Battery pack

Abstract

To provide a battery pack which improves loading efficiency of a battery cell and the other component.SOLUTION: A battery pack comprises: a first laminate and a second laminate each including a plurality of battery cells disposed side by side in a first direction; a case in which the first laminate and the second laminate are stored; a plurality of bus bars electrically connecting the plurality of battery cells; a first plate on which a first aggregate in the plurality of bus bars is loaded; and a second plate on which a second aggregate different from the first aggregate in the plurality of bus bars is loaded and which is a separated body from the first plate. The first plate and the second plate extend in a second direction, which is orthogonal to the first direction, so as to reach a surface of the second laminate from a surface of the first laminate, and the first plate and the second plate are disposed side by side in the first direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present technology relates to battery packs. [Background technology]

[0002] JP 2021-136162 A (Patent Document 1) shows a case that is assembled to a battery assembly composed of multiple single cells and supports a bus bar, which consists of multiple split cases that are divided in the arrangement direction of the single cells and connected at connecting parts.

[0003] Patent Document 1 describes how the above configuration makes it possible to absorb the electrode tolerances between the unit cells and to satisfactorily assemble the bus bar module to the battery assembly. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2021-136162 A Summary of the Invention [Problem to be solved by the invention]

[0005] When a bus bar, which is provided as a general terminal for both poles of a battery pack, is pulled out from one side in a transverse direction perpendicular to the stacking direction of the battery cells, the bus bar tends to become long, which can reduce the mounting efficiency of the battery cells and other components.

[0006] In a battery pack in which a plurality of assembled batteries are arranged in a transverse direction perpendicular to the stacking direction of the battery cells, there is still room for improvement in conventional battery packs from the viewpoint of improving the mounting efficiency of the battery cells and other components.

[0007] An object of the present technology is to provide a battery pack with high mounting efficiency of battery cells and other components. [Means for solving the problem]

[0008] The present technology provides the following battery pack.

[0009] [1] A battery pack comprising: a first stack and a second stack, each including a plurality of battery cells aligned in a first direction; a case for housing the first stack and the second stack; a plurality of bus bars electrically connecting the plurality of battery cells; a first plate on which a first set of the plurality of bus bars is mounted; and a second plate separate from the first plate on which a second set of the plurality of bus bars different from the first set is mounted, wherein the first plate and the second plate extend along a second direction perpendicular to the first direction from above the first stack to above the second stack, and the first plate and the second plate are aligned along the first direction.

[0010] [2] The battery pack described in [1], wherein the multiple battery cells included in the first stack and the second stack are electrically connected in series by multiple bus bars, and the positive electrode side common terminals and negative electrode side common terminals of the multiple series-connected battery cells are located on the same side with respect to the first stack and the second stack in the second direction.

[0011] [3] The battery pack according to [1] or [2], wherein a first set and a second set of the plurality of bus bars each include a bus bar connecting a battery cell included in the first stack and a battery cell included in the second stack.

[0012] [4] The battery pack according to any one of [1] to [3], further comprising: a first connector that aggregates first voltage detection lines for a plurality of battery cells to which a first set of the plurality of bus bars is connected; and a second connector that aggregates second voltage detection lines for a plurality of battery cells to which a second set of the plurality of bus bars is connected.

[0013] [5] The battery pack described in any one of [1] to [4], wherein the first stack and the second stack each include an even and equal number of battery cells, and the first plate and the second plate have the same width in the first direction.

[0014] [6] The battery pack described in any one of [1] to [4], wherein the first stack and the second stack each include an odd number of battery cells that are the same as each other, and the widths in the first direction of the first plate and the second plate are different from each other.

[0015] [7] The battery pack according to any one of [1] to [6], wherein the case supports the first stack and the second stack in a first direction. Effect of the Invention

[0016] According to the present technology, it is possible to prevent the connection structure using the bus bars from becoming complicated, and as a result, it is possible to provide a battery pack with high mounting efficiency of the battery cells and other components. [Brief description of the drawings]

[0017] [Figure 1] FIG. [Diagram 2] FIG. 2 is a perspective view showing a battery cell included in a battery pack. [Diagram 3] FIG. 2 is a perspective view showing a case member (excluding a lid portion) of the battery pack. [Figure 4] 4A and 4B are diagrams showing an arrangement of bus bar plates and bus bars in a battery pack according to the present embodiment. [Diagram 5] FIG. 1 is a diagram (part 1) showing an arrangement of bus bar plates and bus bars in a battery pack according to a reference example. [Figure 6] 13 is a diagram (part 2) showing an arrangement of bus bar plates and bus bars in a battery pack according to a reference example. FIG. [Figure 7] 13 is a top view showing an arrangement of a bus bar plate and bus bars in a battery pack according to a modified example. FIG. [Figure 8] 8 is a diagram showing the voltage detection wires and connectors shown in FIG. 7 as viewed from the side (X-axis direction) of the battery cell. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] 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 will not be repeated.

[0019] In the embodiments described below, when referring to the number, amount, etc., the scope of the present technology is not necessarily limited to the number, amount, etc., unless otherwise specified. In addition, in the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. In addition, the present technology is not necessarily limited to those that achieve all of the effects and advantages mentioned in the present embodiment.

[0020] In this specification, the words "comprise", "include" and "have" are open-ended, i.e., when a certain configuration is included, other configurations may or may not be included.

[0021] Furthermore, when geometric terms and terms expressing positional and directional relationships, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along" are used in this specification, 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 one state, and the relative positional relationships can be inverted or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

[0022] In this specification, the term "battery" is not limited to lithium ion batteries, but 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.

[0023] In this specification, a "battery cell" can be mounted in a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), an electric vehicle (BEV), etc. However, the use of the "battery cell" is not limited to being mounted in a vehicle.

[0024] 1 is a perspective view of a battery pack 1. As shown in FIG. 1, the battery pack 1 includes a battery cell 100 and a separator member 200.

[0025] The battery cells 100 are rectangular battery cells, and multiple battery cells 100 are provided along the Y-axis direction (first direction). The separator members 200 are provided between the multiple battery cells 100. The separator members 200 prevent unintended electrical conduction between adjacent battery cells 100. The separator members 200 ensure electrical insulation between adjacent battery cells 100.

[0026] Fig. 2 is a perspective view showing the battery cell 100. As shown in Fig. 2, the battery cell 100 has a rectangular shape. The battery cell 100 has an electrode terminal 110, a housing 120, and a gas release valve 130.

[0027] The electrode terminal 110 is formed on the housing 120. The electrode terminal 110 has a positive electrode terminal 111 and a negative electrode terminal 112 aligned along an X-axis direction (second direction) perpendicular to a Y-axis direction (first direction). The positive electrode terminal 111 and the negative electrode terminal 112 are spaced apart from each other in the X-axis direction.

[0028] The housing 120 has a rectangular parallelepiped shape and forms the external appearance of the battery cell 100. The housing 120 includes a case body 120A that contains an electrode body and an electrolyte (not shown), and a sealing plate 120B that seals an opening of the case body 120A. The sealing plate 120B is joined to the case body 120A by welding.

[0029] The housing 120 has an upper surface 121, a lower surface 122, a first side surface 123, a second side surface 124, and two third side surfaces 125.

[0030] The upper surface 121 is a plane perpendicular to the Z-axis direction (third direction) perpendicular to the Y-axis direction and the X-axis direction. The electrode terminals 110 are disposed on the upper surface 121. The lower surface 122 faces the upper surface 121 along the Z-axis direction.

[0031] Each of the first side surface 123 and the second side surface 124 is formed of a plane perpendicular to the Y-axis direction. Each of the first side surface 123 and the second side surface 124 has the largest area among the multiple side surfaces of the housing 120. Each of the first side surface 123 and the second side surface 124 has a rectangular shape when viewed in the Y-axis direction. Each of the first side surface 123 and the second side surface 124 has a rectangular shape with the X-axis direction being the long side direction and the Z-axis direction being the short side direction when viewed in the Y-axis direction.

[0032] The multiple battery cells 100 are basically stacked such that the first side surfaces 123 and the second side surfaces 124 of the battery cells 100, 100 adjacent to each other in the Y-axis direction face each other (exceptions will be described later.) In the portion stacked in this manner, the positive electrode terminals 111 and the negative electrode terminals 112 are arranged alternately in the Y-axis direction where the multiple battery cells 100 are stacked.

[0033] Gas exhaust valve 130 is provided on top surface 121. When the temperature of battery cell 100 rises (thermal runaway) and the internal pressure of housing 120 exceeds a predetermined value due to gas generated inside housing 120, gas exhaust valve 130 exhausts the gas to the outside of housing 120.

[0034] Fig. 3 is a perspective view showing a case member 300 that houses the battery cells 100. For ease of illustration, the lid portion of the case member 300 is not shown in Fig. 3.

[0035] As shown in Fig. 3, the case member 300 defines an internal space that houses the battery cells 100. A stack (battery assembly 1) of multiple battery cells 100 stacked in the Y-axis direction is housed in the internal space of the case member 300. In the example of Fig. 3, the battery assembly 1 is arranged in three rows in the X-axis direction, but in the battery pack according to the present technology, the number of rows of the battery assembly 1 is not particularly limited.

[0036] The side surface of the case member 300 directly supports the stack of battery cells 100 by restraining it in the Y-axis direction (cell-to-pack structure). The stack of battery cells 100 abuts against the case member 300 at part α in FIG.

[0037] Fig. 4 is a diagram showing the arrangement of bus bar plates 400 and bus bars 500 in a battery pack according to this embodiment. In the example shown in Fig. 4, a battery pack 1A (first stack), a battery pack 1B (second stack), and a battery pack 1C (third stack) are arranged in three rows in the X-axis direction. The three battery packs 1A, 1B, and 1C are housed in a case member 300 and supported by the case member 300 in the Y-axis direction.

[0038] Busbar plate 400 includes busbar plate 410 (first plate) and busbar plate 420 (second plate). A portion (first set) of the plurality of busbars 500 is mounted on busbar plate 410. The other portion (second set) of the plurality of busbars 500 is mounted on busbar plate 420. Busbar plates 410 and 420 are provided separately from each other.

[0039] Bus bar plates 410, 420 extend along the X-axis direction (second direction) perpendicular to the Y-axis direction so as to reach above battery pack 1A to above battery pack 1B and battery pack 1C. Bus bar plates 410, 420 are arranged side by side along the Y-axis direction.

[0040] In each of the assembled batteries 1A, 1B, and 1C, the positive electrode terminals 111 and negative electrode terminals 112 of adjacent battery cells 100 are connected by a bus bar 500. The bus bar 510 spans between the assembled batteries 1A, 1B, and 1C and connects the electrode terminals 110 of the different assembled batteries to each other. The multiple battery cells 100 included in the assembled batteries 1A, 1B, and 1C are electrically connected in series by the bus bars 500 and 510.

[0041] The general terminal bus bar 610 (positive electrode side general terminal) and the general terminal bus bar 620 (negative electrode side general terminal) are provided as general terminals on both pole sides of the assembled batteries 1A, 1B, and 1C. The general terminal bus bars 610 and 620 are both connected to the assembled battery 1C. That is, the general terminal bus bars 610 and 620 are located on the same side of the assembled batteries 1A, 1B, and 1C in the X-axis direction.

[0042] 4, each of the assembled batteries 1A, 1B, and 1C includes an even and equal number (10) of battery cells 100. Therefore, the three strings of assembled batteries 1A, 1B, and 1C include a total of 30 battery cells 100.

[0043] The bus bar plates 410, 420 have the same width in the Y-axis direction. Therefore, the bus bar plates 410, 420 are arranged so as to cover 15 battery cells 100 each.

[0044] 5 and 6 are diagrams showing the arrangement of bus bar plates 400A, 400B, 400C and bus bar 500 in a battery pack according to a reference example. In the example shown in Fig. 5 and Fig. 6, three assembled batteries 1A, 1B, 1C are also provided, arranged in three rows in the X-axis direction.

[0045] In the reference example of FIG. 5, when attempting to pull out the general terminal bus bars 610, 620 from one side in the X-axis direction (transverse direction), one of the general terminals (general terminal bus bar 610) becomes longer, and the bus bar 510 connecting the battery pack 1B and the battery pack 1C is also formed longer.

[0046] The increase in the length of total terminal bus bar 610 and bus bar 510 increases the manufacturing cost of the battery pack, and also increases the vibration and impact acting on bus bar 510.

[0047] 6, two bus bars 510 connecting the battery pack 1B and the battery pack 1C are joined to the electrode terminal 110 of the battery cell 100 located midway in the Y-axis direction of the battery pack 1B and the electrode terminal 110 of the battery cell 100 located midway in the Y-axis direction of the battery pack 1C. More specifically, the bus bar 510 connecting the battery pack 1B and the battery pack 1C is provided near the center of the batteries 1B and 1C in the Y-axis direction.

[0048] 6, the above-described arrangement of busbar 510 allows both of general terminal busbars 610, 620 to be connected to battery pack 1C. As a result, the lengths of busbar 510 and general terminal busbar 610 in the X-axis direction can be shortened compared to the example of FIG.

[0049] Bus bar plate 400 shown in Fig. 4 achieves the same arrangement of bus bars 500, 510 as in Fig. 6. Therefore, the lengths of bus bar 510 and general terminal bus bar 610 in the X-axis direction can be shortened.

[0050] Furthermore, by using two bus bar plates 410, 420 that are separated from each other in the Y-axis direction (stacking direction of the battery cells 100), it is possible to easily absorb tolerances in the stacking direction of the battery cells 100. As a result, the weldability of the bus bar 500 can be improved.

[0051] In this way, the battery pack according to the present embodiment prevents the connection structure of the battery cells 100 by the bus bar 500 from becoming complicated. As a result, it is possible to provide a battery pack with high mounting efficiency of the battery cells 100 and other components.

[0052] FIG. 7 is a top view showing the arrangement of bus bar plate 400 and bus bars 500 in a battery pack according to a modified example.

[0053] In the modification shown in FIG. 7 as well, a battery pack 1A (first stack), a battery pack 1B (second stack), and a battery pack 1C (third stack) are arranged in three rows in the X-axis direction.

[0054] Busbar plate 400 includes busbar plate 410 (first plate), busbar plate 420 (second plate), and busbar plate 430 (third plate). A portion (first set) of the plurality of busbars 500 is mounted on busbar plate 410. Another portion (second set) of the plurality of busbars 500 is mounted on busbar plate 420, and yet another portion (third set) of the plurality of busbars 500 is mounted on busbar plate 430. Busbar plates 410, 420, 430 are provided separately from one another.

[0055] The multiple battery cells 100 included in the assembled batteries 1A, 1B, and 1C are electrically connected in series by bus bars 500 and 510.

[0056] The general terminal bus bar 610 (positive electrode side general terminal) and the general terminal bus bar 620 (negative electrode side general terminal) are provided as general terminals on both pole sides of the assembled batteries 1A, 1B, and 1C. The general terminal bus bar 610 is connected to the assembled battery 1A. The general terminal bus bar 620 is connected to the assembled battery 1C.

[0057] 7, the battery packs 1A, 1B, and 1C each include an odd and equal number (23) of battery cells 100. Therefore, the three strings of battery packs 1A, 1B, and 1C include a total of 69 battery cells 100.

[0058] The width in the Y-axis direction of busbar plates 410 and 430 is the same. The width in the Y-axis direction of busbar plate 420 is larger than the width in the Y-axis direction of busbar plates 410 and 430. In other words, the widths in the Y-axis direction of busbar plates 410 and 430 and busbar plate 420 are different from each other.

[0059] The bus bar plates 410, 430 are each arranged so as to cover 15 (5 cells×3 rows) battery cells 100. The bus bar plate 420 is arranged so as to cover 39 (13 cells×3 rows) battery cells 100.

[0060] A voltage detection line 700 is connected to each battery cell 100. The voltage detection line 700 is connected via a connector 800 to the outside of the assembled batteries 1A, 1B, 1C.

[0061] 8 is a diagram showing the voltage detection wire 700 and the connector 800 as viewed from the side (X-axis direction) of the battery cell 100. As shown in FIG 8, a plurality of voltage detection wires 700 each connected to a plurality of battery cells 100 are aggregated and connected to the connector 800.

[0062] Referring again to FIG. 7, the connector 800 includes a connector 810 (a first connector), a connector 820 (a second connector), and a connector 830 (a third connector).

[0063] The connector 810 aggregates voltage detection wires 700 (first voltage detection wires) for the battery cells 100 to which the multiple bus bars 500 (first set) mounted on the bus bar plate 410 are connected. The connector 820 aggregates voltage detection wires 700 (second voltage detection wires) for the battery cells 100 to which the multiple bus bars 500 (second set) mounted on the bus bar plate 420 are connected. The connector 830 aggregates voltage detection wires 700 (third voltage detection wires) for the battery cells 100 to which the multiple bus bars 500 (third set) mounted on the bus bar plate 430 are connected.

[0064] In this way, the voltage detection line 700 is separated into a plurality of groups in the Y-axis direction, and each group is collected and connected to a separate connector 810, 820, 830. By arranging the voltage detection line 700 and the connector 800 in this way, the overall length of the voltage detection line 700 can be shortened. As a result, the impedance of the voltage detection line 700 is reduced.

[0065] In the examples of Figures 7 and 8, an example is shown in which the voltage detection line 700 is constructed using a cable, but the same idea as in the examples of Figures 7 and 8 can be adopted even when the voltage detection line is constructed using a flexible printed circuit board.

[0066] As described above, in the battery pack according to this embodiment, it is possible to easily absorb tolerances in the stacking direction of the battery cells 100, thereby improving the weldability of the bus bar 500, and also to improve the mounting efficiency of the battery cells 100 and other components.

[0067] When the number of stacked battery cells 100 is large (for example, 20 or more), the tolerance in the stacking direction tends to become large, so the arrangement of bus bar plate 400 and bus bar 500 shown in this embodiment is particularly effective.

[0068] Furthermore, in a cell-to-pack structure in which the case member 300 directly supports the battery pack 1, the battery cells 100 at the ends in the stacking direction are located close to the side walls of the case member 300 and there is little excess space within the case member 300, so the arrangement of the bus bars 500 and the common terminal bus bar 600 shown in this embodiment is particularly effective.

[0069] The number of divisions of bus bar plate 400 (two or three in the above example) and its width can be changed as appropriate.

[0070] For example, as in the example of Fig. 7, when the number of stacked cells of the assembled batteries 1A, 1B, 1C is 23 cells, the Y-axis direction may be divided into three parts (3+17+3), three parts (5+7+11), five parts (3+3+11+3+3), or five parts (3+5+7+5+3). Furthermore, the Y-axis direction may be divided into two parts (2+21), two parts (4+19), four parts (2+9+10+2), or four parts (4+7+8+4). All of these, including the number of stacked battery cells 100 (23), are merely examples.

[0071] Furthermore, the case member 300 is not limited to one that directly supports the battery pack 1, but may be one that houses a battery module including the battery pack 1 (cell-module-pack structure).

[0072] Although the embodiment of the present technology has been described above, the embodiment disclosed herein should be considered as 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 scope and meaning equivalent to the claims. [Explanation of symbols]

[0073] 1, 1A, 1B, 1C battery pack, 100 battery cell, 110 electrode terminal, 111 positive terminal, 112 negative terminal, 120 housing, 120A case body, 120B sealing plate, 121 upper surface, 122 lower surface, 123 first side, 124 second side, 125 third side, 130 gas exhaust valve, 200 separator member, 300 case member, 400, 400A, 400B, 400C, 410, 420, 430 bus bar plate, 500, 510 bus bar, 600, 610, 620 total terminal bus bar, 700 voltage detection line, 800, 810, 820, 830 connector.

Claims

1. a first stack and a second stack, each of which includes a plurality of battery cells arranged in a first direction; a case that houses the first stack and the second stack; a plurality of bus bars electrically connecting the plurality of battery cells; a first plate on which a first set of the plurality of bus bars is mounted; a second plate separate from the first plate, on which a second set of the plurality of bus bars different from the first set is mounted, the first plate and the second plate extend along a second direction perpendicular to the first direction so as to extend from above the first stack to above the second stack, The first plate and the second plate are aligned along the first direction.

2. the plurality of battery cells included in the first stack and the second stack are electrically connected in series by the plurality of bus bars; 2 . The battery pack according to claim 1 , wherein positive and negative terminals of the plurality of series-connected battery cells are located on the same side with respect to the first stack and the second stack in the second direction.

3. 3. The battery pack according to claim 1, wherein the first set and the second set of the plurality of bus bars each include a bus bar that connects a battery cell included in the first stack and a battery cell included in the second stack.

4. a first connector in which first voltage detection lines for the plurality of battery cells to which the first set of the plurality of bus bars is connected are aggregated; 3 . The battery pack according to claim 1 , further comprising: a second connector to which second voltage detection lines for the plurality of battery cells to which the second set of the plurality of bus bars is connected are aggregated.

5. the first stack and the second stack each include an even number of battery cells that is the same as each other, 3. The battery pack according to claim 1, wherein the first plate and the second plate have the same width in the first direction.

6. the first stack and the second stack each include an odd number of battery cells that is the same as each other, The battery pack according to claim 1 or 2, wherein the first plate and the second plate have different widths in the first direction.

7. The battery pack according to claim 1 , wherein the case supports the first stack and the second stack in the first direction.

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