Battery Module

Abstract

This battery module (1) is provided with: a battery stack (2) in which a plurality of batteries (8) each having an output terminal (18) are aligned; a bus bar (4) which electrically connects the output terminals (18) of the batteries (8) to each other; and a bus bar plate (6) which covers a surface of the battery stack (2), in said surface the output terminals (18) being arranged, while having an opening (22) at a position overlapping with the output terminals (18) so that the bus bar (4) is arranged in the opening (22). If one of the bus bar plate (6) and the battery stack (2) is taken as a first member and the other is taken as a second member, the first member has an urging part (26) and the second member has an urge-receiving part (28). Since the urging part (26) urges the second member, the first member and the second member are urged in directions opposite to each other; and since the urge-receiving part (28) is in contact with the first member, displacements of the first member and the second member are restricted.

Description

[Technical field]

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

[0002] Battery modules in which multiple batteries are electrically connected are known as power sources that require a high output voltage, such as for vehicles. With regard to such energy storage modules, for example, Patent Document 1 discloses an energy storage module that includes a battery stack in which multiple batteries are stacked, a bus bar that electrically connects the output terminals of the batteries, and a surface plate (bus bar plate) that covers the surface of the battery stack on which the output terminals are located. This surface plate has an opening at a position opposite the output terminal, and the bus bar is held by being fitted into this opening. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-133169 A Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, in conventional battery modules, positioning pins are provided on one of the battery stack or the bus bar plate and positioning holes are provided on the other, and the battery stack and the bus bar plate are positioned by passing the positioning pins through the positioning holes. However, with this structure, misalignment between the battery stack and the bus bar plate is likely to occur due to dimensional and positional tolerances of each part, making it difficult to meet the demand for even higher positional accuracy between the two.

[0005] The present disclosure has been made in light of these circumstances, and has a purpose to provide a technique for improving the positioning accuracy between a battery stack and a bus bar plate. [Means for solving the problem]

[0006] One aspect of the present disclosure is a battery module. The battery module includes a battery stack in which a plurality of batteries each having an output terminal are arranged, a bus bar that electrically connects the output terminals of the batteries, and a bus bar plate that covers the surface of the battery stack on which the output terminals are arranged and has openings at positions overlapping with the output terminals, in which the bus bar is arranged. When one of the bus bar plate and the battery stack is a first member and the other is a second member, the first member has a biasing portion and the second member has a biasing receiving portion, the biasing portion presses the second member to bias the first member and the second member in opposite directions, and the biasing receiving portion abuts against the first member to restrict displacement of the first member and the second member.

[0007] Any combination of the above components and conversion of the expressions of the present disclosure between methods, devices, systems, etc. are also valid aspects of the present disclosure. Effect of the Invention

[0008] According to the present disclosure, it is possible to improve the positioning accuracy between the battery stack and the bus bar plate. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a battery module according to a first embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the battery module. [Diagram 3] Fig. 3(A) is an enlarged plan view showing a region including a biasing portion in a battery module, and Fig. 3(B) is an enlarged plan view showing a region including a biasing receiving portion in a battery module. [Figure 4] Fig. 4(A) is a plan view of a biasing portion according to Modification 1. Fig. 4(B) is a plan view of a biasing portion according to Modification 2. [Diagram 5] FIG. 11 is a plan view of a battery module according to a second embodiment. [Figure 6]Fig. 6(A) is a plan view showing an enlarged view of a region including a biasing portion in a battery module, and Fig. 6(B) is a perspective view showing an enlarged view of a region including a biasing portion in a battery module. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present disclosure will be described below with reference to the drawings based on preferred embodiments. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, members, and processes shown in each drawing are given the same reference numerals, and duplicated descriptions are omitted as appropriate. In addition, the scale and shape of each part shown in each drawing are set for convenience to facilitate explanation, and are not to be interpreted as being limiting unless otherwise specified. In addition, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not represent any order or importance, but are intended to distinguish one configuration from another. In addition, some of the members that are not important in explaining the embodiment in each drawing are omitted.

[0011] (Embodiment 1) Fig. 1 is a perspective view of a battery module according to embodiment 1. Fig. 2 is an exploded perspective view of the battery module. The battery module 1 includes a battery stack 2, a plurality of bus bars 4, and a bus bar plate 6.

[0012] The battery stack 2 has a structure in which multiple batteries 8 are arranged. The battery stack 2 has multiple batteries 8, multiple separators 10, and a pair of restraining members 12.

[0013] Each battery 8 is a rechargeable secondary battery such as a lithium ion battery, a nickel-hydrogen battery, or a nickel-cadmium battery. Each battery 8 is a so-called prismatic battery, and has a flattened rectangular exterior can 14. A substantially rectangular opening (not shown) is provided on one side of the exterior can 14, and an electrode assembly, an electrolyte, etc. are accommodated in the exterior can 14 through this opening. A substantially rectangular sealing plate 16 is fitted into the opening of the exterior can 14 to cover the opening.

[0014] A pair of output terminals 18 are disposed on the sealing plate 16. Specifically, the positive terminal 18a is disposed near one end in the longitudinal direction, and the negative terminal 18b is disposed near the other end. In the following, when it is not necessary to distinguish the polarities of the pair of output terminals 18, the positive terminal 18a and the negative terminal 18b will be collectively referred to as the output terminals 18.

[0015] The exterior can 14, sealing plate 16, and output terminal 18 are conductive and made of a metal such as aluminum, iron, or stainless steel. The exterior can 14 and sealing plate 16 are joined by, for example, laser welding. Each output terminal 18 is inserted into a through hole formed in the sealing plate 16. An insulating seal member is interposed between each output terminal 18 and each through hole. The exterior can 14 may be covered with an insulating film (not shown) such as a shrink tube.

[0016] The battery 8 has a valve portion 19 on the sealing plate 16. The valve portion 19 is disposed between a pair of output terminals 18 on the sealing plate 16. The valve portion 19 is configured to open when the internal pressure of the battery 8 rises to or above a predetermined value, thereby allowing gas inside the battery 8 to be released. The valve portion 19 is configured, for example, with a thin-walled portion that is thinner than other portions of the sealing plate 16, and a linear groove formed on the surface of the thin-walled portion. In this configuration, when the internal pressure of the battery 8 rises, the thin-walled portion tears starting from the groove, opening the valve portion 19.

[0017] In the description of this embodiment, for convenience, the sealing plate 16 is the upper surface of the battery 8, and the bottom surface of the exterior can 14 facing the sealing plate 16 is the lower surface of the battery 8. The battery 8 has four side surfaces connecting the upper surface and the lower surface. Two of the four side surfaces are a pair of long side surfaces connected to the two opposing long sides of the sealing plate 16. Each long side surface is the surface with the largest area among the surfaces of the battery 8, that is, the main surface. The remaining two side surfaces excluding the two long sides are a pair of short side surfaces connected to the short sides of the sealing plate 16. For convenience, the surface of the upper surface side of the battery 8 in the battery stack 2 is the upper surface of the battery stack 2, the surface of the lower surface side of the battery 8 is the lower surface of the battery stack 2, and the surface of the short side side of the battery 8 is the side surface of the battery stack 2. These directions and positions are defined for convenience. Therefore, for example, a portion defined as the upper surface in this disclosure does not necessarily mean that it is located above a portion defined as the lower surface.

[0018] The multiple batteries 8 are arranged at a predetermined interval so that the main surfaces of adjacent batteries 8 face each other. In this embodiment, the batteries 8 are arranged horizontally. In the following, the direction in which the batteries 8 are arranged is referred to as the arrangement direction X, the direction that is horizontal and perpendicular to the arrangement direction X is referred to as the horizontal direction Y, and the direction that is perpendicular to the arrangement direction X and the horizontal direction Y is referred to as the vertical direction Z.

[0019] The batteries 8 are arranged so that the output terminals 18 face the same direction. In this embodiment, the batteries 8 are arranged so that the output terminals 18 face vertically upward. When adjacent batteries 8 are connected in series, the batteries 8 are arranged so that the positive terminal 18a of one battery 8 and the negative terminal 18b of the other battery 8 are adjacent to each other. When adjacent batteries 8 are connected in parallel, the batteries 8 are arranged so that the positive terminal 18a of one battery 8 and the positive terminal 18a of the other battery 8 are adjacent to each other.

[0020] A separator 10 is disposed between two adjacent batteries 8. This provides electrical insulation between the two batteries 8. The separator 10 is also called an insulating spacer, and is made of, for example, an insulating resin sheet. Examples of resins that may be used to form the separator 10 include polypropylene (PP), polybutylene terephthalate (PBT), polycarbonate (PC), and Noryl (registered trademark) resin (modified PPE). Note that only some of the separators 10 are shown in FIG. 2.

[0021] The multiple batteries 8 are restrained in the arrangement direction X by a pair of restraining members 12 extending in the arrangement direction X of the batteries 8. The restraining members 12 are also called bind bars, and are elongated members that are long in the arrangement direction X of the batteries 8. In this embodiment, a pair of restraining members 12 are arranged in the horizontal direction Y. Each restraining member 12 is made of a metal such as iron or stainless steel.

[0022] For example, the multiple batteries 8 are sandwiched in the arrangement direction X by a pair of end plates (not shown) in a state where they are arranged alternately with the multiple separators 10. The pair of end plates are adjacent to the batteries 8 located at both ends in the stacking direction X via the separators 10. The pair of restraining members 12 are arranged to sandwich the multiple batteries 8, the multiple separators 10, and the pair of end plates in the horizontal direction Y, and both ends of each restraining member 12 are fixed to the pair of end plates. For example, the restraining members 12 have bent portions at both ends in the arrangement direction X that overlap the main surfaces of the end plates, and these bent portions are fixed to the end plates by screws or the like.

[0023] The multiple batteries 8 are restrained in the arrangement direction X by a pair of restraining members 12, and are positioned in the arrangement direction X. Each restraining member 12 has a pair of arms 20 facing each other in the vertical direction Z. The multiple batteries 8 are sandwiched in the vertical direction Z by the pair of arms 20. As a result, each battery 8 is positioned in the vertical direction Z.

[0024] The bus bar 4 is a generally strip-shaped member made of metal such as copper or aluminum. One end of the bus bar 4 is connected to the positive terminal 18a of one of two adjacent batteries 8, and the other end is connected to the negative terminal 18b of the other battery 8. This electrically connects the output terminals 18 of the batteries 8 to each other. The bus bar 4 may also be used to connect the output terminals 18 of the same polarity of multiple adjacent batteries 8 in parallel to form a battery block, and the battery blocks may be further connected in series to each other.

[0025] The bus bar plate 6 is a plate-like member that covers the upper surface of the battery stack 2 on which the output terminals 18 are located. The bus bar plate 6 can also function as part of a holder case that houses the battery stack 2. The bus bar plate 6 is made of resin, such as polypropylene (PP), polybutylene terephthalate (PBT), polycarbonate (PC), or Noryl (registered trademark) resin (modified PPE).

[0026] The busbar plate 6 has multiple openings 22 that expose the output terminals 18 of the multiple batteries 8 at positions that overlap with the output terminals 18 of the multiple batteries 8 in the vertical direction Z. A busbar 4 is placed in each opening 22. For example, the busbar plate 6 is placed on the top surface of the battery stack 2, and then the busbar 4 is fitted into each opening 22. Alternatively, the busbar 4 is fitted into each opening 22 of the busbar plate 6, and the busbar plate 6 holding the multiple busbars 4 is placed on the top surface of the battery stack 2. The position of the multiple busbars 4 relative to the battery stack 2 is determined by the busbar plate 6.

[0027] With the bus bar plate 6 placed on the top surface of the battery stack 2 and the bus bar 4 placed in the opening 22, the output terminal 18 and the bus bar 4 come into contact with each other. In this state, the output terminal 18 and the bus bar 4 are joined by laser welding or the like. As a result, the output terminals 18 of the multiple batteries 8 are electrically connected to each other.

[0028] The bus bar plate 6 is positioned relative to the battery stack 2 and then fixed, for example, by screws to an end plate. A cover plate (not shown) is placed on the top surface of the bus bar plate 6. Covering the top surface of the bus bar plate 6 with the cover plate can prevent condensation water, dust, and the like from coming into contact with the output terminals 18, the bus bars 4, and the like.

[0029] When one of the busbar plate 6 and the battery stack 2 is the first member and the other is the second member, the first member has the biasing portion 26 and the second member has the biasing portion 28. In this embodiment, the busbar plate 6 is the first member and the battery stack 2 is the second member. However, the busbar plate 6 may also be the second member and the battery stack 2 may be the first member. In other words, the busbar plate 6 may be provided with the biasing portion 28, and the battery stack 2 may be provided with the biasing portion 26.

[0030] Fig. 3(A) is an enlarged plan view showing a region including the biasing portion 26 in the battery module 1. Fig. 3(B) is an enlarged plan view showing a region including the biasing portion 28 in the battery module 1.

[0031] The urging section 26 has an elastically deformable shape, and with the bus bar plate 6 placed on the battery stack 2, it uses its elastic force to press the battery stack 2 (second member). In this embodiment, the urging section 26 presses the separator 10. Therefore, the separator 10 is the counterpart member 24 that is directly biased by the bus bar plate 6. When the urging section 26 presses the separator 10, the bus bar plate 6 (first member) and the battery stack 2 (second member) are biased in opposite directions.

[0032] Specifically, the biasing portion 26 presses the separator 10 in the first direction A, so that the battery stack 2 including the separator 10 is biased in the first direction A. Meanwhile, the bus bar plate 6 including the biasing portion 26 is biased in the second direction B opposite to the first direction A by a reaction force from the separator 10. In this embodiment, the first direction A and the second direction B are parallel to the horizontal direction Y.

[0033] When the bus bar plate 6 and the battery stack 2 are biased in opposite directions, the biasing force receiving portion 28 abuts against the bus bar plate 6. This restricts the displacement of the bus bar plate 6 and the battery stack 2. The amount of elastic deformation of the biasing portion 26 and the positional relationship between the biasing portion 26 and the biasing force receiving portion 28 in the horizontal direction Y are determined so that the first member abuts against the biasing force receiving portion 28 when the biasing force (pressing force) of the biasing portion 26 is applied to the second member.

[0034] The bus bar plate 6 of this embodiment has three openings 30 in the center in the horizontal direction Y. Each opening 30 is rectangular and has a pair of edges extending in the arrangement direction X and a pair of edges extending in the horizontal direction Y. The two openings 30 are arranged at both ends in the arrangement direction X. The biasing parts 26 are arranged in the two openings 30. The biasing parts 26 are, for example, leaf spring-shaped. Specifically, the biasing parts 26 have an arm 32 that extends along the top surface of the battery stack 2 from the edge of the opening 30 extending in the horizontal direction Y toward the center in the arrangement direction X, and a tip part 34 that bends and extends from the tip of the arm 32 in the first direction A. The arm 32 bends with the base end that contacts the edge of the opening 30 as a fulcrum, so that the tip part 34 can be displaced in the first direction A and the second direction B.

[0035] The separator 10 has a protrusion 36 that is pressed by the biasing portion 26. The protrusion 36 protrudes in the vertical direction Z from the opening 30 in which the biasing portion 26 is disposed toward the bus bar plate 6. The protrusion 36 is flat and extends in the arrangement direction X and the vertical direction Z, and has a pressing surface 38 that faces the tip 34. When the tip 34 presses the pressing surface 38 in the first direction A due to elastic deformation of the arm 32, the separator 10 and therefore the battery stack 2 are biased in the first direction A. Furthermore, the biasing portion 26 and therefore the bus bar plate 6 are biased in the second direction B by a reaction force from the pressing surface 38 in the second direction B.

[0036] The remaining opening 30 is disposed in the center in the arrangement direction X. The biasing portion 28 protrudes from this opening 30 in the vertical direction Z. The biasing portion 28 has a shape similar to that of the protrusion 36 and has a flat portion 40 facing the first direction A. The flat portion 40 abuts against the busbar plate 6 to restrict the displacement of the busbar plate 6 in the second direction B and the displacement of the battery stack 2 in the first direction A. The busbar plate 6 has a straight portion 42 facing the second direction B and extending parallel to the flat portion 40, and the straight portion 42 abuts against the flat portion 40. In this embodiment, the straight portion 42 is an edge portion of the opening 30 extending in the arrangement direction X.

[0037] The protrusion 36 may also function as the biasing receiver 28. In other words, the shapes and arrangements of the biasing portion 26 and the protrusion 36 are set so that the distance between the tip 34 of the biasing portion 26 when it is not elastically deformed and the edge of the opening 30 facing the tip 34 is shorter than the dimension of the protrusion 36 in the horizontal direction Y. As a result, when the tip 34 presses the pressing surface 38, the surface 44 of the protrusion 36 opposite the pressing surface 38 comes into contact with the edge of the opening 30, and the protrusion 36 is sandwiched between the biasing portion 26 and the edge of the opening 30. As a result, the battery stack 2 is biased in the first direction A by the biasing portion 26, and the bus bar plate 6 is biased in the second direction B by the reaction force. Furthermore, the protrusion 36 comes into contact with the edge of the opening 30, restricting the displacement of the bus bar plate 6 and the battery stack 2.

[0038] Furthermore, the biasing portion 26 may have any shape as long as it is elastically deformable in the horizontal direction Y (first direction A and second direction B). For example, the following modified shapes of the biasing portion 26 can be given. FIG. 4(A) is a plan view of the biasing portion 26 according to Modification 1. As shown in FIG. 4(A), the biasing portion 26 according to Modification 1 is a leaf spring having a curved shape that protrudes in the first direction A from an edge portion extending in the arrangement direction X of the opening portion 30. The top of the biasing portion 26 presses the protrusion 36 in the first direction A, thereby biasing the battery stack 2 in the first direction A. Meanwhile, the bus bar plate 6 is biased in the second direction B by a reaction force from the protrusion 36 in the second direction B.

[0039] 4(B) is a plan view of the urging portion 26 according to Variation 2. Variation 2 is a variation of the urging portion 26 when the bus bar plate 6 is the second member and the battery stack 2 is the first member. In this variation, the urging portion 26 is provided on the protrusion 36.

[0040] The biasing portion 26 according to the second modification is approximately L-shaped and has an arm 32 extending in the arrangement direction X and a tip 34 extending in the horizontal direction Y. One end of the arm 32 is connected to the protrusion 36, and the other end of the arm 32 is connected to one end of the tip 34. The other end of the tip 34 abuts against an edge of the opening 30 extending in the arrangement direction X. The arm 32 elastically deforms, displacing the tip 34 in the horizontal direction Y. The tip 34 presses the edge of the opening 30 in the first direction A, biasing the bus bar plate 6 in the first direction A. Meanwhile, the battery stack 2 is biased in the second direction B by a reaction force from the bus bar plate 6 in the second direction B.

[0041] As another modification, the urging portion 26 may be shaped to extend linearly from a corner of the opening 30 toward the protrusion 36. The urging portion 26 may be circular or bellows-shaped when viewed from the vertical direction Z, or may be a coil spring or the like. In this case, the urging portion 26 is sandwiched between the protrusion 36 and an edge portion of the opening 30 extending in the arrangement direction X. The curved, linear, circular, bellows-shaped, or coil spring-shaped urging portion 26 may be provided on either the bus bar plate 6 or the battery stack 2.

[0042] As described above, the battery module 1 according to this embodiment includes a battery stack 2 in which a plurality of batteries 8 each having an output terminal 18 are arranged, a busbar 4 that electrically connects the output terminals 18 of each battery 8, and a busbar plate 6 that covers the surface of the battery stack 2 on which the output terminals 18 are arranged, the busbar plate 6 having openings 22 at positions overlapping with the output terminals 18, and in which the busbar 4 is arranged. When one of the busbar plate 6 and the battery stack 2 is defined as a first member and the other as a second member, the first member has a biasing portion 26 and the second member has a biasing portion 28. When the biasing portion 26 presses the second member, the first member and the second member are biased in opposite directions, and when the biasing portion 28 comes into contact with the first member, the displacement of the first member and the second member is restricted.

[0043] In this way, by using the biasing force of the biasing members 26 to regulate the position of the busbar plate 6 relative to the battery stack 2, it is possible to prevent misalignment between the battery stack 2 and the busbar plate 6 caused by dimensional and positional tolerances of various parts, thereby further improving the positional accuracy of the two. As a result, the busbars 4 and output terminals 18 can be welded more accurately, improving the quality of the battery module 1.

[0044] Furthermore, the battery stack 2 of this embodiment has a separator 10 that is placed between two adjacent batteries 8 to provide electrical insulation between the two batteries 8, and the biasing member 26 presses the separator 10. This increases the positional accuracy of the battery stack 2 and the bus bar plate 6 without the need for a separate member for positioning the bus bar plate 6 relative to the battery stack 2.

[0045] Moreover, the second member in this embodiment has a protrusion 36 that is pressed by the biasing portion 26. In this way, by providing a dedicated protrusion 36 that receives the biasing force from the biasing portion 26, the biasing force of the biasing portion 26 can be applied to the second member more reliably. Also, the magnitude of the biasing force can be more easily adjusted.

[0046] Moreover, the biasing force receiving portion 28 of the present embodiment has a flat portion 40, and the flat portion 40 abuts against the first member to restrict the displacement of the first member and the second member. This can further improve the positional accuracy of the bus bar plate 6.

[0047] In the present embodiment, the two biasing portions 26 are arranged to sandwich the biasing portion 28 in the arrangement direction X. This makes it possible to more stably position the bus bar plate 6. Note that even if the two biasing portions 28 are arranged to sandwich the biasing portion 26 in the arrangement direction X, the bus bar plate 6 can be similarly stably positioned.

[0048] (Embodiment 2) The second embodiment has a common configuration with the first embodiment, except that the object to be pressed by the biasing portion 26 is different. The following description of the second embodiment will focus on the configuration that differs from the first embodiment, and the common configuration will be explained briefly or omitted. FIG. 5 is a plan view of a battery module 1 according to the second embodiment. FIG. 6(A) is a plan view showing an enlarged view of a region including the biasing portion 26 in the battery module 1. FIG. 6(B) is a perspective view showing an enlarged view of a region including the biasing portion 26 in the battery module 1.

[0049] When one of the bus bar plate 6 and the battery stack 2 is the first member and the other is the second member, the first member has the biasing portion 26 and the second member has the biasing portion 28. In this embodiment, the bus bar plate 6 is the first member and the battery stack 2 is the second member. However, the bus bar plate 6 may also be the second member and the battery stack 2 may be the first member.

[0050] The urging portion 26 has an elastically deformable shape, and with the bus bar plate 6 placed on the battery stack 2, it uses its elastic force to press the battery stack 2 as the second member. In this embodiment, the urging portion 26 presses one of the pair of constraint members 12. Therefore, the constraint member 12 is the counterpart member 24 that is directly biased by the bus bar plate 6. By designing the urging portion 26 to press the constraint member 12, it is possible to increase the positional accuracy of the battery stack 2 and the bus bar plate 6 without providing a separate member for positioning the bus bar plate 6. When the urging portion 26 presses the constraint member 12, the bus bar plate 6 as the first member and the battery stack 2 as the second member are biased in opposite directions.

[0051] Specifically, the biasing portion 26 presses the constraint members 12 in the first direction A, so that the battery stack 2, including the constraint members 12, is biased in the first direction A. Meanwhile, the bus bar plate 6, including the biasing portion 26, is biased in a second direction B opposite to the first direction A by a reaction force from the constraint members 12. In this embodiment, the first direction A and the second direction B are parallel to the horizontal direction Y. With the bus bar plate 6 and the battery stack 2 biased in opposite directions, the biasing portion 28 comes into contact with the bus bar plate 6. This restricts the displacement of the bus bar plate 6 and the battery stack 2.

[0052] In this embodiment, the busbar plate 6 has biasing portions 26 on both ends in the arrangement direction X at one end side in the horizontal direction Y. The biasing portions 26 are leaf springs having arms 32 that extend in the arrangement direction X from corners of the body portion 6a of the busbar plate 6 along the top surface of the battery stack 2, and tips 34 that bend from the tips of the arms 32 in the first direction A and extend toward the restraining member 12. The body portion 6a is a flat plate-like portion that spreads in the arrangement direction X and the horizontal direction Y and covers the top surface of the battery stack 2. The arms 32 flex with their base ends in contact with the body portion 6a as a fulcrum, allowing the tips 34 to be displaced in the first direction A and the second direction B.

[0053] The restraining member 12 has a notch 50 at a position facing the biasing portion 26, and the tip portion 34 fits into the notch 50. When the tip portion 34 presses the restraining member 12 in the first direction A due to elastic deformation of the arm portion 32, the battery stack 2 is biased in the first direction A. Furthermore, the bus bar plate 6 is biased in the second direction B by a reaction force in the second direction B from the restraining member 12.

[0054] The biasing portion 28 is provided on the separator 10. The biasing portion 28 protrudes in the vertical direction Z from an opening 30 provided in the center of the bus bar plate 6 in the arrangement direction X and the horizontal direction Y. The biasing portion 28 comes into contact with the bus bar plate 6 to restrict the displacement of the bus bar plate 6 in the second direction B and the displacement of the battery stack 2 in the first direction A. The manner in which the biasing portion 28 comes into contact with the bus bar plate 6 is the same as in the first embodiment. Note that the restraining member 12 on the opposite side to the restraining member 12 pressed by the biasing portion 26 may function as the biasing portion 28.

[0055] The above describes the embodiments of the present disclosure in detail. The above-mentioned embodiments merely show specific examples of implementing the present disclosure. The contents of the embodiments do not limit the technical scope of the present disclosure, and many design changes such as changes, additions, and deletions of components are possible within the scope of the invention defined in the claims. A new embodiment with design changes has the effects of the combined embodiments and modifications. In the above-mentioned embodiments, the contents for which such design changes are possible are emphasized by adding notations such as "in this embodiment" and "in this embodiment", but design changes are permitted even in contents without such notations. Any combination of components included in the embodiments is also valid as an aspect of the present disclosure.

[0056] The urging portions 26 and the urging receiving portions 28 may be arranged in the arrangement direction X. The first direction A and the second direction B may be parallel to the arrangement direction X. The modified shapes of the urging portions 26 described in the first embodiment can be applied to the urging portions 26 of the second embodiment as long as they can function to position the battery stack 2 and the bus bar plate 6. The number of batteries 8 included in the battery module 1 is not particularly limited. The structure of each portion of the battery module 1, including the shape of the restraining members 12 and the method of restraining the battery stack 2 by the restraining members 12, is not particularly limited. [Explanation of symbols]

[0057] REFERENCE SIGNS LIST 1 battery module, 2 battery stack, 4 bus bar, 6 bus bar plate, 8 battery, 10 separator, 12 restraining member, 18 output terminal, 22 opening, 26 biasing portion, 28 biasing receiving portion, 36 protrusion, 40 flat portion.

Claims

1. a battery stack in which a plurality of batteries each having an output terminal are arranged; a bus bar electrically connecting the output terminals of each battery to each other; a bus bar plate covering a surface of the battery stack on which the output terminals are arranged, the bus bar plate having openings at positions overlapping with the output terminals, the bus bars being arranged in the openings; When one of the bus bar plate and the battery stack is defined as a first member and the other is defined as a second member, the first member has a biasing portion and the second member has a biasing receiving portion, When the biasing portion presses the second member, the first member and the second member are biased in opposite directions to each other, and when the biasing portion abuts against the first member, displacement of the first member and the second member is restricted. the battery stack has a restraint member that extends in an arrangement direction of the batteries and restrains the battery stack in the arrangement direction; the bus bar plate is a first member and the battery stack is the second member; The biasing portion presses the restraining member. Battery module.

2. The bias receiving portion has a flat surface portion, The battery module according to claim 1 , wherein the flat portion abuts against the first member, thereby restricting displacement of the first member and the second member.

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