Battery pack and method for manufacturing same

Abstract

The invention provides a battery pack and a method for manufacturing the same, wherein the mounting density of battery cells can be increased, and cooling, pressing and fixing of the battery cells can be performed. A battery pack (1) includes a battery case (10), battery cells (20), and a refrigerant jacket (30), in which the refrigerant jacket (30) includes two plasticized thin plates (31, 32) that are surface-bonded to each other, a refrigerant inlet (33) as a gap portion, a refrigerant passage (34), and a refrigerant outlet (35), and the battery cells (20) and the refrigerant jacket (30) are arranged alternately in surface contact within the battery case (10). A non-compressed fluid having a predetermined pressure flows into a refrigerant passage (34) of the refrigerant jacket (30), and the refrigerant jacket (30) is expanded by plastic deformation, thereby sandwiching and fixing the battery cell and the refrigerant jacket between the two end plates (11, 12).

Description

Technical Field

[0001] The present invention relates to a battery pack for BEV (battery electric vehicle) and a method for manufacturing the same. Background Art

[0002] The battery cells used in the battery pack for battery electric vehicles (BEV) need to be loaded with pressure applied by an arbitrary load. Therefore, in most battery packs at present, multiple cells are bundled into a bundle to form a tightly bound battery module, and multiple modules are loaded (for example, refer to Patent Document 1). In addition, the battery cells need to be temperature managed for performance. At present, in order to cope with the heat generated during charging and discharging, a water jacket for cooling (heating as needed) is arranged under the module mounting part, and temperature management is performed from the bottom surface of the battery cell.

[0003] In such a module-to-pack (Module To Pack = MTP) battery pack, the amount of battery cells that can be loaded is limited due to the space used by the structure of each battery module. In order to cope with the increase in the number of battery cells to be loaded in response to the requirements of battery capacity expansion or high voltage, a cell-to-pack (Cell To Pack = CTP) method in which battery cells are directly loaded onto a battery pack has also been studied (for example, see Patent Documents 2 and 3).

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2013-16467

[0007] [Patent Document 2] Japanese Patent Publication No. 2023-502274

[0008] [Patent Document 3] Japanese Patent Publication No. 2023-509695 Summary of the invention

[0009] [Problems to be solved by the invention]

[0010] However, in the cell-pack method, it is a huge issue to balance arranging the individual battery cells in the pack and applying pressure to the battery cells for mounting. In addition, in the case of fast charging, battery temperature management becomes more important, but there is a limit to bottom surface cooling, so cooling of the cell side is required.

[0011] The present invention has been made to solve such a problem, and an object of the present invention is to provide a battery pack capable of increasing the mounting density of battery cells and cooling, pressing and fixing each battery cell.

[0012] [Technical means to solve the problem]

[0013] The present invention for solving the above-mentioned problem is a battery pack 1, comprising: a battery case 10, which is roughly box-shaped; a plurality of battery cells 20, which are accommodated in the battery case; and a plurality of refrigerant jackets 30, which cool the plurality of battery cells. The battery pack 1 is characterized in that it is formed in the following manner: each of the refrigerant jackets 30 comprises: two plastic thin plates (31, 32) which are surface-jointed with each other, a refrigerant inlet 33 formed as a gap between the two thin plates, a refrigerant passage 34, and a refrigerant outlet 35, the battery cells 20 and the refrigerant jackets 30 are alternately surface-contacted in the battery case 10 and arranged along a first direction (AA), a non-compressed fluid of a specified pressure flows into the refrigerant passage 34 of each refrigerant jacket 30, and the refrigerant jacket 30 expands by plastic deformation, thereby clamping and fixing the plurality of battery cells 20 and the plurality of refrigerant jackets 30 between two end plates (11, 12) facing each other in the first direction.

[0014] With this structure, after the battery cells and the refrigerant jackets before expansion are alternately arranged with gaps between the two opposing end plates, the refrigerant jackets are expanded, thereby fixing the battery cells while applying pressure to the battery cells.

[0015] In addition, the refrigerant jacket expands due to plastic deformation, so even if the hydraulic pressure is reduced to zero, the deformed state can be maintained, and the pressure on the battery cell can be maintained, so that no other pressing mechanism is required and the structure can be simplified.

[0016] The following structure may be preferably adopted: the two end plates ( 11 , 12 ) are end plates constituting both end portions of the battery cell accommodating portion 17 in the battery case 10 .

[0017] In the above structure, that is, the structure of a battery pack in which the present invention is applied to a unit-group type battery pack in which the battery cells are directly accommodated in a battery case without modularization, the following effects are obtained in addition to the above effects. That is, when the battery cells are mounted on the case, there is a gap with respect to the inner wall of the battery case before the refrigerant jacket expands, so that various mounting methods can be selected, such as mounting in rows or as a whole by gripping with a robot, and mounting from above using a loader.

[0018] Furthermore, since the refrigerant jacket expands to fill the space defined by the battery cells and the inner wall of the battery case, it is also possible to absorb dimensional variations in the battery case or the battery cells during manufacture.

[0019] Furthermore, by allowing the refrigerant (cooling water, etc.) to flow into the refrigerant flow path between the two thin plates constituting the expanded refrigerant jacket, the side surface of the unit can be cooled, and rapid charging with severe heat generation can be handled.

[0020] In addition, although the refrigerant jacket is hollow and lightweight, it is rigid and thus contributes to improving the rigidity of the battery pack as a whole.

[0021] The following structure can preferably be adopted: the battery cell 20 constitutes a unit assembly 20A in which a plurality of units are arranged and joined in a row in a second direction (BB) orthogonal to the first direction (AA), and the unit assembly 20A and the refrigerant jacket 30 are arranged in the battery housing 10 in alternating surface contact in the first direction (AA).

[0022] With the above structure, the battery cells can be arranged two-dimensionally in the battery pack, so that a high-density arrangement is possible.

[0023] The following structure can be preferably adopted: the refrigerant jacket 30 has: an end 30a protruding more than one end side of the unit assembly 20A in the second direction (BB), and the other end 30b protruding more than the other end side of the unit assembly 20A, the refrigerant inlet 33 has: a one-side inlet piping 33a protruding from one side side of the one end 30a toward the first direction (AA), and the other-side inlet piping 33b protruding from the other side side of the one end 30a toward the first direction (AA), and the refrigerant outlet 35 has: a one-side inlet piping 33a protruding from one side side of the other end 30b toward the first direction (AA). A one-side outlet piping 35a protruding in the first direction (AA), and another-side outlet piping 35b protruding in the first direction (AA) from the other side of the other end portion 30b, and configured such that when the two refrigerant jackets 30 are adjacent to each other with the unit assembly 20A sandwiched therebetween, the one-side inlet piping 33a of one refrigerant jacket 30 is connected to the other-side inlet piping 33b of the other refrigerant jacket 30, and the one-side outlet piping 35a of one refrigerant jacket 30 is connected to the other-side outlet piping 35b of the other refrigerant jacket 30.

[0024] In particular, a structure in which the connection between the one-side inlet pipe 33 a and the other-side inlet pipe 33 b and the connection between the one-side outlet pipe 35 a and the other-side outlet pipe 35 b are respectively performed through a flexible hose 36 can be preferably adopted.

[0025] Through these structures, the refrigerant inlets and refrigerant outlets of multiple refrigerant jackets can be easily combined with each other, the uncombined refrigerant inlet and refrigerant outlet of the end refrigerant jacket can be sealed, and then the refrigerant can be injected from the refrigerant inlet of the base end refrigerant jacket, thereby allowing the refrigerant to flow to all the refrigerant jackets.

[0026] The predetermined pressure is preferably 10 times or more of the pressure of the refrigerant during normal use, and more preferably 3 MPa±0.5 MPa.

[0027] With this structure, the refrigerant jacket can be appropriately expanded, and the battery cell can be fixed while applying pressure to the battery cell.

[0028] It is preferable that the battery cell 20 or the cell assembly 20A is fixed to the adjacent refrigerant jacket 30 by bonding.

[0029] With this structure, when the refrigerant jacket is expanded, the arrangement of the battery cells can be prevented from being shifted.

[0030] The manufacturing method of the battery pack 1 of the present invention is a method for manufacturing the battery pack 1, wherein the battery pack 1 comprises: a battery case 10, which is roughly box-shaped; a plurality of battery cells 20, which are accommodated in the battery case 10; and a plurality of refrigerant jackets 30, which cool the plurality of battery cells 20. In the method, each of the refrigerant jackets 30 comprises: two thin plates (31, 32) with plasticity that are surface-jointed with each other, a refrigerant inlet 33 formed as a gap between the two thin plates (31, 32), a refrigerant passage 34, and a refrigerant inlet 33 formed as a gap between the two thin plates (31, 32). The method comprises the following steps: in the battery housing 10, the battery cells 20 and the refrigerant jackets 30 are alternately brought into surface contact with each other and arranged along a first direction (AA) in the battery housing 10; and a non-compressed fluid of a specified pressure is flowed into the refrigerant passage 34 of each refrigerant jacket 30, so that the refrigerant jacket 30 expands through plastic deformation, thereby clamping and fixing the plurality of battery cells 20 and the plurality of refrigerant jackets 30 between two end plates (11, 12) facing each other in the first direction.

[0031] With this structure, after the battery cells and the refrigerant jackets before expansion are alternately arranged with gaps between the two opposing end plates, the refrigerant jackets are expanded, thereby fixing the battery cells while applying pressure to the battery cells.

[0032] In addition, the symbols in the above parentheses are symbols representing the symbols of the corresponding components of the embodiments described later as an example of the present invention.

[0033] [Effects of the Invention]

[0034] According to the battery pack and the manufacturing method thereof of the present invention, after battery cells and the refrigerant jackets before expansion are alternately arranged with gaps between two opposing end plates, the refrigerant jackets are expanded, thereby fixing the battery cells while applying pressure to the battery cells.

[0035] In addition, the refrigerant jacket expands due to plastic deformation, so even if the hydraulic pressure is reduced to zero, the deformed state can be maintained, and the pressure on the battery cell can be maintained, so that no other pressing mechanism is required and the structure can be simplified. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a plan view schematically showing a battery pack according to the first embodiment of the present invention.

[0037] Figure 2 yes Figure 1 An enlarged view of part C of the battery pack.

[0038] Fig. 3(a) and Fig. 3(b) are diagrams showing a unit assembly, Fig. 3(a) is a plan view, and Fig. 3(b) is a front view.

[0039] Fig. 4(a) and Fig. 4(b) are diagrams showing a refrigerant jacket, Fig. 4(a) is a plan view, and Fig. 4(b) is a front view.

[0040] 5( a ) and 5 ( b ) are schematic diagrams showing the DD cross section of the refrigerant jacket of FIG. 4( b ), FIG. 5( a ) showing the state before expansion, and FIG. 5( b ) showing the state after expansion.

[0041] Figure 6(a) to Figure 6(d) Yes means Figure 1 FIG6(a) is a plan view of a method for manufacturing a battery pack, wherein FIG6(b) shows a state of a battery cell group before joining, FIG6(c) shows a state of a unit joint after joining, FIG6(d) shows a state of a joint between a unit joint and a refrigerant jacket before expansion, and FIG6(d) shows a state in which a flexible hose is then installed.

[0042] Figure 7 Yes means Figure 1 A plan view of a method for manufacturing a battery pack shows a state in which a unit assembly and a refrigerant jacket bonded body before expansion are arranged in a battery case.

[0043] Figure 8 It is a plan view showing a battery pack according to a second embodiment of the present invention.

[0044] Fig. 9 yes Figure 8 An enlarged view of part E of the battery pack.

[0045] [Explanation of Symbols]

[0046] 1: Battery Pack

[0047] 10: Battery housing

[0048] 11: Front end panel

[0049] 12: Rear end plate

[0050] 13: Left end plate

[0051] 14: Right end plate

[0052] 15: Bottom plate

[0053] 17: Battery unit storage area

[0054] 20: Battery Cell

[0055] 20A: Unit joint

[0056] 21: Terminal

[0057] 30: Refrigerant jacket

[0058] 30a: One end

[0059] 30b: The other end

[0060] 31, 32: Thin plate

[0061] 33: Refrigerant inlet

[0062] 33a: One side inlet piping

[0063] 33b: Other side inlet piping

[0064] 34: Refrigerant passage

[0065] 35: Refrigerant outlet

[0066] 35a: One side outlet piping

[0067] 35b: Other side outlet piping

[0068] 36: Flexible hose

[0069] 37: Refrigerant supply piping

[0070] 38: Refrigerant return pipe

[0071] 40: Unit

[0072] S: Space DETAILED DESCRIPTION

[0073] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0074] [First embodiment]

[0075] This embodiment is a form in which the refrigerant inlet pipe and the refrigerant outlet pipe of the refrigerant jacket are connected by a flexible hose. Figure 1 and Figure 1 C section enlargement Figure 2 As shown, the battery pack 1 of the present embodiment includes a battery case 10 , a plurality of battery cells 20 , and a plurality of refrigerant jackets 30 .

[0076] The battery case 10 has a thin box shape consisting of a front end plate 11 and a rear end plate 12 provided at both ends in the first direction (front-rear direction AA), a left end plate 13 and a right end plate 14 provided at both ends in the second direction (left-right direction BB), a bottom plate 15, and an upper plate (not shown).

[0077] As shown in FIG. 3(a) and FIG. 3(b), the battery cell 20 in this embodiment is a square lithium-ion battery with two terminals 21 protruding from the upper side. The battery cell 20 is composed of a unit assembly 20A in which six cells are arranged in a row and joined in the second direction (left-right direction). In the present invention, the shape of the battery cell 20 is not limited to a square shape, and may be, for example, a cylindrical shape. In the case of a square shape, there is no need to fill the space between the battery cells 20 with resin, and the environmental load during recycling is small. In addition, the type of battery is not limited to a lithium-ion battery, and may be an all-solid-state lithium-ion battery or a sodium-ion battery.

[0078] The refrigerant jacket 30 is a component that is arranged in the battery case 10 so as to alternately come into surface contact with the unit assembly 20A in the first direction (front-back direction) and cools each battery cell 20. As shown in Fig. 4(a) and Fig. 4(b), each refrigerant jacket 30 is a roller-joined component that includes two aluminum thin plates 31 and 32 (see Fig. 5(a) and Fig. 5(b)) that are surface-joined to each other, a refrigerant inlet 33 formed as a gap between the two thin plates, a refrigerant passage 34, and a refrigerant outlet 35. By allowing a non-compressed fluid of a specified pressure (water of 3.4 MPa in this embodiment) to flow into the refrigerant passage 34 of the refrigerant jacket 30, the refrigerant passage 34 is pushed open, so that even a refrigerant of normal pressure (water of 0.3 MPa) can flow. At the same time, the refrigerant jacket 30 expands due to plastic deformation, so that the unit assembly 20A and the refrigerant jacket 30 are clamped and fixed to the front end plate 11 and the rear end plate 12 of the two end plates constituting the battery unit accommodating portion 17 (see Figure 1 )between.

[0079] The refrigerant jacket 30 has one end 30a protruding from one end side (left side) of the unit assembly 20A in the second direction (left-right direction), and the other end 30b protruding from the other end side (right side) of the unit assembly 20A. The refrigerant inlet 33 has one surface side inlet piping 33a protruding from one surface side (front side) of the one end 30a to the first direction (front-back direction), and the other surface side inlet piping 33b protruding from the other surface side (rear side) of the one end 30a to the first direction (front-back direction). On the other hand, the refrigerant outlet 35 has one surface side outlet piping 35a protruding from one surface side (front side) of the other end 30b to the first direction (front-back direction), and the other surface side outlet piping 35b protruding from the other surface side (rear side) of the other end 30b to the first direction (front-back direction).

[0080] like Figure 2 As shown, one side inlet piping 33a of one of the two adjacent refrigerant jackets 30 sandwiching the unit assembly 20A is connected to the other side inlet piping 33b of the other refrigerant jacket 30 via an aluminum flexible hose 36. In addition, one side outlet piping 35a of one refrigerant jacket 30 is connected to the other side outlet piping 35b of the other refrigerant jacket 30 via a flexible hose 36. In this way, the refrigerant inlets 33 of all the refrigerant jackets 30 arranged in the battery case 10 are connected to each other, and the refrigerant outlets 35 are also connected to each other, and the one side inlet piping 33a and the one side outlet piping 35a of the refrigerant jacket 30 of the frontmost section are not provided, and one side is sealed. On the other hand, the refrigerant supply piping 37 is connected to the other side inlet piping 33b of the refrigerant jacket 30 of the last section (refer to Figure 1 ), a refrigerant return pipe 38 is connected to the outlet pipe 35a on one side (refer to Figure 1 When refrigerant (water) is supplied from the refrigerant supply pipe 37 to the group of refrigerant jackets 30 connected in this way, the water branches and flows in parallel to the refrigerant passages 34 of each refrigerant jacket 30 to cool the battery cells 20 and then merges and flows to the refrigerant return pipe 38.

[0081] The two terminals 21 protruding from the upper side of each battery cell 20 (see FIG. 3 (a) and FIG. 3 (b)) are connected to a busbar (not shown) as a conductor plate by welding, and are connected in parallel and series within the battery pack, and finally integrated into a positive terminal (not shown) and a negative terminal (not shown) as the battery pack as a whole. By applying a voltage between the positive terminal and the negative terminal from the outside, each battery cell 20 can be charged, and the power after charging each battery cell 20 can be supplied from the positive terminal and the negative terminal to the vehicle drive motor, etc.

[0082] Next, a method for manufacturing the battery pack 1 of the present embodiment configured as described above will be described.

[0083] First, as shown in FIGS. 6( a ) and 6 ( b ), a plurality of battery cells 20 are arranged in a row in the second direction (left-right direction) in multiple numbers (six in this embodiment) and joined to form a cell assembly 20A ( FIG. 6( b )).

[0084] Next, the unit assembly 20A and the refrigerant jacket 30 are alternately arranged in a first direction (front-rear direction) in a manner of surface contact with each other and connected to each other. Specifically, first, one refrigerant jacket 30 is connected to one unit assembly 20A in a manner of surface contact (Fig. 6(c)), and an aluminum flexible hose 36 is respectively installed on a side inlet pipe 33a and a side outlet pipe 35a provided at the left and right ends of the refrigerant jacket 30 (Fig. 6(d)).

[0085] Next, if Figure 7 As shown, the bonded body of the cell assembly 20A and the refrigerant jacket 30 is sequentially aligned and bonded in the battery case 10. By bonding, the alignment of the battery cells 20 can be prevented from being misaligned in the step of expanding the refrigerant jacket 30 described later.

[0086] At this time, if Figure 2 As shown, in two refrigerant jackets 30 adjacent to each other with the unit assembly 20A interposed therebetween, the inlet pipe 33b on the other side and the outlet pipe 35b on the other side of the other refrigerant jacket 30 are respectively inserted into the flexible hose 36 respectively installed on the inlet pipe 33a on one side and the outlet pipe 35a on the other side of the refrigerant jacket 30, thereby connecting the inlet pipes (33a, 33b) and the outlet pipes (35a, 35b) to each other. In addition, the inlet pipe 33a on the one side and the outlet pipe 35a on the one side of the refrigerant jacket 30 at the frontmost stage are not provided, and one side is sealed.

[0087] When all the unit assemblies 20A and the bonding bodies of the refrigerant jackets 30 are aligned and bonded, the refrigerant inlets 33 of all the refrigerant jackets 30 disposed in the battery case 10 are connected to each other, and the refrigerant outlets 35 are connected to each other.

[0088] In such a formation, Figure 7In the block-shaped unit body 40 in which the unit assembly 20A and the refrigerant jacket 30 are alternately arranged, since the thickness of the refrigerant jacket 30 is before expansion, the size of the unit body 40 in the first direction (front-back direction) is sufficiently smaller than the size of the battery unit accommodating portion 17 in the battery case 10. Therefore, in the first direction, there is a space S between the unit body 40 and the rear end plate 12 or the front end plate 11, and various conveying methods of the unit assembly 20A and the refrigerant jacket 30 can be adopted.

[0089] Next, the outlet piping 35a on one side of the last section of the refrigerant jacket 30 is sealed, and then the refrigerant supply piping 37 is connected to the inlet piping 33b on the other side, so that a non-compressed fluid of a specified pressure (water at 3.4 MPa in this embodiment) flows into the refrigerant passage 34 of the refrigerant jacket 30 (refer to Figure 4(b)). The non-compressed fluid may be the same as or different from the refrigerant. As a result, the refrigerant jacket 30 expands due to plastic deformation, so that even if the refrigerant pressure is zero, the deformed state can be maintained, and even the refrigerant at normal pressure (water at 0.3 MPa) flows in the expanded refrigerant passage 34. At the same time, the pressure on the battery cell 20 can also be maintained, so the unit assembly 20A and the refrigerant jacket 30 are clamped and fixed between the rear end plate 12 and the front end plate 11 of the two end plates constituting the battery cell housing 17, so that the position of the terminal 21 of the battery cell 20 can be accurately positioned ( Figure 1 ).

[0090] On the surface of each battery cell 20 where the terminal 21 is arranged (on the Figure 1 A bus bar (not shown) serving as a conductor plate is placed thereon and welded to each terminal 21.

[0091] Furthermore, the coolant supply pipe 37 and the coolant return pipe 38 are connected, the gap around the unit body 40 is filled with urethane foam, and an upper plate (not shown) is attached, thereby completing the battery pack 1.

[0092] According to this embodiment, after the battery cells 20 and the refrigerant jackets 30 before expansion are alternately arranged in a state where there is a gap relative to the two opposing end plates (11, 12), the refrigerant jackets 30 are expanded, thereby fixing the battery cells 20 while applying pressure to the battery cells 20.

[0093] Furthermore, since the refrigerant jacket 30 expands due to plastic deformation, it can maintain the deformed state even if the hydraulic pressure is reduced to zero, and can also maintain the pressure on the battery cell 20, so that no other pressing mechanism is required, and the structure can be simplified.

[0094] [Second embodiment]

[0095] This embodiment is different from the first embodiment in that the flexible hose 36 is not used as the piping for connecting the refrigerant jackets 30 to each other, but straight steel pipes (33a, 33b, 35a, 35b) are connected to each other. The same reference numerals are given to the same or substantially the same components as those in the first embodiment, and repeated descriptions are omitted. Figure 8 A plan view showing a battery pack according to this embodiment, Fig. 9 It shows an enlarged view of part E.

[0096] The refrigerant jacket 30 has: one end 30a protruding further than one end side (left side) of the unit assembly 20A in the second direction (left-right direction), and the other end 30b protruding further than the other end side (right side) of the unit assembly 20A. The refrigerant inlet 33 has: a one-side inlet pipe 33a protruding from one side side (front side) of the one end 30a to the first direction (front direction), and the other-side inlet pipe 33b protruding from the other side side (rear side) of the one end 30a to the first direction (rear direction). The outer periphery of the other-side inlet pipe 33b is formed to a size that is pressed into and fitted into the inner periphery of the one-side inlet pipe 33a.

[0097] On the other hand, the refrigerant outlet 35 includes: a one-side outlet pipe 35a protruding from one side (front side) of the other end 30b in the first direction (front direction), and another-side outlet pipe 35b protruding from the other side (rear side) of the other end 30b in the first direction (rear direction). The outer periphery of the another-side outlet pipe 35b is also formed to a size that is pressed into and fitted into the inner periphery of the one-side outlet pipe 35a.

[0098] When the two refrigerant jackets 30 are crimped by sandwiching the unit assembly 20A, the inlet pipe 33a on one side of the refrigerant jacket 30 is pressed into and fitted with the inlet pipe 33b on the other side of the other refrigerant jacket 30 to connect. In addition, the outlet pipe 35a on one side of the refrigerant jacket 30 is pressed into and fitted with the outlet pipe 35b on the other side of the other refrigerant jacket 30 to connect. In this way, the refrigerant inlets 33 of all the refrigerant jackets 30 arranged in the battery case 10 are connected to each other, and the refrigerant outlets 35 are connected to each other. The inlet pipe 33a on one side and the outlet pipe 35a on one side of the refrigerant jacket 30 at the front stage are not provided, and one side is sealed. On the other hand, the inlet pipe 33b on the other side of the refrigerant jacket 30 at the rear stage is connected to the refrigerant supply pipe 37, and the outlet pipe 35a on one side is connected to the refrigerant return pipe 38.

[0099] For a group of refrigerant jackets 30 connected in this way, a refrigerant supply pipe 37 is connected to the inlet pipe 33b on the other side, so that a non-compressed fluid of a specified pressure (water of 3.4 MPa in this embodiment) flows into the refrigerant passage 34 of the refrigerant jacket 30 (refer to Figure 4(b)). Thus, as in the first embodiment, the refrigerant jacket 30 expands due to plastic deformation, and even a refrigerant of normal pressure (water of 0.3 MPa) flows in the expanded refrigerant passage 34. At the same time, the unit assembly 20A and the refrigerant jacket 30 are clamped and fixed between the rear end plate 12 and the front end plate 11 of the two end plates constituting the battery unit housing 17, so that the position of the terminal 21 of the battery unit 20 can be accurately positioned ( Figure 1 ).

[0100] At this time, due to the expansion of each refrigerant jacket 30, tension is applied to the fitting parts of the inlet piping 33a on one side and the inlet piping 33b on the other side, and the fitting parts of the outlet piping 35a on one side and the outlet piping 35b on the other side, but the thickness of one end 30a and the other end 30b of the refrigerant jacket 30 also expands, so the fitting can be maintained.

[0101] The other structures are the same as those of the first embodiment, and the manufacturing method is the same as that of the first embodiment except that the flexible hose 36 is not used in the assembly process. Figure 2 ) is installed on one side inlet piping 33a and one side outlet piping 35a, so the assembly process can be simplified.

[0102] As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, Various deformation|transformation is possible within the range of the technical idea described in a claim, specification, and drawing.

[0103] For example, in the above-mentioned embodiments, an example of a battery pack 1 in a unit-group type in which the battery cells 20 are not modularized but directly accommodated in the battery case 10 is described, but the present invention is not limited thereto and can also be applied to a battery pack 1 in a module-group type. In the above-mentioned case, in the frame of the module, the battery cells 20 and the refrigerant jackets 30 can be alternately brought into surface contact and arranged in a first direction, and a non-compressed fluid of a specified pressure can be flowed into the refrigerant passage 34 of each refrigerant jacket 30, so that the refrigerant jacket 30 expands due to plastic deformation, thereby clamping and fixing a plurality of battery cells 20 and a plurality of refrigerant jackets 30 between two end plates facing each other in the first direction, thereby forming a module, and arranging a plurality of modules in the battery pack 1.

[0104] The pipe connection structure on the inlet side and the outlet side of the refrigerant jacket 30 is not limited to the structure of the above-described embodiments, and any structure may be used as long as the refrigerant can flow through the refrigerant jacket 30 .

Claims

1. A battery pack comprising: The battery casing is box-shaped; A plurality of battery cells are housed in the battery housing; and A plurality of refrigerant jackets are provided to cool the plurality of battery cells, wherein the battery pack is formed by: Each of the refrigerant jackets includes: two plastic thin plates that are surface-jointed with each other, a refrigerant inlet formed as a gap between the two thin plates, a refrigerant passage, and a refrigerant outlet. The battery cells and the refrigerant jackets are alternately in surface contact with each other in the battery housing and arranged along a first direction. A non-compressed fluid at a predetermined pressure is flowed into the refrigerant passage of each refrigerant jacket to expand the refrigerant jacket by plastic deformation, thereby sandwiching and fixing the plurality of battery cells and the plurality of refrigerant jackets between two end plates facing each other in the first direction. 2 . The battery pack according to claim 1 , wherein the two end plates are end plates constituting both end portions of a battery cell housing portion in the battery case.

3. The battery pack according to claim 2, wherein the plurality of battery cells constitute a unit assembly in which a plurality of battery cells are arranged in a row in a second direction orthogonal to the first direction and are joined together, The unit assemblies and the refrigerant jackets are disposed in the battery case so as to be in surface contact with each other alternately in the first direction.

4. The battery pack according to claim 3, wherein the refrigerant jacket has: one end portion protruding further than one end side of the unit assembly in the second direction, and another end portion protruding further than the other end side of the unit assembly, The refrigerant inlet includes: a first side inlet pipe protruding from a first side of the first end portion toward the first direction; and a second side inlet pipe protruding from the second side of the first end portion toward the first direction. The refrigerant outlet includes: a first side outlet pipe protruding from a first side of the other end portion toward the first direction, and a second side outlet pipe protruding from the other side of the other end portion toward the first direction. The structure is such that when the two refrigerant jackets are adjacent to each other with the unit assembly sandwiched therebetween, the inlet pipe on one side of one refrigerant jacket is connected to the inlet pipe on the other side of the other refrigerant jacket. The one-side outlet pipe of one refrigerant jacket is connected to the other-side outlet pipe of the other refrigerant jacket. 5 . The battery pack according to claim 4 , wherein the connection between the one-side inlet pipe and the other-side inlet pipe and the connection between the one-side outlet pipe and the other-side outlet pipe are respectively performed via flexible hoses. 6 . The battery pack according to claim 4 , wherein the prescribed pressure is 10 times or more the pressure of the refrigerant in normal use. 7 . The battery pack according to claim 6 , wherein the prescribed pressure is 3 MPa±0.5 MPa. 8 . The battery pack according to claim 3 , wherein the battery cell or the cell assembly is fixed to the adjacent refrigerant jacket by bonding.

9. A method for manufacturing a battery pack, comprising: The battery casing is box-shaped; A plurality of battery cells are housed in the battery housing; and A plurality of refrigerant jackets are provided to cool the plurality of battery cells. In the manufacturing method of the battery pack, Each of the refrigerant jackets includes: two plastic thin plates that are surface-jointed with each other, a refrigerant inlet formed as a gap between the two thin plates, a refrigerant passage, and a refrigerant outlet. The manufacturing method of the battery pack comprises the following steps: In the battery housing, the battery cells and the refrigerant jackets are alternately in surface contact with each other in the battery housing and arranged along a first direction; and A non-compressed fluid at a predetermined pressure is flowed into the refrigerant passage of each refrigerant jacket to expand the refrigerant jacket by plastic deformation, thereby sandwiching and fixing the plurality of battery cells and the plurality of refrigerant jackets between two end plates facing each other in the first direction.

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