Battery cell case

Abstract

The present invention provides a battery cell case designed to suppress temperature variations within the battery cells. [Solution] The battery cell case according to the disclosed technology has a first outer wall 2 and a second outer wall 3, a plurality of main partition walls 4 provided connecting the first outer wall 2 and the second outer wall 3, which alternately divide the area between the first outer wall 2 and the second outer wall 3 into a plurality of cell chambers for housing battery elements and a plurality of cooling chambers 6 through which a cooling medium passes, and a plurality of sub-partition walls 7 provided connecting the main partition walls 4 on both sides of each cooling chamber 6, which divide the cooling chamber 6 into a plurality of cooling passages 8, wherein the amount of sub-partition walls 7 per unit length in the cell height direction H, which is the direction connecting the first outer wall 2 and the second outer wall 3 in each cooling chamber 6, is greater in the central part of the cell height direction H and less at the ends of the cell height direction H.

Description

Technical Field

[0001] The disclosed technology relates to a battery cell case.

Background Art

[0002] As an example of a conventional battery cell case, the "frame body" described in Patent Document 1 can be cited. In the battery module of this document, a plurality of battery cells are held by a first frame body and a second frame body in a stacked state. The frame body is provided with a plurality of slit bars. Cooling air passages are formed between the battery cells by the slit bars. The slit bars are arranged at equal intervals. Therefore, the cooling air passages are also evenly arranged between the battery cells.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described conventional technology, temperature variations may occur depending on the location of the battery cell during use. In particular, the central part of the battery cell tends to be hotter than the edge part. This is because the amount of heat generation is larger in the central part than in the edge part, and the cooling capacity is likely to be insufficient. Therefore, the central part of the battery cell is greatly deformed and the stress tends to be high. In addition, variations in deterioration occur due to the temperature difference within the battery cell.

[0005] An object of the disclosed technology is to provide a battery cell case that suppresses temperature variations of the battery cell.

Means for Solving the Problems

[0006] A battery cell case in one aspect of the disclosed technology is a battery cell case for housing a battery cell, comprising a first outer wall and a second outer wall, a plurality of main partitions provided connecting the first outer wall and the second outer wall, which alternately divide the region between the first outer wall and the second outer wall into a plurality of cell chambers for housing battery elements and a plurality of cooling chambers for passing a cooling medium, and a plurality of sub-partitions provided connecting the main partitions on both sides of a cooling chamber, which divide the cooling chamber into a plurality of cooling passages, wherein the amount of sub-partitions per unit length in the cell height direction, which is the direction connecting the first outer wall and the second outer wall in each cooling chamber, is greater in the central part in the cell height direction and less at the ends in the cell height direction.

[0007] In the battery cell case of the above embodiment, sub-partitions are more numerous in the center of each cooling chamber in the cell height direction and less numerous at the ends in the cell height direction. As a result, the contact surface between the cooling medium and the battery cell case is larger in the center of the cell height direction than at the ends. This results in higher cooling efficiency in the center and reduced temperature variation within the battery cell. Furthermore, this structure makes the center of the cell height direction more rigid than the ends in the cell height direction. This configuration provides high resistance to load caused by expansion of the cell chamber during use. This is because the rigidity of the center of the cell height direction, which is a part that is prone to temperature rise, is high.

[0008] In the battery cell case of the above embodiment, it is also desirable that the amount of sub-partitions per unit length in the cell height direction in each cooling chamber is even less at one end in the cell height direction than at the other end. In this case, there is a difference in rigidity between one end and the other end in the cell height direction. When the less rigid end is facing downwards, even if there is a collision with something else, the lower side of the battery cell case will deform preferentially. As a result, damage to the cell chamber is minimized.

[0009] In any of the above embodiments of the battery cell case, it is also desirable that the surface area of ​​the sub-partition per unit length in the cell height direction in each cooling chamber is larger in the center in the cell height direction and smaller at the ends in the cell height direction. This results in higher cooling capacity in the center in the cell height direction. Therefore, excessive temperature rise in the center in the cell height direction during use is suppressed.

[0010] In any of the above embodiments of a battery cell case, it is desirable that a cooling medium supply member is also provided to supply a cooling medium to each cooling chamber, and that the cooling medium supply member has a first flow path connected to the cooling passage located closer to the first outer wall and a second flow path connected to the cooling passage located closer to the second outer wall separately formed therein. In this configuration, more cooling medium flows into the cooling passage located near the center in the cell height direction. As a result, the cooling capacity is higher in the central part in the cell height direction.

[0011] In any of the above embodiments of a battery cell case, it is also desirable that the spacing between sub-partitions in each cooling chamber is narrower in the center of the cell height direction and wider at the ends of the cell height direction. In this case, there will be many sub-partitions in the center of the cell height direction and few sub-partitions at the ends.

[0012] In any of the above embodiments of a battery cell case, it is desirable that the thickness of the sub-partition wall in each cooling chamber is greater in the center in the cell height direction and smaller at the ends in the cell height direction. In this case, the rigidity is high in the center in the cell height direction, even towards the ends.

[0013] In a battery cell case where the surface area of ​​sub-partitions per unit length in the cell height direction differs between the central and end parts of each cooling chamber, it is desirable that the surface area of ​​the sub-partition in the central part of the cell height direction is greater than the surface area of ​​the sub-partition at the end parts of the cell height direction. By creating a difference in the surface area of ​​a single sub-partition between the central and end parts, the cooling capacity can be further enhanced in the central part of the cell height direction. [Effects of the Invention]

[0014] According to the disclosed technology, a battery cell case is provided that suppresses temperature variations in battery cells.

Brief Description of the Drawings

[0015] [Figure 1] It is a cross-sectional view of a battery cell case according to an embodiment. [Figure 2] It is a cross-sectional view showing the cooling chamber portion in FIG. 1. [Figure 3] It is a cross-sectional view showing the battery cell case and the lid member. [Figure 4] It is a cross-sectional view showing the lid member in a comparative example. [Figure 5] It is a plan view for explaining the arrangement of the supply path of the cooling medium in the lid member. [Figure 6] It is a schematic diagram for explaining the situation of the cell chamber during temperature rise. [Figure 7] It is a cross-sectional view (Part 1) showing the cooling chamber portion according to a modification. [Figure 8] It is a front view (Part 1) showing the situation where the battery cell case according to the modification of FIG. 7 collides with an obstacle. [Figure 9] It is a front view (Part 2) showing the situation where the battery cell case according to the modification of FIG. 7 collides with an obstacle. [Figure 10] It is a cross-sectional view (Part 2) showing the cooling chamber portion according to a modification. [Figure 11] It is a cross-sectional view (Part 3) showing the cooling chamber portion according to a modification. [Figure 12] It is a cross-sectional view showing a modification of the shape of the sub partition wall. [Figure 13] It is a cross-sectional view (Part 4) showing the cooling chamber portion according to a modification.

Embodiments for Carrying Out the Invention

[0016] This embodiment embodies the disclosed technology as the battery cell case 1 shown in FIG. 1. In FIG. 1, a cross-section of the battery cell case 1 is shown. The battery cell case 1 has a certain length in the direction perpendicular to the plane of FIG. 1 (hereinafter referred to as the "thickness direction"). The cross-sectional structure shown in FIG. 1 is approximately the same anywhere in the thickness direction of the battery cell case 1.

[0017] As shown in FIG. 1, the battery cell case 1 has a first outer wall 2 and a second outer wall 3. The first outer wall 2 and the second outer wall 3 are located at the upper and lower ends of the battery cell case 1 in FIG. 1. The battery cell case 1 further has a main partition wall 4. The main partition wall 4 is provided by connecting the first outer wall 2 and the second outer wall 3. There are a plurality of main partition walls 4 in the battery cell case 1. The main partition wall 4 divides the region between the first outer wall 2 and the second outer wall 3 in the battery cell case 1 into a plurality of chambers.

[0018] In the battery cell case 1, there are two types of chambers partitioned by the main partition wall 4, namely a cell chamber 5 and a cooling chamber 6. There are a plurality of both the cell chamber 5 and the cooling chamber 6. The cell chamber 5 and the cooling chamber 6 are arranged alternately. The cell chamber 5 is a space for accommodating battery elements. The cell chamber 5 with the battery elements accommodated is the battery cell. The cooling chamber 6 is a space for allowing a cooling medium to pass through.

[0019] The cooling chamber 6 is provided with a sub partition wall 7. As shown in FIG. 2, the sub partition wall 7 connects the main partition walls 4 on both sides of the cooling chamber 6. There are a plurality of sub partition walls 7 in one cooling chamber 6. The sub partition wall 7 divides the cooling chamber 6 into a plurality of cooling paths 8. The cooling path 8 is each individual space partitioned by the sub partition wall 7 among the cooling chambers 6 sandwiched between the adjacent main partition walls 4. In contrast, the whole of the plurality of cooling paths 8 from the first outer wall 2 to the second outer wall 3 in FIG. 2 is collectively referred to as one cooling chamber 6. The shape of the sub partition wall 7 in FIG. 2 is not linear but a curved shape curved up and down.

[0020] Returning to Figure 1, the battery cell case 1 is shown with a third outer wall 10 and a fourth outer wall 11 at both the left and right ends. The first outer wall 2, the second outer wall 3, the third outer wall 10, and the fourth outer wall 11 form the outer shape of the battery cell case 1. Each of the first outer wall 2, the second outer wall 3, the third outer wall 10, and the fourth outer wall 11 has an air chamber 9 inside. The "chamber" located immediately inside the third outer wall 10 and the fourth outer wall 11 is the cooling chamber 6.

[0021] As shown by the arrows in Figure 2, the direction connecting the first outer wall 2 and the second outer wall 3 in the cooling chamber 6 is called the cell height direction H. The arrangement of the sub-partition walls 7 in the battery cell case 1 is not uniform with respect to the cell height direction H. As is clear from Figure 2, the spacing between the sub-partition walls 7 is short in the central part of the cell height direction H (S1) and wide at the ends of the cell height direction H (S2). In other words, considering the amount of sub-partition walls 7 per unit length of the cell height direction H, there are more in the central part of the cell height direction H and fewer at the ends of the cell height direction H.

[0022] In the battery cell case 1 with the above structure, the cell chamber 5 and the cooling chamber 6 are through each other in the thickness direction. Therefore, during actual use, both ends in the thickness direction are closed by the lid member. At least one side of the closure by the lid member is performed after the battery elements are placed in the cell chamber 5. As shown in Figure 3, the lid member 12 has a first flow path 13 and a second flow path 14 formed therein.

[0023] Figure 3 is a cross-sectional view of the battery cell case 1 with the lid member 12 attached, at position AA in Figure 1. That is, it is a cross-sectional view at the position of the cooling chamber 6, not at the position of the main partition wall 4 or the cell chamber 5. However, the parts near the top and bottom ends in Figure 1 are omitted in Figure 3. In Figure 3, the ends in the left-right direction are closer to the first outer wall 2 and the second outer wall 3 in Figure 1. In other words, the left-right direction in Figure 3 corresponds to the cell height direction H shown in Figure 2.

[0024] As shown in Figure 3, the lid member 12 has a weir 17 between the first channel 13 and the second channel 14. Therefore, the first channel 13 and the second channel 14 are separated and are separate channels. The first channel 13 and the second channel 14 are groove-shaped portions provided on one side of the lid member 12 before it is installed in the battery cell case 1.

[0025] Figure 3 shows the first channel 13 and the second channel 14 connected to the cooling passage 8. The lid member 12 is a cooling medium supply member that supplies the cooling medium to the cooling passage 8 through the first channel 13 and the second channel 14. The arrows in Figure 3 indicate the flow of the cooling medium in the first channel 13, the second channel 14, and the cooling passage 8. The cooling medium may be a liquid or a gas. The first channel 13 and the second channel 14 are not connected to the cell chamber 5 in Figure 1.

[0026] In Figure 3, the cooling passage 8 to the left of the center corresponds to the cooling passage 8 above the center in Figure 1, that is, closer to the first outer wall 2. The first flow path 13 is connected to these cooling passages 8. In Figure 3, the cooling passage 8 to the right of the center corresponds to the cooling passage 8 below the center in Figure 1, that is, closer to the second outer wall 3. The second flow path 14 is connected to these cooling passages 8. Therefore, the cooling medium supplied from both the left and right sides in Figure 3 (both the top and bottom sides in Figure 1) flows into the cooling passages 8 separately without merging in the center.

[0027] Comparing the amount of cooling medium flowing into each cooling passage 8, we find that the cooling passages 8 closer to the center in the cell height direction H have a larger flow rate, while those closer to the ends have a smaller flow rate. This is shown in Figure 3 by the length of the downward arrows for each cooling passage 8. The amount of cooling medium flowing into each cooling passage 8 depends on the flow velocity of the cooling medium flowing horizontally through the first passage 13 and the second passage 14 in Figure 3.

[0028] In Figure 3, near both ends in the left-right direction, that is, upstream of the flow of the cooling medium in the first channel 13 and the second channel 14, the flow velocity of the cooling medium is high. Therefore, the direction of the cooling medium flow is less likely to change. Consequently, the amount of cooling medium flowing into the cooling channel 8 at that point is small. On the other hand, near the weir 17, closer to the center, that is, downstream of the flow, the flow velocity of the cooling medium is slow. Therefore, the direction of the cooling medium flow is more likely to change. Consequently, the amount of cooling medium flowing into the cooling channel 8 at that point is large. As a result, the above-mentioned differences in the amount of cooling medium flowing into each cooling channel 8 occur.

[0029] As a result, when the battery cell case 1 is in use, there is a difference in the cooling capacity for the cell chamber 5 depending on the position in the cell height direction H. Naturally, the cooling capacity is higher in the central part of the cell height direction H and relatively lower in the part near the edges. On the other hand, the amount of heat generated in the cell chamber 5 during use tends to be higher in the central part and relatively lower near the edges. Therefore, when the battery cell case 1 is in use, temperature variations in the cell height direction H are suppressed. This is because the cooling capacity is higher in the part with a lot of heat generated and lower in the part with a little heat generated. As a result, the part with a lot of heat generated is cooled intensively, and the degradation of the battery elements in the cell chamber 5 is suppressed.

[0030] This will be further explained by comparing it with the case where the lid member 15 shown in Figure 4 is used instead of the lid member 12 shown in Figure 3. The lid member 15 in Figure 4 supplies the cooling medium to one cooling chamber 6 through a single channel 16, rather than a pair of first channel 13 and second channel 14. While Figure 3 shows the central part in the cell height direction H, Figure 4 shows a part closer to one end. Part of the first outer wall 2 is visible in Figure 4.

[0031] When the lid member 15 is used, the cooling medium is supplied from the side of the second outer wall 3 opposite the first outer wall 2, and flows into all the cooling passages 8 in one cooling chamber 6 via the flow path 16. In this case, the position with the highest cooling capacity is the end position closer to the first outer wall 2. This position is different from the position where the heat generation in the cell chamber 5 is highest. Therefore, the lid member 15 does not have the effect of suppressing temperature variations in the cell chamber 5. In contrast, with the lid member 12 in Figure 3, the effect of suppressing temperature variations is obtained as described above.

[0032] The actual lid member 12 has multiple pairs of first flow channels 13 and second flow channels 14 formed therein, corresponding to the multiple cooling chambers 6 shown in Figure 1. The lid member 12 also has supply paths formed therein to supply the cooling medium to the multiple first flow channels 13 and second flow channels 14, as shown in Figure 5. Figure 5 shows the case where the number of cooling chambers 6 in the battery cell case 1 is four. The lid member 12 has cooling medium inlets 18 and 19. Inlets 18 are inlets connected to four first flow channels 13. Inlets 19 are inlets connected to four second flow channels 14.

[0033] Supply passages 20, 21, 22, and 23 are provided between the inlet 18 and the four first flow channels 13. Supply passages 20 and 23 are outward-facing supply passages that connect to the outermost of the four first flow channels 13. Supply passages 21 and 22 are inward-facing supply passages that connect to the innermost of the four first flow channels 13.

[0034] Let B1 be the cross-sectional area of ​​the outer supply passage 20, and B2 be the cross-sectional area of ​​the inner supply passage 21. In the lid member 12, the cross-sectional area B2 is larger than the cross-sectional area B1. A similar relationship exists between the outer supply passage 23 and the inner supply passage 22. There are also four supply passages between the inlet 19 and the four second flow paths 14, and the above relationship of cross-sectional areas also holds true. As a result, in this embodiment, a larger amount of cooling medium is supplied to the cooling chambers 6 located closer to the inside of the battery cell case 1 than to those located closer to the outside. Therefore, the cooling chambers 6 located closer to the inside of the battery cell case 1 have a higher cooling capacity than the cooling chambers 6 located closer to the outside. During use, the temperature of the cell chambers 5 located closer to the inside of the battery cell case 1 tends to rise more easily, but excessive temperature rise is suppressed due to the above relationship of cooling capacity.

[0035] In Figure 3, the other end of the battery cell case 1 (the lower end in the figure, or the back end in the thickness direction) is omitted, but a cover member is also attached to the back end. The back cover member is a cooling medium discharge member. A groove-shaped flow path is also provided in the cooling medium discharge member. The groove-shaped flow path of the cooling medium discharge member can be either a type divided in the middle as in Figure 3, or a continuous type as in Figure 4. This is because the discharge side has less impact on the flow rate of the cooling medium compared to the supply side.

[0036] The lid member 12 is not the only component that contributes to suppressing temperature variations in the battery cell case 1. The battery cell case 1 itself also contains a configuration that helps suppress temperature variations. This is the uneven arrangement of the sub-partition walls 7, as explained in Figure 2. The surface of the sub-partition walls 7 is where heat is discharged from the battery cell case 1 to the cooling medium.

[0037] In areas where there is a large amount of sub-partition wall 7 per unit length H in the cell height direction, heat dissipation occurs more easily compared to areas where there is less. This is because the surface area of ​​sub-partition wall 7 per unit length H in the cell height direction is larger. Therefore, in the battery cell case 1, considering the surface area of ​​sub-partition wall 7 per unit length H in the cell height direction, it is wider in the center of H and narrower at the ends of H in the cell height direction. As a result, in the battery cell case 1, due to the uneven arrangement of sub-partition wall 7, the cooling capacity is higher in the center of H in the cell height direction and relatively lower at the ends of H in the cell height direction. Therefore, the battery cell case 1 in this embodiment has the effect of suppressing temperature variations in the cell chamber 5.

[0038] The uneven arrangement of the sub-partitions 7 in the battery cell case 1 contributes not only to suppressing temperature variations but also to improving the rigidity of the battery cell case 1. This is because the greater the amount of sub-partitions per unit length H in the cell height direction, the stronger the resistance to deformation. In the battery cell case 1, the central part, where expansion is greater, has higher rigidity than the ends.

[0039] When the battery cell case 1 is in use, the cell chamber 5 tends to bulge, especially in the center, due to expansion, as shown in Figure 6. Although Figure 6 is a rather exaggerated depiction, in this state, stress concentrates in the center of the cell height direction H of the entire battery cell case 1. However, in the battery cell case 1, the rigidity of the central part is increased in the cooling chamber 6 adjacent to the cell chamber 5, as described above. Therefore, deformation of the cell chamber 5 is suppressed even when the temperature rises.

[0040] A modified version of the battery cell case 1 will be described. Figure 7 shows a further modification of the non-uniform arrangement of the sub-partition walls 7 described in Figure 2, with the arrangement on the first outer wall 2 side and the second outer wall 3 side being asymmetrical. In this modified battery cell case 31, the spacing between the sub-partition walls 7 is greater at the end of the second outer wall 3 side than at the end of the first outer wall 2 side, where spacing S21 is greater. Of course, both spacing S21 and S22 are greater than the spacing S1 at the center. In other words, the amount of sub-partition walls 7 per unit length in the cell height direction H is even less at one end (second outer wall 3 side) in the cell height direction H than at the other end (first outer wall 2 side). In a battery cell case 31 employing such an arrangement of sub-partition walls 7, there is a difference in rigidity between the first outer wall 2 side and the second outer wall 3 side. The second outer wall 3 side has lower rigidity than the first outer wall 2 side.

[0041] In a battery cell case 31 that employs this structure in all cooling chambers 6, the effect of reducing impact during collisions can be obtained. Figure 8 shows the situation when the battery cell case 31 collides with some kind of obstacle 33. In the example in Figure 8, the battery cell case 31 is fixed to the floor surface by a mounting stay 32 with the end on the second outer wall 3 side facing downwards.

[0042] In this situation, if the battery cell case 31 collides with the obstacle 33, the lower end of the battery cell case 31, which has relatively less rigidity, will deform preferentially over the upper end. As a result, the direction of the load on the battery cell case 31 changes, and as shown in Figure 9, the entire battery cell case 31 tilts and lifts up. This actually reduces damage to each cell chamber 5.

[0043] Figure 10 shows a modified example in which the shape of the sub-partition wall 7 is made linear. As shown, the shape of the sub-partition wall 7 is arbitrary. In the battery cell case 41 of the example in Figure 10, the relationship between the spacing S1 and the spacing S2 is the same as that explained in Figure 2.

[0044] Figure 11 shows a compromise example between Figure 2 and Figure 10. In the battery cell case 51 of the example in Figure 11, a straight sub-partition wall 7 is used in the part near the end in the cell height direction H, and a curved sub-partition wall 7 is used in the part near the center. The advantage of this is the suppression of temperature variation as mentioned above. Considering the surface area of ​​a single sub-partition wall 7, the curved sub-partition wall 7 has a larger surface area than the straight sub-partition wall 7. Therefore, in terms of cooling capacity, the curved sub-partition wall 7 is superior to the straight sub-partition wall 7.

[0045] The example in Figure 11 focuses on the surface area of ​​a single sub-partition wall 7, and is designed so that the surface area of ​​the sub-partition wall 7 in the central part of the cell height direction H is larger than the surface area of ​​the sub-partition wall 7 at the ends of the cell height direction H. As a result, in the example in Figure 11, the cooling capacity is increased in the central part of the cell height direction H, where heat generation is high during use.

[0046] The method for increasing the surface area of ​​a single sub-bulb 7 is not limited to the curved sub-bulb 7 shown in Figure 2, etc. As shown in Figure 12, the surface area can also be increased by adding an uneven surface to the sub-bulb 7. The structure shown in Figure 12 can be used for the sub-bulb 7 in the central part of the cell height direction H. Alternatively, the structure shown in Figure 12 may be used for all sub-bulb 7. The specific shape of the uneven surface is arbitrary and does not need to be as complex as that shown in Figure 12.

[0047] Figure 13 shows a case where the thickness of the sub-partition wall 7 is varied. In the example of the battery cell case 61 in Figure 13, the thickness of the sub-partition wall 7 is greater in the center of the cell height direction H and smaller at the ends of the cell height direction H. The advantage of doing this is the improvement in rigidity mentioned above. The thicker the sub-partition wall 7, the stronger it contributes to the improvement in rigidity. In the example of Figure 13, by varying the thickness of the sub-partition wall 7, the rigidity of the center of the cell height direction H, which is susceptible to load due to expansion, is improved. In the example of Figure 13, it can also be said that the amount of sub-partition wall 7 per unit length in the cell height direction H is greater in the center of the cell height direction H and less at the ends of the cell height direction H, depending on the thickness of the sub-partition wall 7.

[0048] Even when the central sub-partition wall 7 is thickened as shown in Figure 13, it is possible to improve the cooling performance of the central part compared to the edges. This is because the structure in which the first flow path 13 and the second flow path 14 are separated in the lid member 12, as explained in Figure 3, sufficiently improves the heat capacity of the central part and suppresses the temperature rise in the central part. As shown in Figure 11, it is also possible to increase the surface area of ​​the sub-partition wall 7 in the central part. Even for a linear sub-partition wall 7 like the one in Figure 10, it is possible to create a difference in thickness. Figures 7, 10, 11, and 13 only show the cooling chamber 6, but the other parts, the cell chamber 5, the first outer wall 2, the second outer wall 3, the third outer wall 10, and the fourth outer wall 11, are the same as in Figure 1.

[0049] As described in detail above, according to this embodiment, in a battery cell case 1 with a structure in which cell chambers 5 and cooling chambers 6 are arranged alternately, the cooling chamber 6 is divided into multiple cooling passages 8 by sub-partitions 7, and the arrangement of the sub-partitions 7 is made uneven. As a result, a battery cell case 1 is realized in which the rigidity of the central part of the battery cell is improved. Furthermore, temperature variations of the battery cell during use are also suppressed.

[0050] These embodiments and examples are merely illustrative and do not limit the disclosed technology in any way. Therefore, the disclosed technology can naturally be improved and modified in various ways without departing from its essence. For example, the type of battery element housed in the cell chamber 5 is not limited. The cell chamber 5 and cooling chamber 6 in a single battery cell case 1 are optional. In addition to the illustrated configuration, the lid member 12 may incorporate busbars or other structures for electrical conductivity. The air chamber 9 is not essential. [Explanation of Symbols]

[0051] 1 Battery cell case 17 Weir 2 1st outer wall 18 Inlet 3 2nd outer wall 19 Inlet 4 Main bulkhead 20 Supply channel 5 Cell chambers 21 Supply lines 6 Cooling room 22 Supply path 7 Sub-bulkhead 23 Supply channel 8 Cooling passage 31 Battery cell case 12 Lid component 41 Battery cell case 13 First channel 51 Battery cell case 14 Second channel 61 Battery cell case

Claims

1. A battery cell case for housing battery cells, The first exterior wall and the second exterior wall, A plurality of main partitions are provided connecting the first outer wall and the second outer wall, and alternately divide the region between the first outer wall and the second outer wall into a plurality of cell chambers for housing battery elements and a plurality of cooling chambers for passing a cooling medium, Each of the cooling chambers is provided with a number of secondary partitions connecting the main partitions adjacent to each of the cooling chambers, which divide the cooling chamber into a number of cooling passages. A battery cell case in which the amount of the sub-partition wall per unit length in the cell height direction, which is the direction connecting the first outer wall and the second outer wall in each cooling chamber, is greater in the central part in the cell height direction and less at the ends in the cell height direction.

2. A battery cell case according to claim 1, A battery cell case in which the amount of the sub-partition wall per unit length in the cell height direction in each cooling chamber is less at one end in the cell height direction than at the other end.

3. A battery cell case according to claim 1 or claim 2, A battery cell case in which the surface area of ​​the sub-partition per unit length in the cell height direction in each cooling chamber is larger in the central part in the cell height direction and smaller at the ends in the cell height direction.

4. A battery cell case according to claim 1 or claim 2, Each of the cooling chambers has a cooling medium supply member that supplies a cooling medium, The cooling medium supply member includes: A first flow path connected to the one of the cooling passages located closer to the first outer wall, A battery cell case in which a second flow path is formed separately for each of the aforementioned cooling passages, the one located closer to the second outer wall.

5. A battery cell case according to claim 1, A battery cell case in which the spacing between the sub-partitions in each of the cooling chambers is narrow in the center in the cell height direction and wide at the ends in the cell height direction.

6. A battery cell case according to claim 1, A battery cell case in which the thickness of the sub-partition wall in each of the cooling chambers is greater in the center in the cell height direction and smaller at the ends in the cell height direction.

7. A battery cell case according to claim 3, A battery cell case in which the surface area of ​​the sub-partition at the center in the cell height direction is larger than the surface area of ​​the sub-partition at the end in the cell height direction.

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