Method for manufacturing battery module

Abstract

The present invention provides a method for manufacturing a battery module, the battery module comprising: a laminate formed from a stacked plurality of units, each unit including first and second cell groups in which a plurality of cells extending in a first direction are arranged in a second direction orthogonal to the first direction and a temperature regulation plate which is disposed between the first cell group and the second cell group and which extends in the second direction; and a case accommodating the laminate. The method comprises: filling gaps in the laminate accommodated in the case with a fluid filler and then curing the filler; and, prior to the filling with the filler, sealing an opening in a lateral surface of the case in which the laminate is accommodated with an outflow prevention member configured to restrict the movement of fluid.

Description

Battery module manufacturing method

[0001] The present invention relates to a method for manufacturing a battery module.

[0002] Electric vehicles capable of running on a motor using power stored in battery modules within a battery pack are known. For example, Patent Document 1 discloses a battery pack disposed at the center of the lower part of the body of an electric vehicle and including multiple battery modules. The battery module in Patent Document 1 includes a stack of multiple units, each including a first cell group, a second cell group, and a temperature control plate disposed between the first and second cell groups.

[0003] Special Publication No. 2023-502274

[0004] In the manufacturing process of a battery module, after the above-mentioned stack is housed in a case, potting may be performed to fill the inside of the case with a filler. However, due to the structure of the stack, an opening may be required on the side of the case. If this opening is located on the side of the case, some of the filler may leak out of the case through the opening during potting.

[0005] Therefore, an object of the present invention is to provide a method for manufacturing a battery module that allows for appropriate filling of a filler.

[0006] In order to solve the above problem, one embodiment of the present invention provides a method for manufacturing a battery module including: a stack in which a plurality of units are stacked, each unit including a first cell group and a second cell group in which a plurality of cells extending in a first direction are arranged in a second direction perpendicular to the first direction, and a temperature control plate disposed between the first cell group and the second cell group and extending in the second direction; and a case that houses the stack, the method comprising: filling gaps in the stack housed in the case with a fluid filler and hardening the filler; and before filling the filler, blocking an opening on a side of the case that houses the stack with an anti-flow member configured to restrict the movement of fluid.

[0007] According to the present invention, it is possible to appropriately fill the filler.

[0008] FIG. 1 is a cross-sectional view showing an example of the configuration of a battery module according to this embodiment. FIG. 2 is a schematic view showing the configuration of a laminate. FIG. 3 is a flowchart illustrating a method for manufacturing a battery module according to this embodiment. FIG. 4 is a plan view showing an example of a battery module in a state immediately before the step of attaching an anti-flow member. FIG. 5 is a plan view illustrating the step of attaching an anti-flow member. FIG. 6 is a vertical cross-sectional view illustrating the step of attaching an anti-flow member. FIG. 7 is a plan view illustrating an example of a potting step. FIG. 8 is a vertical cross-sectional view illustrating another example of the potting step.

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Specific dimensions, materials, numerical values, etc. shown in the embodiments are merely examples for facilitating understanding of the invention and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

[0010] (Battery Module) Fig. 1 is a cross-sectional view showing an example of the configuration of a battery module 1 according to this embodiment. In Fig. 1, the X' direction indicates the width direction of the battery module 1, the Y' direction indicates the length direction of the battery module 1, and the Z' direction indicates the height direction of the battery module 1.

[0011] The battery module 1 may be mounted on a vehicle such as an electric vehicle equipped with a motor generator as a drive source. The vehicle is not limited to an electric vehicle, but may also be a hybrid electric vehicle equipped with a motor generator and an engine as a drive source. The battery module 1 is not limited to being mounted on a vehicle, but may also be mounted on various devices.

[0012] The battery module 1 includes a case 10 , a laminate 12 , and a bus bar module 14 .

[0013] The case 10 defines an accommodation space S therein. The case 10 has an upper cover 20, a side plate 22, and a lower cover 24. The space surrounded by the upper cover 20, the side plate 22, and the lower cover 24 is the accommodation space S. The laminate 12 and the bus bar module 14 are accommodated in the accommodation space S inside the case 10. The laminate 12 is located above the bus bar module 14 in the Z' direction.

[0014] The upper cover 20 is disposed above the stack 12 in the Z′ direction. The upper cover 20 has a rectangular flat plate shape. The upper cover 20 covers the upper side of the stack 12 in the Z′ direction.

[0015] The lower cover 24 is disposed below the bus bar module 14 in the Z′ direction. The lower cover 24 has a rectangular flat plate shape. The lower cover 24 covers the lower side of the bus bar module 14 in the Z′ direction.

[0016] A pair of side plates 22 are arranged on both sides of the laminate 12 and the bus bar module 14 in the X' direction. The side plates 22 have a rectangular flat plate shape. The side plates 22 cover both sides of the laminate 12 and the bus bar module 14 in the X' direction. An upper cover 20 is connected to an upper end of each side plate 22 in the Z' direction. A lower cover 24 is connected to a lower end of each side plate 22 in the Z' direction.

[0017] The stack 12 includes a plurality of cells 30. The cells 30 are single cells of a rechargeable secondary battery, such as a lithium-ion battery. While the cells 30 are assumed to be cylindrical, they may be formed in various shapes, such as a rectangular column or an elliptical column. Each of the plurality of cells is arranged upright so as to extend in the height direction of the battery module 1 (direction Z' in FIG. 1 ). The cells 30 have positive and negative electrodes. The stack 12 will be described in detail later.

[0018] The bus bar module 14 has a bus bar plate 40, a plurality of bus bars 42, and a plurality of wires 44. The bus bar plate 40 holds the plurality of bus bars 42. The bus bars 42 are formed in a sheet or plate shape from a conductive material. The wires 44 electrically connect any electrode of any cell 30 to any bus bar 42. The bus bar 42 electrically connects the electrodes of the plurality of cells 30 via the wires 44. The plurality of cells 30 are connected in parallel and in series via the wires 44 and the bus bars 42.

[0019] FIG. 2 is a schematic diagram showing the configuration of the laminate 12. FIG. 2 shows the laminate 12 shown in FIG. 1 as viewed from the Z' direction in FIG. 1. In FIG. 2, the X direction is a first direction corresponding to the extension direction of the cells 30. In FIG. 2, the Y direction is a second direction perpendicular to the X direction and corresponds to the direction in which the multiple cells 30 are arranged. In FIG. 2, the Z direction is a third direction perpendicular to the X direction and the Y direction and corresponds to the stacking direction of the units 50 described below. The X direction in FIG. 2 corresponds to the Z' direction in FIG. 1, the Y direction in FIG. 2 corresponds to the Y' direction in FIG. 1, and the Z direction in FIG. 2 corresponds to the X' direction in FIG. 1.

[0020] The laminate 12 includes a plurality of units 50. Each of the plurality of units 50 includes a first cell group 60, a second cell group 62, a temperature control plate 64, and an insulating sheet 66. Two types of units 50 may be included: those that include the insulating sheet 66, and those that do not include the insulating sheet 66. Hereinafter, for ease of explanation, the first cell group 60 and the second cell group 62 may be collectively referred to simply as cell groups without distinction.

[0021] Each of the first cell group 60 and the second cell group 62 includes a plurality of cells 30. Each of the plurality of cells 30 is arranged to extend in a first direction (the X direction in FIG. 2 ). That is, the central axis of the cell 30 extends in the X direction.

[0022] The first cell group 60 is configured such that a plurality of cells 30 extending in a first direction are aligned in a second direction (Y direction in FIG. 2 ) perpendicular to the first direction. In the example of FIG. 2 , six cells 30 aligned in the Y direction are shown as the first cell group 60. However, the number of cells 30 constituting the first cell group 60 may be five or less, or seven or more, as long as it is plural.

[0023] The second cell group 62 is a cell group configured separately from the first cell group 60, and is configured so that the plurality of cells 30 extending in a first direction are aligned in a second direction (Y direction in FIG. 2 ) perpendicular to the first direction. The direction in which the plurality of cells 30 constituting the second cell group 62 are aligned is the same as the direction in which the plurality of cells 30 constituting the first cell group 60 are aligned. Hereinafter, for convenience of explanation, the direction in which the plurality of cells 30 constituting the cell group are aligned may be referred to as the parallel direction.

[0024] 2, six cells 30 arranged in the Y direction are shown as the second cell group 62. However, the number of cells 30 constituting the second cell group 62 may be any plural number, and may be five or less, or seven or more. The number of cells 30 constituting the second cell group 62 is assumed to be the same as the number of cells 30 constituting the first cell group 60, but may be different from the number of cells 30 constituting the first cell group 60.

[0025] The temperature control plate 64 is disposed between the first cell group 60 and the second cell group 62. The temperature control plate 64 is formed in a corrugated shape. The temperature control plate 64 is disposed so that the longitudinal direction, which corresponds to the direction of wave propagation in the temperature control plate 64, is the same as the parallel arrangement direction of the cells 30 of the cell group.

[0026] A first cell group 60 is connected to a first of the two surfaces of the temperature control plate 64 via an adhesive. Each of the cells 30 of the first cell group 60 is housed in a valley portion formed in the first surface of the temperature control plate 64. A second cell group 62 is connected to a second of the two surfaces of the temperature control plate 64 via an adhesive. Each of the cells 30 of the second cell group 62 is housed in a valley portion formed in the second surface of the temperature control plate 64.

[0027] Although not shown in the figure, a flow path through which a heat medium can flow is formed inside the temperature control plate 64. The temperature control plate 64 exchanges heat between the heat medium flowing through the internal flow path and the first cell group 60 and the second cell group 62. This heat exchange adjusts the temperatures of the first cell group 60 and the second cell group 62.

[0028] The unit 50 is formed by at least bonding a first cell group 60 to a first surface of a temperature control plate 64 and bonding a second cell group 62 to a second surface of the temperature control plate 64 .

[0029] The multiple units 50 are stacked in a third direction (Z direction in FIG. 2 ) that is perpendicular to the extension direction (first direction) of the cells 30 and the parallel arrangement direction (second direction) of the cells 30. In other words, the third direction is the stacking direction in which the multiple units 50 are stacked. When the multiple units 50 are stacked, the first cell groups 60 and the second cell groups 62 are arranged alternately along the stacking direction.

[0030] The laminate 12 is formed by stacking a plurality of units 50 with an insulating sheet 66 interposed therebetween. The insulating sheet 66 is formed in a sheet shape from an insulator. The insulating sheet 66 is located between the first cell group 60 of one unit 50 and the second cell group 62 of the other unit 50 of two adjacent units 50. The insulating sheet 66 prevents contact between adjacent cell groups in the stacking direction.

[0031] The insulating sheet 66 is adhered via an adhesive to at least one of the two cell groups sandwiching the insulating sheet 66. The insulating sheet 66 may be adhered to a portion of at least one of the first cell group 60 and the second cell group 62 of the unit 50 on the side opposite to the temperature control plate 64.

[0032] Hereinafter, for ease of explanation, the cell group of the first cell group 60 and the second cell group 62 of the unit 50 to which the insulating sheet 66 is adhered may be referred to as the specific cell group. For example, the specific cell group may be the second cell group 62. In this case, the insulating sheet 66 is adhered via an adhesive to a portion of the second cell group 62, which is the specific cell group, on the side opposite to the temperature control plate 64.

[0033] (Manufacturing Method of Battery Module) Fig. 3 is a flowchart illustrating a manufacturing method of the battery module 1 according to this embodiment. As shown in Fig. 3, the manufacturing method of the battery module 1 includes a unit creation process S100, a stacking process S200, an assembly process S300, a wire bonding process S400, an outflow prevention member attachment process S450, and a potting process S500. Each process of the manufacturing method of the battery module 1 may be performed by a manufacturing machine, by a person, or by a collaboration between a manufacturing machine and a person.

[0034] In the unit fabrication process S100, a unit 50 is fabricated, which includes a first cell group 60, a second cell group 62, and a temperature control plate 64. In the stacking process S200, a plurality of the fabricated units 50 are stacked to form a stacked body 12.

[0035] In the assembling step S300, the bus bar module 14 and the prepared laminate 12 are assembled to at least some of the members that make up the case 10. For example, in the assembling step S300, the upper cover 20 and the side plates 22 may be assembled to the laminate 12, and the lower cover 24 may be assembled after the potting step S500. In the wire bonding step S400, the electrodes of the cells 30 and the bus bars 42 are connected by wires 44.

[0036] In the outflow prevention member attachment step S450, an outflow prevention member, which will be described later, is attached to the partially manufactured battery module 1. The outflow prevention member and the outflow prevention member attachment step S450 will be described in detail later.

[0037] In the potting process S500, a first filler is filled into the case 10 housing the laminate 12 and the busbar module 14. In the potting process S500, a fluid first filler is injected into the case 10 so that the first filler fills the gaps in the laminate 12. In the potting process S500, the first filler is hardened after a predetermined time has passed under predetermined conditions after the first filler is injected. The predetermined conditions and the predetermined time vary depending on the type and characteristics of the first filler. As the first filler injected into the case 10 hardens, the ability to fix the position of the laminate 12 inside the case 10 improves, thereby improving the structural, electrical, and environmental characteristics of the battery module 1.

[0038] 4 is a plan view showing an example of the battery module 1 immediately before the outflow prevention member attachment step S450. Fig. 4 shows the stack 12 as viewed from the bus bar module 14 side, and the bus bar module 14 is omitted from Fig. 4.

[0039] As shown in Fig. 4 , side plates 22, which are part of the case 10, are attached to both sides of the stack 12 in the stacking direction of the units 50 (Z direction in Fig. 4 ). Although not visible in Fig. 4 , an upper cover 20, which is part of the case 10, is attached to the back side of the stack 12 in the extension direction of the cells 30 (X direction in Fig. 4 ). The end of the side plate 22 on the upper cover 20 side is connected to the upper cover 20.

[0040] The temperature control plate 64 includes an extension section 100. The extension section 100 is a portion of the temperature control plate 64 that extends from an end of the parallel direction of the cells 30 in the cell group (Y direction in FIG. 4 ) in a direction away from the parallel direction of the cells 30. The extension section 100 is located at one end of the temperature control plate 64 in the parallel direction of the cells 30. In the example of FIG. 4 , the extension section 100 is located at the right end of the temperature control plate 64. The extension section 100 is formed in a flat plate shape.

[0041] The extension portion 100 protrudes outside the case 10 beyond the end of the side plate 22 in the direction in which the cells 30 are arranged side by side. The end of the temperature control plate 64 opposite to the extension portion 100 is located inside the case 10.

[0042] The battery module 1 includes a pipe 110 , a first electrode terminal 112 , and a second electrode terminal 114 .

[0043] The piping 110 is formed in the shape of a pipe having a flow path therein. The piping 110 is provided in the extension portion 100 of the temperature control plate 64. The piping 110 is located outside the case 10. The piping 110 extends in the stacking direction of the stack 12 (Z direction in FIG. 4 ). In other words, the piping 110 extends in a direction intersecting the plane of the extension portion 100 of the temperature control plate 64. The piping 110 connects the extension portions 100 of the multiple temperature control plates 64 together. The flow path inside the piping 110 communicates with the flow path inside the temperature control plate 64. A heat medium to be supplied to each temperature control plate 64 flows through the piping 110.

[0044] The first electrode terminal 112 and the second electrode terminal 114 are formed of a conductive material. The first electrode terminal 112 is disposed at an end of the battery module 1 where the piping 110 is located. The second electrode terminal 114 is disposed at an end opposite to the end where the piping 110 is located. The first electrode terminal 112 and the second electrode terminal 114 are electrically connected to the multiple cells 30 connected in parallel and in series.

[0045] The first electrode terminal 112 includes a first portion 120 extending outside the battery module 1 and one or more second portions 122 bent relative to the first portion 120. The second portions 122 are located closer to the battery module 1 than the first portion 120. The second portions 122 are disposed near the piping 110 between the piping 110 and a cell 30 at the end of the cell group in the parallel direction.

[0046] The second electrode terminal 114 includes a first portion 124 extending outside the battery module 1 and one or more second portions 126 bent relative to the first portion 124. The second portion 126 is located closer to the battery module 1 than the first portion 124. The second portion 126 is located near the cell 30 at the end of the cell group in the parallel direction, that is, the cell 30 at the end opposite the pipe 110.

[0047] The piping 110 may be installed, for example, when the laminate 12 is produced, when the laminate 12 is assembled to at least a portion of the case 10, or after wire bonding. The first electrode terminal 112 and the second electrode terminal 114 may be installed, for example, when the laminate 12 is assembled to at least a portion of the case 10, or after wire bonding.

[0048] 4 , a first opening 130 is provided on the side of the case 10, which includes the upper cover 20 and the side plate 22, on the side facing the piping 110. The piping 110 is located outside the case 10 with respect to the first opening 130. The first opening 130 includes a first partial opening 130a located between adjacent temperature control plates 64, and a second partial opening 130b located between the side plate 22 and the temperature control plate 64.

[0049] A second opening 132 is provided on the side of the case 10 opposite the piping 110. The second opening 132 includes an opening located between the side plate 22 and the temperature control plate 64. Hereinafter, for ease of explanation, the first opening 130 and the second opening 132 may be collectively referred to simply as the opening without distinction.

[0050] As such, since there is an opening on the side of the case 10, if the potting step S500 is carried out in the state shown in Figure 4, some of the filler injected into the case 10 in the potting step S500 may leak out of the case 10 through the opening.

[0051] Therefore, the manufacturing method of the battery module 1 of this embodiment includes an attachment step S450 of the outflow prevention member. Hereinafter, for convenience of explanation, the manufacturing method of the battery module 1 of this embodiment may be referred to as the present manufacturing method.

[0052] Fig. 5 is a plan view illustrating the outflow prevention member attachment step S450. In Fig. 5, the outflow prevention member 150 used in the outflow prevention member attachment step S450 is indicated by hatching. Fig. 6 is a vertical cross-sectional view illustrating the outflow prevention member attachment step S450. Hereinafter, for convenience of explanation, the battery module 1 under manufacture that is the target of the outflow prevention member attachment step S450 may be referred to as the target module.

[0053] The outflow prevention member 150 is configured to be able to restrict the movement of fluid. The outflow prevention member 150 is attached to the target module so as to close the opening in the side surface of the case 10.

[0054] The outflow prevention member 150 includes a first member 150a, a second member 150b, and a third member 150c. The first member 150a is attached so as to block the first partial opening 130a of the first opening 130. The second member 150b is attached so as to block the second partial opening 130b of the first opening 130. The third member 150c is attached so as to block the second opening 132.

[0055] The first member 150a is formed in a block shape that fits into the space surrounded by, for example, the adjacent temperature control plates 64, the first cell group 60 and the second cell group 62 with the insulating sheet 66 sandwiched therebetween, and the second portion 122 of the first electrode terminal 112 located between the temperature control plates 64. Note that the shape of the first member 150a is not limited to the shape exemplified in Fig. 5, and various shapes may be used that close the first partial opening 130a to an extent that the outflow of filler from the first partial opening 130a is restricted.

[0056] The first member 150a may be supported by, for example, at least one of the cell 30, the temperature control plate 64, and the second portion 122 of the first electrode terminal 112, which form the space in which the first member 150a is housed.

[0057] The second member 150b is formed, for example, in a block shape that fits into the space surrounded by the side plate 22, the cell group adjacent to the side plate 22, the temperature control plate 64, and the piping 110. Note that the shape of the second member 150b is not limited to the shape exemplified in Fig. 5, and may be various shapes that close the second partial opening 130b to an extent that the outflow of filler from the second partial opening 130b can be restricted.

[0058] The second member 150b may be supported by, for example, at least one of the cell 30, the temperature control plate 64, the side plate 22, and the piping 110 that form the space in which the second member 150b is housed.

[0059] The third member 150c is formed, for example, in the shape of a flat plate extending from one side plate 22 to the other side plate 22. The shape of the third member 150c is not limited to the shape exemplified in Fig. 5 and may be various shapes that close the second opening 132 to an extent that the outflow of the filler from the second opening 132 can be restricted.

[0060] The third member 150c is disposed so as to abut against an end of each side plate 22 opposite the piping 110 and an end of the upper cover 20 opposite the piping 110. With the third member 150c abutting against the side plates 22 and the upper cover 20, the portion of the laminate 12 opposite the piping 110 and the second portion 126 of the second electrode terminal 114 are positioned inside the case 10.

[0061] Note that the embodiment is not limited to the case where all of the first member 150 a, the second member 150 b, and the third member 150 c are attached to the target module. In the outflow prevention member attachment step S450, at least some of the outflow prevention members 150 may be attached to openings in the side surfaces of the case 10 of the target module.

[0062] In the potting step S500 following the outflow prevention member attachment step S450, a filler is filled into the inside of the case 10 of the target module with the outflow prevention member 150 attached, and is then hardened.

[0063] The outflow prevention member 150 may be left as a part of the battery module 1 after the filler is hardened in the potting step S500. In other words, the outflow prevention member 150 may be included in the finished battery module 1.

[0064] In this manufacturing method of this aspect, there is no need to provide a step of removing the outflow prevention member 150 after the potting step S500, and therefore the manufacturing process of the battery module 1 can be simplified.

[0065] Furthermore, the outflow prevention member 150 may be removed from the opening in the side surface of the case 10 after the filler has hardened in the potting step S500. In this embodiment, a step of removing the outflow prevention member 150 is required after the potting step S500.

[0066] However, in this manufacturing method, the anti-outflow member 150 is not included in the finished battery module 1, so the weight of the battery module 1 can be reduced by the weight of the anti-outflow member 150 compared to the method in which the anti-outflow member 150 is left in place.

[0067] In addition, a portion of the anti-flow member 150 attached in the anti-flow member attachment step S450 may be removed after the potting step S500, and another portion may remain as part of the battery module 1 after the potting step S500.

[0068] The outflow prevention member 150 may be formed, for example, by pre-curing the filler used in the potting step S500 into the shapes of the first member 150 a, the second member 150 b, and the third member 150 c. In other words, the outflow prevention member 150 may have the same physical properties as the filler after hardening.

[0069] By making the physical properties of the outflow prevention member 150 the same as those of the hardened filler, after the filler is filled and hardened in the potting step S500, the filler and the outflow prevention member 150 are substantially integrated. As a result, the manufacturing method of this aspect can be substantially the same as filling the openings in the side surfaces of the case 10 with the filler in the potting step S500. Therefore, the manufacturing method of this aspect can achieve the desired characteristics of the manufactured battery module 1.

[0070] Furthermore, the outflow prevention member 150 may be made of a material different from the filler used in the potting step S500. For example, the outflow prevention member 150 may be made of a general-purpose synthetic resin such as urethane or polypropylene.

[0071] The filler used in the potting step S500 can be more expensive than general-purpose synthetic resins. In this manufacturing method, the outflow prevention member 150 is made of a material different from the filler used in the potting step S500, thereby reducing the cost of the outflow prevention member 150 itself.

[0072] It should be noted that a portion of the outflow prevention member 150 may be made of a material with the same physical properties as the filler after hardening, and the other portion may be made of a material different from the filler.

[0073] Furthermore, when the outflow prevention member 150 is made of a material other than the filler used in the potting process S500, the outflow prevention member 150 may be made of a material that makes the flexibility of the outflow prevention member 150 at least greater than the flexibility of the case 10.

[0074] In this manufacturing method, the flexibility of outflow prevention member 150 is increased, which makes it possible to change the shape of outflow prevention member 150 when it is attached to an opening. As a result, in this manufacturing method, outflow prevention member 150 can be easily handled when it is attached to an opening, and outflow prevention member 150 can fit better to the opening.

[0075] Furthermore, if the outflow prevention member is to be removed after the potting step S500, the outflow prevention member 150 may be made of a material that provides a higher releasability between the outflow prevention member 150 and the hardened filler used in the potting step S500 than the releasability between the cell 30 and the hardened filler.

[0076] When the filler hardens in the potting step S500, the outflow prevention member 150 comes into contact with the hardened filler. In this embodiment of the manufacturing method, the releasability of the outflow prevention member 150 and the hardened filler is improved, making it easier to separate the outflow prevention member 150 from the hardened filler after the potting step S500. This makes it easier to handle the outflow prevention member 150 when removing it from the opening.

[0077] 7 is a plan view illustrating an example of the potting step S500. In FIG. 7, the laminate 12 housed inside the case 10 is omitted to avoid cluttering the drawing.

[0078] In the potting process S500, the case 10 is in a position where, for example, the lower cover 24 is not attached, the upper cover 20 is positioned vertically downward, and the case 10 is horizontal. In other words, the case 10 is in a position where the bus bar 42 is positioned vertically above the laminate 12 inside the case 10.

[0079] Each of the multiple bus bars 42 is arranged, for example, to extend from one side plate 22 to the other side plate 22. The multiple bus bars 42 are arranged at a distance from one another in the parallel arrangement direction of the cells 30 (the Y direction in FIG. 7 ), which is a direction intersecting the extension direction of the bus bars 42.

[0080] Predetermined gaps 170 are formed between adjacent bus bars 42 and between bus bars 42 and outflow prevention member 150. Predetermined gaps 170 communicate with the storage space S inside case 10, and in potting step S500, filler can be injected through these gaps 170.

[0081] As a comparative example, let us assume that the filler is injected uniformly at approximately the same time into all of the gaps 170. In this example, the air in the housing space S is difficult to escape, and air accumulates in at least a portion of the interior of the case 10, which may result in some portions not being filled with the filler.

[0082] In light of this, as shown in Fig. 7 , in the present manufacturing method, the timing for starting injection of the filler may be shifted for at least some of the gaps 170 among the plurality of gaps 170. For example, in the example of Fig. 7 , the start of injection of the filler into the cross-hatched gaps 170 among the plurality of gaps 170 may be delayed by a predetermined time from the start of injection of the filler into the non-cross-hatched gaps 170 among the plurality of gaps 170.

[0083] In this manufacturing method, by staggering the start of filler injection, air can be released from gaps 170 where no filler has been injected when the filler is injected. Therefore, this manufacturing method can prevent air from accumulating inside case 10, and can prevent the occurrence of areas where the filler is not filled.

[0084] Also, as shown in Figure 7, in this embodiment, gaps 170 without cross-hatching, where the injection of filler begins first, and gaps 170 with cross-hatching, where the injection of filler begins later, are set up alternately.

[0085] In this manufacturing method, the gaps 170 for delaying the start of filling agent injection are alternately set in different locations, so that filling agent and air removal can be performed efficiently.

[0086] 8 is a vertical cross-sectional view illustrating another example of the potting step S500. In the example of Fig. 8, in the outflow prevention member attachment step S450, a fourth member 150d is further attached as the outflow prevention member 150 to the target module.

[0087] The fourth member 150d is formed, for example, in a flat plate shape. The fourth member 150d is disposed on the upper surface side of the bus bar 42 and attached so as to close the gap 170 of the bus bar 42. An injection port 180 that communicates with the accommodation space S of the case 10 is formed at the end of the fourth member 150d on the side of the pipe 110.

[0088] 8, in the potting step S500, the case 10 is tilted relative to the horizontal so that the end on the pipe 110 side is positioned vertically above the horizontal and the end on the opposite side from the pipe 110 is positioned vertically below the horizontal. Then, in the potting step S500, the filler is injected from the injection port 180, as indicated by the outline arrow 182.

[0089] In this manufacturing method, the filler injected into the interior of the case 10 moves due to its own weight toward the end of the interior of the case 10 opposite the pipe 110. Furthermore, in this manufacturing method, the fourth member 150d is provided, so that even if the case 10 is tilted, the filler is prevented from leaking out of the gaps 170 of the bus bars 42. As a result, in this manufacturing method, the filler is prevented from leaking out of the case 10 and can fill the gaps in the laminate 12 inside the case 10 with the filler.

[0090] As described above, the battery module 1 of the present embodiment includes a stack 12 in which a plurality of units 50 are stacked, each unit including a first cell group 60 and a second cell group 62 in which a plurality of cells 30 extending in a first direction are aligned in a second direction perpendicular to the first direction, and a temperature control plate 64 disposed between the first cell group 60 and the second cell group 62 and extending in the second direction, and a case 10 that houses the stack 12. The manufacturing method for the battery module 1 of the present embodiment includes filling gaps in the stack 12 housed in the case 10 with a fluid filler and hardening the filler. The manufacturing method for the battery module 1 of the present embodiment also includes blocking an opening on a side surface of the case 10 housing the stack 12 with an outflow prevention member 150 configured to restrict fluid movement before filling the filler.

[0091] As a result, in the manufacturing method for a battery module of this embodiment, when filling the gaps of the laminate 12 housed in the case 10 with a fluid filler, the outflow prevention member 150 can prevent the filler from leaking out of the case 10 through the opening in the side surface of the case 10. Therefore, in the manufacturing method for a battery module of this embodiment, it is possible to properly fill the filler.

[0092] The battery module 1 of the present embodiment further includes a pipe 110 that is provided at one end of the temperature control plate 64 in the second direction, extends in the stacking direction of the stack 12, and through which a heat medium flows to be supplied to the temperature control plate 64. An opening is provided on the pipe 110 side of the case 10. The pipe 110 is located outside the case 10 with respect to the opening.

[0093] As described above, in the battery module 1 of the present embodiment, the piping 110 is provided at the end of the temperature control plate 64 of the laminate 12, and because the piping 110 is located outside the opening, the opening of the case 10 cannot be simply covered with a plate material such as the side plate 22. However, in the manufacturing method of the battery module 1 of the present embodiment, even if the opening is provided on the piping 110 side, the opening is blocked by the outflow prevention member 150. Therefore, in the manufacturing method of the battery module 1 of the present embodiment, even if the opening is provided on the piping 110 side, the outflow prevention member 150 can prevent the filler from leaking out of the case 10 through the opening.

[0094] While the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such embodiments. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present invention.

[0095] REFERENCE SIGNS LIST 1 battery module 10 case 12 laminate 30 cell 50 unit 60 first cell group 62 second cell group 64 temperature control plate 110 piping 130 first opening 130a first partial opening 130b second partial opening 132 second opening 150 outflow prevention member

Claims

1. A method for manufacturing a battery module comprising: a stack of multiple stacked units, each unit including a first cell group and a second cell group in which multiple cells extending in a first direction are aligned in a second direction perpendicular to the first direction, and a temperature control plate disposed between the first cell group and the second cell group and extending in the second direction; and a case that houses the stack, the method comprising: filling gaps in the stack housed in the case with a fluid filler and hardening the filler; and, prior to filling the filler, blocking an opening on a side of the case that houses the stack with an outflow prevention member configured to restrict the movement of fluid.

2. The method for manufacturing a battery module described in claim 1, wherein the battery module further comprises a pipe provided at one end of the temperature control plate in the second direction, extending in the stacking direction of the stack, and through which a heat medium to be supplied to the temperature control plate flows, the opening being provided on the pipe side of the case, and the pipe being located outside the case relative to the opening.

3. The method for manufacturing a battery module according to claim 1, wherein the outflow prevention member has the same physical properties as the filler after hardening.

4. The method for manufacturing a battery module according to claim 1, wherein the outflow prevention member remains as part of the battery module after the filler has hardened.

5. The method for manufacturing a battery module according to claim 1, wherein the outflow prevention member is removed from the opening after the filler has hardened.

6. The method for manufacturing a battery module according to claim 1, wherein the releasability between the outflow prevention member and the filler after hardening is higher than the releasability between the cell and the filler after hardening.

7. The method for manufacturing a battery module according to claim 1, wherein the flexibility of the anti-flow member is higher than the flexibility of the case.

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