Patent Application
20240213627
The present application claims priority from Japanese Patent Application No. 2022-204732 filed on Dec. 21, 2022, the entire contents of which are hereby incorporated by reference.
The disclosure relates to a battery-cell coupling structure.
A known battery pack structure is disclosed in, for example, Japanese Unexamined Patent Application Publication (JP-A) No. 2014-199716.
Battery packs, which are formed of multiple battery cells stored in a case so as to be able to output a predetermined voltage and capacity, are widely used as power sources of various devices, vehicles, and the like. Multiple battery cells are stored in a case of a battery module constituting a battery pack, and a positive electrode terminal and a negative electrode terminal are provided on a first side surface of the case. Inside the case, the battery cells are coupled in series, parallel, or series-parallel via bus bars.
Such battery modules are stacked in, for example, three layers and are coupled and fixed to one another via a bracket, and the positive electrode terminals and the negative electrode terminals are electrically coupled to one another via bus bars. As described above, various shapes of bus bars are prepared according to a predetermined voltage or the like of the battery pack, and the battery modules are electrically coupled to one another via the bus bars.
An aspect of the disclosure provides a battery-cell coupling structure including battery cells, a first electrode coupling plate, and a second electrode coupling plate. The battery cells are arranged in a first direction. The first electrode coupling plate includes an insulating substrate and a first coupling terminal provided at a first end of the insulating substrate in a second direction orthogonal to the first direction. The second electrode coupling plate includes the insulating substrate, the first coupling terminal, and a second coupling terminal provided at a second end of the insulating substrate in the second direction. The battery-cell coupling structure is configured to electrically couple the battery cells to each other. Each of the battery cells includes a first electrode provided at a first end in the second direction and a second electrode provided at a second end in the second direction. The first electrode coupling plate is disposed between the battery cells adjacent to each other in the first direction to couple the battery cells in series. The second electrode coupling plate is disposed between the battery cells adjacent to each other in the first direction to couple the battery cells in parallel. The battery cells are coupled in series, parallel, or series-parallel with one or both of the first electrode coupling plate and the second electrode coupling plate.
The accompanying drawings are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the specification, serve to describe the principles of the disclosure.
In the battery pack described in JP-A No. 2014-199716, the shapes of the bus bars are changed each time, for example, the number of the battery modules stored in the battery pack, the layout of the battery modules, or the method of coupling the battery modules is changed. This leads to a problem in that it is difficult to reduce the manufacturing cost, such as the die cost for manufacturing the bus bars.
In addition, when the conventional battery pack is used in an apparatus, such as an electric automobile, that uses a large number of battery modules, there are numerous coupling points with bus bars. Hence, the task of coupling the bus bars and the positive and negative electrode terminals by welding or the like is performed many times, making the task complex. Similarly, there also is a task of coupling and fixing the battery modules in the battery pack to one another, making the task complex.
It is desirable to provide a battery-cell coupling structure capable of coupling, in series, parallel, or series-parallel, multiple battery cells arranged at least in one direction with two types of electrode coupling plates.
A coupling structure 10 for battery cells 11 according to an embodiment of the disclosure will be described in detail below with reference to the drawings. Factors including, without limitation, numerical values, shapes, materials, components, positions of the components, and how the components are coupled to each other are illustrative only and not to be construed as limiting to the disclosure. Further, elements in the following example embodiments which are not recited in a most-generic independent claim of the disclosure are optional and may be provided on an as-needed basis. The drawings are schematic and are not intended to be drawn to scale. Throughout the present specification and the drawings, elements having substantially the same function and configuration are denoted with the same numerals to avoid any redundant description. The front-rear direction in the drawings corresponds to the thickness direction of the battery cells 11, the left-right direction in the drawings corresponds to the transverse width direction of the battery cells 11, and the top-bottom direction in the drawings corresponds to the height direction of the battery cells 11. The front-rear direction is the direction in which the battery cells 11 are arranged (arrangement direction) and corresponds to a first direction in the disclosure. The left-right direction corresponds to a second direction in the disclosure.
As will be described in detail below, the coupling structure 10 for the battery cells 11 according to this embodiment uses at least two types of electrode coupling plates, namely, the first electrode coupling plates 31 and the second electrode coupling plates 34 (see
As illustrated in
In this embodiment, the battery cells 11 and the first electrode coupling plates 31 are press-fitted into the battery case 12, so that positive electrode plates 21 and negative electrode plates 22 of the battery cells 11 are electrically coupled to first coupling terminals 33 of the first electrode coupling plates 31 with a desired contact pressure. The second electrode coupling plates 34 are also press-fitted into the battery case 12 and thereby being electrically coupled to the battery cells 11 with a desired contact pressure.
With this structure, in the coupling structure 10 for the battery cells 11, the battery cells 11, the first electrode coupling plates 31, and the second electrode coupling plates 34 can be electrically coupled to one another without using welding or bolt fastening. This simplifies the manufacturing process of the assembled batteries 14, reduces the component count and the materials, and thus reduces the manufacturing cost. Furthermore, in recycling the assembled battery 14, the assembled battery 14 can be disassembled by pulling out the battery cells 11 and other components, without needing to remove welded or bolt-fastened portions. Thus, the work time is significantly reduced.
The coupling structure 10 for the battery cells 11 is not limited to the structure having a press-fitting structure as long as the desired contact pressure is ensured to maintain good electrical coupling. For example, urging members (not illustrated) may be disposed between the battery case 12 and the battery cells 11 at both ends in the arrangement direction in each assembled battery 14 so as to press the battery cells 11 and the like from both sides in the arrangement direction.
For example, the battery pack 13 is disposed below the floor of a vehicle, such as an automobile or a train, and supplies electric power to a motor and various electrical components. In the field of automobiles, in recent years, electrical vehicles (EVs), hybrid electrical vehicles (HEVs), plug-in hybrid electrical vehicles (PHEVs), and the like have become widespread.
The coupling structure 10 for the battery cells 11 according to this embodiment may be used in a case other than the case where the battery cells 11 constituting the assembled battery 14 are electrically coupled to one another. For example, the coupling structure 10 may also be used to electrically couple individual battery cells 11 directly arranged in the battery case 12 of the battery pack 13 to one another. Besides these cases, the coupling structure 10 for the battery cells 11 according to this embodiment may be used to continuously and electrically couple multiple battery cells 11 arranged at least in the arrangement direction of the multiple battery cells 11 to one another.
As illustrated in
As illustrated in
This structure enables the positive electrode plate 21 and the negative electrode plate 22 of the battery cell 11 to be electrically coupled to the coupling terminals of the first electrode coupling plates 31 or the coupling terminals of the second electrode coupling plates 34 on both sides in the arrangement direction, in the arrangement direction of the battery cells 11 (front-rear direction).
As illustrated in
The insulating substrate 32 is an insulating plate made of, for example, resin, such as a thermosetting resin. As described above, because the first electrode coupling plate 31 also serves as the separator, the insulating substrate 32 has substantially the same rectangular shape as the battery cell 11 in front view. The first coupling terminal 33 is, for example, a rectangular columnar bus bar. The bus bar is cut to a length substantially equal to the length of the insulating substrate 32 in the short direction (top-bottom direction) thereof, and is integrated with the insulating substrate 32 by resin molding.
As illustrated in
With this structure, an arrangement region W1 in the first electrode coupling plate 31 where the first coupling terminal 33 is provided is thicker than the remaining part, i.e., a region W2, in the first electrode coupling plate 31, and serves as a projection 36. When the first electrode coupling plate 31 is disposed between adjacent battery cells 11, the projection 36, which is the arrangement region W1 where the first coupling terminal 33 is provided, engages with the steps 24 (see
Because the first electrode coupling plate 31 has only the first coupling terminal 33, a projection 37 made solely of resin is provided at a second end of the insulating substrate 32 in the long direction thereof. In the first electrode coupling plate 31, the projection 37 has the same shape as the projection 36. With this structure, the first electrode coupling plate 31 has a substantially I-shaped cross-section in the long direction.
As illustrated in
With this structure, the second electrode coupling plate 34 is disposed between battery cells 11 adjacent to each other in the arrangement direction of the battery cells 11 to couple the battery cells 11 in parallel. Similarly to the first electrode coupling plate 31, the second electrode coupling plate 34 also serves as a separator. The second electrode coupling plate 34 will be described with reference to the description of the first electrode coupling plate 31 as appropriate.
The first electrode coupling plate 31 and the second electrode coupling plate 34 both have the projections 36 and 37, but differ in the presence/absence of the bus bar in the projection 37. Because the first electrode coupling plate 31 and the second electrode coupling plate 34 can be molded with the same mold, the mold cost is reduced.
As illustrated in
When the battery cells 11 are coupled in series, only the first electrode coupling plates 31 are used, and the first electrode coupling plates 31 are disposed between the adjacent battery cells 11. The first electrode coupling plates 31 are disposed between the battery cells 11 such that the first coupling terminals 33 are positioned alternately on the right side, left side, right side, left side, and so on. By rotating the first electrode coupling plate 31 by 180 degrees about a vertical axis, the position of the first coupling terminal 33 can be changed, so that the first electrode coupling plate 31 can be used in the series coupling.
As indicated with circles 41 and 42, the projections 36 and 37 of the first electrode coupling plates 31 fit between the positive electrode plates 21 and the negative electrode plates 22 of the adjacent battery cells 11. In other words, the battery cells 11 fit between the projections 36 and 37 of the first electrode coupling plates 31 and are fixed in position. With this structure, the battery cells 11 are unlikely to be displaced in the long direction of the battery cells 11 (left- right direction) by vibration of a vehicle or the like. Thus, contact between the first coupling terminals 33 of the first electrode coupling plates 31 and the positive electrode plates 21 and the negative electrode plates 22 of the battery cells 11 is maintained, and good electrical coupling between the battery cells 11 and the first electrode coupling plates 31 is maintained.
As described above, the battery cells 11 and the like are press-fitted into the battery case 12 and thus are pressed in the arrangement direction. This also helps maintain electrical coupling between the first coupling terminals 33 of the first electrode coupling plates 31 and the positive electrode plates 21 and the negative electrode plates 22 of the battery cells 11.
As illustrated in
When the battery cells 11 are coupled in parallel, only the second electrode coupling plates 34 are used, and the second electrode coupling plates 34 are disposed between the adjacent battery cells 11. As illustrated in
As indicated with circles 51 and 52, the projections 36 of the second electrode coupling plates 34 fit between the positive electrode plates 21, and the projections 37 of the second electrode coupling plates 34 fit between the negative electrode plates 22 of the adjacent battery cells 11. In other words, the battery cells 11 fit between the projections 36 and 37 of the second electrode coupling plates 34 and are fixed in position. With this structure, the battery cells 11 are unlikely to be displaced in the long direction of the battery cells 11 (left-right direction) by vibration of a vehicle or the like. Thus, good electrical coupling between the battery cells 11 and the second electrode coupling plates 34 is maintained.
As illustrated in
The series-parallel coupling of the battery cells 11 is achieved with two types of electrode coupling plates, namely, the first electrode coupling plates 31 and the second electrode coupling plates 34. Thus, the manufacturing cost is significantly reduced. In addition, because the battery cells 11 are fixed in position by the first electrode coupling plates 31 and the second electrode coupling plates 34, good electrical coupling between the battery cells 11, the first electrode coupling plates 31, and the second electrode coupling plates 34 is maintained.
As described above, the coupling structure 10 for the battery cells 11 according to this embodiment uses one type of the battery cells 11 in which, as illustrated in
Next, a coupling structure 60 for battery cells 61 according to another embodiment of the disclosure will be described in detail with reference to the drawings. In the description of this embodiment, the same reference signs basically denote the same members, and repeated descriptions will be omitted. The front-rear direction in the drawings corresponds to the thickness direction of the battery cells 61, the left-right direction in the drawings corresponds to the transverse width direction of the battery cells 61, and the top-bottom direction in the drawings corresponds to the height direction of the battery cells 61. The front-rear direction is the direction in which the battery cells 61 are arranged (arrangement direction) and corresponds to the first direction in the disclosure. The left-right direction corresponds to the second direction in the disclosure.
The coupling structure 60 for the battery cells 61 according to this embodiment differs from the coupling structure 10 for the battery cells 11 described above in the structure of the battery cells. That is, a positive electrode plate 62 and a negative electrode plate 63 of the battery cell 61 are provided on inner side surfaces of a housing 64 of the battery cell 61. However, also in the coupling structure 60 for the battery cells 61 according to this embodiment, similarly to the coupling structure 10 for the battery cells 11, the battery cells 61 are coupled in series, parallel, or series-parallel with two types of electrode coupling plates, namely, a first electrode coupling plate 71 having only a first coupling terminal 73 and a second electrode coupling plate 72 having the first coupling terminal 73 and a second coupling terminal 74.
Hence, in the following description, the structures of the battery cell 61, the first electrode coupling plate 71, and the second electrode coupling plate 72 will be mainly described with reference to the description of the coupling structure 10 for the battery cells 11, which has been given with reference to
As illustrated in
As illustrated in
The insulating substrate 75 is an insulating plate made of, for example, resin, such as a thermosetting resin. As described above, because the first electrode coupling plate 71 also serves as the separator, the insulating substrate 75 has substantially the same rectangular shape as the battery cell 61 in front view. The first coupling terminal 73 is, for example, a plate-like bus bar. The bus bar is cut to a length substantially equal to the length of the insulating substrate 75 in the short direction (top-bottom direction) thereof, and is integrated with the insulating substrate 75 by resin molding.
As illustrated in
In the first electrode coupling plate 71, the thickness of the bus bar in the arrangement direction (front-rear direction) is slightly larger than the thickness of the insulating substrate 75. The first coupling terminal 73 protrudes from the side surfaces 75A and 75B of the insulating substrate 75 to both sides in the arrangement direction by about several millimeters. Because the first electrode coupling plate 71 has only the first coupling terminal 73, a structure made of resin and protruding by about several millimeters is provided on a second side of the insulating substrate 75 in the long direction thereof.
As illustrated in
As described above, because the first coupling terminal 73 protrudes in the arrangement direction from the side surfaces 75A and 75B of the insulating substrate 75, the first coupling terminal 73 easily comes into contact with the positive electrode plate 62 and the negative electrode plate 63 of the battery cells 61. When, for example, the battery cells 61 and the first electrode coupling plates 71 are press-fitted into the battery case 12, the battery cells 61 and the first electrode coupling plates 71 are pressed in the arrangement direction and are electrically coupled to each other. At this time, owing to the structure of the first coupling terminals 73, good contact state is easily maintained.
Also in the coupling structure 60 for the battery cells 61, similarly to the coupling structure 10 for the battery cells 11, the battery cells 61 are coupled in series with only the first electrode coupling plates 71. With this structure, the series coupling is achieved with multiple first electrode coupling plates 71 having the same structure.
Furthermore, the first electrode coupling plates 71, which have substantially the same size as the battery cells 61 in front view, can be disposed in the arrangement area for the battery cells 61, together with the battery cells 61. Thus, there is no need to change the size or the like of the insulating substrates 75 depending on the size of the battery case 12 or a frame (not illustrated) of the assembled battery 14. Thus. the manufacturing cost is significantly reduced.
As illustrated in
The second electrode coupling plate 72 is disposed between battery cells 61 adjacent to each other in the arrangement direction of the battery cells 61 to couple the battery cells 61 in parallel. Similarly to the first electrode coupling plate 71, the second electrode coupling plate 72 also serves as a separator. Because the first electrode coupling plate 71 and the second electrode coupling plate 72 can be molded with the same mold, the mold cost is reduced. The second electrode coupling plate 72 will be described with reference to the description of the first electrode coupling plate 71 as appropriate.
As illustrated in
When the battery cells 61 are coupled in parallel, only the second electrode coupling plates 72 are used, and the second electrode coupling plates 72 are disposed between adjacent battery cells 61. As illustrated in
As described above, because the first coupling terminal 73 and the second coupling terminal 74 protrude in the arrangement direction from the side surfaces 75A and 75B of the insulating substrate 75, the first coupling terminal 73 and the second coupling terminal 74 easily come into contact with the positive electrode plates 62 and the negative electrode plates 63 of the battery cells 61. When, for example, the battery cells 61 and the second electrode coupling plates 72 are press-fitted into the battery case 12, the battery cells 61 and the second electrode coupling plates 72 are pressed in the arrangement direction and are electrically coupled to each other. At this time, owing to the structures of the first coupling terminal 73 and the second coupling terminal 74, good contact state is easily maintained.
Also in the coupling structure 60 for the battery cells 61, similarly to the coupling structure 10 for the battery cells 11, the series-parallel coupling structure is achieved with the first electrode coupling plates 71 and the second electrode coupling plates 72. Although not illustrated, as described with reference to
The series-parallel coupling of the battery cells 61 is achieved with two types of electrode coupling plates, namely, the first electrode coupling plates 71 and the second electrode coupling plates 72. Thus, the manufacturing cost is significantly reduced.
As described above, the coupling structure 60 for the battery cells 61 according to this embodiment also achieves the series, parallel, or series-parallel coupling structure with one type of the battery cells 61, illustrated in
In addition, the battery cells 61 and the first electrode coupling plates 71 and the second electrode coupling plates 72 can be electrically coupled to one another without using welding or bolt fastening. This simplifies the manufacturing process of the assembled batteries 14, reduces the component count and the materials, and thus reduces the manufacturing cost. Furthermore, in recycling the assembled battery 14, the assembled battery 14 can be disassembled by pulling out the battery cells 11 and other components, without needing to remove welded or bolt-fastened portions. Thus, the work time is significantly reduced.
In this embodiment, the battery cells 11 and 61 are arranged upright on, for example, the bottom surface of the battery case 12. Although the cases have been described where the battery cells 11 and 61 arranged at least in the arrangement direction (front-rear direction) are coupled in series, parallel, or series-parallel with the coupling structures 10 and 60, the disclosure is not limited to these cases. For example, the battery cells 11 and 61 arranged in a laid manner on the bottom surface of the battery case 12 and stacked in the height direction of the battery case 12 may be coupled in series, parallel, or series-parallel with the coupling structures 10 and 60, by arranging the first electrode coupling plates 31 and 71 and the second electrode coupling plates 34 and 72 between the battery cells 11 and 61 adjacent to each other in the height direction.
As described with reference to
A battery-cell coupling structure according to an embodiment of the disclosure includes a first electrode coupling plate having a first coupling terminal, and a second electrode coupling plate having the first coupling terminal and a second coupling terminal. When battery cells adjacent to each other in the arrangement direction are coupled in series, the first electrode coupling plate is used. When the adjacent battery cells are coupled in parallel, the second electrode coupling plate is used. When the battery cells arranged in the arrangement direction are coupled in series-parallel, the first electrode coupling plate and the second electrode coupling plate are used. With this structure, the battery cells arranged at least in the arrangement direction can be coupled to each other in series, parallel, or series-parallel with two types of electrode coupling plates, namely, the first electrode coupling plate and the second electrode coupling plate. Although the facility for manufacturing the battery cells is expensive, and the manufacturing cost of the battery cells is high, by achieving the above-described three types of coupling structures with the first electrode coupling plate, the second electrode coupling plate, and one type of battery cells, the manufacturing cost is significantly reduced. Furthermore, because a battery pack can be formed by stacking the battery cells, the first electrode coupling plates, and the second electrode coupling plates, the manufacture of the battery pack is simplified, and the manufacturing cost thereof is reduced. In addition, because the electrodes are fixed without using welding or bolt fastening, the assembled battery can be easily disassembled for recycling.
| Number | Date | Country | Kind |
|---|---|---|---|
| JP 2022-204732 | Dec 2022 | JP | national |
