JP7763886B2 - Separator member and battery pack - Google Patents

Description

The present invention relates to a separator member and a battery pack.

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.

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

In addition, if one of the battery cells that make up the battery generates abnormal heat, heat insulation material is placed between adjacent battery cells to prevent the heat from being transferred to adjacent battery cells (for example, Patent Documents 1 to 5).

Japanese Patent Application Laid-Open No. 2023-056747 International Publication No. 2019/187313 International Publication No. 2019/031457 JP 2010-010460 A Japanese Patent Application Laid-Open No. 2022-062288

In these circumstances, there was a need for technology that could improve the cooling efficiency of battery cells under normal conditions while suppressing heat transfer to adjacent battery cells in the event of an abnormality.

The present invention provides a separator member and battery pack that improves the cooling efficiency of battery cells under normal conditions while suppressing heat transfer to adjacent battery cells in the event of an abnormality.

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 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 section disposed on a surface different from the cooling section facing surface has a double wrapping film .
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.

Further, a fifth aspect of the present invention 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 ,
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 section disposed on a surface different from the cooling section facing surface has a double wrapping film .

According to the present invention, heat insulating material is placed between adjacent battery cells in the stacking direction, so even if one battery cell generates abnormal heat, heat transfer to adjacent battery cells can be suppressed. On the other hand, since the battery cells generate heat, they need to be properly cooled. However, a heat transfer section extending from the packaging film that seals the heat insulating material is placed on at least one side of the battery cell, which promotes heat removal from the battery cell and improves cooling efficiency.

1 is a partially cutaway bottom view of a battery pack 1 according to an embodiment of the present invention. FIG. 2 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. FIG. 2 is a perspective view of the battery cell 21 and the separator member 30 as seen obliquely from above. FIG. 2 is a front view of the separator member 30. 10 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. 10 is a process diagram showing another example of a procedure for producing a separator member 30 by overlapping a heat insulating material 31 and a packaging film 32. FIG. 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. 10A to 10C are process diagrams showing an example of a procedure for stacking battery cells 21 and separator members 30 in a battery housing portion 15. FIG. 10 is a front view of a separator member 30 according to a first modified example. FIG. 10 is a front view of a separator member 30 according to a second modified example. FIG. 10 is a front view of a separator member 30 according to a third modified example. FIG. 10 is a front view of a separator member 30 according to a fourth modified example. FIG. 10 is a front view of a separator member 30 according to a fifth modified example. FIG. 13 is a front view of a separator member 30 according to a sixth modified example. FIG. 13 is a front view of a separator member 30 according to a seventh modified example.

A battery pack and separator member according to one embodiment of the present invention will be described below with reference to the accompanying drawings. Note that, for simplicity and clarity of explanation, 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-to-rear direction, but this is not intended to be limiting.

As shown in FIG. 1, the battery pack 1 is constructed 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.

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 compartments 15. The battery storage compartments 15 are arranged in a row in the fore-and-aft direction, and each battery storage compartment 15 contains a cell stack 20.

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 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, or rear cross member 11B, or may be a restraining member or the like provided separately from these cross members to fit along the cross members.

As shown in Figure 2, the cell stack 20 is composed of multiple rectangular battery cells 21 stacked in the left-right direction, with separator members 30 provided between adjacent battery cells 21 in the stacking direction.

As shown in Figure 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.

As shown in FIG. 3, the separator member 30 includes an insulating material 31 and packaging films 32A and 32B. The separator member 30 is formed by stacking the packaging film 32A, the insulating material 31, and the packaging film 32B in this order.

The insulating material 31 is made of a silica-based insulating material and is formed to be 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 insulating material 31 between adjacent battery cells 21, heat transfer to adjacent battery cells 21 can be suppressed even if one battery cell 21 generates abnormally much heat.

As shown in Figure 4, the packaging film 32 consists of packaging films 32A and 32B arranged on both sides of the insulating material 31 so as to sandwich the insulating material 31 from both sides. The packaging films 32 (32A and 32B) are larger than the insulating material 31 and have an insulating material sealing portion 33 and a heat transfer portion 34.

The insulation sealing portion 33 is part of the packaging film 32 that is approximately the same size as the insulation 31, is located approximately in the center of the packaging film 32 in the front-to-rear direction, and holds the insulation 31 from both sides. In Figures 4 and subsequent drawings (except Figure 8), the portion that overlaps with the insulation 31 is shown cross-hatched.

The heat transfer section 34 is the portion of the packaging film 32 other than the insulating material sealing section 33, and extends forward and backward and downward from the insulating material sealing section 33. The insulating material sealing section 33 and the heat transfer section 34 are formed as an integrated part of the packaging film 32.

In detail, the heat transfer section 34 comprises a forward heat transfer section 34F extending forward from the insulating material sealing section 33, a rearward heat transfer section 34B extending rearward from the insulating material sealing section 33, and a lower heat transfer section 34D extending downward from the insulating material sealing section 33.

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

As shown in FIG. 3 , when the battery cell 21 and separator member 30 are assembled within the battery case 10, the front heat transfer portion 34F and the rear heat transfer portion 34B are folded to abut against a pair of short side surfaces 23S of the battery cell 21, the lower heat transfer portion 34D is folded to abut 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 extending from the heat insulating material sealing portion 33. However, this is not limited to this, and it is sufficient that at least one of the front heat transfer portion 34F, the rear heat transfer portion 34B, and the lower heat transfer portion 34D is provided. The heat transfer portion 34 may also include an upper heat transfer portion that abuts against the upper surface 23U on which the cell terminal 21a is located.

Such a separator member 30 can be produced 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 of the packaging film 32 in the front-to-rear direction, with its upper end 31a aligned with the vertical center line CL of the packaging film 32.

Next, the packaging film 32 is folded along the vertical centerline CL, and the insulating material 31 is sandwiched between the packaging film 32 to form the insulating material sealing section 33. After that, the unnecessary lower corners of the packaging film 32 in the front-to-rear direction are cut off, leaving the separator member 30 with the front heat transfer section 34F, rear heat transfer section 34B, and lower heat transfer section 34D extending from the insulating material sealing section 33.

Another manufacturing procedure, as shown in Figure 6, involves preparing two packaging films 32 (32A, 32B) that are 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 that order, sandwiching the insulating material 31 between the two packaging films 32A and 32B to form the insulating material sealing portion 33 and bonding them together. Then, the unnecessary upper end and lower front-to-rear corners of the packaging film 32 are cut off to form the separator member 30.

Another manufacturing procedure, as shown in Figure 7, involves preparing a sheet of packaging film 32 that is at least twice the area of the insulating material 31, and cutting off the four unnecessary corners. Next, the insulating material 31 is placed in the front-to-back center of the packaging film 32, aligning the upper end 31a of the insulating 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 insulating material 31 is sandwiched between the packaging films 32 to form the insulating material sealing portion 33, and then the two films are bonded together.

Next, the procedure for producing the battery pack 1 will be described with reference to FIG.
First, the insulating material sealing portion 33 of the separator member 30 in a flat, unfolded state is superimposed on and adhered to the long side surface 23L of the battery cell 21. Then, the battery cell 21 and separator member 30, with the 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.

As the separator member 30 is inserted into the battery housing section 15, it comes into contact with the side wall 15S and bottom plate 12 and is bent, with the front heat transfer section 34F and rear heat transfer section 34B being 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. Naturally, at this time, the insulating material 31 is in contact with the long side surface 23L of the battery cell 21 via the packaging film 32.

The above operation is repeated to alternately arrange multiple 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. Because the battery pack 1 has insulating material 31 arranged between adjacent battery cells 21, heat transfer to adjacent battery cells 21 is suppressed even if one battery cell 21 generates abnormally much heat.

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 rear heat transfer section 34B extending from the heat insulating material 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.

Heat generated in the battery cells 21 during charging and discharging of the battery pack 1 is transferred to the bottom plate 12 via the lower heat transfer section 34D and then cooled by the water jacket 13. Heat generated in the battery cells 21 during charging and discharging of the battery pack 1 is transferred to the side wall 15S via the front heat transfer section 34F and 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 via the water jacket 13, and air cooling can also be used.

In addition, since the packaging film 32 is formed by overlapping two sheets of packaging film 32A and 32B, the cross-sectional area for heat transfer is larger than when there is only one sheet of packaging film 32, improving heat dissipation.

The separator member 30 has both the insulating function of the 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 insulating material 31 suppresses heat transfer to adjacent battery cells 21. Furthermore, compared to when the insulating and cooling functions are each provided by separate components, the number of parts, cost, and weight can be reduced, improving loading efficiency.

Next, modified examples of the separator member 30 will be described with reference to FIGS.
9, in the separator member 30 of the first modification, the size of the heat insulating material 31 is formed 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.

As shown in Figure 10, the separator member 30 of the second modified example has four corners 31b of the heat insulating material 31 that 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.

As shown in FIG. 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 insulating material 31 is smaller than the lower heat transfer portion 34DA of the packaging film 32A arranged on the other side of the insulating 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).

In the double-layered region of the lower heat transfer section 34D, the cross-sectional area of the packaging film 32 is large, improving heat dissipation. In the single-layered region, reduced thermal resistance improves cooling performance, allowing for efficient heat dissipation.

As shown in FIG. 12, in the separator member 30 of the fourth modified example, the front heat transfer section 34FB and rear heat transfer section 34BB of the packaging film 32B arranged on one side of the insulating material 31 are smaller than the front heat transfer section 34FA and rear heat transfer section 34BA of the packaging film 32A arranged on the other side of the insulating material 31. The effects of the single and double regions are similar to those of the separator member 30 of the third modified example.

As shown in FIG. 13, in the separator member 30 of the fifth modified example, the size of the packaging film 32B arranged on one side of the insulating material 31 is smaller than the size of the packaging film 32A arranged on the other side of the insulating material 31. As a result, the front heat transfer section 34F, rear heat transfer section 34B, and lower heat transfer section 34D of the packaging film 32 have double-layered and single-layered regions. The effects of the single-layered and double-layered regions are similar to those of the separator member 30 of the third modified example. Furthermore, because there are fewer double-layered regions compared to the third and fourth modified examples, 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.

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 cell 21 and stored in the battery storage section 15, thereby reducing damage to the packaging film 32 due to friction generated at the corners of the battery cell 21. Note that the tapered shape may be such that the entire outer edge 34a shown in (A) is tapered, or that only the corners shown in (B) are tapered. Alternatively, the corners of the outer edge 34a shown in (C) may be arc-shaped.

As shown in Figure 15, the separator member 30 of the seventh modified example has a substantially semicircular cutout 35 provided 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).

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 comprising 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 if the heat transfer section 34 comprises 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.

This specification also describes at least the following items. Note that the elements in parentheses correspond to those in the above-mentioned embodiments, but are not limited to these.

(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 packaging device 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 cell,
The heat transfer portion is bent and arranged along 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.

According to (1), since heat insulating material is placed between adjacent battery cells in the stacking direction, even if one battery cell generates abnormal heat, heat transfer to adjacent battery cells can be suppressed. On the other hand, since the battery cells generate heat, they need to be properly cooled. However, since a heat transfer section extending from the packaging film that seals the heat insulating material is placed on at least one side of the battery cell, heat removal from the battery cell can be promoted, improving cooling efficiency.

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

According to (2), heat transfer sections are 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 layer of packaging film, resulting in a large cross-sectional area and improved heat dissipation.

(3) The separator member according to (1),
The heat transfer portion is bent and arranged along three surfaces (bottom surface 23B, short side surface 23S) of the four surfaces perpendicular 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.

(3) This makes it possible to prevent a decrease in cooling efficiency due to wrinkles and air intrusion that can occur in areas where the packaging film is doubled.

(4) The separator member according to (1),
The heat transfer portion is bent and arranged along three surfaces (bottom surface 23B, short side surface 23S) of the four surfaces perpendicular to the opposing surfaces, excluding the surface on which the cell terminals are arranged,
The heat transfer portions disposed on the three surfaces have outer edge portions (outer edge portions 34 a) formed in a tapered or arc shape so as not to overlap corners of the battery cells.
Separator member.

(4) This prevents damage to the packaging film caused by friction at the corners of the battery cells when they are stacked.

(5) The separator member according to (1),
The heat transfer portion is bent and arranged along three surfaces (bottom surface 23B, short side surface 23S) of the four surfaces perpendicular 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 in their outer edges so as not to overlap corners of the battery cells.
Separator member.

(5) According to this feature, 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.

(6) The separator member according to any one of (1) to (5),
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) allows the insulation material to be properly sealed.

(7) The separator member according to any one of (1) to (5),
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) allows the insulation material to be properly sealed.

(8) A plurality of battery cells (battery cells 21) each having a cell terminal (terminal 21 a) disposed on one surface (upper surface 23U) of a hexahedron;
a separator member (separator member 30) disposed between the battery cells;
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 packaging device 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 cell,
The heat transfer portion is bent and arranged so as to follow the inner circumferential surface (side wall 15S) of the accommodating portion and 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).
Battery pack.

According to (8), since heat insulating material is placed between adjacent battery cells in the stacking direction, even if one battery cell generates abnormal heat, heat transfer to adjacent battery cells can be suppressed. Meanwhile, since the battery cells generate heat, they need to be properly cooled. However, on at least one side of the battery cell, a heat transfer section extending from the packaging film that seals the heat insulating material is held between the inner surface of the housing section and the battery cell, which promotes heat removal from the battery cell and improves cooling efficiency.

(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 a region where the packaging film is single-layered,
The heat transfer unit disposed on a surface (short side surface 23S) different from the cooling unit facing surface has a double packaging film.
Battery pack.

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

(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.

According to (10), the packaging film can be folded while being guided into the storage section.

1 Battery pack 13 Water jacket (cooling section)
15 Battery storage section (storage section)
15S side wall (inner peripheral surface)
20 Cell stack 21 Battery cell 21a Cell terminal 23B Bottom surface (cooling portion facing surface)
23L long side (opposite side)
23S Short side (side different from the cooling section facing side)
23U Top surface (the surface where the cell terminals are located)
30 Separator member 31 Heat insulating material 32, 32A, 32B Packaging film 33 Heat insulating material sealing portion 34 Heat transfer portion 34B Rear heat transfer portion (heat transfer portion)
34D Lower heat transfer section (heat transfer section)
34F Front heat transfer section (heat transfer section)
34a Outer edge portion 35 Notch

Claims (8)

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. 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. 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. 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. 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. 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. 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. 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.