Separator member and battery pack

Abstract

To provide a separator member and a battery pack that improve the cooling efficiency of battery cells under normal conditions while suppressing heat transfer to adjacent battery cells in the event of an abnormality.SOLUTION: A separator member 30, which is disposed between adjacent battery cells 21 of a cell stack 20 in which a plurality of battery cells 21 are stacked, includes a heat insulating material 31 and a packaging film 32. The packaging film 32 includes an insulating material sealing portion 33 that seals the insulating material 31, and a heat transfer portion 34 that extends from the insulating material sealing portion 33 without sealing the insulating material 31. The insulating material 31 and the insulating material sealing portion 33 are disposed on the long side surface 23L that faces the adjacent battery cells 21, and the heat transfer portion 34 is disposed by folding it so as to follow at least one of the four surfaces perpendicular to the long side surface 23L, excluding the top surface 23U on which the cell terminals 21a are disposed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a separator member and a battery pack. [Background technology]

[0002] In recent years, efforts to realize a low-carbon or carbon-free society have become more active, and research and development into electrification technologies is being conducted in vehicles to reduce CO2 emissions and improve energy efficiency.

[0003] Batteries play an important role in electrification technology. Because batteries are heat-generating components, cooling control is performed to maintain the battery temperature within a desired temperature range from the standpoint of safety and preventing battery degradation.

[0004] Furthermore, in the event that one of the battery cells that make up the battery generates abnormal heat, a heat insulating material is placed between adjacent battery cells to prevent the heat from being transferred to the adjacent battery cells (for example, Patent Documents 1 to 5). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-056747 [Patent Document 2] International Publication No. 2019 / 187313 [Patent Document 3] International Publication No. 2019 / 031457 [Patent Document 4] Japanese Patent Application Laid-Open No. 2010-010460 [Patent Document 5] Japanese Patent Publication No. 2022-062288 Summary of the Invention [Problem to be solved by the invention]

[0006] In such a situation, there is a need for a technology that can improve the cooling efficiency of battery cells under normal conditions while suppressing heat transfer to adjacent battery cells when an abnormality occurs.

[0007] The present invention provides a separator member and a battery pack that improve the cooling efficiency of battery cells under normal conditions while suppressing heat transfer to adjacent battery cells when an abnormality occurs. [Means for solving the problem]

[0008] A first aspect of the present invention is A separator member disposed between adjacent battery cells in a cell stack in which a plurality of battery cells are stacked, each battery cell having a hexahedron shape and a cell terminal disposed on one surface of the battery cells, A heat insulating material and a packaging film are provided, The packaging film is a heat insulating material sealing portion that seals the heat insulating material; a heat transfer portion that does not seal the heat insulating material and extends from the heat insulating material sealing portion, the heat insulating material and the heat insulating material sealing portion are disposed on opposing surfaces facing the adjacent battery cells, The heat transfer portion is provided on one of four surfaces perpendicular to the opposing surface. The cell terminal is bent and arranged along three surfaces excluding the one surface on which the cell terminal is arranged, Of the three aspects mentioned above, the heat transfer section disposed on a cooling section facing surface facing the cooling section that cools the battery cells includes an area where the packaging film is single-layered, The heat transfer section, which is disposed on a surface different from the cooling section facing surface, has a double wrapping film. do. A second aspect of the present invention is A separator member disposed between adjacent battery cells in a cell stack in which a plurality of battery cells are stacked, each battery cell having a hexahedron shape and a cell terminal disposed on one surface of the battery cells, A heat insulating material and a packaging film are provided, The packaging film is a heat insulating material sealing portion that seals the heat insulating material; a heat transfer portion that does not seal the heat insulating material and extends from the heat insulating material sealing portion, the heat insulating material and the heat insulating material sealing portion are disposed on opposing surfaces facing the adjacent battery cells, The heat transfer portion is bent and arranged along three of the four surfaces perpendicular to the opposing surface, excluding the surface on which the cell terminal is arranged, The heat transfer portions arranged on the three surfaces each include an area where the packaging film is in a single layer. A third aspect of the present invention is A separator member disposed between adjacent battery cells in a cell stack in which a plurality of battery cells are stacked, each battery cell having a hexahedron shape and a cell terminal disposed on one surface of the battery cells, A heat insulating material and a packaging film are provided, The packaging film is a heat insulating material sealing portion that seals the heat insulating material; a heat transfer portion that does not seal the heat insulating material and extends from the heat insulating material sealing portion, the heat insulating material and the heat insulating material sealing portion are disposed on opposing surfaces facing the adjacent battery cells, The heat transfer portion is bent and arranged along three of the four surfaces perpendicular to the opposing surface, excluding the surface on which the cell terminal is arranged, The heat transfer portions disposed on the three surfaces have tapered or arc-shaped outer edges so as not to overlap the corners of the battery cells. A fourth aspect of the present invention is A separator member disposed between adjacent battery cells in a cell stack in which a plurality of battery cells are stacked, each battery cell having a hexahedron shape and a cell terminal disposed on one surface of the battery cells, A heat insulating material and a packaging film are provided, The packaging film is a heat insulating material sealing portion that seals the heat insulating material; a heat transfer portion that does not seal the heat insulating material and extends from the heat insulating material sealing portion, the heat insulating material and the heat insulating material sealing portion are disposed on opposing surfaces facing the adjacent battery cells, The heat transfer portion is bent and arranged along three of the four surfaces perpendicular to the opposing surface, excluding the surface on which the cell terminal is arranged, The heat transfer portions disposed on the three surfaces have notches formed in their outer edges so as not to overlap the corners of the battery cells.

[0009] In addition, the present invention 5 The aspect is A plurality of battery cells each having cell terminals arranged on one surface of a hexahedron; a separator member disposed between the battery cells; a housing portion that houses a cell stack in which the separator member is disposed between adjacent battery cells; a cooling unit that cools the battery cells; A battery pack comprising: The separator member is A heat insulating material and a packaging film are provided, The packaging film is a heat insulating material sealing portion that seals the heat insulating material; a heat transfer portion that does not seal the heat insulating material and extends from the heat insulating material sealing portion, the heat insulating material and the heat insulating material sealing portion are disposed on opposing surfaces facing the adjacent battery cells, The heat transfer portion is bent and arranged so as to follow between at least one of four surfaces orthogonal to the opposing surface, excluding the one surface on which the cell terminal is arranged, and an inner circumferential surface of the accommodating portion. 、 the heat transfer unit disposed on a cooling unit facing surface facing the cooling unit includes a region where the packaging film is single-layered, The heat transfer section, which is disposed on a surface different from the cooling section facing surface, has a double wrapping film. do. [Effects of the Invention]

[0010] According to the present invention, since a heat insulating material is disposed between adjacent battery cells in the stacking direction, even if one battery cell generates abnormal heat, heat transfer to the adjacent battery cell can be suppressed. On the other hand, since the battery cells generate heat and need to be cooled appropriately, a heat transfer part extending from the packaging film that seals the heat insulating material is disposed on at least one side of the battery cell, which can promote heat removal from the battery cell and improve cooling efficiency. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a partially cutaway bottom view of a battery pack 1 according to an embodiment of the present invention. [Figure 2] 1 is a perspective view of a cell stack 20 in which a plurality of battery cells 21 and separator members 30 are stacked, as viewed obliquely from above. [Figure 3] FIG. 2 is a perspective view of a battery cell 21 and a separator member 30 viewed obliquely from above. [Figure 4] FIG. 2 is a front view of the separator member 30. [Figure 5] 1 is a process diagram showing an example of a procedure for producing a separator member 30 by overlapping a heat insulating material 31 and a packaging film 32. FIG. [Figure 6] 10 is a process diagram showing another example of the procedure for producing a separator member 30 by overlapping a heat insulating material 31 and a packaging film 32. FIG. [Figure 7] 10 is a process diagram showing yet another example of the procedure for producing a separator member 30 by overlapping a heat insulating material 31 and a packaging film 32. FIG. [Figure 8] 10 is a process diagram showing an example of a procedure for stacking battery cells 21 and separator members 30 inside a battery housing portion 15. FIG. [Figure 9] FIG. 2 is a front view of a separator member 30 of a first modified example. [Figure 10] FIG. 10 is a front view of a separator member 30 of a second modified example. [Figure 11] FIG. 10 is a front view of a separator member 30 of a third modified example. [Figure 12] FIG. 10 is a front view of a separator member 30 of a fourth modified example. [Figure 13] FIG. 10 is a front view of a separator member 30 of a fifth modified example. [Figure 14] FIG. 10 is a front view of a separator member 30 of a sixth modified example. [Figure 15] FIG. 13 is a front view of a separator member 30 of a seventh modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] A battery pack and separator member according to one embodiment of the present invention will be described below with reference to the accompanying drawings. For simplicity and clarity, the stacking direction of the battery cells is defined as the left-right direction, and the direction perpendicular to the stacking direction and the up-down direction of the battery cells is defined as the front-rear direction. However, the present invention is not limited to these.

[0013] 1, the battery pack 1 is configured by mounting multiple cell stacks 20 inside a battery case 10 and covering it 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, 11R provided on both the left and right sides of the bottom plate 12, a front cross member 11F connecting the pair of side frames 11L, 11R, multiple central cross members 11M, and a rear cross member 11B.

[0014] The front cross member 11F forms the front wall of the battery case 10, and the rear cross member 11B forms the rear wall of the battery case 10. The central cross member 11M divides the interior of the battery case 10 into multiple battery storage sections 15. The battery storage sections 15 are arranged in a line in the front-to-rear direction, and each battery storage section 15 has a cell stack 20 disposed therein.

[0015] A water jacket 13 through which a refrigerant circulates is provided below the bottom plate 12, cooling the cell stack 20 placed on the bottom plate 12 from below. That is, the cell stack 20 is sandwiched between side walls 15S on both sides in the stacking direction and is housed in the battery housing section 15 while placed on the bottom plate 12. The side walls 15S may be any of the front cross member 11F, central cross member 11M, and rear cross member 11B, or may be a restraining member or the like provided separately from these cross members so as to fit along the cross members.

[0016] As shown in FIG. 2, the cell stack 20 is configured by stacking a plurality of rectangular battery cells 21 in the left-right direction, with separator members 30 provided between adjacent battery cells 21 in the stacking direction.

[0017] As shown in FIG. 3, the rectangular battery cell 21 is a hexahedron and has an upper surface 23U on which a pair of terminals 21a for outputting power from the battery cell 21 is arranged, a bottom surface 23B facing the bottom plate 12 of the battery case 10, a pair of long side surfaces 23L connecting the upper surface 23U and the bottom surface 23B and facing each other in the stacking direction, and a pair of short side surfaces 23S connecting the upper surface 23U and the bottom surface 23B and facing each other in the front-to-rear direction.

[0018] 3, the separator member 30 includes a heat insulating material 31 and packaging films 32A and 32B. The separator member 30 is formed by stacking the packaging film 32A, the heat insulating material 31, and the packaging film 32B in this order.

[0019] The heat insulating material 31 is made of a silica-based heat insulating material, and is formed to have approximately the same size as the opposing surfaces of adjacent battery cells 21, i.e., the long side surfaces 23L of the battery cells 21, and is placed between the adjacent battery cells 21. By placing the heat insulating material 31 between the adjacent battery cells 21, it is possible to suppress heat transfer to the adjacent battery cells 21 even if one battery cell 21 generates abnormally much heat.

[0020] 4, the packaging film 32 is made up of packaging films 32A and 32B disposed on both sides of the heat insulating material 31 so as to sandwich the heat insulating material 31 from both sides. The packaging films 32 (32A and 32B) are larger than the size of the heat insulating material 31 and have a heat insulating material sealing portion 33 and a heat transfer portion 34.

[0021] The heat insulating material sealing portion 33 is a part 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-rear direction, and holds the heat insulating material 31 from both sides. In Figure 4 and subsequent drawings (except Figure 8), the portion that overlaps with the heat insulating material 31 is shown by cross-hatching.

[0022] The heat transfer section 34 is a portion of the packaging film 32 other than the heat insulating material sealing section 33, and extends in the front-rear direction and downward from the heat insulating material sealing section 33. The heat insulating material sealing section 33 and the heat transfer section 34 are formed as an integrated packaging film 32.

[0023] In detail, the heat transfer section 34 comprises a forward heat transfer section 34F extending forward continuously from the insulation sealing section 33, a rearward heat transfer section 34B extending rearward continuously from the insulation sealing section 33, and a lower heat transfer section 34D extending downward continuously from the insulation sealing section 33.

[0024] The front heat transfer portion 34F and the rear heat transfer portion 34B have approximately the same size as the pair of short side surfaces 23S of the battery cell 21, and the lower heat transfer portion 34D is formed to be approximately the same size as the bottom surface 23B of the battery cell 21.

[0025] As shown in Fig. 3, when the battery cell 21 and the separator member 30 are assembled in the battery case 10, the front heat transfer portion 34F and the rear heat transfer portion 34B are folded and respectively abut against a pair of short side surfaces 23S of the battery cell 21, the lower heat transfer portion 34D is folded and abuts against the bottom surface 23B of the battery cell 21, and the heat insulating material sealing portion 33 abuts against the long side surface 23L of the battery cell 21. Note that in the example shown in Fig. 4, the heat transfer portion 34 includes the front heat transfer portion 34F, the rear heat transfer portion 34B, and the lower heat transfer portion 34D that extend from the heat insulating material sealing portion 33, but this is not limiting and at least one of the front heat transfer portion 34F, the rear heat transfer portion 34B, and the lower heat transfer portion 34D may be provided. Furthermore, the heat transfer portion 34 may also be provided with an upper heat transfer portion that abuts against the upper surface 23U on which the cell terminal 21a is arranged.

[0026] Such separator members 30 can be made by various procedures, which are described below. 5, a sheet of packaging film 32 having an area at least twice the area of ​​the heat insulating material 31 is prepared. Then, the heat insulating material 31 is placed on the center part of the packaging film 32 in the front-rear direction, with its upper end 31a aligned with the vertical center line CL of the packaging film 32.

[0027] Next, the packaging film 32 is folded along the vertical center line CL, and the insulating material 31 is sandwiched between the packaging film 32 on both sides to form the insulating material sealing portion 33. After that, the unnecessary lower corners of the packaging film 32 in the front-to-back direction are cut off to form the separator member 30 in which the front heat transfer portion 34F, rear heat transfer portion 34B, and lower heat transfer portion 34D extend from the insulating material sealing portion 33.

[0028] 6, another manufacturing procedure involves preparing two packaging films 32 (32A, 32B) larger than the area of ​​the insulating material 31, overlapping one packaging film 32A, the insulating material 31, and the other packaging film 32B in this order, sandwiching the insulating material 31 between the two packaging films 32A and 32B to form the insulating material sealing portion 33, and then laminating them together.Then, the upper end and the lower corners in the front-to-rear direction of the packaging film 32, which are unnecessary portions, are cut off to form the separator member 30.

[0029] 7, in another manufacturing procedure, a sheet of packaging film 32 having an area at least twice the area of ​​the thermal insulation material 31 is prepared, and four unnecessary corners are cut off. Next, the thermal insulation material 31 is placed in the front-to-rear center of the packaging film 32 while aligning the upper end 31a of the thermal insulation material 31 with the vertical center line CL of the packaging film 32. Next, the packaging film 32 is folded along the vertical center line CL, and the thermal insulation material 31 is sandwiched between the packaging films 32 to form the thermal insulation material sealing portion 33, and the two films are then bonded together.

[0030] Next, the procedure for producing the battery pack 1 will be described with reference to FIG. First, the heat insulating material sealing portion 33 of the separator member 30 in a flat plate-like state is overlapped and adhered to the long side surface 23L of the battery cell 21. Then, the battery cell 21 and separator member 30, with the heat insulating material 31 fixed to the long side surface 23L of the battery cell 21 via the packaging film 32, are inserted from the separator member 30 side into the battery storage section 15 of the battery case 10, which is surrounded on three sides by the side walls 15S and the bottom plate 12.

[0031] As the separator member 30 is inserted into the battery housing section 15, it comes into contact with the side wall 15S and the bottom plate 12 and is bent, so that the front heat transfer section 34F and the rear heat transfer section 34B are sandwiched between the side wall 15S and the short side surface 23S of the battery cell 21. The lower heat transfer section 34D is sandwiched between the bottom plate 12 and the bottom surface 23B of the battery cell 21, and is housed in the battery housing section 15. At this time, the heat insulating material 31 is naturally in contact with the long side surface 23L of the battery cell 21 via the packaging film 32.

[0032] The above-described operation is repeated to alternately arrange a plurality of separator members 30 and battery cells 21 and accommodate them in the battery housing section 15. As a result, the cell stack 20, in which separator members 30 are arranged between adjacent battery cells 21, is accommodated in the battery housing section 15, and the battery pack 1 is assembled. In the battery pack 1, heat insulating materials 31 are arranged between adjacent battery cells 21, so that even if one battery cell 21 generates abnormal heat, heat transfer to adjacent battery cells 21 is suppressed.

[0033] Furthermore, as described above, by sequentially accommodating multiple separator members 30 and battery cells 21 in the battery accommodating section 15, the front heat transfer section 34F and the rear heat transfer section 34B extending from the insulation sealing section 33 are sandwiched between the short side surface 23S of each battery cell 21 and the side wall 15S, and the lower heat transfer section 34D is sandwiched and positioned between the bottom surface 23B and the bottom plate 12.

[0034] Heat generated in the battery cells 21 as the battery pack 1 is charged and discharged is transferred to the bottom plate 12 via the lower heat transfer section 34D, and is then cooled by the water jacket 13. Heat generated in the battery cells 21 as the battery pack 1 is charged and discharged is transferred to the side wall 15S via the front heat transfer section 34F and the rear heat transfer section 34B. If a cooling mechanism is also provided on the side wall 15S, the cooling area can be further increased, allowing the battery cells 21 to be cooled more effectively. The cooling method is not limited to cooling with a refrigerant using the water jacket 13, and air cooling may also be used.

[0035] 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 when there is a single packaging film 32, and heat dissipation is improved.

[0036] The separator member 30 has both the heat insulating function of the heat insulating material 31 and the cooling function of the heat transfer section 34. Under normal circumstances, the heat transfer section 34 cools the battery cells 21, and when a battery cell 21 generates abnormal heat, the heat insulating material 31 can suppress heat transfer to adjacent battery cells 21. Furthermore, compared to when the heat insulating function and the cooling function are each configured as separate members, the number of parts, cost, and weight can be reduced, and loading efficiency is improved.

[0037] Next, modified examples of the separator member 30 will be described with reference to FIGS. 9, in the separator member 30 of the first modified example, the size of the heat insulating material 31 is formed to be slightly smaller than the long side surface 23L of the battery cell 21, and both sides of the heat insulating material 31 are sandwiched between packaging films 32A and 32B. This allows the heat insulating material 31 to be sealed more reliably by the heat insulating material sealing portion 33.

[0038] 10 , in the separator member 30 of the second modified example, four corners 31b of the heat insulating material 31 are rounded. 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.

[0039] 11, in the separator member 30 of the third modified example, the size of the lower heat transfer portion 34DB of the packaging film 32B arranged on one side of the thermal insulation material 31 is smaller than the lower heat transfer portion 34DA of the packaging film 32A arranged on the other side of the thermal insulation material 31. As a result, the front heat transfer portion 34F and the rear heat transfer portion 34B have a double layer of packaging film 32, but the lower heat transfer portion 34D has a double region (34DA+34DB) and a single region (34DA).

[0040] In the double-layered region of the lower heat transfer portion 34D, the heat dissipation property is improved because the cross-sectional area of ​​the packaging film 32 is large. In the single-layered region, the thermal resistance is reduced, improving the cooling property and allowing for efficient heat dissipation.

[0041] 12, in the separator member 30 of the fourth modified example, the front heat transfer portion 34FB and the rear heat transfer portion 34BB of the packaging film 32B arranged on one side of the thermal insulation material 31 are smaller than the front heat transfer portion 34FA and the rear heat transfer portion 34BA of the packaging film 32A arranged on the other side of the thermal insulation material 31. The effects of the single region and the double region are similar to those of the separator member 30 of the third modified example.

[0042] 13, in the separator member 30 of the fifth modification, the size of the packaging film 32B arranged on one side of the thermal insulation material 31 is smaller than the size of the packaging film 32A arranged on the other side of the thermal insulation material 31. As a result, the front heat transfer section 34F, the rear heat transfer section 34B, and the lower heat transfer section 34D of the packaging film 32 have double-layered regions and single-layered regions. The effects of the single-layered regions and double-layered regions are similar to those of the separator member 30 of the third modification. Furthermore, since there are fewer double-layered regions compared to the third and fourth modifications, it is possible to suppress a decrease in cooling efficiency due to wrinkles and air intrusion that may occur in the double-layered regions of the packaging film 32.

[0043] As shown in FIG. 14 , in the separator member 30 of the sixth modified example, the outer edge 34a of the heat transfer portion 34 (34F, 34B, 34D) is tapered. This prevents the heat transfer portions 34 from overlapping when the heat transfer portions 34 are folded along the bottom surface 23B and short side surface 23S of the battery cells 21 and accommodated in the battery accommodation portion 15, thereby suppressing damage to the packaging film 32 due to friction generated at the corners of the battery cells 21. Note that the tapered shape may be such that the entire outer edge 34a is tapered, as shown in (A), or that only the corners are tapered, as shown in (B). Furthermore, instead of being tapered, the corners of the outer edge 34a, as shown in (C), may be arc-shaped.

[0044] 15, the separator member 30 of the seventh modified example has a substantially semicircular cutout 35 formed in the outer edge 34a of the packaging film 32 that abuts the corners of the battery cells 21. This prevents the packaging film 32 from being damaged by friction generated at the corners of the battery cells 21 when the battery cells 21 are stacked while the packaging film 32 is folded. The semicircular shape may be an oval semicircular shape as shown in (A), a perfect semicircular shape as shown in (B), or a combination of a trapezoidal shape and a semicircular shape as shown in (C).

[0045] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. are possible as appropriate. For example, in the above embodiment, the heat transfer section 34 is exemplified as having a lower heat transfer section 34D that is bent and arranged along the bottom surface 23B, and a front heat transfer section 34F and a rear heat transfer section 34B that are bent and arranged along the short side surface 23S, but this is not limited to this, and it is sufficient that the heat transfer section 34 has at least one of the lower heat transfer section 34D, the front heat transfer section 34F, and the rear heat transfer section 34B. Furthermore, the water jacket 13 provided below the bottom plate 12 is used as an example of the cooling section, but this is not limiting, and the cooling section may be an air-cooling device that cools the short side surfaces 23S of the battery cells 21 with air.

[0046] This specification also describes at least the following: Note that the components in parentheses correspond to those in the above-described embodiment, but are not limited to these.

[0047] (1) A separator member (separator member 30) disposed between adjacent battery cells in a cell stack (cell stack 20) ​​in which a plurality of battery cells (battery cells 21) are stacked, each battery cell having a cell terminal (terminal 21 a) disposed on one surface (upper surface 23U) of a hexahedron, The package includes a heat insulating material (heat insulating material 31) and a packaging film (packaging film 32), The packaging film is a heat insulating material sealing portion (heat insulating material sealing portion 33) that seals the heat insulating material; a heat transfer portion (heat transfer portion 34) extending from the heat insulating material sealing portion without sealing the heat insulating material, the heat insulating material and the heat insulating material sealing portion are disposed on an opposing surface (long side surface 23L) that faces the adjacent battery cells, The heat transfer portion is bent and arranged so as to follow at least one surface (bottom surface 23B, short side surface 23S) of four surfaces (top surface 23U, bottom surface 23B, short side surface 23S) perpendicular to the opposing surface. Separator member.

[0048] According to (1), since a heat insulating material is disposed between adjacent battery cells in the stacking direction, even if one battery cell generates abnormal heat, heat transfer to the adjacent battery cell can be suppressed. On the other hand, since the battery cells generate heat and need to be cooled appropriately, a heat transfer part extending from the packaging film that seals the heat insulating material is disposed on at least one side of the battery cell, which can promote heat removal from the battery cell and improve cooling efficiency.

[0049] (2) The separator member according to (1), The heat transfer portion is bent and arranged along three surfaces (bottom surface 23B and short side surface 23S) of the four surfaces orthogonal to the opposing surfaces, excluding the surface on which the cell terminals are arranged, Of the three aspects mentioned above, The heat transfer section is disposed on the cooling section facing surface (bottom surface 23B) facing the cooling section (water jacket 13) that cools the battery cells, and includes an area where the packaging film is single-layered, The heat transfer unit arranged on a surface (short side surface 23S) different from the cooling unit facing surface has a double packaging film. Separator member.

[0050] According to (2), the heat transfer section is arranged on three sides of the battery cell, excluding the cell terminal arrangement surface, thereby further improving cooling efficiency. Furthermore, the heat transfer section arranged on the cooling section-facing surface that faces the cooling section that cools the battery cell includes an area where the packaging film is single-layered, thereby reducing thermal resistance and improving cooling efficiency via the cooling section-facing surface. Furthermore, the heat transfer section arranged on a surface other than the cooling section-facing surface has a double-layered packaging film, resulting in a large cross-sectional area and improved heat dissipation.

[0051] (3) The separator member according to (1), The heat transfer portion is bent and arranged along three surfaces (bottom surface 23B and short side surface 23S) of the four surfaces orthogonal to the opposing surfaces, excluding the surface on which the cell terminals are arranged, The heat transfer portions arranged on the three surfaces each include an area where the packaging film is single-layered. Separator member.

[0052] According to (3), it is possible to suppress a decrease in cooling efficiency due to wrinkles or air intrusion that may occur in the area where the packaging film is doubled.

[0053] (4) The separator member according to (1), The heat transfer portion is bent and arranged along three surfaces (bottom surface 23B and short side surface 23S) of the four surfaces orthogonal to the opposing surfaces, excluding the surface on which the cell terminals are arranged, The heat transfer parts arranged on the three surfaces have outer edges (outer edge parts 34a) that are tapered or arc-shaped so as not to overlap the corners of the battery cells. Separator member.

[0054] According to (4), damage to the packaging film caused by friction at the corners of the battery cells when the battery cells are stacked can be suppressed.

[0055] (5) The separator member according to (1), The heat transfer portion is bent and arranged along three surfaces (bottom surface 23B and short side surface 23S) of the four surfaces orthogonal to the opposing surfaces, excluding the surface on which the cell terminals are arranged, The heat transfer parts arranged on the three surfaces have notches (notches 35) formed on their outer edges so as not to overlap the corners of the battery cells. Separator member.

[0056] According to (5), damage to the packaging film caused by friction at the corners of the battery cells when folding the packaging film or stacking the battery cells can be prevented.

[0057] (6) A separator member according to any one of (1) to (5), The packaging film has two films sandwiching the heat insulating material, and the heat insulating material sealing portion is formed by overlapping the two films. Separator member.

[0058] According to (6), the heat insulating material can be properly sealed.

[0059] (7) A separator member according to any one of (1) to (5), The packaging film has a single film sandwiching the heat insulating material and being folded to form the heat insulating material sealing portion. Separator member.

[0060] According to (7), the heat insulating material can be properly sealed.

[0061] (8) A plurality of battery cells (battery cells 21) each having a cell terminal (terminal 21a) disposed on one surface (upper surface 23U) of a hexahedron; a separator member (separator member 30) disposed between the battery cells; a battery pack (battery pack 1) including: a storage section (battery storage section 15) that stores a cell stack (cell stack 20) ​​in which the separator member is disposed between adjacent battery cells; The separator member is The package includes a heat insulating material (heat insulating material 31) and a packaging film (packaging film 32), The packaging film is a heat insulating material sealing portion (heat insulating material sealing portion 33) that seals the heat insulating material; a heat transfer portion (heat transfer portion 34) extending from the heat insulating material sealing portion without sealing the heat insulating material, the heat insulating material and the heat insulating material sealing portion are disposed on an opposing surface (long side surface 23L) that faces the adjacent battery cells, The heat transfer portion is bent and arranged so as to fit between at least one of the four surfaces (top surface 23U, bottom surface 23B, short side surface 23S) perpendicular to the opposing surface, excluding the surface on which the cell terminal is arranged (bottom surface 23B, short side surface 23S), and the inner peripheral surface (side wall 15S) of the accommodating portion. Battery pack.

[0062] According to (8), since a heat insulating material is disposed between adjacent battery cells in the stacking direction, even if one battery cell generates abnormal heat, heat transfer to the adjacent battery cell can be suppressed. On the other hand, since the battery cells generate heat and need to be cooled appropriately, a heat transfer portion extending from the packaging film that seals the heat insulating material is held on at least one side of the battery cell between the inner circumferential surface of the housing portion and the battery cell, which promotes heat removal from the battery cell and improves cooling efficiency.

[0063] (9) The battery pack according to (8), a cooling unit (water jacket 13) that cools the battery cells; The heat transfer unit disposed on the cooling unit facing surface (bottom surface 23B) facing the cooling unit includes an area where the packaging film is single-layered, The heat transfer unit arranged on a surface (short side surface 23S) different from the cooling unit facing surface has a double packaging film. Battery pack.

[0064] According to (9), the battery cells can be appropriately cooled by the cooling unit. Furthermore, the heat transfer unit located on the cooling unit-facing surface includes an area where the packaging film is single-layered, thereby reducing thermal resistance and improving the cooling efficiency via the cooling unit-facing surface. Furthermore, the heat transfer unit located on a different surface from the cooling unit-facing surface has a double-layered packaging film, resulting in a large cross-sectional area and improved heat dissipation.

[0065] (10) The battery pack according to (8) or (9), The battery cells and the separator members are inserted into the housing portions along the stacking direction and arranged alternately. Battery pack.

[0066] According to (10), the packaging film can be folded while being guided into the storage section. [Explanation of symbols]

[0067] 1 battery pack 13 Water jacket (cooling section) 15 Battery compartment (compartment) 15S side wall (inner surface) 20 cell stack 21 Battery Cells 21a Cell terminal 23B Bottom surface (surface facing cooling section) 23L long side (opposite side) 23S Short side (side opposite to the cooling section) 23U top surface (the surface where the cell terminals are located) 30 Separator member 31 Insulation 32, 32A, 32B Packaging film 33 Insulation sealing part 34 Heat transfer section 34B Rear heat transfer section (heat transfer section) 34D Lower heat transfer section (heat transfer section) 34F Front heat transfer section (heat transfer section) 34a outer edge 35 Notch

Claims

1. A separator member disposed between adjacent battery cells in a cell stack in which a plurality of battery cells are stacked, each battery cell having a hexahedron shape and a cell terminal disposed on one surface of the battery cells, A heat insulating material and a packaging film are provided, The packaging film is a heat insulating material sealing portion that seals the heat insulating material; a heat transfer portion that does not seal the heat insulating material and extends from the heat insulating material sealing portion, the heat insulating material and the heat insulating material sealing portion are disposed on opposing surfaces facing the adjacent battery cells, The heat transfer portion is bent and arranged along three of the four surfaces perpendicular to the opposing surface, excluding the surface on which the cell terminal is arranged, Of the three aspects mentioned above, the heat transfer section disposed on a cooling section facing surface facing the cooling section that cools the battery cells includes an area where the packaging film is single-layered, The heat transfer unit disposed on a surface different from the cooling unit facing surface has a double packaging film. Separator member.

2. A separator member disposed between adjacent battery cells in a cell stack in which a plurality of battery cells are stacked, each battery cell having a hexahedron shape and a cell terminal disposed on one surface of the battery cells, A heat insulating material and a packaging film are provided, The packaging film is a heat insulating material sealing portion that seals the heat insulating material; a heat transfer portion that does not seal the heat insulating material and extends from the heat insulating material sealing portion, the heat insulating material and the heat insulating material sealing portion are disposed on opposing surfaces facing the adjacent battery cells, The heat transfer portion is bent and arranged along three of the four surfaces perpendicular to the opposing surface, excluding the surface on which the cell terminal is arranged, The heat transfer portions arranged on the three surfaces each include an area where the packaging film is single-layered. Separator member.

3. A separator member disposed between adjacent battery cells in a cell stack in which a plurality of battery cells are stacked, each battery cell having a hexahedron shape and a cell terminal disposed on one surface of the battery cells, A heat insulating material and a packaging film are provided, The packaging film is a heat insulating material sealing portion that seals the heat insulating material; a heat transfer portion that does not seal the heat insulating material and extends from the heat insulating material sealing portion, the heat insulating material and the heat insulating material sealing portion are disposed on opposing surfaces facing the adjacent battery cells, The heat transfer portion is bent and arranged along three of the four surfaces perpendicular to the opposing surface, excluding the surface on which the cell terminal is arranged, The heat transfer parts arranged on the three surfaces have tapered or arc-shaped outer edges so as not to overlap corners of the battery cells. Separator member.

4. A separator member disposed between adjacent battery cells in a cell stack in which a plurality of battery cells are stacked, each battery cell having a hexahedron shape and a cell terminal disposed on one surface of the battery cells, A heat insulating material and a packaging film are provided, The packaging film is a heat insulating material sealing portion that seals the heat insulating material; a heat transfer portion that does not seal the heat insulating material and extends from the heat insulating material sealing portion, the heat insulating material and the heat insulating material sealing portion are disposed on opposing surfaces facing the adjacent battery cells, The heat transfer portion is bent and arranged along three of the four surfaces perpendicular to the opposing surface, excluding the surface on which the cell terminal is arranged, The heat transfer parts arranged on the three surfaces have notches formed in their outer edges so as not to overlap corners of the battery cells. Separator member.

5. 5. The separator member according to claim 1, The packaging film has two films sandwiching the heat insulating material therebetween stacked together to form the heat insulating material sealing portion. Separator member.

6. 5. The separator member according to claim 1, The packaging film has a single film sandwiching the heat insulating material therebetween folded to form the heat insulating material sealing portion. Separator member.

7. A plurality of battery cells each having cell terminals arranged on one surface of a hexahedron; a separator member disposed between the battery cells; a housing portion that houses a cell stack in which the separator member is disposed between adjacent battery cells; a cooling unit that cools the battery cells, The separator member is A heat insulating material and a packaging film are provided, The packaging film is a heat insulating material sealing portion that seals the heat insulating material; a heat transfer portion that does not seal the heat insulating material and extends from the heat insulating material sealing portion, the heat insulating material and the heat insulating material sealing portion are disposed on opposing surfaces facing the adjacent battery cells, the heat transfer portion is bent and arranged so as to follow between at least one of four surfaces orthogonal to the opposing surface, excluding the surface on which the cell terminal is arranged, and an inner circumferential surface of the accommodating portion; the heat transfer unit disposed on a cooling unit facing surface facing the cooling unit includes a region where the packaging film is single-layered, The heat transfer unit disposed on a surface different from the cooling unit facing surface has a double packaging film. Battery pack.

8. The battery pack according to claim 7, The battery cells and the separator members are inserted into the housing portions along the stacking direction and arranged alternately. Battery pack.

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