WO2023032152A1 - Busbar and battery module - Google Patents

Abstract

One embodiment provides a busbar which electrically connects two electrode terminals disposed to be spaced apart from each other. The busbar comprises a layered plate body, a first joint part, and a second joint part, wherein a plurality of conductive plates are stacked in the layered plate body. The first joint part is formed in an end section on one side of the layered plate body in the length direction of the layered plate body, the length direction crossing the stacked direction of the plurality of conductive plates, and is joined to a separate first conductive member different from the layered plate body. The second joint part is formed in an end section on the opposite side from the first joint part in the length direction of the layered plate body, and is joined to the layered plate body and a separate second conductive member different from the first conductive member.

Description

Busbar and battery module

Embodiments of the present invention relate to busbars and battery modules.

In a battery module or the like that includes a plurality of batteries (single cells), the electrode terminals of one battery and the electrode terminals of another battery are electrically connected via bus bars. In this case, the bus bar is connected to each of the two electrode terminals (the first electrode terminal and the second electrode terminal) by being joined by laser welding or the like. In recent years, battery modules formed from a plurality of batteries are required to have higher output. A battery module with high output performance is required to appropriately suppress a temperature rise in a bus bar that electrically connects two electrode terminals even when a large current flows. For this reason, busbars are required to have an appropriate cross-sectional area that is perpendicular or substantially perpendicular to the extending direction of the electrical path, and to appropriately suppress an increase in electrical resistance in the busbar. In addition, in battery modules and the like, it is required that the stress applied from the busbars to the electrode terminals to which the busbars are connected is appropriately relieved. In each of the batteries (single cells) that form the battery module, it is required to effectively prevent the deterioration of the hermeticity of the internal cavities caused by the stress from the busbars to the electrode terminals.

Japanese Patent Application Laid-Open No. 2009-87761

The problem to be solved by the present invention is to provide a bus bar in which a cross-sectional area orthogonal or substantially orthogonal to the extending direction of an electric path is ensured to have an appropriate size, and the stress applied to the electrode terminals is appropriately relaxed; An object of the present invention is to provide a battery module having the bus bar.

According to embodiments, a busbar is provided that electrically connects between two electrode terminals that are spaced apart from each other. The busbar includes a stacking plate body, a first joint and a second joint. The laminated plate comprises a plurality of conductive plates each having electrical conductivity, and in the laminated plate, the plurality of conductive plates are stacked. The first joint portion is formed at one end of the stacked plate body in the longitudinal direction of the stacked plate body that intersects the stacking direction of the plurality of conductive plates, and is a conductive member separate from the stacked plate body. It is joined to a first conductive member. The second joint is formed at an end opposite to the first joint in the longitudinal direction of the stacked plate body, and is a second conductive member separate from the stacked plate body and the first conductive member. of the conductive member.

FIG. 1 is a schematic diagram showing an example of a single battery according to an embodiment. FIG. 2 is a schematic diagram showing an example of the battery module of the embodiment. FIG. 3 is a schematic diagram showing the busbar according to the first embodiment as viewed from one side in the first direction. FIG. 4 is a schematic diagram showing a bus bar according to the first embodiment, two electrode terminals to which the bus bar is connected, and a configuration in the vicinity of these in a cross section orthogonal or substantially orthogonal to the third direction; be. FIG. 5 shows a bus bar according to a first modification of the first embodiment, two electrode terminals to which the bus bar is connected, and a configuration in the vicinity of these in a cross section orthogonal or substantially orthogonal to the third direction. It is the schematic which shows a bus-bar. FIG. 6 shows a bus bar according to a second modification of the first embodiment, two electrode terminals to which the bus bar is connected, and a configuration in the vicinity of these in a cross section orthogonal or substantially orthogonal to the third direction. It is the schematic which shows a bus-bar. FIG. 7 shows a bus bar according to a third modification of the first embodiment, two electrode terminals to which the bus bar is connected, and a configuration in the vicinity of these in a cross section orthogonal or substantially orthogonal to the third direction. It is the schematic which shows a bus-bar. FIG. 8 is a schematic diagram showing the bus bar according to the second embodiment as viewed from one side in the first direction. FIG. 9 is a schematic diagram showing a bus bar according to a second embodiment, two electrode terminals to which the bus bar is connected, and a configuration in the vicinity of these when the bus bar is viewed from one side in the third direction; be. FIG. 10 shows a bus bar according to a modification of the second embodiment, two electrode terminals to which the bus bar is connected, and a configuration in the vicinity of these when the bus bar is viewed from one side in the third direction. 1 is a schematic diagram showing FIG.

Hereinafter, embodiments will be described with reference to the drawings. A battery module according to an embodiment includes a plurality of batteries. The plurality of batteries comprises a first battery and a second battery. The first battery has a first electrode terminal, and the second battery has a second electrode terminal. In the battery module, the busbar electrically connects the first terminal of the first battery and the second terminal of the second battery. The bus bar is connected to each of the first electrode terminal and the second electrode terminal by being joined by laser welding or the like.

[battery]
First, a single battery provided in the battery module will be described. FIG. 1 shows an example of a battery 1 alone. A battery 1 that is a single cell includes an electrode group 2 and an outer container 3 in which the electrode group 2 is accommodated. In one example, such as FIG. 1, the exterior container 3 is formed from metals, such as aluminum, an aluminum alloy, iron, or stainless steel. The exterior container 3 includes a container body 5 and a lid 6. Here, in the battery 1 and the outer container 3, the depth direction (direction indicated by arrows X1 and X2) and the lateral direction (direction indicated by arrows Y1 and Y2) crossing (perpendicular or substantially perpendicular to) the depth direction , and a height direction (direction indicated by arrows Z1 and Z2) that intersects (perpendicularly or substantially perpendicularly) to both the depth direction and the lateral direction are defined. In the example shown in FIG. 1 and the like, in each of the battery 1 and the outer container 3, the dimension in the depth direction is smaller than the dimension in the lateral direction and the dimension in the height direction.

The container body 5 includes a bottom wall 7 and a peripheral wall 8. An internal cavity 10 in which the electrode group 2 is housed is defined by a bottom wall 7 and a peripheral wall 8 . In the battery 1, the internal cavity 10 opens toward the side opposite to the side where the bottom wall 7 is located in the height direction. The peripheral wall 8 surrounds the inner cavity 10 along the entire circumference. The lid 6 is attached to the container body 5 by welding or the like at the opening of the internal cavity 10 . The lid 6 is thus attached to the peripheral wall 8 at the end opposite the bottom wall 7 . The lid 6 and the bottom wall 7 face each other across the internal cavity 10 in the height direction. The internal cavity 10 is sealed and sealed to the exterior of the outer container 3 .

The electrode group 2 includes a positive electrode and a negative electrode (both not shown). Further, in the electrode group 2, a separator (not shown) is interposed between the positive electrode and the negative electrode. The separator is made of an electrically insulating material and electrically insulates the positive electrode from the negative electrode.

The positive electrode includes a positive electrode current collector such as a positive electrode current collector foil, and a positive electrode active material-containing layer carried on the surface of the positive electrode current collector. The positive electrode current collector is, but not limited to, aluminum foil or aluminum alloy foil, etc., and has a thickness of about 5 μm to 20 μm. The positive electrode active material-containing layer comprises a positive electrode active material and may optionally contain a binder and a conductive agent. Examples of positive electrode active materials include, but are not limited to, oxides, sulfides, and polymers that can intercalate and deintercalate lithium ions. The positive electrode current collector has a positive electrode current collecting tab as a portion on which the positive electrode active material-containing layer is not supported.

The negative electrode includes a negative electrode current collector such as a negative electrode current collector foil, and a negative electrode active material-containing layer (not shown) carried on the surface of the negative electrode current collector. The negative electrode current collector is, but not limited to, aluminum foil, aluminum alloy foil, copper foil, or the like, and has a thickness of about 5 μm to 20 μm. The negative electrode active material containing layer comprises a negative electrode active material and may optionally contain a binder and a conductive agent. Examples of the negative electrode active material include, but are not limited to, metal oxides, metal sulfides, metal nitrides, and carbon materials that can occlude and release lithium ions. The negative electrode current collector includes a negative electrode current collecting tab as a portion where the negative electrode active material-containing layer is not supported.

In the electrode group 2, a pair of current collecting tabs is formed by the positive electrode current collecting tab and the negative electrode current collecting tab. A pair of current collecting tabs protrude from the electrode group 2 . In one example, in the electrode group 2, the positive electrode current collecting tab protrudes to one side of the battery 1 in the lateral direction, and the negative electrode current collecting tab is on the opposite side of the lateral direction of the battery 1 to the side from which the positive electrode current collecting tab protrudes. protrude to In another example, each of the pair of current collecting tabs in the electrode group 2 protrudes in the height direction of the battery 1 toward the side where the lid 6 is located. In this case, the pair of current collecting tabs are positioned apart from each other in the lateral direction of the battery 1 .

In addition, in the internal cavity 10, the electrode group 2 is held (impregnated) with an electrolytic solution (not shown). The electrolytic solution may be a non-aqueous electrolytic solution in which an electrolyte is dissolved in an organic solvent, or an aqueous electrolytic solution such as an aqueous solution. A gel electrolyte may be used instead of the electrolytic solution, or a solid electrolyte may be used. When a solid electrolyte is used as the electrolyte, the solid electrolyte may be interposed between the positive electrode and the negative electrode in place of the separator in the electrode group. In this case, the solid electrolyte electrically insulates the positive electrode from the negative electrode.

In the battery 1 , a pair of electrode terminals 11 are attached to the outer surface (upper surface) of the lid 6 of the outer container 3 . The electrode terminal 11 is made of a conductive material such as metal. One of the electrode terminals 11 is the positive terminal of the battery 1 and the other of the electrode terminals 11 is the negative terminal of the battery 1 . Each of the electrode terminals 11 penetrates the lid 6 through a corresponding through hole (not shown) and is inserted into the internal cavity 10 . An insulating member 12 and an insulating gasket (not shown) are provided between each of the electrode terminals 11 and the lid 6 . Each of the electrode terminals 11 is prevented from contacting the lid 6 by the insulating member 12 and the insulating gasket, and is electrically insulated from the exterior container 3 including the lid 6 . Moreover, at the portions of the electrode terminals 11 penetrating through the lids 6 , airtightness between the lids 6 and the electrode terminals 11 is ensured by insulating gaskets. Therefore, even if the cover 6 is formed with through-holes for penetrating the electrode terminals 11 , the internal cavity 10 is properly sealed from the outside of the outer container 3 .

The positive electrode current collecting tab of the electrode group 2 is electrically connected to the corresponding positive electrode terminal of the electrode terminals 11 via one or more leads (positive electrode lead). Further, the negative electrode current collecting tab of the electrode group 2 is electrically connected to one of the corresponding negative electrode terminals 11 via one or more leads (negative lead). In each of the electrode terminals 11, the portion inserted into the internal cavity 10 is connected to the corresponding lead. Each of the leads is formed from a conductive material such as metal. In addition, in the internal cavity 10 of the outer container 3, each of the pair of current collecting tabs and leads is electrically connected to the outer container 3 (container body 5 and lid 6) by one or more insulating members (not shown). insulated to

The positive electrode terminal and the lead (positive electrode side lead) that electrically connects the positive electrode current collector tab and the positive electrode terminal are each preferably made of the same material as the positive electrode current collector. As a result, in the electrical path between the positive electrode current collecting tab and the positive electrode terminal, the contact resistance at the connection portion of the positive electrode current collecting tab to the lead, the contact resistance at the connection portion of the positive electrode terminal to the lead, etc. reduced. Similarly, the negative electrode terminal and the lead (negative electrode side lead) that electrically connects the negative electrode current collector tab and the negative electrode terminal are each preferably made of the same material as the negative electrode current collector. . As a result, in the electrical path between the negative electrode current collecting tab and the negative electrode terminal, the contact resistance at the connection portion of the negative electrode current collecting tab to the lead, the contact resistance at the connection portion of the negative electrode terminal to the lead, etc. reduced. For example, when the negative electrode current collector is aluminum foil, it is preferable that each of the negative electrode lead and the negative electrode terminal is made of aluminum. Each of the terminals is preferably formed from copper.

In addition, in the example of FIG. 1, the lid 6 is formed with a gas release valve 13 and an injection port. A sealing plate 15 is welded to the outer surface of the lid 6 to close the injection port. It should be noted that the gas release valve 13, the injection port, and the like may not be provided in the battery.

Also, the configuration of the battery (single cell) is not limited to the example shown in FIG. In one example, the exterior of the battery may be formed from a laminate film instead of the exterior container 3 . In this case, in the battery casing, the metal layer is sandwiched between two electrically insulating insulating layers, and the outer surface of the casing is formed by one of the two insulating layers. Then, the electrode group is housed inside the exterior portion formed from the laminate film.

[Battery module]
Next, a battery module including a plurality of batteries (single cells) as described above will be described. FIG. 2 shows an example of the battery module 20. As shown in FIG. The battery module 20 includes batteries 1A and 1B. Batteries 1A and 1B have the same configuration as battery 1 in the example of FIG. In the battery module 20, the battery (first battery) 1A has an electrode terminal (first electrode terminal) 11A as one of the pair of electrode terminals 11, and the battery (second battery) 1B has a pair of electrode terminals. 11, an electrode terminal (second electrode terminal) 11B is provided. The battery module 20 also includes a bus bar 21. In the battery module 20, a bus bar is provided between the electrode terminal (first electrode terminal) 11A of the battery 1A and the electrode terminal (second electrode terminal) 11B of the battery 1B. 21 are electrically connected. The bus bar 21 is connected to each of the electrode terminals 11A and 11B by being joined by laser welding or the like.

Here, in one example of FIG. 2, one of the electrode terminal 11A of the battery 1A and the electrode terminal 11B of the battery 1B is a positive terminal, and the other of the electrode terminals 11A and 11B is a negative terminal. Therefore, in the example of FIG. 2 , the batteries 1A and 1B are electrically connected in series by the bus bar 21 . In another example, two bus bars similar to bus bar 21 may be used to electrically connect two batteries in parallel. In this case, one of the two bus bars electrically connects the positive terminals of the two batteries. The other of the two bus bars electrically connects the negative terminals of the two batteries.

[Busbar]
A bus bar according to an embodiment will be described below. The busbar electrically connects between the two electrode terminals, as described above. For example, in a battery module including a first battery and a second battery, the busbar electrically connects between the first electrode terminal of the first battery and the second electrode terminal of the second battery. . The busbar is formed from a conductive material such as metal.

(First embodiment)
First, the busbar 21 according to the first embodiment will be described. The bus bar 21 of the present embodiment electrically connects the two electrode terminals 11A and 11B in the example battery module 20 of FIG. FIG. 3 shows the busbar 21 of the present embodiment, and FIG. 4 shows the busbar 21 of the present embodiment, two electrode terminals 11A and 11B to which the busbar 21 is connected (joined), and the configuration of the vicinity thereof. . As shown in FIGS. 3 and 4, etc., the busbar 21 has a first direction (directions indicated by arrows Z3 and Z4) and a second direction that intersects (perpendicularly or substantially perpendicularly) the first direction. (directions indicated by arrows Y3 and Y4), and a third direction (directions indicated by arrows X3 and X4) that intersects (perpendicular or substantially perpendicular to) both the first direction and the second direction is defined. 3 shows the busbar 21 as viewed from one side in the first direction, and FIG. 4 shows the busbar 21 in a cross section perpendicular or substantially perpendicular to the third direction.

In this embodiment, the bus bar 21 includes a pair of connector plates 22A and 22B and a stack plate body 23. Each of the connector plates 22A and 22B has a plate length direction, a plate width direction that intersects (perpendicularly or substantially perpendicular to) the plate length direction, and an intersects (perpendicular to) both the plate length direction and the plate width direction. or substantially perpendicular to each other) is defined. In each of the connector plates 22A and 22B, the plate thickness direction matches or substantially matches the first direction of the busbars 21, and the plate length direction matches or substantially matches the second direction of the busbars 21. As shown in FIG. In each of the connector plates 22A and 22B, the plate width direction matches or substantially matches the third direction of the bus bar 21 .

The connector plate (first connector plate) 22A is a conductive member (first conductive member) made of a conductive material, and is joined to the electrode terminal (first electrode terminal) 11A of the battery 1A by ultrasonic welding or the like. be done. The connector plate 22A is joined (connected) to the electrode terminal 11A in a state in which the electrode terminal 11A abuts from one side (arrow Z3 side) of the bus bar 21 in the first direction. 2 and 4, the connector plate 22A is joined to the electrode terminal 11A in a state of contacting the electrode terminal 11A from the side facing the outer surface of the lid 6 of the battery 1A. As shown in an example of FIG. 3, the connector plate 22A is formed with a through hole 25A penetrating through the connector plate 22A in the plate thickness direction. The connector plate 22A is joined to the electrode terminal 11A on the surface facing the side where the electrode terminal 11A (battery 1A) is located in the plate thickness direction (the first direction of the busbar 21) and at the site around the through hole 25A. be done.

The connector plate (second connector plate) 22B is a conductive member (second conductive member) made of a conductive material, and is joined to the electrode terminal (second electrode terminal) 11B of the battery 1B by ultrasonic welding or the like. be done. The electrode terminal 11B abuts against the connector plate 22B from the side (arrow Z3 side) where the electrode terminal 11A abuts the connector plate 22A in the first direction of the bus bar 21 . Then, the connector plate 22B is joined (connected) to the electrode terminals 11B while the electrode terminals 11B are in contact with each other as described above. 2 and 4, the connector plate 22B is joined to the electrode terminal 11B in a state of contacting the electrode terminal 11B from the side facing the outer surface of the lid 6 of the battery 1B. As shown in an example of FIG. 3, the connector plate 22B is formed with a through hole 25B penetrating through the connector plate 22B in the plate thickness direction. The connector plate 22B is joined to the electrode terminal 11B on the surface facing the side where the electrode terminal 11B (battery 1B) is located in the plate thickness direction (the first direction of the bus bar 21) and at the site around the through hole 25B. be done.

In the bus bar 21, the connector plates 22A and 22B are relayed by the stacked plate body 23. The stacked plate body 23 includes a plurality of conductive plates 26, and in one example such as FIG. 4, four conductive plates 26 are provided. Each of the plurality of conductive plates 26 is made of a conductive material and has electrical conductivity. In the stacked plate body 23, a plurality of conductive plates 26 are stacked against each other. In each of the plurality of conductive plates 26, the plate length direction, the plate width direction that intersects (perpendicularly or substantially perpendicular to) the plate length direction, and the plate length direction and the plate width direction that intersect (perpendicularly) or substantially orthogonal) are defined. In the stacked plate body 23, the plurality of conductive plates 26 are stacked in a state in which the plate thickness direction of each conductive plate 26 matches or substantially matches the stacking direction.

In addition, in the stacked plate body 23, the stacking direction of the plurality of conductive plates 26 is defined as the thickness direction. In the stacked plate body 23, the length direction intersecting (perpendicular or substantially perpendicular) to the stacking direction and the width direction intersecting (perpendicular or substantially perpendicular) to both the stacking direction and the length direction is defined. The length direction of the stacked plate body 23 matches or substantially matches the plate length direction of each of the conductive plates 26 . The width direction of the stacked plate body 23 matches or substantially matches the plate width direction of each conductive plate 26 and matches or substantially matches the third direction of the bus bar 21 . Among the plurality of conductive plates 26 forming the stacked plate body 23, the conductive plate 26A is positioned closest to the electrode terminals 11A and 11B, and the conductive plate 26B is located near the electrode terminals 11A and 11B. most distal to the

Each of the plurality of conductive plates 26 has an edge surface E1 forming one end in the plate length direction and an edge surface E2 forming an end opposite to the edge surface E1 in the plate length direction. In addition, the stacked plate body 23 has an end S1 on one side in the length direction and an end S2 on the side opposite to the end S1 in the length direction. In one example such as FIG. 4 , the edge surfaces E1 of the plurality of conductive plates 26 are not displaced or hardly displaced with respect to each other in the length direction of the stacked plate body 23 . For this reason, in one example such as FIG. 4 , the end S1 of the stacked plate body 23 is formed by the edge surfaces E1 of all the conductive plates 26 . In addition, in one example such as FIG. 4 , the edge surfaces E2 of the plurality of conductive plates 26 are not displaced or hardly displaced with respect to each other in the longitudinal direction of the stacked plate body 23 . For this reason, in one example such as FIG. 4 , the end S2 of the stacked plate body 23 is formed by the edge surfaces E2 of all the conductive plates 26 .

In one example, the edge surfaces E1 of one or more of the conductive plates 26 are offset from the edge surfaces E1 of the other conductive plates 26 in the longitudinal direction of the stacked plate body 23, and all of the conductive plates 26 The end S1 of the stacked plate body 23 is formed only by the edge face E1 of a part of the conductive plate 26 inside. In this case, the edge surface E1 of the remaining conductive plate 26 is shifted toward the end S2 with respect to the end S1 of the plate stack 23. As shown in FIG. Similarly, the edge surface E2 of one or more of the conductive plates 26 is offset from the edge surface E2 of the other conductive plate 26 in the longitudinal direction of the stack 23, and one of all the conductive plates 26 The end S2 of the laminated plate body 23 is formed only by the edge surface E2 of the conductive plate 26 of the part. In this case, the edge surface E2 of the remaining conductive plate 26 is shifted from the end S2 of the plate stack 23 toward the end S1.

In addition, bending positions B1 and B2 are formed between ends S1 and S2 in the length direction of the stacked plate body 23 . At the bending position B1, the portion adjacent to the bending position B1 on the side opposite to the end S1 bends with respect to the portion between the end S1 and the bending position B1. At the bent position B1, the portion of each of the plurality of conductive plates 26 adjacent to the bent position B1 on the side opposite to the end S1 is the side away from the electrode terminals 11A and 11B in the first direction of the bus bar 21. It bends (to the distal side with respect to the electrode terminals 11A and 11B). At the bending position B2, the portion adjacent to the bending position B2 on the side opposite to the end S2 bends with respect to the portion between the end S2 and the bending position B2. At the bent position B2, the portion of each of the plurality of conductive plates 26 adjacent to the bent position B2 on the side opposite to the end S2 is the side away from the electrode terminals 11A and 11B in the first direction of the bus bar 21. It bends (to the distal side with respect to the electrode terminals 11A and 11B).

In the overlapping plate body 23, the portion between the bending positions B1 and B2 in the length direction is formed in a convex shape protruding from the electrode terminals 11A and 11B in the first direction of the busbar 21. As shown in FIG. Therefore, in each of the conductive plates 26 of the laminated plate body 23, the portion between the bending positions B1 and B2 in the length direction is the portion between the end S1 and the bending position B1, and the portion between the end S2 and the bending position B2. and protrudes away from the electrode terminals 11A and 11B. Therefore, in the laminated plate body 23, a convex apex 28 is formed between the bending positions B1 and B2 in the length direction, and the apex 28 forms a convex protruding end between the bending positions B1 and B2. do.

In one example such as FIG. 4 , each of the plurality of conductive plates 26 is formed in a curved shape in a convex portion between bending positions B1 and B2 in the longitudinal direction of the stacked plate body 23 . In each curved shape of the conductive plate 26 formed between the bending positions B1 and B2, the sides on which the electrode terminals 11A and 11B are located are inside the curve in the first direction. The side away from 11A and 11B is the outside of the curve. In addition, in the convex portion between bending positions B1 and B2 in the longitudinal direction of the stacking plate body 23, the surfaces of the plurality of conductive plates 26 facing the stacking direction are curved.

4 and other examples, the cross-sectional shape of each of the conductive plates 26 at the convex portion between the bending positions B1 and B2 in the cross section orthogonal or substantially orthogonal to the third direction (the width direction of the stacked plate body 23) is arcuate or substantially arcuate. The center of the arcuate or substantially arcuate cross-sectional shape formed by each of the conductive plates 26 in the convex portion is positioned on the side of the plate stack 23 on which the electrode terminals 11A and 11B are positioned in the first direction. . In one example, in a cross section orthogonal or substantially orthogonal to the third direction (the width direction of the stacked plate body 23), the cross-sectional shape of each of the plurality of conductive plates 26 at the convex portion is U-shaped. Alternatively, it may be substantially U-shaped or the like. 4 and other examples, each of the conductive plates 26 is separated from the adjacent conductive plate 26 in the stacking direction over the entire dimension or substantially the entire dimension along the plate length direction from the edge surface E1 to the edge surface E2. abut.

In the stacked plate body 23, a joint portion ( A first junction) 27A is formed. A joint portion 27A of the stacked plate body 23 is joined to the connector plate 22A by ultrasonic welding or the like. In the laminated plate body 23, the joint portion 27A is formed at a portion between the end S1 and the bending position B1. In addition, in one example such as FIG. 4, the joint portion 27A is formed on the conductive plate 26A that is positioned closest to the electrode terminals 11A and 11B among the plurality of conductive plates 26 . In the conductive plate 26A, a joint portion 27A is formed on the surface facing the electrode terminals 11A and 11B in the first direction. For this reason, in the example of FIG. 4 and the like, the stacked plate body 23 (conductive plate 26A) is in contact with the connector plate 22A from the side opposite to the side where the electrode terminals 11A and 11B are located in the first direction. Joint portion 27A of body 23 is joined to connector plate 22A.

In the stacked plate body 23, the end portion on the side opposite to the joint portion 27A in the length direction, that is, the portion near the end S2 in the length direction is joined to the connector plate 22B, which is a conductive member (second conductive member). A joint portion (second joint portion) 27B is formed. The joint portion 27B of the stacked plate body 23 is joined to the connector plate 22B by ultrasonic welding or the like. In the laminated plate body 23, the joint portion 27B is formed at a portion between the end S2 and the bending position B2. In addition, in one example such as FIG. 4, the joint portion 27B is formed on the conductive plate 26A that is positioned closest to the electrode terminals 11A and 11B among the plurality of conductive plates 26 . A joint portion 27B is formed on the surface of the conductive plate 26A that faces the side where the electrode terminals 11A and 11B are located in the first direction. For this reason, in the example of FIG. 4 and the like, the stacked plate body 23 (conductive plate 26A) is in contact with the connector plate 22B from the side opposite to the electrode terminals 11A and 11B in the first direction. Joint portion 27B of body 23 is joined to connector plate 22B.

In the stacked plate body 23, the plurality of conductive plates 26 are joined together at the joining portion 27A and its vicinity in the longitudinal direction, such as the portion between the end S1 and the bending position B1. Further, in the laminated plate body 23, the plurality of conductive plates 26 are joined to each other at the joining portion 27B and its vicinity in the longitudinal direction, such as the portion between the end S2 and the bending position B2. . However, in the stacked plate body 23, each of the conductive plates 26 is not joined to the other conductive plates 26 except for the joints 27A and 27B and their vicinities. For example, each of the conductive plates 26 is not joined to the other conductive plate 26 at the portion between the bent positions B1 and B2 in the longitudinal direction of the stacked plate body 23 . Therefore, in the stacked plate body 23, a non-joint portion is formed in which each of the conductive plates 26 is not joined to the other conductive plate 26 over most of the length direction.

In one example, a joint portion (first joint portion) 27A may be formed on the conductive plate 26B positioned farthest to the electrode terminals 11A and 11B among the plurality of conductive plates 26. . In this case, in a state in which the stacked plate body 23 (conductive plate 26B) is in contact with the connector plate 22A from the side where the electrode terminals 11A and 11B are located in the first direction, the joint portion 27A of the stacked plate body 23 is connected to the connector plate (the second direction). 1 connector plate) 22A. Similarly, a joint portion (second joint portion) 27B may be formed on the conductive plate 26B positioned most distally with respect to the electrode terminals 11A and 11B among the plurality of conductive plates 26 . In this case, in a state in which the stacked plate body 23 (conductive plate 26B) is in contact with the connector plate 22B from the side where the electrode terminals 11A and 11B are positioned in the first direction, the joint portion 27B of the stacked plate body 23 is connected to the connector plate (second 2 connector plate) 22B.

Each of the plurality of conductive plates 26 forming the stacked plate body 23 has a plate thickness T0. The plate thicknesses T0 of the plurality of conductive plates 26 are the same or substantially the same as each other. Also, each of the connector plates 22A and 22B has a plate thickness T1. The thickness T1 of the connector plates 22A and 22B is the same or substantially the same as each other. The plate thickness T0 of each of the plurality of conductive plates 26 is thinner than the plate thickness T1 of the connector plates 22A and 22B. In one example, the total thickness T0 of the plurality (all) of the conductive plates 26 is the same or substantially the same as the thickness T1 of each of the connector plates 22A and 22B. Here, if the number of conductive plates 26 forming the stacked plate body 23 is n (n is an integer of 2 or more), the total thickness T0 of all the conductive plates 26 is represented by the value (n×T0). be In one example, the plate width W of each of the plurality of conductive plates 26 is the same or substantially the same size (width) as the plate width of each of the connector plates 22A and 22B.

The connector plate (first connector plate) 22A is preferably made of the same material as the electrode terminal (first electrode terminal) 11A, and the connector plate (second connector plate) 22B is preferably made of the same material as the electrode terminal (first electrode terminal). (Second electrode terminal) It is preferably made of the same material as 11B. Each of the plurality of conductive plates 26 is preferably made of a material having higher thermal and electrical conductivity than at least one of the connector plates 22A and 22B, and is more thermally conductive than both the connector plates 22A and 22B. More preferably, it is made of a highly conductive material. In one example, each of the electrode terminals 11A, 11B is made of aluminum and each of the connector plates 22A, 22B is made of aluminum. Each of the conductive plates 26 is made of copper, which has higher thermal conductivity (thermal conductivity) and electrical conductivity (conductivity) than aluminum. In another example, electrode terminals 11A and connector plate 22A are each formed from aluminum, and electrode terminals 11B and connector plate 22B are each formed from copper. Each of the conductive plates 26 is then formed from silver, which has higher thermal and electrical conductivity than aluminum and copper.

In this embodiment, a plurality of conductive plates 26 are stacked on the stacked plate body 23 of the busbar 21 . Then, the stacked plate body 23 is joined to a connector plate 22A, which is a conductive member different from the stacked plate body 23, at a joining portion 27A formed at one end in the longitudinal direction. A connector plate 22B, which is a conductive member different from the overlapping plate body 23 and the connector plate 22A, is joined to a connector plate 22B at a joint portion 27B formed at the end opposite to the portion 27A. In the laminated plate body 23, the plate thickness T0 of each of the plurality of conductive plates 26 is thin, but the total value (n×T0) of the plate thickness T0 of the plurality of conductive plates 26 is a certain thickness (size). Therefore, in the stacked plate body 23, the cross-sectional area of each of the plurality of conductive plates 26 (the cross-sectional area of the single conductive plate 26) is small, but the cross-sectional area of the stacked plate body 23, which is the total value of the cross-sectional areas of the plurality of conductive plates 26, is small. The overall cross-sectional area is secured to a certain size.

Therefore, in the busbar 21 of the present embodiment, even if the stacked plate body 23 in which a plurality of conductive plates 26 are stacked is provided, the cross-sectional area of the entire stacked plate body 23 orthogonal or substantially orthogonal to the extending direction of the electric path is , is properly sized. Therefore, the cross-sectional area of the busbar 21 that is orthogonal or substantially orthogonal to the extending direction of the electrical path is ensured to have an appropriate size, and an increase in electrical resistance in the busbar 21 is appropriately suppressed. As a result, even if a large current flows through the busbar 21 that electrically connects the electrode terminals 11A and 11B, the temperature rise in the busbar 21 is appropriately suppressed. By allowing a large current to flow through the busbar 21, it becomes possible to achieve a high output power of the battery module 20 including the batteries 1A and 1B.

Further, stress from the busbar 21 acts on each of the electrode terminals 11A and 11B to which the busbar 21 is joined (connected). A stress acts in the second direction of the bus bar 21 on the electrode terminals 11A and 11B. In the busbar 21 of the present embodiment, as described above, the stacked plate body 23 in which the plurality of conductive plates 26 are stacked is provided. Therefore, when one plate member having the same or substantially the same cross-sectional area as the total value of the cross-sectional areas of the plurality of conductive plates 26 (the cross-sectional area of the entire stacked plate body 23) is provided instead of the stacked plate body 23 The stress applied to each of the electrode terminals 11A and 11B is relaxed as compared with the above.

Here, it is assumed that n (n is an integer equal to or greater than 2) conductive plates 26 are stacked in the stacked plate body 23, and each of the n conductive plates 26 has a plate thickness T0 and a plate width W. In the stacked plate body 23 of this embodiment, as described above, each of the conductive plates 26 is not joined to the other conductive plates 26 over most of the length direction. Therefore, the layered plate 23 can be substantially regarded as a so-called layered beam. The geometrical moment of inertia I0 of the laminated plate body 23 can be calculated in the same manner as the geometrical moment of inertia of the laminated beam, and is calculated according to Equation (1). Further, as a comparative example, one plate member having the same plate thickness as the total value (n×T0) of the plate thickness T0 of the n conductive plates 26 and having the same plate width W as the conductive plate 26 is provided in place of the stacking plate 23 . In the comparative example, the geometrical moment of inertia I1 in one plate member is calculated as shown in Equation (2).

I0=n×((W×T0 ³ )/12) (1)
I1=(W×(n×T0) ³ )/12=n ³ ×((W×T0 ³ )/12) (2)

As shown by equations (1) and (2), the geometrical moment of inertia I0 of the laminated plate body 23 is relative to the geometrical moment of inertia I1 of one plate member having the same cross-sectional area as the laminated plate body 23. , 1/ ⁿ² . Therefore, by providing the laminated plate body 23 on the bus bar 21, the geometrical moment of inertia of the laminated plate body 23 is reduced, so that the stress applied from the bus bar 21 to each of the electrode terminals 11A and 11B is appropriately relaxed. be done. By relaxing the stress applied to the electrode terminal 11A, in the battery 1A, the stress applied to an insulating gasket or the like disposed near the electrode terminal 11A is also alleviated. In the battery 1A, the stress on the insulating gasket and the like is appropriately relieved, thereby effectively preventing the deterioration of the hermeticity of the internal cavity 10 due to the stress from the busbar 21 to the electrode terminal 11A. Similarly, in the case of the battery 1B, the relaxation of the stress applied to the electrode terminals 11A effectively prevents deterioration of the hermeticity of the internal cavity 10 due to the stress from the bus bar 21 to the electrode terminals 11B. be.

As described above, in the busbar 21 of the present embodiment, the cross-sectional area orthogonal or substantially orthogonal to the extending direction of the electrical path is ensured to have an appropriate size, and the voltage is applied from the busbar 21 to the electrode terminals 11A and 11B. applied stresses are appropriately relieved. Further, in the bus bar 21 of the present embodiment, the bent positions B1 and B2 described above are formed in the laminated plate body 23, and the portion between the bent positions B1 and B2 in the length direction is formed in a convex shape. By forming the convex shape (bend structure) on the stacked plate body 23 as described above, the stress applied from the bus bar 21 to the electrode terminals 11A and 11B is further relieved.

In addition, in the present embodiment, by forming the connector plate 22A from the same material as the electrode terminal 11A, it is possible to effectively prevent the formation of gaps in the joining portion of the connector plate 22A to the electrode terminal 11A. The bonding performance between the plate 22A and the electrode terminal 11A is improved. Similarly, by forming the connector plate 22B from the same material as that of the electrode terminals 11B, it is possible to effectively prevent the formation of gaps in the connecting portions of the connector plate 22B and the electrode terminals 11B, thereby effectively preventing the connector plate 22B from forming the electrode terminals 11B. The bonding performance with the terminal 11B is improved.

In addition, in the present embodiment, each of the conductive plates 26 is made of a material having higher thermal conductivity and electrical conductivity than at least one of the connector plates 22A and 22B. The temperature rise at the bus bar 21 is further appropriately suppressed. Therefore, by forming each of the conductive plates 26 from a material having higher thermal and electrical conductivity than at least one of the connector plates 22A and 22B, the conductive plates 26 are formed from the same material as the connector plates 22A and 22B. It is possible to further increase the current flowing through the bus bar 21 as compared with the case where the bus bar 21 is connected. This makes it possible to increase the output of the battery module 20 including the batteries 1A and 1B. Moreover, by forming each of the conductive plates 26 from a material having higher thermal conductivity and electrical conductivity than at least one of the connector plates 22A and 22B, the number of conductive plates 26 forming the stacked plate body 23 can be reduced. Even if it is reduced, it is possible to pass the same amount of electric current to the bus bar 21 as when the conductive plate 26 is made of the same material as the connector plates 22A and 22B.

(Modification of the first embodiment)
Modifications of the above-described first embodiment will be described below. In the first modification shown in FIG. 5, the conductive plates 26 do not contact adjacent conductive plates 26 in the stacking direction in the portion between the bending positions B1 and B2 of the stacked plate body 23 . A gap 31 is formed between each of the plurality of conductive plates 26 and adjacent conductive plates 26 in the stacking direction in the portion between the bending positions B1 and B2 of the stacked plate body 23 . In this modified example, the stacked plate body 23 includes a pair of plate contact portions 32A and 32B and a plate spacing portion 33. As shown in FIG.

The plate contact portion (first plate contact portion) 32A is formed at the end portion of the stack plate body 23 in the longitudinal direction on the side where the joint portion (first joint portion) 27A is located, and is curved with the end S1. It is formed in the portion between position B1. At the plate contact portion 32A, each of the plurality of conductive plates 26 contacts the conductive plate 26 adjacent in the stacking direction. Further, in the stacked plate body 23, the plurality of conductive plates 26 are joined to each other at the plate contact portion 32A. The plate contact portion (second plate contact portion) 32B is formed at the end portion of the stack plate body 23 in the longitudinal direction on the side where the joint portion (second joint portion) 27B is located, and is curved with the end S2. It is formed in the portion between position B2. For this reason, the plate contact portion 32B is formed at the end of the stack plate body 23 on the side opposite to the plate contact portion 32A in the longitudinal direction. At the plate contact portion 32B, each of the plurality of conductive plates 26 contacts the conductive plate 26 adjacent in the stacking direction. Further, in the stacked plate body 23, the plurality of conductive plates 26 are joined to each other at the plate contact portion 32B.
In this modified example, the edge surface E1 of each of the plurality of conductive plates 26 is offset from the edge surface E1 of the other conductive plate 26 in the length direction of the stacked plate body 23 . An end S1 of the stacked plate body 23 is formed only by the edge surface E1 of the conductive plate 26A on the most proximal side with respect to the electrode terminals 11A and 11B. Among the conductive plates 26 other than the conductive plate 26A, the edge surface E1 of the conductive plate 26 on the distal side with respect to the electrode terminals 11A and 11B is located away from the end S1 toward the end S2. In addition, in this modification, the edge surface E2 of each of the plurality of conductive plates 26 is offset from the edge surface E2 of the other conductive plate 26 in the length direction of the stacked plate body 23. As shown in FIG. An end S2 of the plate stack 23 is formed only by the edge surface E2 of the conductive plate 26A that is closest to the electrode terminals 11A and 11B. Among the conductive plates 26 other than the conductive plate 26A, the edge surface E2 of the conductive plate 26 on the distal side with respect to the electrode terminals 11A and 11B is located away from the end S2 toward the end S1.

The plate separation portion 33 is formed between the plate contact portions 32A and 32B in the longitudinal direction of the stacked plate body 23, and is formed in a convex portion between the bending positions B1 and B2. In the plate spacing portion 33 (protruding portion), each of the plurality of conductive plates 26 is formed in a curved shape. In this modified example as well, in the curved shape of each of the conductive plates 26 formed in the plate spacing portion 33, the side where the electrode terminals 11A and 11B are positioned in the first direction is the inner side of the curve. The side away from 11A and 11B is the outside of the curve.

However, in the plate spacing portion 33 of this modified example, the curvature of the curved shape increases as the conductive plate 26 is located closer to the electrode terminals 11A and 11B. Therefore, among the plurality of conductive plates 26, the conductive plate 26A closest to the electrode terminals 11A and 11B has the largest curvature of the curved shape at the plate separation portion 33, and the electrode terminals 11A and 11B have the largest curvature. The curvature of the curved shape at the plate separation portion 33 is the smallest at the most distal conductive plate 26B. In this modification, by varying the curvature of the curved shape for each conductive plate 26 in the plate spacing portion 33 as described above, the conductive plates adjacent to each of the plurality of conductive plates 26 in the stacking direction in the plate spacing portion 33 26, a gap 31 is formed.

Also in this modified example, each of the conductive plates 26 is not joined to the other conductive plate 26 in the portion between the bent positions B1 and B2 in the longitudinal direction of the stacked plate body 23 . That is, each of the conductive plates 26 is not joined to the other conductive plates 26 at the plate separation portion 33 . Therefore, even in the stacked plate body 23 of this modified example, a non-joint portion is formed in which each of the conductive plates 26 is not joined to the other conductive plate 26 over most of the length direction.

This modified example also has the same actions and effects as those of the first embodiment and the like. Therefore, in the busbar 21 of this modified example as well, the cross-sectional area perpendicular or substantially perpendicular to the extending direction of the electrical path is ensured to have an appropriate size, and the stress applied from the busbar 21 to the electrode terminals 11A and 11B is reduced. is appropriately mitigated. In addition, in this modification, a gap 31 is formed between each of the plurality of conductive plates 26 and the adjacent conductive plate 26 in the stacking direction in the plate separation portion 33 . Therefore, the heat dissipation property of the laminated plate body 23 of the busbar 21 is improved, and the temperature rise in the busbar 21 is further appropriately suppressed.

Also in the second modified example shown in FIG. 6, similarly to the modified example of FIG. In the portion 33, a gap 31 is formed between each of the plurality of conductive plates 26 and adjacent conductive plates 26 in the stacking direction. However, in this modified example, the edge surfaces E1 of the plurality of conductive plates 26 are not displaced or hardly displaced with respect to each other in the longitudinal direction of the stacked plate body 23 . Edge surfaces E1 of all the conductive plates 26 form an end S1 of the stacked plate body 23. As shown in FIG. In addition, in this modification, the edge surfaces E2 of the plurality of conductive plates 26 are not displaced or hardly displaced with respect to each other in the longitudinal direction of the stacked plate body 23 . Edge surfaces E2 of all the conductive plates 26 form an end S2 of the stacked plate body 23. As shown in FIG.

Further, in the stacked plate body 23 of this modified example, the conductive plate 26 positioned closer to the electrode terminals 11A and 11B along the length direction of the stacked plate body 23 from the edge surface E1 to the edge surface E2. The extension length becomes shorter. Then, the closer the conductive plate 26 is positioned to the proximal side with respect to the electrode terminals 11A and 11B, the more the plate separation portion 33 (the convex portion between the bending positions B1 and B2) along the length direction of the laminated plate body 23 becomes. Extension length is shortened. Therefore, among the plurality of conductive plates 26, the conductive plate 26A closest to the electrode terminals 11A and 11B has the shortest extension length along the longitudinal direction of the stacked plate body 23, and the electrode terminal The extension length along the longitudinal direction of the stack 23 is the longest at the conductive plate 26B that is the most distal with respect to 11A and 11B. In this modification, as described above, each of the conductive plates 26 in the stacked plate body 23 has a different extension length along the length direction, so that in the plate separation portion 33, each of the plurality of conductive plates 26 and the stacking direction A gap 31 is formed between the conductive plates 26 adjacent to each other.

Also in this modification, since the gap 31 is formed in the plate separation portion 33, the heat dissipation of the stacked plate body 23 of the busbar 21 is improved, and the temperature rise in the busbar 21 is further reduced, as in the modification of FIG. Properly suppressed. In addition, in this modification, the edge surfaces E1 of the plurality of conductive plates 26 are not displaced or hardly displaced with respect to each other in the longitudinal direction of the stacked plate body 23 . The edge surfaces E2 of the plurality of conductive plates 26 are not displaced or hardly displaced from each other in the longitudinal direction of the stacked plate body 23. As shown in FIG. Therefore, workability is improved in assembling (forming) the plate stack 23 and forming the bus bar 21 .

In addition, in the third modification shown in FIG. 7, the connector plates 22A and 22B are not provided on the busbar 21, and the busbar 21 is formed only from the laminated plate body 23. As shown in FIG. In this modification, the joint portion (first joint portion) 27A of the stacked plate body 23 is joined to the electrode terminal (first conductive member) 11A of the battery 1A, which is a conductive member different from the stacked plate body 23. be. The joint portion (second joint portion) 27B of the stacked plate body 23 is joined to the electrode terminal (second conductive member) 11B of the battery 1B, which is a conductive member different from the stacked plate body 23 and the electrode terminal 11A. be done. Note that, in a modification, only one of the connector plates 22A and 22B may be provided on the bus bar 21 .

Even if at least one of the connector plates 22A and 22B is not provided on the bus bar 21 as in the modified example of FIG. . Therefore, even in the modified example shown in FIG. 7, etc., the same functions and effects as those of the first embodiment and the like can be obtained. That is, even in the busbar 21 of the modified example of FIG. applied stresses are appropriately relieved. In addition, in the bus bar 21 provided with the stacked plate body 23 as in the first embodiment, the number of the conductive plates 26 forming the stacked plate body 23 is not particularly limited as long as it is two or more. .

(Second embodiment)
Next, a busbar 21 according to a second embodiment will be described. The busbar 21 of this embodiment is obtained by modifying the busbar 21 of the first embodiment and the like as follows. Therefore, in the bus bar 21 of the present embodiment, description of the same configuration as that of the first embodiment and the like will be omitted.

FIG. 8 shows the busbar 21 of this embodiment, and FIG. 9 shows the configuration of the busbar 21 of this embodiment, two electrode terminals 11A and 11B to which the busbar 21 is connected (joined), and their vicinity. . Also in the bus bar 21 of this embodiment, as in the above-described embodiments, the first direction (the direction indicated by arrows Z3 and Z4), the second direction (the direction indicated by arrows Y3 and Y4), and the third direction Directions (directions indicated by arrows X3 and X4) are defined. 8 shows the busbar 21 as viewed from one side in the first direction, and FIG. 10 shows the busbar 21 as viewed from one side in the third direction.

In this embodiment, the bus bar 21 also includes connector plates 22A and 22B, and the length direction, width direction, and thickness direction of each of the connector plates 22A and 22B are defined in the same manner as in the first embodiment. be done. However, in this embodiment, the bus bar 21 includes a plurality of conductive wires 41 instead of the layered plates 23, and ten conductive wires 41 are provided in an example such as FIGS. Each of the plurality of conductive wires 41 is made of a conductive material and has electrical conductivity. Examples of the material forming the conductive wire 41 include copper. Each of the conductive wires 41 has a central axis, and each of the conductive wires 41 defines an axial direction along the central axis.

Each of the plurality of conductive wires 41 has a bonding portion (first bonding portion) bonded to a connector plate (first connector plate) 22A, which is a conductive member (first conductive member), at one end in the axial direction. bonding portion) 42A is formed. Each of the plurality of conductive wires 41 is bonded to a connector plate (second connector plate) 22B, which is a conductive member (second conductive member), at an end portion opposite to the bonding portion 42A in the axial direction. A bonding portion (second bonding portion) 42B is formed. At each bonding portion 42A, a corresponding one of the conductive wires 41 is bonded to the connector plate 22A, such as by ultrasonic welding. Similarly, at each bonding portion 42B, a corresponding one of the conductive wires 41 is bonded to the connector plate 22B, such as by ultrasonic welding.

Each of the plurality of conductive wires 41 extends in at least one direction of the first direction of the bus bar 21 (thickness direction of the connector plates 22A and 22B) and the third direction of the bus bar 21 (the plate width direction of the connector plates 22A and 22B). at a distance from the other conductive wires 41 . Therefore, in the busbar 21, the plurality of conductive wires 41 do not contact each other. 8 and 9, the plurality of conductive wires 41 are composed of five conductive wires 41A and five conductive wires 41B. The five conductive wires 41A are arranged apart from each other in the third direction (the width direction of the connector plates 22A and 22B), and the five conductive wires 41B are arranged apart from each other in the third direction. placed. Also, the conductive wire 41A is arranged apart from the conductive wire 41B in the first direction (thickness direction of the connector plates 22A and 22B). The conductive wire 41A extends through a region farther from the electrode terminals 11A and 11B in the first direction than the conductive wire 41B.

In this embodiment, as described above, the busbar 21 is provided with a plurality of conductive wires 41 . Here, the diameter of each of the plurality of conductive wires 41 is small, and the cross-sectional area of each of the conductive wires 41 is small. However, by providing a plurality of conductive wires 41 , particularly by increasing the number of conductive wires 41 , the total cross-sectional area of the plurality of conductive wires 41 can be secured to some extent. In the busbar 21 of the present embodiment, the total value of the cross-sectional areas of the plurality of conductive wires 41 is the cross-sectional area orthogonal or substantially orthogonal to the extending direction of the electrical path. Therefore, even if an electrical path is formed in the busbar 21 by a plurality of conductive wires 41, the cross-sectional area of the busbar 21 orthogonal or substantially orthogonal to the extending direction of the electrical path is ensured to have an appropriate size.

Also, in the present embodiment, a plurality of conductive wires 41 are provided on the bus bar 21 as described above. Therefore, the stress applied from the bus bar 21 to each of the electrode terminals 11A and 11B is reduced compared to the case where the plate-like portions integrated with the connector plates 22A and 22B are provided instead of the plurality of conductive wires 41. be.

As described above, in the busbar 21 of the present embodiment as well, the cross-sectional area orthogonal or substantially orthogonal to the extending direction of the electric path is ensured to have an appropriate size, and voltage is applied from the busbar 21 to the electrode terminals 11A and 11B. applied stresses are appropriately relieved. Therefore, this embodiment also has the same functions and effects as those of the above-described embodiments.

(Modification of Second Embodiment)
In a variant of the second embodiment shown in FIG. 10, the busbar 21 is not provided with connector plates 22A, 22B, and the busbar 21 is formed only from a plurality of conductive wires 41. As shown in FIG. In this modification, each bonding portion (first bonding portion) 42A of the conductive wire 41 is bonded to the electrode terminal (first conductive member) 11A of the battery 1A, which is a conductive member different from the conductive wire 41. be. Each bonding portion (second bonding portion) 42B of the conductive wire 41 is bonded to the electrode terminal (second conductive member) 11B of the battery 1B, which is a conductive member different from the conductive wire 41 and the electrode terminal 11A. be done. Note that, in a modification, only one of the connector plates 22A and 22B may be provided on the bus bar 21 .

Even if at least one of the connector plates 22A and 22B is not provided on the bus bar 21 as in the modification of FIG. Prepare. Therefore, even in the modified example shown in FIG. 10, etc., the same functions and effects as those of the second embodiment and the like can be obtained. That is, even in the busbar 21 of the modified example shown in FIG. applied stresses are appropriately relieved. In the busbar 21 provided with a plurality of conductive wires 41 as in the second embodiment, the number of conductive wires 41 provided on the busbar 21 is not particularly limited as long as it is two or more.

According to at least one of these embodiments or examples, the busbar comprises a stacking plate, in which a plurality of conductive plates are stacked. The stacked plate body is connected to a first conductive member, which is a conductive member different from the stacked plate body, at a first joint portion formed at one end of the stacked plate body in the longitudinal direction of the stacked plate body. spliced. In addition, the laminated plate body is separated from the laminated plate body and the first conductive member at the second joint portion formed at the end opposite to the first joint portion in the longitudinal direction of the laminated plate body. is joined to a second conductive member, which is the conductive member of the As a result, a cross-sectional area perpendicular or substantially perpendicular to the direction in which the electrical path extends can be ensured to have an appropriate size, and a bus bar can be provided in which the stress applied to the electrode terminals is appropriately relaxed.

Although several embodiments of the invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

Claims (12)

1. A bus bar electrically connecting between two electrode terminals spaced apart from each other,
   a stacked plate body comprising a plurality of conductive plates each having conductivity, wherein the plurality of conductive plates are stacked;
   A first conductive member, which is formed at one end of the stacked plate body in the length direction of the stacked plate body that intersects the stacking direction of the plurality of conductive plates and is separate from the stacked plate body. a first joint joined to the conductive member of
   A second conductive member which is formed at an end opposite to the first joint portion in the longitudinal direction of the stacked plate body and which is a conductive member different from the stacked plate body and the first conductive member. a second joint joined to the member; and a busbar.
2. a first connector plate that serves as the first conductive member to which the first joint portion of the stacked plate is joined and that is joined to a first electrode terminal that is one of the two electrode terminals;
   The second joint portion of the stacked plate body serves as the second conductive member to be joined, and is joined to the second electrode terminal which is one of the two electrode terminals and is different from the first electrode terminal. a second connector plate that
   2. The busbar of claim 1, further comprising:
3. The busbar according to claim 2, wherein the plate thickness of each of the plurality of conductive plates is thinner than the plate thickness of each of the first connector plate and the second connector plate.
4. The bus bar according to claim 3, wherein the total thickness of the plurality of conductive plates is the same as the thickness of each of the first connector plate and the second connector plate.
5. the first connector plate is made of the same material as the first electrode terminal;
   the second connector plate is made of the same material as the second electrode terminal;
   each of the plurality of conductive plates is formed of a material having higher thermal and electrical conductivity than at least one of the first connector plate and the second connector plate;
   A busbar according to any one of claims 2 to 4.
6. a first electrode terminal, which is one of the two electrode terminals, serves as the first conductive member to which the first joint portion of the laminated plate body is joined;
   A second electrode terminal, which is one of the two electrode terminals and is different from the first electrode terminal, serves as the second conductive member to which the second joint portion of the stacked plate body is joined.
   2. The busbar of claim 1.
7. The stacked plate body is
   A first contact portion is formed at the end portion of the stacked plate body on the side where the first joint portion is located in the longitudinal direction, and each of the plurality of conductive plates abuts the conductive plates adjacent to each other in the stacking direction. a plate contact portion;
   A second conductive plate is formed at the end of the stacked plate body on the side where the second joint portion is located in the longitudinal direction, and each of the plurality of conductive plates abuts the conductive plate adjacent to the stacked plate in the stacking direction. a plate contact portion;
   The conductive plate formed between the first plate contact portion and the second plate contact portion in the length direction of the stacked plate body and adjacent to each of the plurality of conductive plates in the stacking direction. a plate separation portion in which a gap is formed between the plates;
   7. The busbar of any one of claims 1-6, comprising:
8. In the stacked plate body,
   whether each of the plurality of conductive plates is formed in the plate separation portion in a curved shape in which the curvature of the conductive plate increases toward the proximal side with respect to the two electrode terminals;
   Each of the plurality of conductive plates is extended in such a manner that the length of extension of the stacked plate body along the longitudinal direction becomes shorter as the conductive plate is positioned closer to the proximal side with respect to the two electrode terminals. ruka,
   8. The busbar of claim 7, wherein the busbar is at least one of:
9. A bus bar electrically connecting between two electrode terminals spaced apart from each other,
   a plurality of conductive wires each having electrical conductivity;
   a first bonding portion formed at one end of each of the plurality of conductive wires and bonded to a first conductive member, which is a conductive member different from the plurality of conductive wires;
   A second conductive member which is formed at an end of each of the plurality of conductive wires opposite to the first bonding portion and which is a conductive member different from the plurality of conductive wires and the first conductive member. a second bonding portion bonded to
   A busbar comprising:
10. a first connector plate that serves as the first conductive member to which the first bonding portions of the plurality of conductive wires are bonded and that is joined to a first electrode terminal that is one of the two electrode terminals; ,
    The second bonding portion of each of the plurality of conductive wires serves as the second conductive member to which the second electrode terminal is one other than the first electrode terminal of the two electrode terminals. a second connector plate joined to the
    10. The busbar of claim 9, further comprising:
11. a first electrode terminal, which is one of the two electrode terminals, serves as the first conductive member to which the first bonding portion of each of the plurality of conductive wires is bonded;
    A second electrode terminal, which is one of the two electrode terminals and is different from the first electrode terminal, is the second conductive member to which the second bonding portions of the plurality of conductive wires are bonded. becomes
    10. The busbar of claim 9.
12. A busbar according to any one of claims 1 to 11;
    a first battery comprising a first electrode terminal being one of the two electrode terminals;
    A second electrode terminal that is one of the two electrode terminals and the first electrode terminal is provided, and the second electrode terminal is electrically connected to the first electrode terminal via the bus bar. a second battery configured to
    A battery module comprising:

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