battery module

Abstract

The present invention relates to a battery module (1), comprising: a plurality of single cells (100) arranged side by side in a first direction and each having a square shape; a restraining mechanism (400, 500) for restraining the plurality of single cells (100) in the first direction; and a restraining force adjustment mechanism (900, 1000) capable of adjusting a restraining load in the first direction generated by the restraining mechanism (400, 500). The restraining force adjustment mechanism (900, 1000) includes an operating portion (920, 1010) that is operated when adjusting the restraining load. The operating portion (920, 1010) is provided on the battery module (1).

Description

Technical Field

[0001] This technology relates to battery modules. Background Art

[0002] Battery modules composed of multiple stacked cells are known. These cells are restrained in the stacking direction by restraining members. Known mechanisms for adjusting the restraining force in the stacking direction include those described in Japanese Patent Application Publication Nos. 2013-20891 and 2021-57149. Summary of the Invention

[0003] The adjustment mechanisms described in Japanese Patent Application Publication No. 2013-20891 and Japanese Patent Application Publication No. 2021-57149 are intended to prevent the restraining force on a single cell from rising to an undesirable level when the ambient temperature or battery module temperature rises. Other mechanisms are needed to adjust the restraining force after the cells have been restrained by restraining components, based on customer requests, for example. The present technology aims to provide a battery module that allows for simple adjustment of the restraining load applied to the cells by a restraining mechanism.

[0004] The battery module according to the present technology comprises: a plurality of cells arranged side by side in a first direction, each having a square shape; a restraining mechanism for restraining the plurality of cells in the first direction; and a restraining force adjustment mechanism capable of adjusting the restraining load in the first direction generated by the restraining mechanism. The restraining force adjustment mechanism includes an operating portion that is operated to adjust the restraining load. The operating portion is provided on the battery module.

[0005] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 This is a perspective view showing the structure of a battery module according to one embodiment of the present technology.

[0007] Figure 2 Observed from the direction of arrow II Figure 1 A three-dimensional diagram of the battery module.

[0008] Figure 3 This is a perspective view showing the structure of a cell and an end plate included in a battery module according to an embodiment of the present technology.

[0009] Figure 4 This is a perspective view showing the structure of a unit included in a battery module according to one embodiment of the present technology.

[0010] Figure 5 Observed from the direction of arrow V Figure 4A cross-sectional view of a unit.

[0011] Figure 6 This is a perspective view showing the structure of a single cell included in a battery module according to an embodiment of the present technology.

[0012] Figure 7 This is a partial perspective view showing the structure of a voltage detection line included in a battery module according to an embodiment of the present technology.

[0013] Figure 8 This is a diagram showing the structure of a restraining force adjustment mechanism according to an example.

[0014] Figure 9 It means when viewed from the Y direction Figure 8 The diagram shows the state of the adjustment mechanism.

[0015] Figure 10 It is a diagram showing the structure of a restraining force adjustment mechanism according to a modification. DETAILED DESCRIPTION

[0016] Hereinafter, embodiments of the present technology will be described, wherein the same reference numerals are assigned to the same or corresponding parts, and the description thereof may not be repeated.

[0017] In addition, in the embodiments described below, when the number, amount, etc. are mentioned, unless otherwise specified, the scope of the present technology is not necessarily limited to the number, amount, etc. In addition, in the embodiments described below, each component is not necessarily essential to the present technology unless otherwise specified.

[0018] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a certain structure is included, other structures other than that structure may be included, or other structures other than that structure may be excluded. Furthermore, the present technology is not limited to achieving all the effects described in this embodiment.

[0019] In this specification, the term "battery" is not limited to lithium-ion batteries and can include other batteries such as nickel-metal hydride batteries. In this specification, the term "electrode" can be used to refer to both positive and negative electrodes. In addition, the term "electrode plate" can be used to refer to both positive and negative plates.

[0020] In the drawings, the stacking direction of the cells is defined as the first direction (Y direction), the direction along which the two electrode terminals of the cells are arranged is defined as the second direction (X direction), and the height direction of the cells is defined as the third direction (Z direction).

[0021] Figure 1 This is a perspective view showing the structure of a battery module according to one embodiment of the present technology. Figure 2 Observed from the direction of arrow II Figure 1 A three-dimensional image of a battery module. Figure 3 This is a perspective view showing the structure of a cell and an end plate included in a battery module according to an embodiment of the present technology.

[0022] The battery module 1 is used as a driving power source for vehicles such as hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), and battery electric vehicles (BEV).

[0023] First, the overall structure of the battery module 1 is described. Figures 1 to 3 As shown, the battery module 1 includes a plurality of cells 10 , an end plate 400 , a restraining member 500 , a lower restraining member 550 , a wiring member 600 , a duct 700 , and a connection terminal 800 .

[0024] The plurality of units 10 are arranged side by side in the first direction (direction Y). In this embodiment, six units 10 are arranged side by side in the direction Y. The number of the plurality of units 10 is not particularly limited as long as it is two or more.

[0025] The plurality of cells 10 are sandwiched between the two end plates 400. The plurality of cells 10 according to the present embodiment are pressed by the end plates 400 and restrained between the two end plates 400.

[0026] The end plates 400 are provided at both ends of the plurality of cells 10 in the Y direction. The end plates 400 are fixed to a base such as a pack case that houses the battery module 1. The end plates 400 are made of, for example, aluminum or iron.

[0027] The restraining members 500 are provided at both ends of the multiple units 10 and the end plates 400 in the X direction. By engaging the restraining members 500 with the end plates 400 while a compressive force in the Y direction is applied to the multiple units 10 and the end plates 400 arranged side by side, and then releasing the compressive force, a tensile force acts on the restraining members 500 connecting the two end plates 400. As a reaction to this, the restraining members 500 press the two end plates 400 toward each other. As a result, the restraining members 500 restrain the multiple units 10 in the first direction (the Y direction).

[0028] The restraint member 500 includes a plate-shaped portion 510, a first flange portion 520, and a second flange portion 530. The restraint member 500 is made of iron, for example.

[0029] The plate-like portion 510 is a member extending in the Y direction. A plurality of openings 511 are provided in the plate-like portion 510. The plurality of openings 511 are provided at intervals in the Y direction. The openings 511 are formed of through holes that penetrate the plate-like portion 510 in the X direction.

[0030] The first flange portion 520 extends from the side surfaces of the plurality of cells 10 to the upper surfaces of the plurality of cells 10. By providing the first flange portion 520, the rigidity of the restraint member 500 formed relatively thin can be ensured.

[0031] The second flange portion 530 is connected to both ends of the plate-shaped portion 510 in the Y direction. The second flange portion 530 is fixed to the end plate 400. Bolt holes 530A are formed in the second flange portion 530. The restraint member 500 is fixed to the end plate 400 by, for example, bolts 500A inserted through the bolt holes 530A. Thus, the restraint member 500 connects the two end plates 400 to each other.

[0032] like Figure 2 As shown, the lower restraint member 550 is provided on the bottom surface of the plurality of units 10 and the end plate 400. The lower restraint member 550 protects the unit cells 100 described later from the bottom surface side. The lower restraint member 550 is made of iron, for example.

[0033] like Figure 1 As shown, the wiring member 600 is provided at a position facing the plurality of cells 10 in the Z direction. The wiring member 600 passes through the center of each of the plurality of cells 10 in the X direction and extends in the Y direction. The wiring member 600 is electrically connected to the plurality of cells 10. The wiring member 600 is, for example, a flexible printed circuit board.

[0034] The duct 700 extends in the Y direction. When viewed in the Z direction, the duct 700 extends at a position overlapping with the wiring member 600. In the Z direction, the duct 700 is arranged between the plurality of units 10 and the wiring member 600.

[0035] The connection terminals 800 are arranged on both sides of the plurality of cells 10 arranged in the Y direction. When viewed from the Z direction, the connection terminals 800 are provided at positions overlapping the end plates 400. The connection terminals 800 connect the battery module 1 to external wiring such as cables (not shown) that are arranged outside the battery module 1.

[0036] A restraining force adjustment mechanism 900 is provided on the end surface of the end plate 400. The restraining force adjustment mechanism 900 includes a bolt member 910 mounted on the end plate 400, a nut member 920 screwed together with the bolt member 910, and a washer member 930.

[0037] Next, the structure of the unit 10 will be described. Figure 4This is a perspective view showing the structure of a unit included in a battery module according to one embodiment of the present technology. Figure 5 Observed from the direction of arrow V Figure 4 A three-dimensional diagram of the unit.

[0038] like Figure 4 as well as Figure 5 As shown, each of the plurality of units 10 includes a plurality of battery cells 100 , a case 200 as a supporting member, and a bus bar 300 .

[0039] The unit 10 includes two or more cells 100. In one embodiment of the present technology, the unit 10 includes an even number of four cells 100. The number of cells 100 in each of the multiple units 10 is not particularly limited, as long as it is two or more. Alternatively, the number of cells 100 in each of the multiple units 10 may be an odd number.

[0040] The plurality of cells 100 are arranged side by side in a first direction (the Y direction). In one embodiment of the present technology, four cells 100 are arranged side by side in the Y direction. The arrangement direction of the plurality of units 10 is the same as the arrangement direction of the plurality of cells 100 in each of the plurality of units 10.

[0041] The housing 200 has a rectangular parallelepiped shape. The housing 200 accommodates a plurality of cells 100. The housing 200 is formed of a resin such as polypropylene. Figures 1 to 3 As shown, the housing 200 is compressed in the first direction (Y direction) by the restraint member 500 .

[0042] The end plate 400 has a bolt hole 400A formed therein. The bolt hole 400A is used to attach the bolt member 910 of the restraining force adjustment mechanism 900 .

[0043] like Figure 4 as well as Figure 5 As shown, the housing 200 includes a front wall portion 210 , a rear wall portion 220 , a first side wall portion 230 , a second side wall portion 240 , and an upper surface portion 250 .

[0044] The front wall portion 210 is a surface adjacent to one of the restraining members 500. Figure 4 As shown in FIG, a plurality of first vents 211 are provided in the front wall portion 210. The first vents 211 are through holes that penetrate the front wall portion 210 in the X direction.

[0045] like Figure 5 As shown, the rear wall 220 is a surface facing the front wall 210 with the plurality of cells 100 interposed therebetween in the X direction. The rear wall 220 is provided with a plurality of second vents 221. The second vents 221 are through holes that penetrate the rear wall 220 in the X direction.

[0046] The first side wall portion 230 and the second side wall portion 240 are arranged side by side along the first direction (Y direction) and face each other.

[0047] like Figure 4 As shown in FIG. 2 , the first side wall portion 230 has a convex portion 231. The convex portion 231 protrudes toward the side opposite to the second side wall portion 240. Figure 5 As shown, the second side wall portion 240 has a recessed portion 241. The recessed portion 241 is recessed toward the first side wall portion 230 and has a shape that can engage with the protruding portion 231. Among the plurality of units 10, the protruding portions 231 of adjacent units 10 are respectively engaged with the recessed portions 241.

[0048] The upper surface portion 250 includes a first wall portion 251, a second wall portion 252, a third wall portion 253, a fourth wall portion 254, an engaging surface 255, and a hole portion 256. The first wall portion 251 is formed with two parallel walls extending in the Y-axis direction at the center portion in the X-direction. The second wall portion 252, the third wall portion 253, and the fourth wall portion 254 are arranged on both sides of the first wall portion 251 in the X-direction to define the installation position of the bus bar 300. A notch 252A is formed in the second wall portion 252 for passing the voltage detection line 610 described later. The second flange portion 530 of the restraint component 500 is engaged with the engaging surface 255. The hole portion 256 is connected to the gas exhaust valve 130 described later.

[0049] The bus bar 300 is made of a conductor, and the plurality of bus bars 300 electrically connect the plurality of cells 100 to each other.

[0050] Figure 6 This is a perspective view showing the structure of a single cell included in a battery module according to an embodiment of the present technology.

[0051] like Figure 6 As shown, the battery cell 100 is, for example, a lithium-ion battery and has a square shape.

[0052] The cell 100 according to this embodiment includes an electrode terminal 110 , a case 120 , and a gas release valve 130 .

[0053] The electrode terminal 110 is formed on the case 120. The electrode terminal 110 includes a positive electrode terminal 111 and a negative electrode terminal 112, which are two electrode terminals 110 arranged side by side along a second direction (X direction) perpendicular to the first direction (Y direction).

[0054] The positive electrode terminal 111 and the negative electrode terminal 112 are provided to be spaced apart from each other in the X direction. The positive electrode terminal 111 and the negative electrode terminal 112 are provided on both sides of the wiring member 600 and the duct 700 in the X direction, respectively.

[0055] The case 120 has a rectangular parallelepiped shape and constitutes the outer appearance of the unit cell 100. The case 120 accommodates an electrode assembly and an electrolyte solution (not shown).

[0056] The housing 120 has an upper surface 121 , a lower surface 122 , a first side surface 123 , a second side surface 124 , and a third side surface 125 .

[0057] The upper surface 121 is a plane perpendicular to the Z direction. The electrode terminal 110 is arranged on the upper surface 121. The lower surface 122 faces the upper surface 121 along a third direction (Z direction) perpendicular to the first direction (Y direction).

[0058] Each of the first side surface 123 and the second side surface 124 is formed by a plane perpendicular to the Y direction. Each of the first side surface 123 and the second side surface 124 has the largest area among the multiple side surfaces of the housing 120. When viewed in the Y direction, each of the first side surface 123 and the second side surface 124 has a rectangular shape. When viewed in the Y direction, each of the first side surface 123 and the second side surface 124 has a rectangular shape with the X direction being the longitudinal direction and the Z direction being the transverse direction.

[0059] The plurality of cells 100 are stacked such that the first side faces 123 and the second side faces 124 between adjacent cells 100 in the Y direction. Thus, the positive terminals 111 and the negative terminals 112 are alternately arranged in the Y direction of the stacked cells 100.

[0060] When the number of cells 100 provided in a unit 10 is an odd number, the posture of the unit 10 may be reversed 180° about the Z axis between adjacent units 10 in the Y direction.

[0061] The gas discharge valve 130 is provided on the upper surface 121. When the internal pressure of the box body 120 becomes higher than a predetermined value due to the gas generated inside the box body 120, the gas discharge valve 130 discharges the gas to the outside of the box body 120. The gas from the gas discharge valve 130 is discharged to the outside of the box body 120. Figure 1 The liquid flows through the pipe 700 in the battery module 1 and is discharged to the outside of the battery module 1.

[0062] Figure 7 This is a partial perspective view showing the structure of a voltage detection line included in a battery module according to an embodiment of the present technology.

[0063] like Figure 7 As shown, the wiring member 600 includes voltage detection lines 610 for detecting voltage. Multiple voltage detection lines 610 extend toward and connect to the busbar 300. One voltage detection line 610 is provided for each of the multiple cells 10. Thus, the voltage detection line 610 can detect the voltage of the cell 10.

[0064] Figure 8 1 is a diagram showing the structure of a restraining force adjustment mechanism 900 according to an example. Figure 8 The end plate 400 and the binding member 500 (binding bar) shown constitute a binding mechanism that constrains the plurality of units 10 in the first direction (Y direction). Bolt members 910 are provided on the end plate 400 in the same direction as the stacking direction (Y direction) of the units 10. Multiple bolt members 910 may be provided. Bolt members 910 can also serve as vehicle-side fastening points; in this case, the bolt members 910 are connected to the vehicle-side fixing bracket.

[0065] Nut member 920 is screwed onto bolt member 910. Screwing nut member 920 toward the right in the figure causes end plate 400 to bend (indicated by the double-dashed line in the figure) in the direction of arrow DR1 (to the right in the figure). This increases the restraining force of unit 10. Nut member 920 constitutes an operating portion that is operated when adjusting the restraining load.

[0066] The amount of deflection of the end plate 400 can be adjusted using a spacer member 930. The spacer member 930 is provided between the end unit 10 and the end plate 400. When the bolt member 910 also serves as a vehicle-side fastening point (fixing member), the spacer member 930 is provided between the end plate 400 and the vehicle-side (base-side) fixing bracket (mounting member).

[0067] In this manner, in the restraining force adjustment mechanism 900, the end plate 400 can be bent toward the stacked structure of the unit 10 by screwing the nut member 920 into the bolt member 910. The amount of deflection of the end plate 400 can be adjusted by adjusting the screwing amount of the nut member 920. Thus, the restraining force generated by the end plate 400 can be adjusted.

[0068] Figure 9 It means when viewed from the Y direction Figure 8 The state of the adjustment mechanism is shown in the figure. Figure 9 As shown, when the cell 100 is projected onto the end plate 400 along the Y direction, the bolt hole 400A for mounting the bolt member 910 is provided within the region of the cell 100 where the electrode body 140 is present (more preferably, within the region where the positive electrode active material layer included in the electrode body 140 is applied). This allows the bolt member 910 to be provided at least in the region where restraint is required.

[0069] Figure 10This figure shows the structure of a restraining force adjustment mechanism 1000 according to a modified example. The plate-shaped portion 510 of the restraining member 500 is fastened to the intermediate plate 20 (another module component) along the X direction (or Z direction) perpendicular to the stacking direction (Y direction) of the cells 10. Specifically, a bolt member 1010 penetrates the plate-shaped portion 510, and the tip of the bolt member 1010 is fixed to the intermediate plate 20.

[0070] When the bolt member 1010 is screwed into the intermediate plate 20, the plate-shaped portion 510 of the restraining member 500 bends to protrude in the direction of arrow DR2 (upward in the figure). As a result, the battery module 1 deforms to shorten in the first direction (Y direction), increasing the restraining force on the cell 10.

[0071] When the bolt members 1010 are loosened and the spacer member 1020 is inserted between the plate-like portion 510 of the restraining member 500 and the intermediate plate 20, the plate-like portion 510 bends, protruding in the direction of arrow DR3 (downward in the figure). In this case, the battery module 1 also deforms, shortening in the stacking direction (Y direction), increasing the restraining force on the cell 10.

[0072] The deflection of the plate-shaped portion 510 of the restraining member 500 can be adjusted by adjusting the screwing amount of the bolt member 1010 and the thickness of the spacer member 1020. Specifically, by adjusting the tightening force of the bolt member 1010, the deflection of the restraining member 500 in the X or Z direction can be adjusted, thereby adjusting the length of the battery module 1 in the Y direction. Here, the bolt member 1010 constitutes the operating portion that is operated when adjusting the restraining load.

[0073] In the battery module 1 according to one embodiment of the present technology, the operating unit for adjusting the restraint load is located on the battery module 1. This allows the restraint load to be easily adjusted after the cells are restrained by the restraining member. Therefore, the restraint load can be easily adjusted according to customer preferences, such as when the battery module 1 is manufactured and shipped.

[0074] Furthermore, in the battery module 1, by forming a unit 10 in which a plurality of single cells 100 are housed side by side in a housing 200 along a first direction (Y direction), and by arranging the plurality of units 10 side by side in the first direction (Y direction), the manufacturing process can be simplified compared to manufacturing the battery module 1 by manufacturing the plurality of single cells 100 as a single unit. An example of this simplification is, for example, passing a small unit 10 through a welding machine to weld the bus bars 300 within the unit 10, and then independently joining the bus bars 300 spanning different units 10, thereby making the welding process more efficient.

[0075] Furthermore, in the battery module 1 , since the unit 10 is configured by accommodating a plurality of cells 100 in the case 200 , the battery module 1 can be easily disassembled or replaced in units of the unit 10 .

[0076] Furthermore, in the battery module 1 , since the unit 10 is constructed by accommodating a plurality of cells 100 in the housing 200 , the battery module 1 can be divided when discarded and the unit 10 can be treated as a unit at a lower voltage, thereby facilitating the disposal of the battery module 1 .

[0077] Furthermore, in the battery module 1 , the single cells 100 can be constrained by the constraining member 500 through the structure of the unit 10 .

[0078] Furthermore, in the battery module 1 , by connecting the plurality of cells 10 to each other via the bus bar 300 , the battery module 1 can be manufactured in units of the cells 10 .

[0079] Furthermore, in the battery module 1 , since one voltage detection line 610 is disposed in one cell 10 , the cost of the battery module 1 can be reduced compared to a case where the voltage detection line 610 is disposed in each battery cell 100 .

[0080] While the embodiments of the present invention have been described, it should be understood that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the technical solutions claimed in this application, and is intended to include all modifications within the meaning and scope equivalent to the technical solutions claimed in this application.

Claims

1. A battery module comprising: A plurality of single cells are arranged side by side along a first direction and each has a square shape; a restraining mechanism for restraining the plurality of battery cells in the first direction; and The restraining force adjustment mechanism is capable of adjusting the restraining load in the first direction generated by the restraining mechanism. The battery module is characterized in that: The restraining force adjustment mechanism includes an operating portion that is operated when adjusting the restraining load. The operating unit is provided on the battery module. The restraint mechanism includes an end plate provided at an end portion of the stack of the plurality of cells in the first direction. The aforementioned binding force adjustment agencies include: At least one bolt member is mounted on the end plate along the first direction; and The nut part is screwed together with the bolt part. The end plate can be bent toward the stacked body by screwing the nut member into the bolt member, and the amount of bending of the end plate can be adjusted by adjusting the amount of screwing of the nut member.

2. The battery module according to claim 1, wherein: The restraining force adjustment mechanism further includes a spacer member provided between the end plate and the stacked body.

3. The battery module according to claim 1 or 2, characterized in that: The bolt member also serves as a fixing member for fixing the battery module to the base.

4. The battery module according to claim 3, characterized in that: The restraining force adjustment mechanism further includes a spacer member provided between the end plate and the mounting member on the base side.

5. The battery module according to any one of claims 1, 2 and 4, characterized in that: The bolt member is provided within a region of a coating area of ​​a positive electrode active material layer included in the electrode body of the unit cell when viewed from the first direction.

6. The battery module according to any one of claims 1, 2 and 4, characterized in that: further comprising a housing that accommodates the plurality of cells and supports the plurality of cells at least in the first direction to form a unit including the plurality of cells; The restraint mechanism restrains the plurality of units in the first direction.

7. A battery module comprising: A plurality of single cells are arranged side by side along a first direction and each has a square shape; a restraining mechanism for restraining the plurality of battery cells in the first direction; and The restraining force adjustment mechanism is capable of adjusting the restraining load in the first direction generated by the restraining mechanism. The battery module is characterized in that: The restraining force adjustment mechanism includes an operating portion that is operated when adjusting the restraining load. The operating unit is provided on the battery module. The restraint mechanism includes two end plates provided at both ends of the stack of the plurality of cells in the first direction and a restraint rod connecting the two end plates. The restraint force adjustment mechanism includes a bolt member that penetrates the restraint rod along a second direction perpendicular to the first direction and is fastened to other components in the battery module. By adjusting the tightening force of the bolt member, the amount of deflection of the restraint rod along the second direction can be adjusted, and the length of the battery module along the first direction can be adjusted.

8. The battery module according to claim 7, characterized in that: further comprising a housing that accommodates the plurality of cells and supports the plurality of cells at least in the first direction to form a unit including the plurality of cells; The restraint mechanism restrains the plurality of units in the first direction.

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