Battery module

Abstract

To firmly fix a flexible printed circuit board.SOLUTION: A flexible printed circuit board 700 is arranged to overlap with a gas duct 600 in a second direction orthogonal to a first direction, and is electrically connected to at least one of multiple battery cells. The gas duct 600 includes a main body portion 610 and an extension portion 620. The extension portion 620 extends from the main body portion 610 in the first direction. The extension portion 620 is wider than the main body portion 610 in a third direction orthogonal to the first direction and the second direction. The flexible printed circuit board 700 is fixed to the extension portion 620.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present technology relates to a battery module. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2023-074270 (Patent Document 1) is a prior art document that discloses the configuration of a battery module. The battery module described in Patent Document 1 includes a plurality of battery cells and a voltage detection line. The voltage detection line extends in the stacking direction of the plurality of battery cells. The voltage detection line is made of a flexible printed circuit board. A voltage detection terminal extends from the voltage detection line. The voltage detection line is connected to the battery cell via the voltage detection terminal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-074270 Summary of the Invention [Problem to be solved by the invention]

[0004] In the battery module described in Patent Document 1, the position of the flexible printed circuit board is fixed by connecting the flexible printed circuit board that forms the voltage detection line to the battery cell. In this case, there is a possibility that the fixing of the flexible printed circuit board may become unstable, so it is required to fix the flexible printed circuit board firmly.

[0005] The present technology has been made to solve the above-mentioned problems, and has an object to provide a battery module that can firmly fix a flexible printed circuit board. [Means for solving the problem]

[0006] The present technology provides the following battery module.

[0007] [1] a plurality of battery cells arranged in a first direction and each having a rectangular shape; a gas duct disposed above the plurality of battery cells and through which gas can flow in at least the first direction; a flexible printed circuit board that is arranged to overlap with the gas duct in a second direction perpendicular to the first direction and is electrically connected to at least one battery cell among the plurality of battery cells; the gas duct includes a main body portion and an extension portion extending from the main body portion in the first direction; the extension portion is wider than the main body portion in a third direction perpendicular to the first direction and the second direction, The flexible printed circuit board is fixed to the extension portion.

[0008] [2] The battery module according to [1], wherein the flexible printed circuit board is fixed in close contact with the gas duct.

[0009] [3] a first step portion is provided in the gas duct between the main body portion and the extension portion such that an upper surface of the main body portion is farther from the plurality of battery cells than an upper surface of the extension portion in the second direction; the flexible printed circuit board includes a first portion overlapping the main body portion and a second portion overlapping the extension portion, a second step portion is provided between the first portion and the second portion of the flexible printed circuit board so that a lower surface of the second portion is closer to the plurality of battery cells than a lower surface of the first portion in the second direction; The battery module according to [1] or [2], wherein the upper surfaces of the first portion and the second portion are formed to be approximately flat at the boundary between the first portion and the second portion.

[0010] [4] a protrusion extending in the first direction toward the other of the first step portion and the second step portion is provided on one of the first step portion and the second step portion; a recess that receives the protrusion in the first direction is provided in the other of the first step portion and the second step portion, The battery module according to [3], wherein the protrusion and the recess are engaged with each other.

[0011] [5] a cover member that covers the flexible printed circuit board from the opposite side of the plurality of battery cells in the second direction; The battery module according to any one of [1] to [4], wherein the cover member includes a protrusion that protrudes toward the flexible printed circuit board in the second direction.

[0012] [6] The battery module according to [5], wherein the gas duct is harder than the cover member.

[0013] [7] The battery module according to any one of [1] to [6], wherein the extension portion protrudes in the first direction from a battery cell located at an end in the first direction among the plurality of battery cells.

[0014] [8] the extension portion extends in the third direction such that one end thereof is farther from the main body portion than the other end thereof; The battery module according to any one of [1] to [7], wherein the flexible printed circuit board has a substantially L-shape. [Effects of the Invention]

[0015] According to the present technology, it is possible to firmly fix a flexible printed circuit board. [Brief explanation of the drawings]

[0016] [Figure 1]1 is a perspective view showing a configuration of a battery module according to an embodiment of the present technology; [Figure 2] 1 is a perspective view showing an internal configuration of a battery module according to an embodiment of the present technology; [Figure 3] 1 is a perspective view showing a configuration of a unit included in a battery module according to an embodiment of the present technology; [Figure 4] 1 is a perspective view showing a configuration of a battery cell according to an embodiment of the present technology; [Figure 5] 1 is a perspective view showing a configuration of a gas duct and a flexible printed circuit board according to an embodiment of the present technology; [Figure 6] 6 is a cross-sectional view of the gas duct and the flexible printed circuit board in FIG. 5, taken along the line VI-VI. [Figure 7] 7 is a perspective view of the gas duct and the flexible printed circuit board and its peripheral configuration in FIG. 5, as viewed in the direction of arrow VII. [Figure 8] FIG. 10 is a schematic diagram showing a state in which a substrate material of a flexible printed circuit board according to a comparative example is cut out from a plate-shaped substrate. [Figure 9] 1 is a schematic diagram illustrating a state in which a base material of a flexible printed circuit board according to an embodiment of the present technology is cut out from a plate-shaped substrate; DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present technology will be described. Note that the same or corresponding parts are denoted by the same reference characters, and description thereof may not be repeated.

[0018] In the embodiments described below, when numbers, amounts, etc. are mentioned, the scope of the present technology is not necessarily limited to those numbers, amounts, etc., unless otherwise specified. Furthermore, in the embodiments described below, each component is not necessarily essential to the present technology, unless otherwise specified. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects and advantages mentioned in the present embodiments.

[0019] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a certain feature is included, other features may or may not be included.

[0020] Furthermore, when geometric terms and terms expressing positional and directional relationships are used in this specification, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along," these terms allow for manufacturing errors and slight variations. When terms expressing relative positional relationships, such as "upper side" and "lower side," are used in this specification, these terms are used to indicate relative positional relationships in a single state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

[0021] In this specification, the term "battery" is not limited to lithium-ion batteries, but may include other batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, the term "electrode" may collectively refer to a positive electrode and a negative electrode.

[0022] The "battery module" can be installed in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs), etc. However, the use of the "battery module" is not limited to in-vehicle use.

[0023] In the drawings, the direction in which the positive and negative terminals of the battery cells are lined up is the X direction, which is the third direction; the direction in which multiple battery cells are stacked is the Y direction, which is the first direction; and the direction in which the gas duct and flexible printed circuit board are lined up and overlapped is the Z direction, which is the second direction.

[0024] Fig. 1 is a perspective view showing a configuration of a battery module according to an embodiment of the present technology, and Fig. 2 is a perspective view showing an internal configuration of a battery module according to an embodiment of the present technology.

[0025] First, a description will be given of the overall structure of the battery module 1. As shown in Fig. 1 and Fig. 2, the battery module 1 according to an embodiment of the present technology includes a plurality of units 10, an end plate 400, a restraining member 500, a gas duct 600, a flexible printed circuit board 700, a cover member 800, and a connection terminal portion 850.

[0026] The multiple units 10 are arranged side by side in a first direction (Y direction). Six of the multiple units 10 according to this embodiment are arranged side by side in the first direction (Y direction). The number of the multiple units 10 is not particularly limited as long as it is two or more. The number of the multiple units may be, for example, 18.

[0027] The multiple units 10 are sandwiched in the first direction (Y direction) between the two end plates 400. The multiple units 10 according to this embodiment are pressed against one end plate 400A and the other end plate 400B, and are constrained between the two end plates 400A and 400B.

[0028] The end plates 400 are provided at both ends of the multiple units 10 in the first direction (Y direction). The end plates 400 are fixed to a base such as a pack case that houses the battery modules 1. The end plates 400 are made of, for example, aluminum, an aluminum alloy, iron, or an iron alloy.

[0029] The restraining members 500 are provided on both ends of the multiple units 10 and the end plates 400 in the X direction. When the restraining members 500 are engaged with the end plates 400 while a compressive force in a first direction (Y direction) is applied to the multiple units 10 and end plates 400 arranged side by side, and the compressive force is then released, a tensile force acts on the restraining members 500 connecting the two end plates 400. In reaction to this, the restraining members 500 press the two end plates 400 in a direction that brings them closer to each other. As a result, the restraining members 500 restrain the multiple units 10 in the first direction (Y direction).

[0030] Restraint member 500 includes a plate-shaped portion 510, a first flange portion 520, and a second flange portion 530. Restraint member 500 is made of, for example, iron or an iron alloy.

[0031] The plate-shaped portion 510 is a member extending in a first direction (Y direction). A plurality of openings 511 are provided in the plate-shaped portion 510. The plurality of openings 511 are provided at intervals from one another in the first direction (Y direction). The openings 511 are configured as through-holes that penetrate the plate-shaped portion 510 in the X direction.

[0032] The first flange portion 520 wraps around from the side surface of the plurality of units 10 in the X direction to the top surface of the plurality of units 10. By providing the first flange portion 520, the rigidity of the restraint member 500, which is formed relatively thin, can be ensured.

[0033] The second flange portion 530 is connected to both ends of the plate-shaped portion 510 in the first direction (Y direction). The second flange portion 530 is fixed to the end plate 400. The second flange portion 530 is fixed to the end plate 400 by a known fixing method such as bolt fastening. In this way, the restraint member 500 connects the two end plates 400 to each other.

[0034] The gas duct 600 is disposed above the multiple units 10. Specifically, the gas duct 600 is disposed above the multiple battery cells 100, which will be described later. The gas duct 600 extends in a first direction (Y direction). The gas duct 600 allows gas to flow through it at least in the first direction (Y direction). When viewed from the Z direction, the gas duct 600 extends at a position that overlaps with the flexible printed circuit board 700. The gas duct 600 is made of, for example, polybutylene terephthalate (PBT).

[0035] The flexible printed circuit board 700 is provided to detect the voltage of the battery cells 100, which will be described later. The flexible printed circuit board 700 is arranged so as to overlap the gas duct 600 in a second direction (Z direction) that is perpendicular to the first direction. The flexible printed circuit board 700 is arranged above the gas duct 600. The flexible printed circuit board 700 is arranged in a position facing the multiple units 10 in the Z direction. The flexible printed circuit board 700 is arranged on the opposite side of the gas duct 600 from the multiple battery cells 100 in the second direction (Z direction). This arrangement allows the flexible printed circuit board 700 to ensure a sufficient insulation distance from the multiple battery cells 100.

[0036] The flexible printed circuit board 700 extends in the Y direction, passing through the center of each of the multiple units 10 in the X direction. Voltage detection lines (not shown) built into the flexible printed circuit board 700 are electrically connected to the multiple units 10. The flexible printed circuit board 700 is made of resin such as polyimide.

[0037] The cover member 800 covers the components of the battery module 1 from above in the Z direction. The cover member 800 is made of, for example, polypropylene.

[0038] The connection terminal portions 850 are arranged on both sides of the multiple units 10 arranged side by side in the first direction (Y direction). The connection terminal portions 850 are fixed to the end plates 400. The connection terminal portions 850 have a negative side connection terminal portion 850A and a positive side connection terminal portion 850B. The connection terminal portions 850 form a path for electrical connection between the battery module 1 and a driving source or the like arranged outside the battery module 1.

[0039] Next, a description will be given of the structure of the unit 10. Fig. 3 is a perspective view showing the configuration of a unit included in a battery module according to an embodiment of the present technology.

[0040] As shown in FIG. 3, each of the multiple units 10 includes multiple battery cells 100, a case 200, and multiple bus bars 300.

[0041] Each unit 10 includes two or more battery cells 100. The unit 10 according to this embodiment includes an even number of battery cells 100, that is, two. The number of battery cells 100 included in each of the multiple units 10 is not particularly limited as long as it is two or more. The number of battery cells 100 included in each of the multiple units 10 may also be an odd number. The total number of battery cells 100 in the battery module 1 is, for example, 12 or 36.

[0042] The plurality of battery cells 100 are lined up in a first direction (Y direction). As shown in Figures 2 and 3, the arrangement direction of the plurality of units 10 and the arrangement direction of the plurality of battery cells 100 in each of the plurality of units 10 are the same direction.

[0043] As shown in FIG. 3 , the case 200 has a rectangular parallelepiped appearance. The case 200 houses at least two battery cells 100 out of a plurality of battery cells 100. In this embodiment, the case 200 houses two battery cells 100. The case 200 can sandwich the two battery cells 100 in the first direction (Y direction) in a state where no load is applied from other components in the first direction (Y direction). The two battery cells 100 do not come into contact with each other because a partition wall (not shown) is disposed between the two battery cells 100.

[0044] The case 200 is made of a resin such as polypropylene. The case 200 is formed by injection molding, for example. As shown in Figures 1 and 2, when the case 200 is assembled to the battery module 1, it is compressed in the first direction (Y direction) by the restraining member 500.

[0045] As shown in FIG. 3, the case 200 has a first side wall portion 210, a second side wall portion 220, a third side wall portion 230, a fourth side wall portion 240, and an upper wall portion 260.

[0046] The first side wall portion 210 and the second side wall portion 220 are arranged side by side in the first direction (Y direction) and face each other, with the battery cell 100 sandwiched between them.

[0047] The third side wall portion 230 is a surface adjacent to one of the restraint members 500. A first ventilation hole 231 is provided in the third side wall portion 230. The first ventilation hole 231 protrudes from the third side wall portion 230 toward the one of the restraint members 500. The first ventilation hole 231 is provided so as to penetrate the third side wall portion 230 in the X direction.

[0048] The fourth side wall portion 240 is a surface that faces the third side wall portion 230 in the X direction, with the multiple battery cells 100 sandwiched therebetween. A second ventilation opening 241 is provided in the fourth side wall portion 240. The second ventilation opening 241 protrudes from the fourth side wall portion 240 toward the other restraint member 500. The second ventilation opening 241 is provided so as to penetrate the fourth side wall portion 240 in the X direction. The second ventilation opening 241 is in communication with the first ventilation opening 231 by a cooling medium passage (not shown) that is provided inside the case 200.

[0049] The upper wall portion 260 includes a plurality of wall portions 262 and a plurality of hole portions 263. The plurality of wall portions 262 are erected in the Z direction. The plurality of wall portions 262 mainly define installation locations for the plurality of bus bars 300. The plurality of hole portions 263 are provided so that the electrode terminals 110 and the gas exhaust valve 130, which will be described later, are exposed from the upper wall portion 260.

[0050] The bus bars 300 are made of a conductor and electrically connect the battery cells 100 to one another.

[0051] The multiple bus bars 300 include a first bus bar 310, a second bus bar 320, and a third bus bar 330. The first bus bar 310 electrically connects the electrode terminals 110 of the battery cells 100 housed in one unit 10. The second bus bar 320 and the third bus bar 330 electrically connect the electrode terminals 110 of the battery cells 100 in one unit 10 and the battery cells 100 in another adjacent unit 10.

[0052] Fig. 4 is a perspective view showing a configuration of a battery cell according to an embodiment of the present technology. As shown in Fig. 4, the battery cell 100 is, for example, a lithium ion battery. The battery cell 100 has a rectangular shape.

[0053] The battery cell 100 according to this embodiment includes an electrode terminal 110, a housing 120, and a gas release valve .

[0054] The electrode terminal 110 is formed on the housing 120. The electrode terminal 110 has a positive electrode terminal 111 and a negative electrode terminal 112. The positive electrode terminal 111 and the negative electrode terminal 112 of the electrode terminal 110 are aligned in a third direction (X direction) that is perpendicular to the first direction (Y direction) and the second direction (Z direction).

[0055] The positive electrode terminal 111 and the negative electrode terminal 112 are spaced apart from each other in the X direction. The positive electrode terminal 111 and the negative electrode terminal 112 are respectively provided on both sides of the gas duct 600 and the flexible printed circuit board 700 in the X direction. The positive electrode terminal 111 and the negative electrode terminal 112 are joined to the bus bar 300 by laser welding or the like.

[0056] The housing 120 has a rectangular parallelepiped shape and forms the external appearance of the battery cell 100. The housing 120 contains an electrode assembly and an electrolyte solution, not shown.

[0057] Housing 120 has upper surface portion 121, lower surface portion 122, first side surface portion 123, second side surface portion 124, and third side surface portion 125.

[0058] The upper surface portion 121 is a plane perpendicular to the Z direction. The electrode terminals 110 are provided on the upper surface portion 121. The upper surface portion 121 is covered by an upper wall portion 260 of the case 200. The lower surface portion 122 faces the upper surface portion 121 in the second direction (Z direction).

[0059] Each side surface of the first side surface portion 123 and the second side surface portion 124 is made up of a plane perpendicular to the Y direction. The first side surface portion 123 and the second side surface portion 124 face each other in a first direction (Y direction). Each side surface of the first side surface portion 123 and the second side surface portion 124 has the largest area among the multiple side surfaces of the housing 120. Each side surface of the first side surface portion 123 and the second side surface portion 124 has a rectangular shape when viewed in the Y direction. Each side surface of the first side surface portion 123 and the second side surface portion 124 has a rectangular shape with the X direction as the longitudinal direction and the Z direction as the lateral direction when viewed in the Y direction.

[0060] A pair of third side surface portions 125 are provided on the battery cell 100. The pair of third side surface portions 125 are arranged side by side in the X direction. Each of the pair of third side surface portions 125 connects the ends of the first side surface portion 123 and the second side surface portion 124. The pair of third side surface portions 125 are arranged opposite the third side wall portion 230 and the fourth side wall portion 240 of the case 200 in the X direction.

[0061] The multiple battery cells 100 are stacked such that the first side surface portions 123 and the second side surface portions 124 of the battery cells 100 adjacent to each other in the Y direction face each other. As a result, the positive electrode terminals 111 and the negative electrode terminals 112 are arranged alternately in the Y direction in which the multiple battery cells 100 are stacked.

[0062] The gas exhaust valve 130 is provided on the upper surface portion 121. When the internal pressure of the housing 120 exceeds a predetermined value due to gas generated inside the housing 120, the gas exhaust valve 130 exhausts the gas to the outside of the housing 120. The gas from the gas exhaust valve 130 flows through the gas duct 600 in FIG. 1 and is exhausted to the outside of the battery module 1.

[0063] Fig. 5 is a perspective view showing a configuration around a gas duct and a flexible printed circuit board according to an embodiment of the present technology. Fig. 6 is a cross-sectional view of the configuration around the gas duct and the flexible printed circuit board in Fig. 5, as seen from the direction of the arrows VI-VI. Fig. 7 is a perspective view of the configuration around the gas duct and the flexible printed circuit board in Fig. 5, as seen from the direction of the arrow VII. Note that Figs. 5 and 7 show a portion of the configuration of the battery module in perspective to facilitate understanding of the present technology.

[0064] As shown in FIGS. 5 to 7, the gas duct 600 includes a main body portion 610 and an extension portion 620.

[0065] The main body 610 extends in a first direction (Y direction) and is located above the multiple battery cells 100 in a second direction (Z direction).

[0066] A flow space 611 is provided in the main body 610. The flow space 611 extends in the first direction (Y direction) to an end on the opposite side to the side on which the extension portion 620 is disposed. Gas discharged from the gas discharge valves 130 of the multiple battery cells 100 can flow through the flow space 611 along the first direction (Y direction). The gas discharged from the gas discharge valves 130 is discharged from the side of the flow space 611 opposite to the side on which the extension portion 620 is disposed.

[0067] The extension portion 620 extends from the main body portion 610 in the first direction (Y direction). The extension portion 620 is arranged to be aligned with the negative side connection terminal portion 850A in the third direction (X direction) (see FIG. 1). The negative side connection terminal portion 850A is arranged shifted to one side from the center of the battery module 1 in the third direction (X direction). By arranging the extension portion 620 in the space adjacent to the negative side connection terminal portion 850A in the third direction (X direction), this space can be utilized, and the extension portion 620 can be provided without increasing the size of the entire battery module 1.

[0068] The extension portion 620 is wider in a third direction (X direction) perpendicular to the first direction (Y direction) and the second direction (Z direction) than the main body portion 610. The maximum width of the extension portion 620 in the third direction (X direction) is, for example, 1.2 to 3.0 times the maximum width of the main body portion 610 in the third direction (X direction).

[0069] The extension portion 620 protrudes in the first direction (Y direction) from the battery cell 101 located at the end of the plurality of battery cells 100 in the first direction (Y direction). The extension portion may be disposed above the plurality of battery cells 100 in the second direction (Z direction). In this case, the extension portion is disposed in a position that does not interfere with the electrode terminals, etc.

[0070] The extending portion 620 has a claw portion 621. The claw portion 621 holds the folded portion 410 of the end plate 400 between the claw portion 621 and the lower surface of the extending portion 620. In this way, the gas duct 600 is fixed to one end plate 400A.

[0071] The flexible printed circuit board 700 includes a first portion 710 and a second portion 720 .

[0072] The first portion 710 is a portion that overlaps in the second direction (Z direction) with the main body portion 610. The first portion 710 extends in the first direction (Y direction).

[0073] The first portion 710 has a substrate main body 711 and a plurality of branch portions 712. The substrate main body 711 is a portion of the first portion 710 that overlaps with the main body portion 610 of the gas duct 600 in the second direction (Z direction).

[0074] The multiple branch portions 712 extend in the third direction (X direction) from the board main body 711. The multiple branch portions 712 are electrically connected to the bus bar 300. As a result, the flexible printed circuit board 700 is electrically connected to at least one battery cell 100 among the multiple battery cells 100 via the multiple branch portions 712 and the bus bar 300.

[0075] The second portion 720 overlaps with the extending portion 620 in the second direction (Z direction). The second portion 720 extends in the XY plane so as to substantially overlap with the extending portion 620. The second portion 720 is wider than the first portion 710 in the third direction (X direction).

[0076] The second portion 720 has a substrate portion 730 and a thickened portion 740. The substrate portion 730 is connected to the substrate main body 711. The substrate main body 711 and the substrate portion 730 are integrally configured. The thickened portion 740 is a plate-shaped member made of resin and provided on the lower surface side of the substrate portion 730. The thickened portion 740 is adhered to the lower surface of the substrate portion 730. As a result, the second portion 720 is thicker than the first portion 710 in the second direction (Z direction). Note that the substrate portion 730 and the thickened portion 740 may be configured as a single member.

[0077] The upper surfaces of the first portion 710 and the second portion 720 are formed to be approximately flat at the boundary between the first portion 710 and the second portion 720. Because the first portion 710 and the substrate portion 730 are integrally formed, the upper surfaces of the first portion 710 and the second portion 720 at the boundary between the first portion 710 and the second portion 720 are smoothly continuous.

[0078] The flexible printed circuit board 700 is fixed to the extending portion 620 of the gas duct 600. Specifically, the substrate portion 730, the thickened portion 740, and the extending portion 620 are provided with through-holes 751 that penetrate these structures in the second direction (Z direction). A fixing member 750 is inserted into the through-holes 751, and the flexible printed circuit board 700 is fixed to the gas duct 600.

[0079] Two fixing members 750 are provided. The two fixing members 750 are arranged at a distance greater than the width of the substrate main body 711 in the third direction (X direction). This increases the distance between the two fixing members 750 and increases the fixed area, compared to when fixing members are provided on the substrate main body 711, thereby enabling the flexible printed circuit board 700 to be fixed to the gas duct 600 more firmly.

[0080] The flexible printed circuit board 700 is fixed in close contact with the gas duct 600. In the present embodiment, no other member is interposed between the gas duct 600 and the flexible printed circuit board 700, but this is not limiting. Other members may be interposed between the gas duct 600 and the flexible printed circuit board 700.

[0081] A connection port 760 is provided above the second portion 720. The connection port 760 electrically connects the voltage detection line in the flexible printed circuit board 700 to an external control unit.

[0082] As shown in FIGS. 5 and 6 , the gas duct 600 has a first step portion 630 between the main body portion 610 and the extending portion 620. The first step portion 630 is provided so that the upper surface of the main body portion 610 is farther from the plurality of battery cells 100 than the upper surface of the extending portion 620 in the second direction (Z direction). The flexible printed circuit board 700 also has a second step portion 770 between the first portion 710 and the second portion 720. The second step portion 770 is provided so that the lower surface of the second portion 720 is closer to the plurality of battery cells 100 than the lower surface of the first portion 710 in the second direction (Z direction). The first step portion 630 and the second step portion 770 are provided so that they can abut against each other. The first step portion 630 and the second step portion 770 each have surfaces that extend on the XZ plane and face each other.

[0083] A convex portion is provided on either the first step portion 630 or the second step portion 770. The convex portion extends in a first direction (Y direction) toward the other of the first step portion 630 or the second step portion 770. In the present embodiment, a convex portion 741 is provided on the second step portion 770. The convex portion 741 extends in the first direction (Y direction) toward the first step portion 630.

[0084] A recess is provided in the other of first step portion 630 and second step portion 770. The recess receives the protrusion in the first direction (Y direction). In this embodiment, first step portion 630 is provided with recess 631. Recess 631 receives protrusion 741 in the first direction (Y direction).

[0085] The convex portion 741 and the concave portion 631 are engaged with each other. This allows the flexible printed circuit board 700 to be positioned mainly in the third direction (X direction). If the protrusion amount of the convex portion 741 in the first direction (Y direction) is made smaller than the depth of the concave portion 631, the first step portion 630 and the second step portion 770 can be brought into contact with each other, allowing the flexible printed circuit board 700 to be positioned relative to the gas duct 600 in the first direction (Y direction) as well.

[0086] As shown in FIG. 6, the cover member 800 covers the flexible printed circuit board 700 from the side opposite the multiple battery cells 100 in the second direction (Z direction). The cover member 800 includes a protrusion 810 that protrudes toward the flexible printed circuit board 700 in the second direction (Z direction). The protrusion 810 abuts against the flexible printed circuit board 700 without pressing against it, thereby supporting the flexible printed circuit board 700. This stabilizes the position of the flexible printed circuit board 700 in the second direction (Z direction). There may be a gap between the flexible printed circuit board 700 and the protrusion 810.

[0087] Because the gas duct 600 is made of polybutylene terephthalate and the cover member 800 is made of polypropylene, the gas duct 600 is harder than the cover member 800. If gas is generated in the battery cell 100, the gas duct 600 is made of a harder material than the cover member 800 so that it has higher resistance to the gas.

[0088] Here, a battery module according to a comparative example will be described. The battery module according to the comparative example has a different flexible printed circuit board configuration from battery module 1 according to the embodiment of the present technology, and therefore, the description of the configuration that is similar to battery module 1 according to the embodiment of the present technology will not be repeated.

[0089] FIG. 8 is a schematic diagram showing a state in which a substrate material of a flexible printed circuit board according to a comparative example is cut out from a plate-shaped substrate.

[0090] As shown in FIG. 8, a substrate material 90 of the flexible printed circuit board according to the comparative example is cut out from a plate-shaped substrate 7. The substrate material 90 is configured in a T-shape. That is, the centers of the main body and the extension portions of the substrate material 90 are arranged at the same position in the DR1 direction. When considering cutting out a large number of substrate materials 90 from a plate-shaped substrate, it is conceivable to alternately arrange the substrate materials 90 by rotating them 180°, as shown in FIG. 8. In this case, excess regions R are formed between the substrate materials 90.

[0091] FIG. 9 is a schematic diagram showing a state in which a base material of a flexible printed circuit board according to an embodiment of the present technology is cut out from a plate-shaped substrate.

[0092] 7 and 9, one end of extension portion 620 extends farther from main body portion 610 in the third direction (X direction) than the other end. As shown in Fig. 7, center position C2 of extension portion 620 is located closer to one end than center position C1 of main body portion 610 in the third direction (X direction). Therefore, flexible printed circuit board 700 has a substantially L-shape.

[0093] 9, the substrate material 70 forming the flexible printed circuit board 700 in one embodiment is substantially L-shaped. When the substrate materials 70 are alternately arranged by being rotated 180 degrees, the excess area between the substrate materials 70 can be reduced compared to the comparative example. Therefore, compared to the comparative example, more substrate materials 70 can be obtained from a plate-shaped substrate of the same area, thereby improving the yield when manufacturing the flexible printed circuit board 700.

[0094] In the battery module 1 according to an embodiment of the present technology, the flexible printed circuit board 700 can be firmly fixed by fixing the flexible printed circuit board 700 to the extension portion 620 of the gas duct 600. Furthermore, since there is no need to provide a separate member for fixing the flexible printed circuit board 700, the number of parts of the battery module 1 can be reduced.

[0095] In the battery module 1 according to an embodiment of the present technology, the flexible printed circuit board 700 is fixed in close contact with the gas duct 600, and therefore the flexible printed circuit board 700 can also serve as part of the gas exhaust path of the gas duct 600, thereby making it possible to form a strong gas exhaust path. Furthermore, the flexible printed circuit board 700 is made of heat-resistant polyimide, making it possible to form an even stronger gas exhaust path.

[0096] In a battery module 1 according to one embodiment of the present technology, the second portion 720 of the flexible printed circuit board 700 located on the extension portion 620 is thickened to ensure the strength of the flexible printed circuit board 700, while the upper surfaces of the first portion 710 and the second portion 720 are formed approximately flat at the boundary between the first portion 710 and the second portion 720, thereby preventing the voltage detection line in the flexible printed circuit board 700 from being forcibly bent.

[0097] In the battery module 1 according to an embodiment of the present technology, by providing the convex portion 741 and the concave portion 631 that engage in the first direction (Y direction), it is possible to fix the flexible printed circuit board 700 to the gas duct 600 without increasing the height of the battery module 1. Furthermore, compared to when the fixing member is provided on the end side opposite to the side where the extension portion of the main body is provided, the position where the convex portion 741 and the concave portion 631 engage is closer to the fixing member 750, which makes it easier to align the fixing member 750.

[0098] In the battery module 1 according to an embodiment of the present technology, the flexible printed circuit board 700 can be more firmly fixed by supporting the flexible printed circuit board 700 with the protrusion 810 of the cover member 800. Furthermore, by supporting the flexible printed circuit board 700, which also serves as part of the gas discharge path, with the gas duct 600 and the cover member 800, a more robust gas discharge path can be configured.

[0099] In a battery module 1 according to one embodiment of the present technology, by making the material of the gas duct 600 harder than the material of the cover member 800, deformation of the flexible printed circuit board 700 fixed to the gas duct 600 can be suppressed.

[0100] In the battery module 1 according to an embodiment of the present technology, the extending portion 620 is made to protrude in the first direction (Y direction) beyond the battery cell 100 located at the end in the first direction (Y direction) among the plurality of battery cells 100, thereby making it possible to prevent the extending portion 620 from interfering with the configuration of other members. Furthermore, the extending portion 620 can easily have a large wide portion in the third direction (X direction), making it possible to easily fix the flexible printed circuit board 700 firmly to the extending portion 620.

[0101] In a battery module 1 according to one embodiment of the present technology, by forming the substrate material 70 of the flexible printed circuit board 700 into an approximately L-shape, it is possible to reduce excess space between the substrate materials 70, thereby improving the yield when manufacturing the flexible printed circuit board 700 from the plate-shaped substrate 7.

[0102] Although the embodiments of the present technology have been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present technology is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0103] 1 battery module, 7 plate-shaped substrate, 10 unit, 70, 90 substrate material, 100, 101 battery cell, 110 electrode terminal, 111 positive electrode terminal, 112 negative electrode terminal, 120 housing, 121 upper surface portion, 122 lower surface portion, 123 first side surface portion, 124 second side surface portion, 125 third side surface portion, 130 gas release valve, 200 case, 210 first side wall portion, 220 second side wall portion, 230 third side wall portion, 231 first ventilation hole, 240 fourth side wall portion, 241 second ventilation hole, 260 upper wall portion, 262 wall portion, 263 hole portion, 300 bus bar, 310 first bus bar, 320 second bus bar, 330 third bus bar, 400, 400A, 400B End plate, 410 folded portion, 500 restraining member, 510 plate-shaped portion, 511 opening, 520 first flange portion, 530 second flange portion, 600 gas duct, 610 main body portion, 611 flow space, 620 extension portion, 621 claw portion, 630 first step portion, 631 recessed portion, 700 flexible printed circuit board, 710 first portion, 711 board main body, 712 branch portion, 720 second portion, 730 board portion, 740 thickened portion, 741 convex portion, 750 fixing member, 751 through hole, 760 connection port, 770 second step portion, 800 cover member, 810 protruding portion, 850 connection terminal portion, 850A negative side connection terminal portion, 850B positive side connection terminal portion, C1, C2 central position, R excess area.

Claims

1. a plurality of battery cells arranged in a first direction and each having a rectangular shape; a gas duct disposed above the plurality of battery cells and through which gas can flow in at least the first direction; a flexible printed circuit board arranged to overlap the gas duct in a second direction perpendicular to the first direction, and electrically connected to at least one battery cell among the plurality of battery cells; the gas duct includes a main body portion and an extension portion extending from the main body portion in the first direction; the extension portion is wider than the main body portion in a third direction perpendicular to the first direction and the second direction; The flexible printed circuit board is fixed to the extension portion.

2. The battery module according to claim 1 , wherein the flexible printed circuit board is fixed in close contact with the gas duct.

3. a first step portion is provided in the gas duct between the main body portion and the extension portion such that an upper surface of the main body portion is farther from the plurality of battery cells than an upper surface of the extension portion in the second direction; the flexible printed circuit board includes a first portion overlapping the main body portion and a second portion overlapping the extension portion, a second step portion is provided between the first portion and the second portion of the flexible printed circuit board such that a lower surface of the second portion is closer to the plurality of battery cells than a lower surface of the first portion in the second direction; 3. The battery module according to claim 1, wherein upper surfaces of the first portion and the second portion are formed substantially flat at the boundary between the first portion and the second portion.

4. a protrusion extending in the first direction toward the other of the first step portion and the second step portion is provided on one of the first step portion and the second step portion; a recess that receives the protrusion in the first direction is provided in the other of the first step portion and the second step portion, The battery module according to claim 3 , wherein the protrusion and the recess are engaged with each other.

5. a cover member that covers the flexible printed circuit board from the opposite side of the plurality of battery cells in the second direction; 3. The battery module according to claim 1, wherein the cover member includes a protrusion that protrudes toward the flexible printed circuit board in the second direction.

6. The battery module according to claim 5 , wherein the gas duct is harder than the cover member.

7. 3 . The battery module according to claim 1 , wherein the extension portion protrudes in the first direction from a battery cell located at an end in the first direction among the plurality of battery cells.

8. the extension portion extends in the third direction such that one end thereof is farther from the main body portion than the other end thereof; 3. The battery module according to claim 1, wherein the flexible printed circuit board has a substantially L-shape.

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