JP7427638B2 - battery module - Google Patents

Description

The present invention relates to a battery module.

For example, a power source for driving a vehicle such as an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle requires a high output voltage and a large amount of power, so a battery module in which a plurality of battery cells are connected is used. A battery module is constructed by electrically connecting electrode terminals of a plurality of battery cells with each other using bus bars. When joining the electrode terminals and the bus bar by welding or the like, it is preferable that the bus bar follow the relative displacement of the electrode terminals caused by variations in the parts constituting the battery module and their assembly. Thereby, the electrode terminal and the bus bar can be bonded with sufficient bonding strength, and a good connection state can be ensured.

Patent Document 1 describes a plurality of unit cells having electrode tabs, a plurality of busbars having a joint portion (joint surface) to be joined to the electrode tabs, a support member (first spacer) supporting the electrode tabs, and a busbar. An assembled battery is disclosed that includes a bus bar holder that holds a bus bar holder. Further, the bus bar holder of this assembled battery has a pressing portion including a projection that partially presses the joint surface of the bus bar toward the electrode tab supported by the first spacer.

Japanese Patent Application Publication No. 2018-181773

In the assembled battery described in Patent Document 1, by pressing the joint surfaces (joint parts) of the busbars toward the electrode tabs (electrode terminals), gaps that may occur between the electrode tabs and the busbars are absorbed, and gaps are removed at multiple locations. The existing electrode tabs and bus bars can be easily brought into contact and joined. However, with the technology described in Patent Document 1, the bus bar can be made to follow the displacement of the electrode tab in the direction in which the electrode tab is pressed, but the bus bar can be made to follow the displacement of the electrode tab in the other direction. There was a problem in that it was difficult to make the busbar follow.

The present invention has been made in order to solve such problems, and provides a battery module in which a bus bar follows the displacement of an electrode terminal and a good connection state between the electrode terminal and the bus bar is ensured. With the goal.

A battery module according to an embodiment includes a plurality of battery cells stacked in a stacking direction, a bus bar formed with a joint part to be joined to an electrode terminal of the battery cells, and a bus bar that presses the joint part toward the electrode terminal. A pressing part is provided and has a spacer sandwiched between adjacent battery cells in the stacking direction, and the pressing part is formed so as to be displaceable in the stacking direction. It has a first claw portion that applies a pressing force to the periphery of the edge.

According to the present invention, it is possible to provide a battery module in which the bus bar follows the displacement of the electrode terminal and ensures a good connection state between the electrode terminal and the bus bar.

1 is a perspective view showing a battery module according to Embodiment 1. FIG. FIG. 2 is an exploded perspective view of the battery module shown in FIG. 1. FIG. FIG. 2 is a plan view of a spacer included in the battery module shown in FIG. 1, viewed from the stacking direction. 2 is a perspective view illustrating a stacking process for constructing the battery module shown in FIG. 1. FIG. FIG. 2 is a perspective view illustrating a pressurizing process for constructing the battery module shown in FIG. 1. FIG. FIG. 2 is a perspective view illustrating an attachment process for constructing the battery module shown in FIG. 1. FIG. 7 is a partial sectional view illustrating details of the attachment process shown in FIG. 6. FIG. FIG. 2 is a plan view showing a laminate to which bus bars are attached when constructing the battery module shown in FIG. 1. FIG. 2 is a diagram illustrating a joining process for constructing the battery module shown in FIG. 1. FIG. FIG. 3 is a perspective view of a battery module according to a second embodiment. 11 is an exploded perspective view of the battery module shown in FIG. 10. FIG. 11 is a front view of a spacer included in the battery module shown in FIG. 10, viewed from the stacking direction. FIG. 11 is a plan view showing a laminate to which bus bars are attached when constructing the battery module shown in FIG. 10. FIG. 11 is a diagram illustrating a joining process for constructing the battery module shown in FIG. 10. FIG.

Embodiment 1
Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following embodiments. Further, in order to clarify the explanation, the following description and drawings are simplified as appropriate. Furthermore, in the following description, the same or equivalent elements are given the same reference numerals, and redundant description will be omitted.

In the following description, the thickness direction of the battery cell 10, in which a plurality of battery cells 10 are stacked, is referred to as the X direction, and the direction orthogonal to the X direction is referred to as the Y direction, and the width direction of the battery cell 10 is referred to as the Y direction. The Z direction is a direction perpendicular to the X direction and the Y direction, and the height direction of the battery cell 10 is defined as the Z direction.

First, with reference to FIG. 1, an overview of the battery module 1 according to the first embodiment will be described. FIG. 1 is a perspective view showing a battery module according to a first embodiment. As shown in FIG. 1, the battery module 1 includes a plurality of stacked battery cells 10 and a plurality of bus bars 20 that electrically connect the battery cells 10 adjacent to each other in the stacking direction (X direction). It has a plurality of spacers 30 sandwiched between battery cells 10.

The plurality of battery cells 10 are arranged side by side so as to be stacked in the X direction with spacers 30 in between. Furthermore, a pair of electrode terminals 14 are provided on the upper surface 11a of the battery cell 10, which are arranged along the Y direction. Then, the bus bar 20 in which a joint portion to be joined to the electrode terminal 14 is formed is joined to the electrode terminal 14 adjacent in the X direction by welding or the like. Thereby, adjacent battery cells 10 in the X direction are electrically connected. Further, each battery cell 10 constituting the battery module 1 is held by a spacer 30, respectively. The spacer 30 is provided with a pressing portion 37 that presses the joint toward the electrode terminal 14 .

In the manufacturing process of the battery module 1, the pressing portions 37 of the spacers 30 can position the electrode terminals 14 and the bus bars 20, and can join the electrode terminals 14 and the bus bars 20 in a state where they are in close contact with each other. Further, when the battery module 1 is used (such as during charging and discharging), the bus bar 20 follows the displacement of the electrode terminal 14, so that a good connection state between the electrode terminal 14 and the bus bar 20 can be maintained.

The detailed configuration of each part of the battery module 1 will be described with reference to FIG. 2. FIG. 2 is an exploded perspective view of the battery module shown in FIG. 1. In addition, in FIG. 2, one battery cell 10, a bus bar 20 attached to one battery cell 10, and a spacer 30 that sandwiches one battery cell 10 from both sides are shown, and other members are not shown. It is omitted. As shown in FIG. 2, the battery cell 10 is a rectangular battery that is long in the Y direction and includes a battery case 11 having a flat rectangular parallelepiped shape and a power generation element housed inside the battery case 11. As the battery cell 10, for example, a secondary battery such as a nickel-hydrogen battery, a lithium ion battery, or an electric double layer capacitor can be used.

The battery case 11 has a top surface 11a, a bottom surface 11b, a pair of first side surfaces 11c with a large area, and a pair of second side surfaces 11d with a narrow area. The top surface 11a and the bottom surface 11b face each other in the Z direction, and each extends in the XY plane. The pair of first side surfaces 11c face each other in the X direction and extend in the YZ plane. The pair of second side surfaces 11d face each other in the Y direction and extend in the XZ plane. Further, near the center of the upper surface 11a, a safety valve 12 for discharging gas inside the battery case 11 and an injection part 13 for injecting electrolyte are provided.

Furthermore, a pair of electrode terminals 14 for external connection are provided at both ends of the upper surface 11a in the Y direction. One of the pair of electrode terminals 14 is a positive electrode terminal 14, and the other is a negative electrode terminal 14. Each electrode terminal 14 is formed of a substantially rectangular conductive metal, and has a flat top surface against which the bus bar 20 comes into contact.

In the battery module 1 according to the present embodiment, the plurality of battery cells 10 are stacked in the thickness direction (X direction) of the battery cells 10 such that electrode terminals 14 of the same polarity are arranged adjacent to each other in the X direction. . The electrode terminals 14 of one battery cell 10 adjacent to each other in the X direction are connected to the electrode terminals 14 of the other battery cell 10 by the bus bar 20 . Thereby, the plurality of battery cells 10 are electrically connected in parallel.

In addition, the battery cells 10 disposed at both ends in the X direction are further connected to other battery cells or other battery modules, or to the external terminals of the positive or negative electrodes provided in the exterior case in which the battery module 1 is housed. electrically connected via.

The bus bar 20 is formed by molding a conductive thin metal plate into a predetermined shape by press working or the like. The bus bar 20 is formed into a substantially U-shape when viewed from the Z direction. The bus bar 20 has two terminal connection parts 21 that each extend toward the outside of the battery cell 10 in the Y direction, and a connection part 23 that extends in the X direction and connects the two terminal connection parts 21. The connecting portion 23 is connected to each terminal connecting portion 21 by bending the terminal connecting portion 21 side downward. That is, the bus bar 20 is formed into a substantially Z-shape when viewed from the X direction.

The two terminal connecting portions 21 of the bus bar 20 are arranged side by side in the X direction and spaced apart from each other. The terminal connection part 21 has a substantially rectangular shape extending in the XY plane so as to correspond to the shape of the electrode terminal 14, and has a joint part joined to the electrode terminal 14 on a flat surface on the side that contacts the electrode terminal 14. . Further, the terminal connection portion 21 has a through hole 22 formed to penetrate the terminal connection portion 21 in the thickness direction (Z direction). The terminal connection portion 21 is arranged to overlap the electrode terminal 14.

Here, regarding the edges forming the outer edge of the terminal connection part 21, a pair of edges existing in the X direction and along the Y direction are respectively referred to as first edges 21a, and The edge existing along the X direction (outside of the X direction) is defined as a second edge 21b.

Both end portions of the connecting portion 23 in the X direction are connected to respective base ends of the two terminal connecting portions 21 . The connecting portions 23 are arranged so as to overlap part of the first cover portions 33 of the spacers 30 adjacent to each other in the X direction.

The spacer 30 is made of an insulating member such as resin. The spacer 30 is arranged so as to be sandwiched between the adjacent first side surfaces 11c of the two battery cells 10. The detailed structure of the spacer 30 will be described with reference to FIG. 3 as appropriate. FIG. 3 is a plan view of the spacer of the battery module shown in FIG. 1, viewed from the stacking direction.

The spacer 30 includes a base plate 31 , a rib 32 , a first cover part 33 , a second cover part 34 , a third cover part 35 , a holding part 36 , a pressing part 37 , and a support plate 38 . The base plate 31 is arranged to face the first side surface 11c of the battery cell 10, and is formed in a plate shape extending in the YZ plane.

A plurality of ribs 32 having different shapes and sizes are formed on the surface of the base plate 31 facing one battery cell 10 . The rib 32 protrudes from the base plate 31 in the X direction, and the end surface in the X direction contacts the first side surface 11c of the battery cell 10. The ribs 32 form a space between the first side surface 11c of the battery cell 10 and the base plate 31. The ribs 32 form a plurality of flow paths through which cooling air for temperature adjustment flows through the space. The shape, size, and arrangement of the ribs 32 for forming the plurality of flow paths are not particularly limited, and may be appropriately designed depending on the required battery characteristics and the like.

In the battery module 1, the inlet 40 for letting the cooling air flow into the flow path is formed by the first cover part 33, and the outlet 50 for letting the cooling air flowing through the flow path flow out is formed by the third cover part 35. It is formed.

The first cover portion 33 is formed into a plate shape that protrudes from the lower end of the base plate 31 in the X direction and extends in the XY plane. The first cover portion 33 is formed excluding the central portion in the Y direction corresponding to the inlet 40. When the battery module 1 is configured, the first cover part 33 partially covers the bottom surface 11b side of the battery cell 10 and forms an inlet 40 opened in the Z direction.

The second cover portion 34 is formed into a plate shape that protrudes from the upper end of the base plate 31 in the X direction and extends in the XY plane. The second cover portion 34 is formed excluding portions corresponding to both ends of the battery cell 10 where the electrode terminals 14 are provided. When the battery module 1 is configured, the second cover part 34 covers the upper surface 11a side of the battery cell 10 except for at least the electrode terminal 14. The second cover part 34 has a shape that does not interfere with the terminal connection part 21 when the bus bar 20 is attached to the stacked body in which the spacer 30 is sandwiched between the battery cells 10. The terminal connecting portions 21 of the bus bar 20 can be overlapped and brought into contact with each other.

The third cover portion 35 is formed into a plate shape that protrudes from both ends of the base plate 31 in the Y direction in the same direction as the direction in which the ribs 32 protrude and extends in the XZ plane. The third cover portion 35 is formed excluding the central portion in the Z direction corresponding to the outlet 50. When the battery module 1 is configured, the third cover portion 35 covers the second side surface 11d side of the battery cell 10 and forms an outlet 50 opened in the Y direction. The first cover part 33 and the third cover part 35 are formed continuously.

The holding portion 36 is formed to protrude from the lower end of the base plate 31 and both ends in the Y direction in a direction opposite to the direction in which the rib 32 protrudes. The holding portion 36 is formed into a plate shape extending in the XY plane and the XZ plane, except for the central portion in the Y direction corresponding to the inlet 40. When the battery module 1 is configured, the holding part 36 contacts a part of the second side surface 11d and the bottom surface 11b of the battery cell 10, and holds the battery cell 10 from the Y direction and the Z direction. Further, when the battery module 1 is configured, the holding portion 36 has a surface that contacts the second side surface 11d in the X direction so that a gap is formed between the base plate 31 of the spacer 30 adjacent in the protruding direction. It extends to In the battery module 1, the cooling air that has flown in from the inlet 40 and flowed through the flow path flows out from the outlet 50 through this gap.

In the battery module 1, movement of the battery cells 10 in the X, Y, and Z directions is regulated by spacers 30 that are arranged to face the battery cells 10 and sandwich the battery cells 10 from both sides in the X direction. In this way, the spacer 30 functions as a cell holder that holds the battery cell 10 from the X, Y, and Z directions. Note that among the two spacers 30 that sandwich one battery cell 10 from both sides in the X direction, one spacer 30 corresponds to a first spacer, and the other spacer 30 corresponds to a second spacer.

A plurality of pressing portions 37 are provided along the Y direction at positions corresponding to the joint portions. In this embodiment, two pairs of pressing portions 37 are provided symmetrically in the Y direction. Each pressing portion 37 is formed to protrude upward from the upper end of the base plate 31 (that is, in the direction away from the battery cell 10). Each pressing portion 37 has a pair of first claw portions 37b formed to be displaceable in the X direction, and a support portion 37a that supports the pair of first claw portions 37b on the base plate 31.

The support portion 37a is formed into a rod shape extending from the upper end of the base plate 31 in the Z direction. A pair of first claw portions 37b extend obliquely downward (that is, in a direction approaching the battery cell 10) at an acute angle from the tip of the support portion 37a. The pair of first claw portions 37b are provided symmetrically in the X direction with the support portion 37a in between. That is, the pressing portion 37 has an anchor shape as a whole.

The pair of first claws 37b each include an end surface that contacts the first edge 21a of the bus bar 20. The end face of the first claw part 37b has a shape bent at an obtuse angle toward the support part 37a so that the distance from the support part 37a in the X direction gradually widens and then narrows as it goes downward. have.

That is, the proximal end side (upper side in the Z direction) of the end face is a slope 37c that is inclined with respect to the Z direction so that the distance from the support part 37a in the X direction gradually increases as it goes downward. . Further, the tip end side (lower side in the Z direction) of the end face is a slope 37d that is inclined with respect to the Z direction so that the distance from the support part 37a in the X direction gradually approaches the lower part.

The pair of first claw portions 37b are configured to be movable in the X direction toward or away from the support portion 37a. The first claw portion 37b is configured to be elastically deformed using the base end of the first claw portion 37b connected to the support portion 37a as a fulcrum due to a pressing force from the end surface side.

When constructing the battery module 1, the pressing part 37 is inserted into the gap G1 formed between the terminal connecting parts 21 (first edges 21a) adjacent in the X direction, and the first claw part 37b 1 edge 21a. Comparing the dimensions in the X direction, the insertion end of the pressing part 37 is smaller than the gap G1, and the maximum width of the pressing part 37 is larger than the gap G1.

A pair of support plates 38 provided symmetrically in the Y direction are formed to protrude upward from the upper end of the holding portion 36, respectively. Each support plate 38 is formed into a plate shape extending in the XZ plane. The support plate 38 is disposed above the battery cell 10 at a position slightly spaced apart from the second edge 21b of the terminal connection part 21 in the Y direction, and is connected to the upper end of the holding part 36. The dimension of the support plate 38 in the X direction is approximately the same as the dimension in the X direction of one terminal connection portion 21 constituting the bus bar 20 .

Next, a method for manufacturing the battery module 1 for constructing the battery module 1 will be described with reference to FIGS. 4 to 8. The manufacturing method of the battery module 1 includes a stacking process of producing a stacked body in which a plurality of battery cells 10 and a plurality of spacers 30 are stacked, a pressurizing process of pressurizing the stacked body, and an attachment process of attaching the bus bar 20 to the stacked body. and a joining step of joining the electrode terminal 14 and the bus bar 20.

FIG. 4 is a perspective view illustrating a stacking process for constructing the battery module shown in FIG. 1. FIG. 5 is a perspective view illustrating a pressurizing process for constructing the battery module shown in FIG. 1. FIG. 6 is a perspective view illustrating an attachment process for constructing the battery module shown in FIG. 1. FIG. 7 is a partial cross-sectional view illustrating details of the attachment process shown in FIG. 6. FIG. 8 is a plan view showing a laminate to which bus bars are attached when constructing the battery module shown in FIG. 1.

First, as shown in FIG. 4, in the stacking process, a plurality of battery cells 10 are arranged with their first side surfaces 11c facing each other so that the polarities of adjacent electrode terminals 14 are the same, and between adjacent battery cells 10 A spacer 30 is placed in each. At this time, the spacer 30 is placed with the base plate 31 facing the first side surface 11c. In this way, a laminate is produced in which a plurality of battery cells 10 and a plurality of spacers 30 are alternately stacked in the X direction.

Subsequently, as shown in FIG. 5, in the pressurizing step, the laminate is pressurized from both sides in the X direction using a pressurizing device. In the stacked body after pressurization, each battery cell 10 is held from the X, Y, and Z directions by the spacer 30 sandwiched between adjacent battery cells 10. Note that the white arrow shown in FIG. 5 indicates the pressurizing direction.

Subsequently, as shown in FIG. 6, in the attachment step, the bus bar 20 is attached to the pressurized laminate. When attaching the bus bar 20, the laminate (electrode terminal 14) and the bus bar 20 (terminal connection part 21) are brought close to each other in the Z direction to a position where the electrode terminal 14 and the terminal connection part 21 can come into contact with each other.

Here, details of the attachment process will be described with reference to FIGS. 7 and 8. FIG. 7 shows a cross section of the laminate shown in FIG. 6 taken along the X direction around one pressing portion 37 provided on the spacer 30. FIG. 8 shows a plan view of a portion of the laminate to which the bus bar 20 is attached, one end in the Y direction viewed from the Z direction. In addition, in FIG. 8, one bus bar 20 is shown among the plurality of bus bars 20 attached to the stacked body, and illustration of the other bus bars 20 is omitted.

As shown in FIGS. 7 and 8, in the attachment process, the pressing portions 37 are pushed into each gap G1 while lowering the bus bar 20 relative to the stacked body, thereby bringing the electrode terminals 14 and the terminal connecting portions 21 into contact with each other.

First, as shown in S1 of FIG. 7, when the bus bar 20 is lowered along the Z direction with respect to the stacked body and the insertion end of the pressing part 37 is inserted into the gap G1, the first edge 21a comes into contact with the slope 37c. We begin to meet each other. Then, as the first edge 21a moves downward along the slope 37c, the first claw 37b is pressed against each first edge 21a on both sides of the gap G1 and is elastically deformed. Accordingly, the first claw portion 37b is gradually displaced in the direction toward the support portion 37a.

When the bus bar 20 is continuously lowered, the first edge 21a starts to come into contact with the slope 37d. Then, as the first edge portion 21a moves downward along the slope 37d, the first claw portion 37b elastically returns. Accordingly, the first claw portion 37b is gradually displaced in a direction away from the support portion 37a.

Next, as shown in S2 of FIG. 7, when the bus bar 20 descends to a position where the electrode terminal 14 and the terminal connection part 21 come into contact with each other and stops, the slope 37d of the first claw part 37b touches the first edge part 21a. While in contact with the periphery (for example, the upper end of the first edge 21a), the first claw portion 37b elastically returns and is locked to the first edge 21a.

In the state where the first claw part 37b is locked to the first edge 21a, the first claw part 37b is connected to the first A pressing force is applied to the periphery of the edge 21a to press the joint portion downward toward the electrode terminal 14 (in the direction indicated by the white arrow in FIG. 7). Note that the broken line shown at S2 in FIG. 7 indicates the initial shape of the pressing portion 37.

As shown in FIG. 8, in this embodiment, each press of the spacer 30 is pressed so as to correspond to a position near both ends of the first edge 21a in the Y direction on the proximal end side and the distal end side of the terminal connection part 21. A section 37 is arranged. That is, four pressing portions 37 provided on one spacer 30 and the other spacer 30 that sandwich the battery cell 10 from both sides are in contact with one terminal connection portion 21 . In this embodiment, each of the first claw portions 37b of the four pressing portions 37 engages with one terminal connection portion 21, so that one terminal connection portion 21 has four contact portions. are doing. Note that in FIG. 8, the hatched portion is the contact portion.

When the bus bar 20 is attached to the laminate and the first claw portion 37b is in a locked state, the four pressing portions 37 arranged around the terminal connection portion 21 are pressed against the two opposing portions in the X direction. By applying a pressing force to the periphery of the first edge 21a, the joint portion of the bus bar 20 is pressed toward the electrode terminal 14. Further, since the terminal connecting portion 21 is clamped from both sides in the X direction by the first claw portions 37b of the pressing portion 37 facing in the X direction, movement in the X direction is restricted.

Subsequently, as shown in FIG. 9, a joining process is performed to join the electrode terminals 14 and the bus bars 20. FIG. 9 is a plan view corresponding to FIG. 8. Moreover, in FIG. 9, the welding range is shown by a broken line. In the joining process, the bus bar 20 is joined to the electrode terminal 14 by welding the top surface of the electrode terminal 14 and the joining part of the terminal connection part 21 in contact with each other. Welding methods such as laser welding and resistance welding can be used to join the electrode terminal 14 and the terminal connection portion 21.

As shown in FIG. 9, the joint preferably exists within a welding range surrounded by four abutting parts. In this way, by sequentially joining the electrode terminals 14 constituting the battery module 1 and the terminal connecting portions 21 of the bus bar 20 within the welding range, the battery module 1 in which the plurality of battery cells 10 are electrically connected can be assembled. Can be built.

When joining the electrode terminal 14 and the bus bar 20, the pressing part 37 applies a pressing force to the periphery of the first edge 21a of the bus bar 20 due to the elastic deformation of the first claw part 37b, thereby causing the bus bar 20 to Press the joint portion toward the electrode terminal 14 with a surface. As a result, the gap between the electrode terminal 14 and the terminal connection part 21 can be reduced, and the electrode terminal 14 and the terminal connection part 21 can be welded in close contact with each other. Bonding strength can be improved.

Furthermore, in the battery module 1, movement of the terminal connecting portion 21 in the X direction is restricted by the first claw portion 37b. Thereby, when bonding the electrode terminals 14 and the busbars 20, the busbars 20 can be accurately positioned with respect to the electrode terminals 14, and bonding failures due to misalignment between the electrode terminals 14 and the busbars 20 can be suppressed. be able to.

With such a configuration, in the battery module 1, when connecting a plurality of battery cells 10 using the bus bars 20, the electrode terminals 14 can be connected without using a special jig or the like for pressing the bus bars 20 against the electrode terminals 14. The bus bar 20 can be easily joined to the bus bar 20. Therefore, when manufacturing the battery module 1, it is possible to reduce the number of manufacturing steps and the manufacturing cost.

Furthermore, according to the present embodiment, there is no need to reduce the weldable area between the electrode terminal 14 and the bus bar 20 in order to provide a space for arranging a dedicated jig or an area to be pressed by the dedicated jig. A sufficient weldable area can be secured. Therefore, the bonding strength between the electrode terminal 14 and the bus bar 20 can be improved.

Further, for example, when the vehicle in which the battery module 1 is mounted is subjected to vibrations or shocks, or when thermal expansion or contraction occurs due to charging and discharging, each battery cell 10 constituting the battery module 1 may be moved to a position by the spacer 30. There may be relative displacement within the regulatory range. Due to such relative displacement between the battery cells 10, a load is applied to the joint where the electrode terminal 14 and the bus bar 20 are joined, which may cause damage, breakage, or peeling of the joint.

On the other hand, since the battery module 1 has a structure in which the first claw portion 37b is elastically deformed, it absorbs the relative displacement between the battery cells 10 when the battery module 1 is used, and the electrode terminal 14 The bus bar 20 can be made to follow. As a result, damage, breakage, and peeling of the joint between the electrode terminal 14 and the bus bar 20 due to relative displacement between the battery cells 10 can be suppressed.

Embodiment 2
Next, a battery module 100 according to a second embodiment will be described. Battery module 100 according to Embodiment 2 has the same configuration as battery module 1 according to Embodiment 1, except that the connection structure between electrode terminal 14 and bus bar 20 is different. Therefore, the battery module 100 according to the present embodiment will be described with a focus on the differences from the battery module 1. Note that in FIGS. 10 to 14, components that are the same as or correspond to those in Embodiment 1 are given the same reference numerals, and redundant explanations will be omitted.

First, with reference to FIG. 10, an overview of the battery module 100 according to the second embodiment will be described. As shown in FIG. 10, the battery module 100 includes a plurality of stacked battery cells 10 and a plurality of bus bars 20 that electrically connect the battery cells 10 adjacent to each other in the stacking direction (X direction). It has a plurality of spacers 300 sandwiched between battery cells 10.

In the battery module 100, the pair of pressing portions 370 are configured by providing the pair of support plates 38 of the spacer 300 with second claw portions 39 that are respectively formed to be movable in the Y direction. The spacer 300 also includes a pressing portion 37 having a pair of first claw portions 37b. The configurations of the battery cell 10 and the bus bar 20 are the same as those of the battery module 1, and the spacer 300 has the same configuration as the spacer 30 except for the pressing parts 37 and 370.

Therefore, details of the pressing portions 37 and 370 of the spacer 300 will be described with reference to FIGS. 11 and 12. FIG. 11 is an exploded perspective view of the battery module shown in FIG. 10. Note that, similarly to FIG. 2, FIG. 11 shows one battery cell 10, a bus bar 20 attached to one battery cell 10, and a spacer 300 that sandwiches one battery cell 10 from both sides. Illustrations of other members are omitted. FIG. 12 is a front view of the spacer included in the battery module shown in FIG. 10, viewed from the stacking direction.

As shown in FIGS. 11 and 12, a plurality of pressing portions 37 are provided along the Y direction at positions corresponding to the joint portions. In this embodiment, a pair of pressing parts 37 are provided symmetrically in the Y direction.

The second claw portion 39 extends obliquely downward (in other words, in the direction approaching the battery cell 10) at an acute angle from the surface of each support plate 38 on the side facing the bus bar 20. Each second claw portion 39 includes an end surface that contacts the second edge 21b of the bus bar 20. The end face of the second claw part 39 is bent at an obtuse angle toward the support plate 38 so that the distance from the support plate 38 in the Y direction gradually widens and then narrows as it goes downward. have.

That is, the base end side (upper side in the Z direction) of the end face is a slope 39c that is inclined with respect to the Z direction so that the distance from the support plate 38 in the Y direction gradually increases downward. . Further, the tip side (lower side in the Z direction) of the end face is a slope 39d that is inclined with respect to the Z direction so that the distance from the support plate 38 in the Y direction gradually approaches the lower part.

The second claw portion 39 is configured to be able to move toward or away from the support plate 38 in the Y direction. The second claw portion 39 is configured to be elastically deformed using the base end of the second claw portion 39 connected to the support portion 37a as a fulcrum due to a pressing force from the end surface side. When constructing the battery module 1, the pressing part 370 is inserted into the gap G2 formed between the terminal connection part 21 (second edge part 21b) and the support plate 38 adjacent in the Y direction, and The claw portion 39 locks onto the second edge portion 21b. The second claw portion 39 engaged with the second edge 21b applies a pressing force to the periphery of the second edge 21b.

The manufacturing method of the battery module 100 for constructing the battery module 100 includes stacking a plurality of battery cells 10 and a plurality of spacers 300 alternately in the X direction through a stacking process and a pressurizing process, and then pressurizing the laminate. Create.

In the attachment step of attaching the bus bar 20 to the stacked body after pressurization, the behavior of the pressing portion 37 is as explained in FIG. 7, so a description thereof will be omitted. Therefore, the behavior of the pressing portion 370 during the attachment process will be explained.

In the attachment process, the stacked body (electrode terminal 14) and the bus bar 20 (terminal connection part 21) are brought close to each other in the Z direction to a position where the electrode terminal 14 and the terminal connection part 21 can come into contact with each other. When the bus bar 20 is lowered relative to the stacked body, as the second edge 21b moves downward along the slope 39c, the second claw portion 39 is pressed against the second edge 21b and elastically deforms. . Accordingly, the second claw portion 39 is gradually displaced in the direction toward the support plate 38.

When the bus bar 20 is subsequently lowered, the second claw portion 39 elastically returns as the second edge portion 21b moves downward along the slope 39d. Accordingly, the second claw portion 39 is gradually displaced in a direction away from the support plate 38.

Next, when the bus bar 20 descends to a position where the electrode terminal 14 and the terminal connection part 21 come into contact with each other and stops, the slope 39d of the second claw part 39 touches the periphery of the second edge 21b (for example, the second edge 21b (upper end), the second claw portion 39 elastically returns and is locked to the second edge portion 21b.

In the stacked body to which the bus bar 20 is attached, since the first claw portion 37b is locked to the first edge 21a, the contact portion where the slope 37d and the periphery of the first edge 21a come into contact is Through this, the first claw portion 37b applies a pressing force to the periphery of the first edge portion 21a to press the joint portion downward toward the electrode terminal 14. In addition, in this embodiment, the second claw portion 39 is in a state of being locked to the second edge portion 21b. Therefore, the second claw portion 39 connects the periphery of the second edge 21b to the periphery of the second edge 21b via the contact portion where the slope 39d and the periphery of the second edge 21b come into contact with each other in a downward direction toward the electrode terminal 14. Apply pressure to press.

FIG. 13 is a plan view showing a laminate to which bus bars 20 are attached when constructing the battery module shown in FIG. 10. FIG. 13 shows a plan view of a part of the stacked body to which the bus bar 20 is attached, and one end in the Y direction viewed from the Z direction. Note that, similarly to FIG. 8, FIG. 13 shows one bus bar 20 among the plurality of bus bars 20 attached to the stacked body, and illustration of the other bus bars 20 is omitted.

As shown in FIG. 13, in this embodiment, each pressing portion 37 of the spacer 300 is positioned on the proximal end side of the terminal connection portion 21 and corresponds to a position closer to the inside of the first edge portion 21a in the Y direction. It is located. Moreover, each pressing portion 370 of the spacer 300 is arranged at the center portion of the second edge portion 21b in the X direction on the distal end side of the terminal connection portion 21.

That is, for one terminal connection portion 21, the pressing portions 37, 370 provided on one spacer 300 that sandwich the battery cell 10 from both sides and the pressing portion 37 provided on the other spacer 300 are in contact with each other. There is. Therefore, one terminal connection part 21 has three contact parts. In FIG. 13, the hatched portion is the contact portion.

When the first claw part 37b and the second claw part 39 are in a locked state by attaching the bus bar 20 to the laminate, the pressing parts 37 and 370 disposed around the terminal connection part 21 move in the X direction. By applying a pressing force to the periphery of the two opposing first edges 21a and the periphery of the second edge 21b, the joint portion of the bus bar 20 is pressed toward the electrode terminal 14.

Further, the terminal connecting portion 21 is restricted from moving in the X direction by the first claw portion 37b of the pressing portion 37 facing in the X direction, and is regulated outward in the Y direction by the second claw portion 39 of the pressing portion 370. movement is regulated.

Next, a joining process when constructing the battery module 100 will be described with reference to FIG. 14. FIG. 14 is a diagram illustrating a joining process for constructing the battery module shown in FIG. 10. FIG. 14 is a plan view corresponding to FIG. 13. Moreover, in FIG. 14, the welding range is shown by a broken line.

As shown in FIG. 14, a joining process is performed to join the electrode terminal 14 and the bus bar 20. In this embodiment, it is preferable that the joint portion exists within a welding range surrounded by three abutting portions. In this way, by sequentially joining the electrode terminals 14 constituting the battery module 100 and the terminal connecting portions 21 of the bus bar 20 within the welding range, the battery module 100 in which a plurality of battery cells 10 are electrically connected can be assembled. Can be built.

The battery module 100 configured in this way has the same effects as the first embodiment. Furthermore, in the battery module 100, in addition to the first claw portion 37b restricting movement of the terminal connection portion 21 in the X direction, the second claw portion 39 restricts movement of the terminal connection portion 21 outward in the Y direction. is regulated.

Therefore, according to the battery module 100 according to the present embodiment, when joining the electrode terminals 14 and the bus bars 20, the accuracy of positioning the bus bars 20 with respect to the electrode terminals 14 is improved, and the position of the electrode terminals 14 and the bus bars 20 is improved. Bonding defects caused by misalignment can be further suppressed.

Furthermore, according to the battery module 100 according to the present embodiment, the followability of the bus bar 20 with respect to the electrode terminals 14 is improved, so that the electrode terminals 14 and Damage, breakage, and peeling of the joint with the bus bar 20 can be further suppressed.

Note that the present invention is not limited to the above embodiments, and can be modified as appropriate without departing from the spirit. For example, the quantity, arrangement, combination, etc. of the pressing parts 37, 370 provided in the spacers 30, 300 are not limited to the above embodiments, and may be appropriately designed according to the shape and size of the joint part, the required pressing force, etc. It is something that

1, 100 Battery module 10 Battery cell 11 Battery case 11a Top surface 11b Bottom surface 11c First side surface 11d Second side surface 12 Safety valve 13 Injection part 14 Electrode terminal 20 Bus bar 21 Terminal connection part 21a First edge 21b Second edge 22 Through hole 23 Connecting portions 30, 300 Spacer 31 Base plate 32 Rib 33 First cover portion 34 Second cover portion 35 Third cover portion 36 Holding portions 37, 370 Pressing portion 37a Supporting portion 37b First claw portions 37c, 37d, 39c, 39d Slope 38 Support plate 39 Second claw portion 40 Inlet 50 Outlet G1, G2 Gap

Claims (3)

A plurality of battery cells stacked in a stacking direction,
a bus bar formed with a joint portion to be joined to the electrode terminal of the battery cell;
A pressing portion that presses the bonding portion toward the electrode terminal is provided, and a spacer is provided between the battery cells adjacent to each other in the stacking direction;
The pressing part is
A battery module having a first claw portion that is formed to be displaceable in the stacking direction and applies a pressing force to a periphery of a first edge of the bus bar that exists in the stacking direction. The spacer includes a first spacer and a second spacer that sandwich one battery cell from both sides in the stacking direction,
The joint portion of the bus bar that is joined to the electrode terminal of one of the battery cells is formed by the pressing portion provided on the first spacer and the pressing portion provided on the second spacer to form the laminated layer. The battery module according to claim 1, wherein a pressing force is applied to the periphery of the two first edges facing each other in the direction. The pressing part is
A second claw that applies a pressing force to a periphery of a second edge of the bus bar that is present in the width direction when the direction in which the two electrode terminals provided in one battery cell are arranged is the width direction. The battery module according to claim 1 or 2, further comprising a section.

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