction D1. Furthermore, the number of claws 92 provided for one cell stack 60 does not necessarily have to be one or multiple pairs; for example, one or multiple claws may be provided without forming a pair.

[0058] In the example described above, the protrusion 64 on the cell stack 60 side is provided on each of the plurality of frame members 62. However, the protrusion 64 does not necessarily have to be provided on each of the plurality of frame members 62, and may be provided only on the frame member 62 located opposite the claw 92 in the stacking direction D1.

[0059] 2-3.Effects According to the battery pack 2 according to the second embodiment described above, when the cell stack 60 is inserted into the battery case 70, each of the pair of claws 92 provided on the case-side bottom wall 71 hooks onto the protrusion 64 provided on the cell-side sidewall SWs. This restricts movement of the cell stack 60 relative to the battery case 70 in both the height direction D2 and the horizontal direction D3. This configuration also makes it possible to suppress misalignment of the cell stack 60 relative to the battery case 70 in both the height direction D2 and the horizontal direction D3 with a simple structure while avoiding an increase in the number of parts.

[0060] The battery pack 2 according to the second embodiment also provides the following effect. Specifically, in the misalignment suppression structure of the battery pack 1 according to the first embodiment, the inside and outside of the battery case 30 communicate with each other through the gap between the claw 50 and the elongated hole 52. As a result, when liquid flows into the vicinity of the battery pack 1, the liquid may enter the inside of the battery case 30. In contrast, in the battery pack 2, the battery case 70 is formed by inserting the metal plate portion 80 into the resin portion 90 formed by injection molding. The pair of claws 92 are formed in the resin portion 90. This achieves a structure in which the cell stack 60 and the battery case 70 engage with each other without causing communication between the inside and outside of the battery case 70. This improves the sealing performance of the battery case 70 while suppressing the misalignment.

[0061] Also in the second embodiment, the pair of claws 92 are provided closer to the center of the cell stack 60 than to the ends in the stacking direction D1. This makes it possible to effectively suppress the above-mentioned misalignment and the above-mentioned bow vibration.

[0062] Furthermore, in the second embodiment, the pair of claws 92 are arranged to sandwich the cell stack 60 from the outside in the horizontal direction D3. This makes it possible to effectively suppress misalignment in the horizontal direction D3, unlike the above-described embodiment, as compared to, for example, an example in which a single claw 92 is provided. More specifically, when the pair of claws 92 engage with the corresponding protrusions 64, the pair of claws 92 bend, thereby effectively suppressing misalignment in the horizontal direction D3 due to the load acting on the cell stack 60.

[0063] Furthermore, the battery pack 1 according to the first embodiment requires two types of frame members 14: one with the claws 50 and one without the claws 50. In contrast, the battery pack 2 according to the second embodiment provides a plurality of protrusions 64 on each of the plurality of frame members 62, thereby eliminating the need to classify the frame members 62 into different types. Even if the position of the protrusions 64 on the cell stack 60 relative to the claws 92 shifts due to variations in the thickness tolerance of the cell stack 60, the claws 92 can be reliably engaged with the protrusions 64 by utilizing the protrusions 64 adjacent to the protrusions 64 that are designed to engage with the claws 92. [Explanation of symbols]

[0064] 1, 2 Battery pack 10, 60 cell stack 12 battery cells 14, 62 Frame members 16 End plate 30, 70 battery case 32, 71 Case side bottom wall 32a Cell facing part 32b Cell cooling air passage 34, 36, 38, 40, 72, 73, 74, 75 Battery case side wall 42, 76 Battery case partition wall 44 Cooling air passage 46 Sealing material 48 Cell side bottom wall 50, 92 nails 52 long hole 64 Protrusion 80 Metal plate part 81, 82, 83, 84, 85, 86, 87, 88 metal plate 90 Resin part SWc Case side wall SWs cell side wall

Claims

1. a cell stack formed by stacking a plurality of battery cells each having a substantially rectangular parallelepiped shape; a battery case having a substantially rectangular parallelepiped shape and accommodating the cell stack; Equipped with the cell stack includes a cell-side bottom wall that faces a case-side bottom wall that is a bottom wall of the battery case, the cell-side bottom wall includes one or more claws formed to extend toward the case-side bottom wall, the case side bottom wall includes one or more elongated holes that are formed to be hooked onto the one or more claws and that are elongated in the stacking direction of the cell stack, the one or more claws and the one or more elongated holes are hooked together, thereby restricting movement of the cell stack relative to the battery case in both a height direction of the cell stack and a horizontal direction of the cell stack perpendicular to the stacking direction; the one or more claws include at least one pair of claws formed at positions spaced apart from each other in the horizontal direction, The case side bottom wall is a pair of cell facing portions that face the cell stack at both ends of the case side bottom wall in the horizontal direction; a cell cooling air passage portion formed between the pair of cell opposing portions in the horizontal direction, recessed downward with respect to the pair of cell opposing portions, and extending along the stacking direction; Including, the battery case further includes a pair of sealing members that seal between each of the pair of cell facing portions and a bottom surface of the cell stack, The one or more elongated holes include at least one pair of elongated holes formed in the pair of cell opposing portions on the outer side of the pair of sealing members in the horizontal direction. Battery pack.

2. The one or more claws are provided at a position closer to the center of the cell stack than to an end of the cell stack in the stacking direction. The battery pack according to claim 1 .

3. the cell-side bottom wall is configured by a plurality of frame members that are provided on the plurality of battery cells and that are formed to cover the plurality of battery cells, The one or more claws are provided on one or more of the frame members. The battery pack according to claim 1 .

4. a cell stack formed by stacking a plurality of battery cells each having a substantially rectangular parallelepiped shape; a battery case having a substantially rectangular parallelepiped shape and accommodating the cell stack; Equipped with the battery case includes a metal plate portion made of a plurality of metal plates that constitutes a part of the battery case, and a resin portion that constitutes another part of the battery case, and is formed by inserting the metal plate portion into the resin portion that is formed by injection molding, the cell stack includes a pair of cell-side side walls facing a pair of case-side side walls that are wall portions of the battery case extending along the stacking direction of the cell stack, the pair of cell-side side walls include one or more protrusions formed to protrude toward at least one side of the pair of case-side side walls, a case-side bottom wall that is a bottom wall of the battery case includes one or more claws that are formed to be hooked onto the one or more protrusions, respectively; the one or more claws are formed in the resin portion, The one or more protrusions and the one or more claws are hooked together, thereby restricting movement of the cell stack relative to the battery case in both the height direction of the cell stack and the horizontal direction of the cell stack, which is perpendicular to the stacking direction. Battery pack.

5. The one or more claws are provided at a position closer to the center of the cell stack than to an end of the cell stack in the stacking direction. The battery pack according to claim 4.

6. The one or more claws include at least one pair of claws arranged to sandwich the cell stack from the outer sides in the horizontal direction. The battery pack according to claim 4.

7. the pair of cell-side side walls are configured by a plurality of frame members provided on the plurality of battery cells and formed to cover the plurality of battery cells, respectively; The one or more protrusions may be a plurality of protrusions, The plurality of protrusions are provided on each of the plurality of frame members. The battery pack according to claim 4.

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