Battery module

Abstract

The utility model relates to a battery module which is provided with a plurality of battery units and a bus. The battery cell has an electrode terminal. The bus bar connects the electrode terminals of the plurality of battery cells to each other. The electrode terminal has a base portion and a protruding portion protruding from the base portion. The protrusion portion is disposed closer to the end portion side of the base portion than the center of the base portion. And the bus is connected with the base part of the electrode terminal in a welding manner. Therefore, the welding area of the electrode terminal and the bus bar can be increased.

Description

Technical Field

[0001] The utility model relates to a battery module, for example, to a battery module comprising a plurality of battery cells and a bus bar, wherein the plurality of battery cells have electrode terminals, and the bus bar connects the electrode terminals of the plurality of battery cells to each other. Background Art

[0002] A typical battery module structure uses a busbar to connect the electrode terminals of multiple battery cells. In the battery module disclosed in Patent Document 1, the through-holes of the busbar are formed as elongated holes to accommodate height variations when connecting adjacent battery cells. The periphery of the protrusions of the electrode terminals is welded to the periphery of the through-holes of the busbar.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-216039

[0004] In the battery module of Patent Document 1, the peripheral edge of the protrusion of the electrode terminal is welded to the peripheral edge of the through-hole of the bus bar, which has a problem of a narrow welding area between the electrode terminal and the bus bar. Utility Model Content

[0005] The present invention is made in view of the above problems and provides a battery module capable of increasing the welding area between electrode terminals and busbars.

[0006] A battery module of one embodiment of the present invention comprises: a plurality of battery cells, each having an electrode terminal; and a busbar, the busbar connecting the electrode terminals of the plurality of battery cells to each other, the electrode terminal having a base and a protrusion protruding from the base, the protrusion being arranged closer to the end side of the base than the center of the base, and the busbar being welded to the base of the electrode terminal.

[0007] Furthermore, the protrusion may have a flat surface parallel to the base portion at a tip of the protrusion, wherein the flat surface serves as a reference surface for measuring a height position of the generatrix relative to the base portion.

[0008] According to the utility model, a battery module capable of increasing the welding area between the electrode terminals and the busbar can be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a diagram showing the positive electrode terminal side of a battery cell in a battery module according to an embodiment. DETAILED DESCRIPTION

[0010] The following describes in detail the specific embodiments of the present invention with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments. In addition, for the sake of clarity, the following description and drawings are appropriately simplified. Here, in the following description, for the sake of clarity, a three-dimensional (XYZ) coordinate system is used for description.

[0011] Figure 1 : is a diagram showing the positive terminal side of a battery cell in a battery module of this embodiment. Figure 1 As shown, the battery module 1 of this embodiment is formed by connecting a plurality of battery cells 2 with bus bars 3. The battery cells 2 are, for example, general lithium-ion battery cells.

[0012] That is, the battery cell 2 is formed, for example, by winding a laminated body of a positive electrode, a separator, and a negative electrode, which is housed in a case 4 and in which an electrolyte is injected. Figure 1 As shown, the opening of the case 4 is covered with a lid 5 , the positive electrode of the wound body is connected to a positive terminal 6 provided on the lid 5 via a positive electrode collector, and the negative electrode of the wound body is connected to a negative terminal provided on the lid 5 via a negative electrode collector.

[0013] At this time, the battery cell 2 is as follows Figure 1 As shown, the shape is generally rectangular and long in the Y-axis direction when viewed from the Z-axis direction, and a plurality of battery cells 2 are arranged in the X-axis direction, and the positive terminals 6 and negative terminals of the battery cells 2 adjacent to each other in the X-axis direction are arranged alternately. Figure 1 In the illustrated battery cell 2 , the positive electrode terminal 6 is arranged on the negative side in the Y-axis direction, and the negative electrode terminal is arranged on the positive side in the Y-axis direction.

[0014] The positive terminal 6 is connected to the negative terminal of the battery cell 2 arranged on the positive side of the X-axis, for example. Here, the positive terminal 6 and the negative terminal constitute the so-called electrode terminal of the battery cell 2. For example, when viewed from the Z-axis direction, the positive terminal 6 and the negative terminal are centrally symmetrical with the center of the battery cell 2 as the center. Figure 1 The structure of the positive electrode terminal 6 shown is described as a representative example.

[0015] The positive terminal 6 is composed of a conductive member such as Figure 1 As shown in FIG, the base portion 6a and the protrusion portion 6b are provided. The base portion 6a is, for example, in the shape of a flat plate substantially parallel to the XY plane and extends in the Y-axis direction.

[0016] like Figure 1As shown, the protrusion 6b protrudes from the base 6a toward the positive Z-axis direction and has a generally truncated cone shape whose diameter decreases toward the positive Z-axis direction. The protrusion 6b has a flat surface 6c substantially parallel to the XY plane at the end portion of the protrusion 6b on the positive Z-axis side. The flat surface 6c is arranged substantially parallel to the surface of the base 6a on the positive Z-axis side.

[0017] For example, Figure 1 As shown, when viewed in the Z-axis direction, the protrusion 6b is positioned toward the negative Y-axis end relative to the center of the base 6a. Specifically, the protrusion 6b is positioned near the negative Y-axis end of the base 6a. Therefore, on the positive Z-axis surface of the base 6a of the positive electrode terminal 6, the area closer to the positive Y-axis side than the protrusion 6b is larger than the area closer to the negative Y-axis side.

[0018] The busbar 3 is made of conductive components. Figure 1 As shown, the busbar 3 is a flat plate that is substantially parallel to the XY plane when viewed from the Z-axis direction and extends in the X-axis direction. Furthermore, the busbar 3 has through-holes 3 a extending in the Z-axis direction at both ends of the busbar 3 on the positive and negative X-axis sides.

[0019] like Figure 1 As shown, the through hole 3a is formed into a shape into which the protrusion 6b of the positive terminal 6 and the protrusion of the negative terminal can be inserted, for example, having a peripheral shape larger than the peripheral shape of the end portion on the negative side of the Z axis of the protrusion 6b of the positive terminal 6 and the protrusion of the negative terminal.

[0020] The protrusion of the negative terminal of the battery cell 2 on the positive side of the X-axis in the adjacent battery cell 2 is inserted into the through hole 3a on the positive side of the X-axis of the busbar 3, and the base of the negative terminal of the battery cell 2 on the positive side of the X-axis is covered with the end of the busbar 3 on the positive side of the X-axis.

[0021] Moreover, the end portion of the busbar 3 on the positive side of the X-axis and the area of the base of the negative terminal of the battery cell 2 on the positive side of the X-axis that is closer to the positive side of the Y-axis than the protrusion are welded together by laser welding or the like to form a connection portion.

[0022] On the other hand, Figure 1 As shown, the protrusion 6b of the positive terminal 6 of the battery cell 2 on the negative side of the X-axis in the adjacent battery cell 2 is inserted into the through hole 3a on the negative side of the X-axis of the busbar 3, and the base 6a of the positive terminal 6 of the battery cell 2 on the negative side of the X-axis is covered with the end portion of the busbar 3 on the negative side of the X-axis.

[0023] And, as Figure 1As shown, regarding the end portion on the negative side of the X-axis of the busbar 3 and the area on the positive side of the Y-axis in the base 6a of the positive terminal 6 of the battery cell 2 on the negative side of the X-axis, which is closer to the positive side of the Y-axis than the protrusion 6b, the opposite parts of the two are welded together by laser welding or the like to form a connecting portion 7.

[0024] In this way, the protrusion of the negative terminal of the battery cell 2 on the positive side of the X-axis in the adjacent battery cell 2 is inserted into the through hole 3a on the positive side of the X-axis of the busbar 3, and the protrusion 6b of the positive terminal 6 of the battery cell 2 on the negative side of the X-axis in the adjacent battery cell 2 is inserted into the through hole 3a on the negative side of the X-axis of the busbar 3, thereby enabling the busbar 3 to be simply positioned by the protrusion of the negative terminal and the protrusion 6b of the positive terminal 6.

[0025] Moreover, the area of the portion where the end portion of the busbar 3 on the negative side of the X-axis and the area of the base 6a of the positive terminal 6 of the battery cell 2 on the negative side of the X-axis that is closer to the positive side of the Y-axis than the protrusion 6b are opposite to each other is larger than the area where the protrusion 6b of the positive terminal 6 and the peripheral portion of the through hole of the busbar are opposite to each other.

[0026] Therefore, the battery module 1 of the present embodiment can increase the welding area between the positive electrode terminal 6 and the bus bar 3 compared to the battery module of Patent Document 1. This also applies to the negative electrode terminal side.

[0027] At this time, for example, when the protrusion 6b of the positive terminal 6 is arranged substantially at the center of the base 6a in the Y-axis direction, the positive terminal 6 and the bus bar 3 need to be connected by welding on both sides of the protrusion 6b.

[0028] In the battery module 1 of this embodiment, the protrusion 6b of the positive electrode terminal 6 is located near the end of the base portion 6a on the negative side of the Y axis. Therefore, in this embodiment, the positive electrode terminal 6 and the bus bar 3 can be connected by simply welding the end of the bus bar 3 on the negative side of the X axis to the area of the base portion 6a of the positive electrode terminal 6 of the battery cell 2 on the negative side of the X axis that faces each other and is closer to the positive side of the Y axis than the protrusion 6b. In other words, a single connection portion 7 is sufficient. This also applies to the negative terminal.

[0029] Here, if a large gap exists between the base 6a of the positive terminal 6 and the bus bar 3, the positive terminal 6 and the bus bar 3 cannot be properly welded together. Therefore, before welding the positive terminal 6 and the bus bar 3 together, it is preferable to measure the height position of the bus bar 3 relative to the base 6a of the positive terminal 6 in the Z-axis direction to check whether welding is possible.

[0030] In this case, in the positive electrode terminal 6 of the battery module 1 of this embodiment, the flat surface 6c of the protrusion 6b is arranged substantially parallel to the surface of the base 6a on the positive side in the Z-axis direction. Therefore, the height position of the busbar 3 in the Z-axis direction can be measured using the flat surface 6c of the protrusion 6b as a reference plane.

[0031] Therefore, the protrusion 6b of the positive electrode terminal 6 can not only play a positioning function for the bus bar 3, but also function as a reference surface for measuring the height position of the bus bar 3 in the Z-axis direction. This also applies to the negative electrode terminal side.

[0032] In the present embodiment, the positive electrode terminal 6 is arranged on the negative side of the battery module 1 in the Y-axis direction, but the arrangement of the negative electrode terminal can be implemented in substantially the same manner.

[0033] In this embodiment, the protrusion 6b of the positive electrode terminal 6 is arranged on the negative side in the Y-axis direction, but the protrusion 6b only needs to be arranged closer to the end side than the center of the base 6a when viewed from the Z-axis direction. This also applies to the negative electrode terminal.

[0034] The protrusion 6b of the positive electrode terminal 6 in this embodiment is generally truncated cone-shaped, but is not limited thereto. The protrusion 6b may be cylindrical, etc., as long as it protrudes from the base 6a in the positive direction of the Z axis. The same applies to the negative electrode terminal.

[0035] The present invention is not limited to the above-described embodiment, and can be appropriately modified within a scope not departing from the gist of the invention.

Claims

1. A battery module, characterized in that: have: a plurality of battery cells having electrode terminals; and a bus bar connecting the electrode terminals of the plurality of battery cells to each other, The electrode terminal has a base portion and a protrusion protruding from the base portion. The protrusion is arranged closer to the end side of the base than to the center of the base. The busbar is connected to the base of the electrode terminal by welding.

2. The battery module according to claim 1, wherein: The protrusion has a flat surface parallel to the base at the top of the protrusion, The flat surface constitutes a reference surface for measuring the height position of the busbar relative to the base.

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