Battery pack

Abstract

To provide a battery pack in which the manufacturing efficiency can be improved and the production cost can be reduced.SOLUTION: A battery pack includes a first battery cell and a second battery cell that are adjacent to each other in a first direction. The first battery cell includes a first housing and a first electrode terminal provided on the first housing. The second battery cell includes a second housing and a second electrode terminal provided on the second housing. The first housing has a first surface including the first direction. The second housing has a second surface that is substantially parallel to the first surface. The first electrode terminal is provided on the first surface of the first housing. The second electrode terminal is provided on the second surface of the second housing. The first electrode terminal and the second electrode terminal include parts that are adjacent to each other in a second direction that is orthogonal to the first direction. In the adjacent parts, the first electrode terminal and the second electrode terminal are joined together.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Japanese Patent Application Laid-Open No. 2013-254739 (Patent Document 1) discloses providing a conductive bridge piece between first and second electrical terminals to establish an electrical and mechanical connection. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-254739 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for reducing the manufacturing cost of assembled batteries and improving manufacturing efficiency. From these perspectives, there is still room for improvement in conventional assembled batteries.

[0005] An object of the present technology is to provide a battery pack that can reduce manufacturing costs and improve manufacturing efficiency. [Means for solving the problem]

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

[0007] [1] An assembled battery comprising: a first battery cell and a second battery cell adjacent to each other in a first direction; the first battery cell includes a first housing and a first electrode terminal provided on the first housing; the second battery cell includes a second housing and a second electrode terminal provided on the second housing; the first housing has a first surface that includes the first direction; the second housing has a second surface that is approximately parallel to the first surface; the first electrode terminal is provided on the first surface of the first housing; and the second electrode terminal is provided on the second surface of the second housing; the first electrode terminal and the second electrode terminal have portions that are adjacent to each other in a second direction that is perpendicular to the first direction; and the first electrode terminal and the second electrode terminal are joined to each other at the adjacent portions.

[0008] [2] The battery pack according to [1], wherein the first electrode terminal and the second electrode terminal are joined by laser welding.

[0009] [3] The battery pack according to [1] or [2], wherein the first surface and the second surface extend in a planar direction that includes the first direction and the second direction.

[0010] [4] The battery pack according to any one of [1] to [3], wherein at least one of the first electrode terminal and the second electrode terminal is formed to be elastically deformable in the second direction before the first electrode terminal and the second electrode terminal are joined.

[0011] [5] The battery pack according to any one of [1] to [4], wherein the first electrode terminal has a convex portion, the second electrode terminal has a concave portion that receives the convex portion, and the first electrode terminal and the second electrode terminal are joined to each other between the convex portion and the concave portion.

[0012] [6] The battery pack according to any one of [1] to [5], wherein at least one of the first electrode terminal and the second electrode terminal has a thickness that varies in the first direction. [Effects of the Invention]

[0013] According to the present technology, an assembled battery that can reduce manufacturing costs and improve manufacturing efficiency is provided. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view showing two adjacent battery cells that constitute a battery pack according to an example. [Figure 2] FIG. 10 is a diagram showing a process for connecting two battery cells. [Figure 3] FIG. 10 is a perspective view showing two adjacent battery cells that constitute a battery pack according to a modified example. [Figure 4] 10A and 10B are diagrams showing modified examples of two electrode terminals connected to each other. [Figure 5] FIG. 5 is a diagram showing a state in which the two electrode terminals shown in FIG. 4 are connected. [Figure 6] 10A and 10B are diagrams showing another modified example of two electrode terminals connected to each other. [Figure 7] FIG. 7 is a diagram showing a state in which the two electrode terminals shown in FIG. 6 are connected. [Figure 8] FIG. 10 is a diagram showing yet another modified example of two electrode terminals connected to each other. [Figure 9] FIG. 9 is a diagram showing a state in which the two electrode terminals shown in FIG. 8 are connected. [Figure 10] FIG. 10 is a diagram showing yet another modified example of two electrode terminals connected to each other. [Figure 11] FIG. 11 is a diagram showing a state in which the two electrode terminals shown in FIG. 10 are connected. [Figure 12] FIG. 10 is a diagram showing yet another modified example of two electrode terminals connected to each other. [Figure 13] FIG. 13 is a diagram showing a state in which the two electrode terminals shown in FIG. 12 are connected together. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present technology will be described. Note that the same or corresponding parts are denoted by the same reference characters, and description thereof may not be repeated.

[0016] In the embodiments described below, when numbers, amounts, etc. are mentioned, the scope of the present technology is not necessarily limited to those numbers, amounts, etc., unless otherwise specified. Furthermore, in the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects and advantages mentioned in the present embodiments.

[0017] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a certain feature is included, other features may or may not be included.

[0018] Furthermore, when geometric terms and terms expressing positional and directional relationships are used in this specification, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along," these terms allow for manufacturing errors and slight variations. When terms expressing relative positional relationships, such as "upper side" and "lower side," are used in this specification, these terms are used to indicate relative positional relationships in a single state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

[0019] In this specification, the term "battery" typically refers to a lithium-ion battery, but the scope of the present technology is not limited thereto and may include other batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, the term "electrode" may collectively refer to a positive electrode and a negative electrode.

[0020] In this specification, a "battery cell" is typically a prismatic cell, but the scope of the present technology is not necessarily limited to this and may include cells of other shapes, such as cylindrical, pouch, and blade types. Furthermore, the "battery cell" can be installed in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). However, the use of the "battery cell" is not limited to in-vehicle use.

[0021] 1 is a perspective view showing two adjacent battery cells 100, 200 included in an assembled battery according to an example. As shown in FIG. 1, the battery cell 100 (first battery cell) and the battery cell 200 (second battery cell) are adjacent to each other in the Y-axis direction (first direction).

[0022] The battery cell 100 includes a housing 110 (first housing) and an electrode terminal 120 (first electrode terminal). The rectangular housing 110 includes a first surface 111 (top surface). The first surface 111 extends in the XY plane (a plane including the X axis and the Y axis). The electrode terminal 120 is provided on the first surface 111 of the housing 110.

[0023] The battery cell 200 includes a housing 210 (second housing) and an electrode terminal 220 (second electrode terminal). The rectangular housing 210 includes a second surface 211 (upper surface). The second surface 211 extends in the XY plane (a plane including the X axis and the Y axis). The electrode terminal 220 is provided on the second surface 211 of the housing 210.

[0024] Each of the housings 110 and 210 houses an electrode body (not shown). A first surface 111 of the housing 110 and a second surface 211 of the housing 210 are provided substantially parallel to each other.

[0025] Fig. 2 is a diagram showing a process for connecting the battery cells 100, 200. As shown in Fig. 2, the electrode terminal 120 has a protruding portion 121 that protrudes from the housing 110 in the Y-axis direction. When the battery cells 100, 200 are arranged in the Y-axis direction, the protruding portion 121 of the electrode terminal 120 overlaps with the electrode terminal 220 in the Z-axis direction (second direction) that is perpendicular to the Y-axis direction. In other words, the electrode terminals 120, 220 have portions that are adjacent to each other in the Z-axis direction.

[0026] 2 shows the electrode terminal 120 in a state before being joined to the electrode terminal 120. From this state, by pressing the protruding portion 121 in the direction of arrow A (-Z direction), the electrode terminal 120 can be deformed (typically elastically, but may be plastically deformed) so that the protruding portion 121 approaches the electrode terminal 220. By irradiating the protruding portion 121 of the electrode terminal 120 and the electrode terminal 220 with a laser beam from above (+Z side) while they are in contact with each other, a laser weld 300 is formed, and the electrode terminals 120, 220 are joined to each other.

[0027] Fig. 3 is a perspective view showing two adjacent battery cells 100, 200 included in a battery pack according to a modified example. In the example shown in Fig. 3, the battery cell 100 (first battery cell) and the battery cell 200 (second battery cell) are also adjacent to each other in the Y-axis direction (first direction).

[0028] The battery cell 100 includes a housing 110 (first housing) and an electrode terminal 120 (first electrode terminal). The rectangular housing 110 includes a first surface 111 (side surface). The first surface 111 extends in the YZ plane (a plane including the Y axis and the Z axis). The electrode terminal 120 is provided on the first surface 111 of the housing 110.

[0029] The battery cell 200 includes a housing 210 (second housing) and an electrode terminal 220 (second electrode terminal). The rectangular housing 210 includes a second surface 211 (side surface). The second surface 211 extends in the YZ plane (a plane including the Y axis and the Z axis). The electrode terminal 220 is provided on the second surface 211 of the housing 210.

[0030] Each of the housings 110 and 210 houses an electrode body (not shown). A first surface 111 of the housing 110 and a second surface 211 of the housing 210 are provided substantially parallel to each other.

[0031] 3, the electrode terminals 120, 220 each have a protruding portion 121, 221 that protrudes from the housings 110, 210 in the Y-axis direction. When the battery cells 100, 200 are arranged in the Y-axis direction, the protruding portion 121 of the electrode terminal 120 overlaps with the electrode terminal 220 in the Z-axis direction (second direction) that is perpendicular to the Y-axis direction. That is, the electrode terminals 120, 220 have portions that are adjacent to each other in the Z-axis direction. In this case, the protruding portion 221 of the electrode terminal 220 also overlaps with the electrode terminal of an adjacent battery cell (not shown) on the +Y side in the Z-axis direction.

[0032] From the state shown in Figure 3, the protruding portion 121 of the electrode terminal 120 is pressed downward (-Z side), and with the protruding portion 121 in contact with the electrode terminal 220, laser light is irradiated from above (+Z side), thereby laser welding the electrode terminals 120 and 220 together.

[0033] 1 to 3, by overlapping portions of the electrode terminals 120, 220 in the Z-axis direction, which is perpendicular to the Y-axis direction, which is the arrangement direction (stacking direction) of the battery cells 100, 200, and directly joining the electrode terminals 120, 220, it is possible to electrically connect the multiple battery cells 100, 200 without using connecting members such as bus bars. This makes it possible to reduce the manufacturing cost of the battery pack including the battery cells 100, 200 and improve manufacturing efficiency.

[0034] In the example of FIGS. 1 to 3, the electrode terminals 120 and 220 are partially overlapped in the Z-axis direction, but the electrode terminals 120 and 220 may be partially overlapped in the X-axis direction.

[0035] 1 to 3, the thickness (dimension in the Z-axis direction) of the protruding portions 121, 221 of the electrode terminals 120, 220 varies in the Y-axis direction. The protruding portions 121, 221 (thin portions) having a relatively small thickness are deformed and used as the joint, thereby facilitating the formation of the laser welded portion 300. However, the shape of the protruding portions 121, 221 is not limited to that shown in FIGS. 1 to 3.

[0036] Next, further modifications of the two electrode terminals 120 and 220 will be described with reference to FIGS.

[0037] 4, the electrode terminal 120 has a protrusion 121A, and the electrode terminal 220 has two protrusions 221A that form a recess that receives the protrusion 121A. As shown in Fig. 5, a joint (laser welded portion 300) between the electrode terminal 120 and the electrode terminal 220 is formed between the protrusion 121A and each of the two protrusions 221A.

[0038] 6, the electrode terminal 120 has a protrusion 121B, and the electrode terminal 220 has a protrusion 221B located on one side of the protrusion 121B. As shown in Fig. 7, a joint (laser welded part 300) between the electrode terminal 120 and the electrode terminal 220 is formed between the protrusion 121A and the protrusion 221A.

[0039] 8, the electrode terminal 120 has a protruding portion 121C and a hole 122C, and the electrode terminal 220 has a base portion 221C and a convex portion 222C. As shown in Fig. 9, the protruding portion 121C of the electrode terminal 120 rides up onto the base portion 221C of the electrode terminal 220, and a joint (laser welded portion 300) between the electrode terminal 120 and the electrode terminal 220 is formed between the protruding portion 121C and the base portion 221C. At this time, the hole 122C of the electrode terminal 120 fits into the convex portion 222C of the electrode terminal 220.

[0040] 10, electrode terminal 120 has a protruding portion 121D, and electrode terminal 220 has a base portion 221D. As shown in Fig. 11, protruding portion 121D of electrode terminal 120 rides up onto base portion 221D of electrode terminal 220, and a joint (laser welded portion 300) between electrode terminal 120 and electrode terminal 220 is formed between protruding portion 121D and base portion 221D. At this time, protruding portion 121D is deformed so as to warp upward in the figure.

[0041] 12, electrode terminal 120 has protruding portion 121E, and electrode terminal 220 has protruding portion 221E. As shown in Fig. 13, protruding portion 121E of electrode terminal 120 fits into the lower part of protruding portion 221E of electrode terminal 220, and a joint (laser welded portion 300) is formed between the tip of protruding portion 121E and the base of protruding portion 221E.

[0042] However, the configuration of the electrode terminals 120, 220 and the laser welded portion 300 is not limited to those shown in FIGS.

[0043] Although the embodiments of the present technology have been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present technology is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0044] 100 battery cell, 110 housing, 111 first surface, 120 electrode terminal, 121 protruding portion, 121A, 121B convex portion, 121C, 121D, 121E protruding portion, 122C hole portion, 200 battery cell, 210 housing, 211 second surface, 220 electrode terminal, 221 protruding portion, 221A, 221B, 222C convex portion, 221C, 221D base portion, 221E protruding portion, 300 laser welded portion.

Claims

1. a first battery cell and a second battery cell adjacent to each other in a first direction; the first battery cell includes a first housing and a first electrode terminal provided on the first housing; the second battery cell includes a second housing and a second electrode terminal provided on the second housing; the first housing has a first surface including the first direction, and the second housing has a second surface substantially parallel to the first surface; the first electrode terminal is provided on the first surface of the first housing, and the second electrode terminal is provided on the second surface of the second housing; the first electrode terminal and the second electrode terminal have portions that are adjacent to each other in a second direction that is perpendicular to the first direction, and the first electrode terminal and the second electrode terminal are joined to each other at the adjacent portions.

2. The battery pack according to claim 1 , wherein the first electrode terminal and the second electrode terminal are joined by laser welding.

3. 3. The battery pack according to claim 1, wherein the first surface and the second surface extend in a planar direction that includes the first direction and the second direction.

4. 3. The battery pack according to claim 1, wherein at least one of the first electrode terminal and the second electrode terminal is formed to be elastically deformable in the second direction before the first electrode terminal and the second electrode terminal are joined together.

5. 3. The battery pack according to claim 1, wherein the first electrode terminal has a convex portion, the second electrode terminal has a concave portion that receives the convex portion, and the first electrode terminal and the second electrode terminal are joined to each other between the convex portion and the concave portion.

6. 3. The battery pack according to claim 1, wherein at least one of the first electrode terminal and the second electrode terminal has a thickness that varies in the first direction.

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