Separating member and battery pack

Abstract

The present invention relates to a separator member and a battery pack which can suppress the transfer of heat to adjacent unit cells when an abnormality occurs and improve the cooling efficiency of the unit cells during normal time. A partition member (30) is disposed between adjacent single cells in a single cell stack (20) in which a plurality of single cells (21) are stacked, and is provided with a heat insulating material (31) and a packaging film (32). The packaging film (32) has: a heat-insulating material sealing section (33) for sealing the heat-insulating material; and a heat transfer section (34) that extends from the heat-insulating material sealing section (33) without sealing the heat-insulating material. The heat-insulating material (31) and the heat-insulating material sealing part (33) are disposed on a long side surface (23L) facing an adjacent single cell, and the heat transfer part (34) is disposed so as to be bent along at least one of four surfaces orthogonal to the long side surface (23L) except for an upper surface (23U) on which the single cell terminal (21a) is disposed.

Description

Technical Field

[0001] The present invention relates to a partition member and a battery pack. Background Art

[0002] In recent years, efforts to achieve a low-carbon or decarbonized society have been actively underway, and research and development related to electrification technologies are being conducted to reduce CO2 emissions and improve energy efficiency in vehicles.

[0003] Batteries play a crucial role in electrification technology. Batteries are heat-generating components, so for safety and to prevent battery degradation, battery cooling control is performed to maintain the battery temperature within a desired range.

[0004] Furthermore, when one of the cells constituting the battery generates abnormal heat, a heat insulating material is placed between the adjacent cells to suppress heat transfer to the adjacent cells (for example, Patent Documents 1 to 5).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2023-056747

[0008] Patent Document 2: International Publication No. 2019 / 187313

[0009] Patent Document 3: International Publication No. 2019 / 031457

[0010] Patent Document 4: Japanese Patent Application Laid-Open No. 2010-010460

[0011] Patent Document 5: Japanese Patent Application Laid-Open No. 2022-062288 Summary of the Invention

[0012] Problems to be solved by the invention

[0013] Under such circumstances, a technology is desired that suppresses heat transfer to adjacent cells when an abnormality occurs while improving the cooling efficiency of the cells during normal operation.

[0014] The present invention provides a partition member and a battery pack that suppress heat transfer to adjacent cells when an abnormality occurs and improve the cooling efficiency of the cells during normal operation.

[0015] Solutions to Problems

[0016] A first aspect of the present invention relates to a separator disposed between adjacent cells in a cell stack formed by stacking a plurality of cells, each cell having a cell terminal disposed on one face of a hexahedron, wherein:

[0017] The partition member includes a heat insulating material and a packaging film,

[0018] The packaging film has:

[0019] a heat insulating material sealing portion for sealing the heat insulating material; and

[0020] a heat transfer portion that does not seal the heat insulating material but extends from the heat insulating material sealing portion,

[0021] The heat insulating material and the heat insulating material sealing portion are arranged on a surface facing the adjacent single cell.

[0022] The heat transfer portion is arranged so as to be bent along at least one of four surfaces perpendicular to the facing surface.

[0023] In addition, a second aspect of the present invention relates to a battery pack comprising:

[0024] A plurality of single cells, each having a single cell terminal disposed on one face of a hexahedron;

[0025] a partition member disposed between the battery cells; and

[0026] The storage portion stores a cell stack having the separator disposed between adjacent cells.

[0027] The partition member includes a heat insulating material and a packaging film,

[0028] The packaging film has:

[0029] a heat insulating material sealing portion for sealing the heat insulating material; and

[0030] a heat transfer portion that does not seal the heat insulating material but extends from the heat insulating material sealing portion,

[0031] The heat insulating material and the heat insulating material sealing portion are arranged on a surface facing the adjacent single cell.

[0032] The heat transfer portion is arranged to be bent along an inner peripheral surface of the housing portion and at least one of four surfaces perpendicular to the facing surface, excluding the one surface on which the cell terminals are arranged.

[0033] Effects of the Invention

[0034] According to the present invention, thermal insulation material is placed between adjacent cells in the stacking direction. This prevents heat transfer to adjacent cells even if one cell overheats abnormally. Furthermore, cells generate heat and therefore require adequate cooling. The presence of a heat transfer portion extending from the heat-sealing insulation wrapping film on at least one surface of the cell facilitates heat removal from the cell, improving cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a partially cutaway bottom view of a battery pack 1 according to one embodiment of the present invention.

[0036] Figure 2 This is a perspective view of a cell stack 20 formed by stacking a plurality of cells 21 and separators 30 as viewed from obliquely above.

[0037] Figure 3 This is a perspective view of the cell 21 and the partition member 30 as viewed from obliquely above.

[0038] Figure 4 It is a front view of the partition member 30.

[0039] Figure 5 This is a process diagram showing an example of a step of laminating the heat insulating material 31 and the packaging film 32 to produce the partition member 30 .

[0040] Figure 6 This is a process diagram showing another example of the steps of laminating the heat insulating material 31 and the packaging film 32 to produce the partition member 30 .

[0041] Figure 7 This is a process diagram showing another example of the steps of laminating the heat insulating material 31 and the packaging film 32 to produce the partition member 30 .

[0042] Figure 8 This is a process diagram showing an example of a procedure for stacking the cells 21 and the spacer members 30 in the battery storage section 15 .

[0043] Figure 9 It is a front view of the partition member 30 of the first modification.

[0044] Figure 10 It is a front view of the partition member 30 of the second modification.

[0045] Figure 11 It is a front view of the partition member 30 of the third modified example.

[0046] Figure 12 It is a front view of the partition member 30 according to the fourth modification.

[0047] Figure 13It is a front view of the partition member 30 of the fifth modification.

[0048] Figure 14 It is a front view of the partition member 30 according to the sixth modification.

[0049] Figure 15 It is a front view of the partition member 30 of the seventh modification.

[0050] Description of Reference Numerals

[0051] 1 battery pack

[0052] 13 Water jacket (cooling part)

[0053] 15 Battery storage area (storage area)

[0054] 15S side wall (inner surface)

[0055] 20 Single cell stack

[0056] 21 single battery

[0057] 21a Single battery terminal

[0058] 23B bottom surface (facing the cooling unit)

[0059] 23L Long side (opposite side)

[0060] 23S Short side (the side facing the cooling unit)

[0061] 23U top surface (the side with battery terminals)

[0062] 30 Separator parts

[0063] 31. Insulation materials

[0064] 32, 32A, 32B packaging film

[0065] 33 Thermal insulation material sealing part

[0066] 34 Heat transfer unit

[0067] 34B rear heat transfer section (heat transfer section)

[0068] 34D Lower heat transfer section (heat transfer section)

[0069] 34F front heat transfer section (heat transfer section)

[0070] 34a outer edge

[0071] 35 incision. DETAILED DESCRIPTION

[0072] The following describes a battery pack and a separator according to one embodiment of the present invention with reference to the accompanying drawings. In this specification, for simplicity and clarity, the stacking direction of the cells is defined as the left-right direction, and the direction perpendicular to the stacking direction and the up-down direction is defined as the front-back direction, but this is not limiting.

[0073] like Figure 1 As shown, the battery pack 1 is constructed by placing a plurality of cell stacks 20 within a battery case 10 and covering the battery case 10 with a battery cover (not shown). The battery case 10 includes a rectangular bottom plate 12 on which the cell stacks 20 are placed, a pair of side frames 11L and 11R provided on the left and right sides of the bottom plate 12, a front cross member 11F connecting the pair of side frames 11L and 11R, a plurality of center cross members 11M, and a rear cross member 11B.

[0074] Front cross member 11F forms the front wall of battery case 10, and rear cross member 11B forms the rear wall of battery case 10. Center cross member 11M divides the interior of battery case 10 into a plurality of battery storage sections 15. Battery storage sections 15 are arranged side by side in the front-to-back direction, and a cell stack 20 is arranged in each battery storage section 15.

[0075] A water jacket 13 for circulating refrigerant is provided below the base plate 12, cooling the cell stack 20 placed on the base plate 12 from below. Specifically, the cell stack 20 is sandwiched between side walls 15S on both sides in the stacking direction, and the cell stack 20 is housed in the battery storage section 15 while placed on the base plate 12. The side walls 15S may be any of the front cross-members 11F, the center cross-member 11M, or the rear cross-member 11B, or may be a restraining member provided separately from these cross-members.

[0076] like Figure 2 As shown, the cell stack 20 is formed by stacking a plurality of rectangular cells 21 in the left-right direction, and a separator 30 is provided between the cells 21 adjacent to each other in the stacking direction.

[0077] like Figure 3 As shown, the square single cell 21 is a hexahedron having: an upper surface 23U, which is provided with a pair of terminals 21a for outputting power from the single cell 21; a bottom surface 23B, which is opposite to the bottom plate 12 of the battery case 10; a pair of long side surfaces 23L, which connect the upper surface 23U and the bottom surface 23B and are opposite in the stacking direction; and a pair of short side surfaces 23S, which connect the upper surface 23U and the bottom surface 23B and are opposite in the front-to-back direction.

[0078] like Figure 3As shown, the partition member 30 includes a heat insulating material 31 and packaging films 32A and 32B. The partition member 30 is formed by laminating the packaging film 32A, the heat insulating material 31, and the packaging film 32B in this order.

[0079] The thermal insulation material 31 is formed of a silica-based thermal insulation material and is formed to be approximately the same size as the opposing surfaces of adjacent cells 21, that is, the long sides 23L of the cells 21. It is arranged between adjacent cells 21. By placing the thermal insulation material 31 between adjacent cells 21, even if one cell 21 generates abnormal heat, heat transfer to the adjacent cell 21 can be suppressed.

[0080] like Figure 4 As shown, wrapping film 32 is composed of wrapping films 32A and 32B, which are placed on both sides of thermal insulation material 31 so as to sandwich thermal insulation material 31 from both sides. Wrapping films 32 (32A, 32B) are larger than thermal insulation material 31 and have a thermal insulation material sealing portion 33 and a heat transfer portion 34.

[0081] The heat insulating material sealing portion 33 is a portion of the packaging film 32 that is approximately the same size as the heat insulating material 31 and is provided approximately in the center of the packaging film 32 in the front-to-back direction to sandwich the heat insulating material 31 from both sides. Figure 4 The accompanying drawings (except Figure 8 ) in which the portion overlapping with the heat insulating material 31 is illustrated with cross hatching.

[0082] The heat transfer portion 34 is a portion of the packaging film 32 excluding the heat insulating material sealing portion 33 and extends in the front-rear direction and downward from the heat insulating material sealing portion 33. The heat insulating material sealing portion 33 and the heat transfer portion 34 are formed as an integrated packaging film 32.

[0083] In detail, the heat transfer part 34 includes: a front heat transfer part 34F, which extends continuously forward from the heat insulating material sealing part 33; a rear heat transfer part 34B, which extends continuously backward from the heat insulating material sealing part 33; and a lower heat transfer part 34D, which extends continuously downward from the heat insulating material sealing part 33.

[0084] The front heat transfer portion 34F and the rear heat transfer portion 34B have substantially the same size as the pair of short side surfaces 23S of the cell 21 , and the lower heat transfer portion 34D is formed substantially the same size as the bottom surface 23B of the cell 21 .

[0085] like Figure 3As shown, when the cell 21 and the partition member 30 are assembled in the battery case 10, the front heat transfer portion 34F and the rear heat transfer portion 34B are bent and respectively abut against the pair of short side surfaces 23S of the cell 21, the lower heat transfer portion 34D is bent and abuts against the bottom surface 23B of the cell 21, and the heat insulating material sealing portion 33 abuts against the long side surface 23L of the cell 21. Figure 4 In the illustrated example, the heat transfer portion 34 includes a front heat transfer portion 34F, a rear heat transfer portion 34B, and a lower heat transfer portion 34D extending from the heat insulating material sealing portion 33. However, the present invention is not limited to this embodiment. It is sufficient to provide at least one of the front heat transfer portion 34F, the rear heat transfer portion 34B, and the lower heat transfer portion 34D. Alternatively, the heat transfer portion 34 may include an upper heat transfer portion that contacts the upper surface 23U where the cell terminals 21a are located.

[0086] Such a partition member 30 can be produced through various steps described below.

[0087] First, if Figure 5 As shown, a wrapping film 32 having a size at least twice the area of ​​the heat insulating material 31 is prepared. Then, the heat insulating material 31 is placed on the front-to-back center portion of the wrapping film 32 while aligning the upper end 31a of the heat insulating material 31 with the vertical center line CL of the wrapping film 32.

[0088] Next, the packaging film 32 is bent at the center line CL in the vertical direction and the insulation material 31 is sandwiched from both sides by the packaging film 32 to form an insulation material sealing portion 33. Thereafter, the lower corners of the packaging film 32 in the front-to-back direction, which are unnecessary portions, are cut off to form a partition component 30 extending from the insulation material sealing portion 33 and having a front heat transfer portion 34F, a rear heat transfer portion 34B and a lower heat transfer portion 34D.

[0089] In addition, other production steps such as Figure 6 As shown, two wrapping films 32 (32A, 32B) larger than the area of ​​the thermal insulation material 31 are prepared. Wrapping film 32A, thermal insulation material 31, and wrapping film 32B are stacked in this order. The thermal insulation material 31 is sandwiched between the two wrapping films 32A and 32B to form a thermal insulation seal 33, which is then bonded together. The upper end and lower corners of the wrapping films 32, which are unnecessary, are then cut away to form the partition member 30.

[0090] Furthermore, other production steps such as Figure 7As shown, a sheet of wrapping film 32 is prepared, at least twice the area of ​​the insulating material 31, and the four corners, representing unnecessary portions, are cut off. Next, the insulating material 31 is placed on the front-to-back center of the wrapping film 32, while its upper end 31a is aligned with the vertical centerline CL of the wrapping film 32. The wrapping film 32 is then folded at the vertical centerline CL, sandwiching the insulating material 31 between the wrapping film 32 to form an insulating material seal 33, and then bonded.

[0091] Next, refer to Figure 8 The steps for producing the battery pack 1 will be described.

[0092] First, the heat insulating material sealing portion 33 of the partition member 30, which has been expanded into a flat plate, is overlapped with and bonded to the long side 23L of the cell 21. Then, the cell 21 and the partition member 30, with the heat insulating material 31 secured to the long side 23L of the cell 21 via the packaging film 32, are inserted from the partition member 30 side into the battery storage portion 15 of the battery case 10, which is surrounded on three sides by the side walls 15S and the bottom plate 12.

[0093] As the partition member 30 is inserted into the battery storage section 15, it abuts against the side walls 15S and the bottom plate 12, bending. The front heat transfer portion 34F and the rear heat transfer portion 34B are sandwiched between the side walls 15S and the short side surfaces 23S of the cells 21. Furthermore, the lower heat transfer portion 34D is sandwiched between the bottom plate 12 and the bottom surface 23B of the cells 21, and is housed within the battery storage section 15. At this point, the heat insulating material 31 naturally contacts the long side surfaces 23L of the cells 21 via the packaging film 32.

[0094] The above operation is repeated, and multiple separators 30 and cells 21 are alternately arranged and stored in the battery storage section 15. Thus, the cell stack 20, with separators 30 arranged between adjacent cells 21, is stored in the battery storage section 15, thereby assembling the battery pack 1. Because the battery pack 1 has the heat insulating material 31 arranged between adjacent cells 21, even if one cell 21 overheats abnormally, heat transfer to adjacent cells 21 is suppressed.

[0095] In addition, as described above, by sequentially accommodating a plurality of partition members 30 and cells 21 in the battery accommodating portion 15, the front heat transfer portion 34F and the rear heat transfer portion 34B extending from the heat insulating material sealing portion 33 are clamped between the short side surface 23S of each cell 21 and the side wall 15S, and the lower heat transfer portion 34D is clamped between the bottom surface 23B and the bottom plate 12.

[0096] Heat generated in the cells 21 during the charging and discharging of the battery pack 1 is transferred to the base plate 12 via the lower heat transfer section 34D, where it is then cooled by the water jacket 13. Furthermore, heat generated in the cells 21 during the charging and discharging of the battery pack 1 is transferred to the side walls 15S via the front heat transfer section 34F and the rear heat transfer section 34B. Furthermore, providing a cooling mechanism on the side walls 15S further increases the cooling area, enabling more efficient cooling of the cells 21. Furthermore, the cooling method is not limited to cooling with a refrigerant in the water jacket 13; air cooling is also possible.

[0097] Furthermore, since the packaging film 32 is formed by overlapping two packaging films 32A and 32B, the cross-sectional area for heat transfer is larger than that of a single packaging film 32, thereby improving heat dissipation.

[0098] The partition member 30 has two functions: a heat-insulating function provided by the heat-insulating material 31 and a cooling function provided by the heat-transferring portion 34. Under normal circumstances, the heat-transferring portion 34 cools the cell 21. When a cell 21 generates abnormal heat, the heat-insulating material 31 prevents heat transfer to adjacent cells 21. Furthermore, compared to using separate components for the heat-insulating and cooling functions, this reduces the number of components, costs, and weight, improving packaging efficiency.

[0099] Next, refer to Figures 9 to 15 Modifications of the partition member 30 will be described.

[0100] like Figure 9 As shown, the heat insulating material 31 of the partition member 30 of the first modification is slightly smaller than the long side 23L of the cell 21, and is sandwiched between wrapping films 32A and 32B on both sides. This allows the heat insulating material 31 to be more securely sealed by the heat insulating material seal 33.

[0101] like Figure 10 As shown, in the partition member 30 of the second modification, the four corners 31b of the heat insulating material 31 are chamfered. This prevents the corners 31b of the heat insulating material 31 from damaging the packaging film 32 when the heat insulating material 31 is sealed by the heat insulating material sealing portion 33.

[0102] like Figure 11 As shown, in the partition member 30 of the third modified example, the lower heat transfer portion 34DB of the wrap film 32B disposed on one side of the heat insulating material 31 is smaller than the lower heat transfer portion 34DA of the wrap film 32A disposed on the other side of the heat insulating material 31. As a result, the wrap film 32 of the front heat transfer portion 34F and the rear heat transfer portion 34B is double-layered, but the lower heat transfer portion 34D has a double-layer region (34DA + 34DB) and a single-layer region (34DA).

[0103] In the double-layered region of the lower heat transfer portion 34D, the cross-sectional area of ​​the packaging film 32 is large, thereby improving heat dissipation. In addition, in the single-layered region, the thermal resistance is low, thereby improving cooling performance and enabling efficient heat dissipation.

[0104] like Figure 12 As shown, in the partition member 30 of the fourth modified example, the front heat transfer portion 34FB and the rear heat transfer portion 34BB of the wrapping film 32B disposed on one side of the heat insulating material 31 are smaller than the front heat transfer portion 34FA and the rear heat transfer portion 34BA of the wrapping film 32A disposed on the other side of the heat insulating material 31. The effects of the single-layer region and the double-layer region are similar to those of the partition member 30 of the third modified example.

[0105] like Figure 13 As shown, in the partition member 30 of the fifth modified example, the size of the wrap film 32B disposed on one side of the heat insulating material 31 is smaller than the size of the wrap film 32A disposed on the other side of the heat insulating material 31. Consequently, the front heat transfer portion 34F, the rear heat transfer portion 34B, and the lower heat transfer portion 34D of the wrap film 32 contain both double-layered and single-layered regions. The effects of the single-layer and double-layered regions are similar to those of the partition member 30 of the third modified example. Furthermore, since the double-layered regions are fewer than in the third and fourth modified examples, wrinkles that might otherwise form in the double-layered regions of the wrap film 32 and a decrease in cooling efficiency due to air intrusion can be suppressed.

[0106] like Figure 14 As shown in FIG. 6 , the outer edge 34a of the heat transfer portion 34 ( 34F, 34B, 34D) of the partition member 30 in the sixth modified example is tapered. This prevents the heat transfer portion 34 from overlapping when the heat transfer portion 34 is bent along the bottom surface 23B and short side surface 23S of the cell 21 and stored in the battery storage compartment 15 , thus suppressing damage to the packaging film 32 caused by friction at the corners of the cell 21. The tapered shape can be applied to the entire outer edge 34a as shown in (A) or to only the corners as shown in (B). Alternatively, the corners of the outer edge 34a can be rounded, as shown in (C).

[0107] like Figure 15 As shown, the spacer member 30 of the seventh modification has a substantially semicircular notch 35 formed on the outer edge 34a of the wrapping film 32 that abuts the corners of the cells 21. This prevents damage to the wrapping film 32 caused by friction at the corners of the cells 21 when the wrapping film 32 is bent while stacking the cells 21. The semicircular shape can be an oblong semicircle as shown in (A), a true circle as shown in (B), or a combination of a trapezoidal and semicircular shapes as shown in (C).

[0108] As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, and it can make deformation|transformation, improvement, etc. as needed.

[0109] For example, in the above embodiment, the heat transfer portion 34 is illustrated as having a structure in which the lower heat transfer portion 34D is bent and arranged along the bottom surface 23B, and the front heat transfer portion 34F and the rear heat transfer portion 34B are bent and arranged along the short side surface 23S, but the present invention is not limited to this. It is sufficient as long as at least one of the lower heat transfer portion 34D, the front heat transfer portion 34F and the rear heat transfer portion 34B is provided.

[0110] In addition, the water jacket 13 provided below the bottom plate 12 is exemplified as the cooling unit, but the present invention is not limited thereto. The cooling unit may also be an air cooling device that cools the short side surfaces 23S of the cells 21 .

[0111] Furthermore, at least the following matters are described in this specification: Although corresponding components and the like in the above-mentioned embodiment are shown in brackets, the present invention is not limited thereto.

[0112] (1) A separator (separator 30) disposed between adjacent cells in a cell stack (cell stack 20) ​​formed by stacking a plurality of cells (cells 21), wherein the cell has a cell terminal (terminal 21a) disposed on one face (upper face 23U) of a hexahedron, wherein:

[0113] The partition member includes a heat insulating material (heat insulating material 31) and a packaging film (packaging film 32).

[0114] The packaging film has:

[0115] a heat insulating material sealing portion (heat insulating material sealing portion 33 ) for sealing the heat insulating material; and

[0116] a heat transfer portion (heat transfer portion 34 ) which does not seal the heat insulating material but extends from the heat insulating material sealing portion,

[0117] The heat insulating material and the heat insulating material sealing portion are arranged on the facing surface (long side surface 23L) facing the adjacent single cell.

[0118] The heat transfer portion is arranged so as to be bent along at least one surface (bottom surface 23B, short side surface 23S) among four surfaces (upper surface 23U, bottom surface 23B, short side surface 23S) perpendicular to the facing surface.

[0119] According to (1), since heat insulating material is disposed between adjacent cells in the stacking direction, even if one cell overheats abnormally, heat transfer to adjacent cells can be suppressed. On the other hand, since cells generate heat, they require appropriate cooling. Since a heat transfer portion extending from the packaging film of the sealing heat insulating material is disposed on at least one surface of the cell, heat dissipation from the cell can be promoted, thereby improving cooling efficiency.

[0120] (2) The partition member according to (1), wherein:

[0121] The heat transfer portion is bent and arranged along three surfaces (bottom surface 23B and short side surface 23S) of the four surfaces perpendicular to the facing surface, excluding the one surface on which the cell terminals are arranged.

[0122] The heat transfer portion disposed on the cooling portion facing surface (bottom surface 23B) facing the cooling portion (water jacket 13) for cooling the battery cells among the three surfaces includes a region where the packaging film is a single layer.

[0123] The packaging film of the heat transfer portion disposed on a surface (short side surface 23S) different from the surface facing the cooling portion among the three surfaces is double-layered.

[0124] According to (2), heat transfer sections are arranged on three surfaces of the cell, excluding the surface where the cell terminals are arranged, thereby further improving cooling efficiency. Furthermore, the heat transfer section arranged on the surface opposite the cooling section that cools the cell includes a region where the packaging film is a single layer, thereby reducing thermal resistance and improving cooling efficiency via the cooling section opposite surface. Furthermore, the heat transfer section arranged on a surface different from the cooling section opposite surface has a double layer of packaging film, thereby increasing its cross-sectional area and improving heat dissipation.

[0125] (3) The partition member according to (1), wherein:

[0126] The heat transfer portion is bent and arranged along three surfaces (bottom surface 23B and short side surface 23S) of the four surfaces perpendicular to the facing surface, excluding the one surface on which the cell terminals are arranged.

[0127] The heat transfer portions arranged on the three surfaces respectively include a region where the packaging film is a single layer.

[0128] According to (3), it is possible to suppress a decrease in cooling efficiency due to wrinkles that may occur in the double-layer region of the packaging film or the intrusion of air.

[0129] (4) The partition member according to (1), wherein:

[0130] The heat transfer portion is bent and arranged along three surfaces (bottom surface 23B and short side surface 23S) of the four surfaces perpendicular to the facing surface, excluding the one surface on which the cell terminals are arranged.

[0131] The outer edge portions (outer edge portions 34 a ) of the heat transfer portions disposed on the three surfaces are formed in a tapered or arcuate shape so as to prevent the heat transfer portions from overlapping the corners of the cells.

[0132] According to (4), it is possible to suppress damage to the packaging film due to friction generated at the corners of the cells when the cells are stacked.

[0133] (5) The partition member according to (1), wherein:

[0134] The heat transfer portion is bent and arranged along three surfaces (bottom surface 23B and short side surface 23S) of the four surfaces perpendicular to the facing surface, excluding the one surface on which the cell terminals are arranged.

[0135] The heat transfer parts arranged on the three surfaces have cutouts (cutouts 35 ) formed at outer edges thereof to prevent the heat transfer parts from overlapping the corners of the cells.

[0136] According to (5), it is possible to suppress the breakage of the packaging film due to friction generated at the corners of the cells when the packaging film is folded or when the cells are stacked.

[0137] (6) The partition member according to any one of (1) to (5), wherein

[0138] The packaging film is formed by overlapping two films sandwiching the thermal insulation material to form the thermal insulation material sealing portion.

[0139] According to (6), the heat insulating material can be properly sealed.

[0140] (7) The partition member according to any one of (1) to (5), wherein

[0141] The packaging film is formed by folding a single film sandwiching the thermal insulation material to form the thermal insulation material sealing portion.

[0142] According to (7), the heat insulating material can be properly sealed.

[0143] (8) A battery pack (battery pack 1) comprising:

[0144] A plurality of cells (cells 21 ) each having a cell terminal (terminal 21 a ) disposed on one face (upper face 23U) of a hexahedron;

[0145] a partition member (partition member 30 ) disposed between the battery cells; and

[0146] The storage portion (battery storage portion 15 ) stores a cell stack (cell stack 20 ) in which the separator is arranged between adjacent cells.

[0147] The partition member includes a heat insulating material (heat insulating material 31) and a packaging film (packaging film 32).

[0148] The packaging film has:

[0149] a heat insulating material sealing portion (heat insulating material sealing portion 33 ) for sealing the heat insulating material; and

[0150] a heat transfer portion (heat transfer portion 34 ) that is not sealed with the heat insulating material but extends from the heat insulating material sealing portion,

[0151] The heat insulating material and the heat insulating material sealing portion are arranged on the facing surface (long side surface 23L) facing the adjacent single cell.

[0152] The heat transfer portion is bent and arranged along at least one surface (bottom surface 23B, short side surface 23S) other than the one surface on which the cell terminals are arranged, of the four surfaces (upper surface 23U, bottom surface 23B, short side surface 23S) perpendicular to the opposing surface, and the inner peripheral surface (side wall 15S) of the storage portion.

[0153] According to (8), since heat insulating material is disposed between adjacent cells in the stacking direction, even if one cell generates abnormal heat, heat transfer to the adjacent cells can be suppressed. On the other hand, since the cells generate heat, they need to be properly cooled. Since the heat transfer portion extending from the packaging film of the sealing heat insulating material on at least one side of the cell is maintained between the inner peripheral surface of the storage portion and the cell, heat dissipation from the cell can be promoted, thereby improving cooling efficiency.

[0154] (9) The battery pack according to (8), wherein:

[0155] The battery pack includes a cooling unit (water jacket 13) for cooling the battery cells.

[0156] The heat transfer portion disposed on the cooling portion facing surface (bottom surface 23B) facing the cooling portion includes a region where the packaging film is a single layer.

[0157] The packaging film of the heat transfer portion disposed on a surface different from the surface facing the cooling portion (short side surface 23S) is double-layered.

[0158] According to (9), the cooling unit can be used to appropriately cool the single cell. Furthermore, the heat transfer unit disposed on the surface facing the cooling unit includes a region where the packaging film is a single layer, thereby reducing thermal resistance and improving cooling efficiency via the surface facing the cooling unit. Furthermore, the heat transfer unit disposed on a surface different from the surface facing the cooling unit has a double layer of packaging film, thereby increasing the cross-sectional area and improving heat dissipation.

[0159] (10) The battery pack according to (8) or (9), wherein:

[0160] The single cells and the spacers are inserted into the housing portion along a stacking direction and are alternately arranged.

[0161] According to (10), the packaging film can be bent while being guided toward the storage portion.

Claims

1. A separator disposed between adjacent cells in a cell stack formed by stacking a plurality of cells, wherein the cells have cell terminals disposed on one face of a hexahedron, wherein: The partition member includes a heat insulating material and a packaging film, The packaging film has: a heat insulating material sealing portion for sealing the heat insulating material; and a heat transfer portion that does not seal the heat insulating material but extends from the heat insulating material sealing portion, The heat insulating material and the heat insulating material sealing portion are arranged on a surface facing the adjacent single cell. The heat transfer portion is arranged so as to be bent along at least one of four surfaces perpendicular to the facing surface.

2. The partition member according to claim 1, wherein The heat transfer portion is arranged so as to be bent along three of the four surfaces perpendicular to the facing surface, excluding the one surface on which the cell terminals are arranged. The heat transfer portion disposed on a cooling portion-opposing surface of the three surfaces that is opposed to a cooling portion for cooling the battery cells includes a region where the packaging film is a single layer. The packaging film of the heat transfer portion disposed on a surface other than the surface facing the cooling portion among the three surfaces is double-layered.

3. The partition member according to claim 1, wherein The heat transfer portion is arranged to be bent along three of the four surfaces perpendicular to the facing surface, excluding the one surface on which the cell terminals are arranged. The heat transfer portions arranged on the three surfaces respectively include a region where the packaging film is a single layer.

4. The partition member according to claim 1, wherein The heat transfer portion is arranged to be bent along three of the four surfaces perpendicular to the facing surface, excluding the one surface on which the cell terminals are arranged. The outer edge portions of the heat transfer portions disposed on the three surfaces are formed in a tapered or arc-shaped shape so as to prevent the heat transfer portions from overlapping with corners of the single cells.

5. The partition member according to claim 1, wherein The heat transfer portion is arranged so as to be bent along three of the four surfaces perpendicular to the facing surface, excluding the one surface on which the cell terminals are arranged. The heat transfer parts arranged on the three surfaces have cutouts formed at outer edges to prevent the heat transfer parts from overlapping corners of the battery cells.

6. The partition member according to any one of claims 1 to 5, wherein The packaging film is formed by overlapping two films sandwiching the thermal insulation material to form the thermal insulation material sealing portion.

7. The partition member according to any one of claims 1 to 5, wherein The packaging film is formed by folding a single film sandwiching the thermal insulation material to form the thermal insulation material sealing portion.

8. A battery pack comprising: A plurality of single cells, each having a single cell terminal disposed on one face of a hexahedron; a partition member disposed between the battery cells; and The storage portion stores a cell stack having the separator disposed between adjacent cells. The partition member includes a heat insulating material and a packaging film, The packaging film has: a heat insulating material sealing portion for sealing the heat insulating material; and a heat transfer portion that does not seal the heat insulating material but extends from the heat insulating material sealing portion, The heat insulating material and the heat insulating material sealing portion are arranged on a surface facing the adjacent single cell. The heat transfer portion is arranged to be bent along an inner peripheral surface of the housing portion and at least one of four surfaces perpendicular to the facing surface, excluding the one surface on which the cell terminals are arranged.

9. The battery pack according to claim 8, wherein: The battery pack includes a cooling unit for cooling the battery cells. The heat transfer portion disposed on the cooling portion-opposing surface facing the cooling portion includes a region where the packaging film is a single layer. The packaging film of the heat transfer portion disposed on a surface different from the surface facing the cooling portion is double-layered.

10. The battery pack according to claim 8 or 9, wherein: The single cells and the spacer members are inserted into the housing portion along a stacking direction and are alternately arranged.

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