A busbar for battery module

Abstract

The present invention discloses a busbar for a battery module, the busbar comprising a circuit board provided with a connector for external charging and discharging, a plurality of connecting aluminum sheets arranged longitudinally on both sides of the circuit board, a plastic frame for fixing the connecting aluminum sheets, and a fixing film for fixing the connecting aluminum sheets and the circuit board; the connector is electrically connected to the connecting aluminum sheets through printed circuits on both sides of the circuit board. The busbar for a battery module of the present invention has higher energy density, stable structure, safe and reliable electrical connection, and high production efficiency.

Description

Technical Field

[0001] The invention relates to a battery manufacturing technology, and in particular to a busbar for a battery module. Background Art

[0002] In the current environment of increasingly depleted oil resources, electric vehicles are increasingly valued as a substitute for traditional fuel vehicles, and China's electric vehicle industry is also developing rapidly with the support of policies. As the core component of electric vehicles, the technology of power batteries is constantly updated, and the grouping technology of power batteries is one of the important directions. The battery module is an integrated body of battery cells, generally composed of several or even dozens of battery cells connected in series and parallel, with the positive and negative electrodes leading out. How to ensure higher capacity density, stable structure, safe and reliable electrical connection, and high efficiency in production after grouping are all directions worth studying. Summary of the invention

[0003] In view of this, the present invention is intended to provide a busbar for a battery module, which has higher energy density, stable structure, safe and reliable electrical connection, and high production efficiency after being grouped.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] An embodiment of the present invention provides a busbar for a battery module, the busbar comprising a circuit board provided with a connector for external charging and discharging, a plurality of connecting aluminum sheets arranged longitudinally on both sides of the circuit board, a plastic frame for fixing the connecting aluminum sheets, and a fixing film for fixing the connecting aluminum sheets and the circuit board; the connector is electrically connected to the connecting aluminum sheets through printed circuits on both sides of the circuit board.

[0006] In the above solution, the plastic frame includes a frame bar and a positioning bar, the frame bar is attached to the outer end of the connecting aluminum sheet, and the positioning bar extends into the gap between two adjacent connecting aluminum sheets.

[0007] In the above solution, the positioning strip is provided with a positioning groove for positioning the connecting aluminum sheet on a side facing the connecting aluminum sheet, and the connecting aluminum sheet is provided with a protrusion that cooperates with the positioning groove.

[0008] In the above solution, a positioning block for positioning the connecting aluminum sheet in the battery module is further provided at the bottom of the plastic frame. One end of the positioning block is fixed to the plastic frame, and the other end cooperates with the corresponding part of the battery cell in the battery module.

[0009] In the above scheme, the positioning block includes a first positioning block and a second positioning block; the first positioning block is arranged on the positioning strip, one end of the first positioning block is inserted into the gap between the poles of two adjacent battery cells, and the two side surfaces of the first positioning block in the first direction respectively abut against the two poles; the second positioning block is arranged on the frame strip, and the inner end of the second positioning block abuts against the battery cell from the second direction; the first direction and the second direction are perpendicular to each other.

[0010] In the above solution, the first positioning block is provided with chamfers of preset size on two side surfaces in the first direction, and the second positioning block is provided with a chamfer of preset size on a side abutting against the battery cell.

[0011] In the above scheme, the upper surface and the lower surface of both sides of the circuit board are provided with the fixing film for fixing the connecting aluminum sheet and the circuit board; a part of the fixing film is fixed to the connecting aluminum sheet, and the other part is fixed to the circuit board.

[0012] In the above solution, the fixing film comprises a base layer and an adhesive layer which are fixedly overlapped and fixed up and down, and the fixing film is fixed to the connecting aluminum sheet or the circuit board by the adhesive force of the adhesive layer.

[0013] In the above solution, an extension strip for fixing the connecting aluminum sheet and the plastic frame is disposed at the outer end of the fixing film, and the extension strip is located above or below the junction of the connecting aluminum sheet and the plastic frame.

[0014] In the above solution, the connecting aluminum sheet and the circuit board are electrically connected via a nickel ribbon, one end of the nickel ribbon is connected to the connecting aluminum sheet, and the other end is connected to the circuit board.

[0015] The busbar for battery module of the present invention comprises a plurality of connecting aluminum sheets, a circuit board electrically connected to the plurality of connecting aluminum sheets respectively, a plastic frame fixing the connecting aluminum sheets and a fixing film fixing the connecting aluminum sheets and the circuit board; the circuit board is provided with a connector for discharging outward or obtaining external charging, and the connector is electrically connected to the connecting aluminum sheets; it can be seen that the busbar for battery module of the present invention improves the original integral plastic wiring harness isolation plate into a plastic frame, which greatly reduces the weight and thickness without reducing the structural stability, improves the energy density of the battery, and fixes the connecting aluminum sheets and the circuit board by a very thin fixing film, further improving the structural stability of the battery module, but the thickness is increased very little.

[0016] Other beneficial effects of the present invention will be further described in the specific implementation manner in conjunction with the specific technical solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1A schematic diagram of a battery module composed of square shell cells in the prior art;

[0018] Figure 2 for Figure 1 Schematic diagram of the center harness isolation plate;

[0019] Figure 3 A schematic diagram of a busbar for a battery module according to an embodiment of the present invention;

[0020] Figure 4 A schematic diagram of the front side of a plastic frame in a busbar for a battery module according to an embodiment of the present invention;

[0021] Figure 5 A schematic diagram of the reverse side of a plastic frame in a busbar for a battery module according to an embodiment of the present invention;

[0022] Figure 6 for Figure 5 A local enlarged schematic diagram of the middle A;

[0023] Figure 7 A schematic diagram of a busbar for a battery module according to an embodiment of the present invention being installed on a battery module;

[0024] Figure 8 for Figure 7 A cross-sectional schematic diagram along the BB direction;

[0025] Fig. 9 for Figure 8 A partial enlarged schematic diagram of point C in the middle;

[0026] Fig.10 A schematic diagram of a fixing film on one side of a circuit board in a busbar for a battery module according to an embodiment of the present invention;

[0027] Fig.11 A schematic diagram of a fixing film on the other side of a circuit board in a busbar for a battery module according to an embodiment of the present invention;

[0028] Fig.12 This is a schematic diagram of a battery module after the fixing film is removed from the busbars in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] It should be noted that, in the description of the embodiments of the present invention, unless otherwise specified and limited, the term "connection" should be understood in a broad sense. For example, it can be an electrical connection or a connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0030] It should be noted that the terms "first\second\third" in the embodiments of the present invention are only used to distinguish similar objects and do not represent a specific order for the objects. It is understandable that the specific order or sequence of "first\second\third" can be interchanged where permitted. It should be understood that the objects distinguished by "first\second\third" can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0031] At present, for square shell batteries, such as Figure 1 , 2 As shown, a common grouping method is to stack several battery cells 2 and buffer insulation sheets 3 in an interlaced manner according to a certain rule, and then form a battery cell group 6 with a stable structure by welding the end plate 4 and the side plate 5 around the battery cell group. Furthermore, in order to connect the battery cells in the battery cell group 6 in series and parallel to supply power or charge externally, and collect information of the battery group, such as temperature information, a wiring harness isolation plate 7 is provided above the battery cell group 6, and a module upper cover plate 8 is placed above the wiring harness isolation plate, and finally a complete battery module 1 is formed.

[0032] The base plate 7.1 of the wiring harness isolation plate is made of plastic. Several connecting aluminum sheets 7.2 are fixed on both sides of the base plate 7.1 by some buckle structures. The connecting aluminum sheets 7.2 are welded together with the poles 2.1 of the 6 types of cells in the battery pack below by laser welding. In the middle of the wiring harness isolation plate 7 is a U-shaped printed circuit board (PCB, Printed Circuit Board) 7.3 pasted with double-sided tape, which is used to collect the voltage and temperature signals of the battery module. The PCB board 7.3 includes a connector 7.3.1 and a printed circuit on the PCB substrate 7.3.2, as well as a nickel sheet 7.3.3 used for the bonding process.

[0033] The main function of the wiring harness isolation board is to transmit the voltage signal of each battery cell 2 in the battery module and the temperature signal of the temperature collection point in the battery module to the connector, and finally transmit it to the battery management system (BMS) through the wiring harness. The nickel sheet 7.3.3 on the PCB board 7.3 and the connecting aluminum sheet 7.2 are electrically connected through the aluminum wire 7.4, and the electrical connection is connected by a bonding process using metal filaments, so that the potential signal on the aluminum sheet is transmitted to the pin of the connector 7.3.1 through the printed circuit 7.3.3 signal. At the same time, there are two temperature sensors 7.5 on the nickel sheet 7.3.3 and the connecting aluminum sheet on the PCB board 7.3, and the temperature signal is still transmitted to the connector 7.3.1 on the PCB board through the bonding process.

[0034] The disadvantages of this solution are: first, an integral substrate 7.1 is required, which will increase the overall height and weight of the battery module and reduce the energy density of the battery module; second, the PCB board 7.3 is attached to the substrate 7.1 by double-sided tape, and the structure is not very stable; third, the aluminum wire welding in the bonding process is relatively complicated, which is not only inefficient, but also the electrical connection is not firm and is easy to break during production, transportation, and even use.

[0035] In response to the above problems, an embodiment of the present invention provides a busbar for a battery module, which may include a circuit board provided with a connector for external charging and discharging, a plurality of connecting aluminum sheets arranged longitudinally on both sides of the circuit board, a plastic frame for fixing the connecting aluminum sheets, and a fixing film for fixing the connecting aluminum sheets and the circuit board; the connector is electrically connected to the connecting aluminum sheets through printed circuits on both sides of the circuit board.

[0036] Here, the bus refers to connecting the battery cells in the battery group in series and parallel to supply power or charge to the outside and collect information of the battery group, which is equivalent to the wiring harness isolation plate 7 mentioned above; the circuit board is equivalent to the PCB board mentioned above; one end of the connecting aluminum sheet is connected to the pole of the battery cell, and the other end is connected to the circuit board, which is equivalent to the connecting aluminum sheet 7.2 mentioned above.

[0037] The principle of the embodiment of the present invention is as follows: the original integral plastic wiring harness isolation plate is improved into a plastic frame, which greatly reduces the weight and thickness without reducing the structural stability, improves the energy density of the battery, and fixes the connecting aluminum sheet and the circuit board with a very thin fixing film, further improving the structural stability of the battery module, but the thickness is increased very little.

[0038] In one embodiment, the plastic frame may include a frame bar and a positioning bar, wherein the frame bar is attached to the outer end of the connecting aluminum sheet, and the positioning bar extends into the gap between two adjacent connecting aluminum sheets. In this way, the connecting aluminum sheets can be better fixed, and it is understandable that it is also feasible not to set the positioning bar.

[0039] In one embodiment, the positioning strip may be provided with a positioning groove for positioning the connecting aluminum sheet on a side facing the connecting aluminum sheet, and the connecting aluminum sheet may be provided with a protrusion that cooperates with the positioning groove, so that the position of the connecting aluminum sheet can be further fixed.

[0040] In one embodiment, the bottom end of the plastic frame may also be provided with a positioning block for positioning the connecting aluminum sheet in the battery module, one end of the positioning block is fixed to the plastic frame, and the other end cooperates with the corresponding part of the battery cell in the battery module. The bottom end of the plastic frame is the reverse side of the plastic frame, and the positioning block may be inserted into the corresponding part of the battery cell, or inserted into the gap between the battery cells, to position the connecting aluminum sheet.

[0041] In one embodiment, the positioning block may include a first positioning block and a second positioning block; the first positioning block is arranged on the positioning bar, one end of the first positioning block is inserted into the gap between the poles of two adjacent cells, and the two sides of the first positioning block in the first direction respectively abut against the two poles; the second positioning block is arranged on the frame bar, and the inner end of the second positioning block abuts against the cell from the second direction; the first direction and the second direction are perpendicular to each other. In this way, the first positioning block positions the first direction of the connecting aluminum sheet, and the second positioning block positions the second direction of the connecting aluminum sheet;

[0042] Here, the first direction refers to two directions on the same straight line, such as front and back or left and right, rather than a single direction; similarly, the second direction also refers to two directions on the same straight line, such as left and right or front and back. Since the plastic frame does not rotate relative to the battery cell, the position of the plastic frame in the horizontal plane is completely determined by limiting the movement of the plastic frame in the first direction and the second direction; while the position of the plastic frame in the vertical direction, i.e., the height direction, will have other structural limitations, which are not the content of the embodiments of the present invention and will not be introduced.

[0043] In one embodiment, the first positioning block may be provided with a preset chamfer on two sides in the first direction, and the second positioning block may be provided with a preset chamfer on a side against the battery cell. The chamfer may make alignment more convenient and efficient during assembly. The preset size may be set according to assembly conditions.

[0044] In one embodiment, the upper and lower surfaces of both sides of the circuit board may be provided with the fixing film for fixing the connecting aluminum sheet and the circuit board; a part of the fixing film is fixed to the connecting aluminum sheet, and another part is fixed to the circuit board. In this way, the circuit board and the connecting aluminum sheet are fixed more firmly. It can be understood that it is also possible to fix only one part of the upper surface or the lower surface. That is, the number of fixing films can be four, that is, one piece each on the upper surface and the lower surface of one side, and one piece each on the upper surface and the lower surface of the other side.

[0045] In one embodiment, the fixing film may include a base layer and an adhesive layer that are fixedly overlapped and fixed, and the fixing film is fixed to the connecting aluminum sheet or the circuit board through the adhesive force of the adhesive layer. Specifically, the base layer may be made of polyethylene terephthalate (PET), and the adhesive layer may be made of a thermosensitive adhesive. In this way, there is no need to set a protective cover outside the adhesive layer, which is convenient for storage, transportation, and assembly, and can be fixed by heating after assembly. It can be understood that the adhesive layer can be other adhesives, and it can also be understood that the fixing film may not be provided with an adhesive layer, and it may be that a self-adhesive is added to the fixing film during manufacturing to increase the self-adhesiveness to achieve the purpose of fixing, etc.

[0046] In one embodiment, an extension strip for fixing the connecting aluminum sheet and the plastic frame is disposed at the outer end of the fixing film, and the extension strip is located above or below the junction of the connecting aluminum sheet and the plastic frame. Here, the junction of the connecting aluminum sheet and the plastic frame may be the junction of the positioning strips of the connecting aluminum sheet and the plastic frame; in this way, the structural stability of the battery module can be further improved.

[0047] In one embodiment, the connecting aluminum sheet and the circuit board can be electrically connected via a nickel strip, one end of the nickel strip being connected to the connecting aluminum sheet and the other end being connected to the circuit board. Specifically, the thickness of the nickel strip can be 0.5 mm, and the width of the nickel strip can be 7 mm. In this way, the electrical connection is firm and is not easily broken during production, transportation, or even use.

[0048] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0049] like Figure 3 As shown, an embodiment of the present invention provides a busbar for a battery module, the busbar comprising a circuit board 11, a plurality of connecting aluminum sheets 12 arranged longitudinally on both sides of the circuit board 11, a plastic frame 13 for fixing the connecting aluminum sheets 12, and a fixing film 14 for fixing the connecting aluminum sheets 12 and the circuit board 11; the circuit board 11 is provided with a connector 111 for external charging and discharging, and the connector 111 is electrically connected to the connecting aluminum sheets 12 through printed circuits (not shown in the figure) on both sides of the circuit board 11.

[0050] In this embodiment, Figure 4-6 As shown, the plastic frame 13 includes a frame bar 131 and a positioning bar 132, wherein the frame bar 131 is attached to the outer end of the connecting aluminum sheet 12, and the positioning bar 132 extends into the gap between two adjacent connecting aluminum sheets 12. In this way, the connecting aluminum sheets 12 can be better fixed.

[0051] In this embodiment, the positioning strip 132 is provided with a positioning groove 133 for positioning the connecting aluminum sheet 12 on one side facing the connecting aluminum sheet 12, and the connecting aluminum sheet 12 is provided with a protrusion 121 that cooperates with the positioning groove 133. In this way, the position of the connecting aluminum sheet 12 can be further fixed.

[0052] In this embodiment, a positioning block for positioning the connecting aluminum sheet 12 in the battery module is further provided at the bottom end of the plastic frame 13, one end of the positioning block is fixed to the plastic frame 13, and the other end cooperates with the corresponding part of the battery cell in the battery module. The bottom end of the plastic frame 13 is the reverse side of the plastic frame 13, and the positioning block can be inserted into the corresponding part of the battery cell, or inserted into the gap between the battery cells, to position the connecting aluminum sheet 12.

[0053] In this embodiment, the positioning block includes a first positioning block 134 and a second positioning block 135; the first positioning block 134 is arranged on the positioning bar 132, one end of the first positioning block 134 is inserted into the gap between the poles 31 of two adjacent cells, and the two sides of the first positioning block 134 in the first direction respectively abut against the two poles 31; the second positioning block 135 is arranged on the frame bar 131, and the inner end of the second positioning block 135 abuts against the cell from the second direction, such as Figure 7-9 shown.

[0054] Here, the first direction refers to Figure 5 The left and right directions shown in FIG. 1 and FIG. 2 are the same, and the second direction also refers to the left and right directions shown in FIG. Figure 5 In this way, by limiting the movement of the plastic frame 13 in the first direction and the second direction, the position of the plastic frame 13 in the horizontal plane can be determined.

[0055] In this embodiment, the first positioning block 134 has chamfers 1341 of preset size on two sides in the first direction, and the second positioning block 135 has a chamfer 1351 of preset size on one side against the battery cell. The chamfers 1341 or 1351 can make alignment more convenient and efficient during assembly.

[0056] In this embodiment, the first positioning block 134 is further provided with a weight-reducing groove 1342 , which reduces the weight of the entire plastic frame and increases the elasticity of the first positioning block 134 , making assembly easier.

[0057] In this embodiment, Fig.10 , 11As shown, the upper and lower surfaces of both sides of the circuit board 11 are provided with the fixing films 14 for fixing the connecting aluminum sheet 12 and the circuit board 11, that is, a total of four fixing films 14 are provided; a part of the fixing films 14 is fixed to the connecting aluminum sheet 12, and another part is fixed to the circuit board 11. In this way, the circuit board 11 and the connecting aluminum sheet 12 are fixed more firmly. It should be noted that the Fig.10 , 11 The fixed film 14 is a three-dimensional image, and is the same observation point, so Fig.11 The rear side of the fixed membrane is blocked, Fig.10 The graphics are slightly different, but in reality they are basically the same.

[0058] In this embodiment, the fixing film 14 includes a base layer (not shown in the figure) and an adhesive layer (not shown in the figure) that are fixed and overlapped up and down. The fixing film 14 is fixed to the connecting aluminum sheet 12 or the circuit board 11 by the adhesive force of the adhesive layer. Specifically, the base layer can be made of PET, and the adhesive layer can be made of a heat-sensitive adhesive. In this way, there is no need to set a protective cover outside the adhesive layer, and storage, transportation, and assembly are convenient. After assembly, heating can be completed to fix.

[0059] In this embodiment, the outer end of the fixing film 14 is provided with an extension bar 141 for fixing the connecting aluminum sheet 12 and the plastic frame 13, and the extension bar 141 is located above or below the junction of the connecting aluminum sheet 12 and the plastic frame 13. In this way, the structural stability of the battery module can be further improved.

[0060] In this embodiment, the fixing film 14 is provided with a clearance hole 142, which facilitates the electrical connection between the circuit board 11 and the connecting aluminum sheet 12 and is a passage for a wire or conductor to enter. The wire or conductor here can be the nickel strip 15 described below (see Fig.12 ).

[0061] In this embodiment, Fig.12 As shown, the connecting aluminum sheet 12 and the circuit board 11 are electrically connected via a nickel strip 15, one end of the nickel strip 15 is connected to the connecting aluminum sheet 12, and the other end is connected to the circuit board 11. Specifically, the thickness of the nickel strip 15 is 0.5 mm, and the width of the nickel strip 15 is 7 mm. In this way, the electrical connection is firm and is not easy to break during production, transportation, or even use.

[0062] In this embodiment, the bus is provided with a temperature sensor 16, which is arranged on the connecting aluminum sheet 12 and electrically connected to the circuit board 11, and is used to sense the temperature of the connecting aluminum sheet 12 and send the sensed temperature to the battery control component (not shown in the figure) through the circuit board 11.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A busbar for a battery module, characterized in that: The busbar comprises a circuit board provided with a connector for external charging and discharging, a plurality of connecting aluminum sheets arranged longitudinally on both sides of the circuit board, a plastic frame for fixing the connecting aluminum sheets, and a fixing film for fixing the connecting aluminum sheets and the circuit board; the connector is electrically connected to the connecting aluminum sheets through printed circuits on both sides of the circuit board; The plastic frame includes a frame bar and a positioning bar, wherein the frame bar is attached to the outer end of the connecting aluminum sheet, and the positioning bar extends into the gap between two adjacent connecting aluminum sheets; The upper surface and the lower surface of both sides of the circuit board are provided with the fixing film for fixing the connecting aluminum sheet and the circuit board; a part of the fixing film is fixedly connected to the connecting aluminum sheet, and another part of the fixing film is fixedly connected to the circuit board; A positioning block for positioning the connecting aluminum sheet in the battery module is also provided at the bottom end of the plastic frame, one end of the positioning block is fixed to the plastic frame, and the other end cooperates with a corresponding part of the battery cell in the battery module; The positioning block includes a first positioning block and a second positioning block; the first positioning block is arranged on the positioning strip, one end of the first positioning block is inserted into the gap between the poles of two adjacent battery cells, and the two side surfaces of the first positioning block in the first direction respectively abut against the two poles; the second positioning block is arranged on the frame strip, and the inner end of the second positioning block abuts against the battery cell from the second direction; the first direction and the second direction are perpendicular to each other.

2. The busbar for a battery module according to claim 1, characterized in that: The positioning strip is provided with a positioning groove for positioning the connecting aluminum sheet on a side facing the connecting aluminum sheet, and the connecting aluminum sheet is provided with a protrusion matched with the positioning groove.

3. The busbar for a battery module according to claim 1, characterized in that: The first positioning block is provided with chamfers of a preset size on two side surfaces in the first direction, and the second positioning block is provided with a chamfer of a preset size on a side abutting against the battery core.

4. The busbar for a battery module according to claim 1, characterized in that: The fixing film comprises a base layer and an adhesive layer which are fixedly overlapped and fixed up and down, and the fixing film is fixed to the connecting aluminum sheet or the circuit board through the adhesive force of the adhesive layer.

5. The busbar for a battery module according to claim 1, characterized in that: An extension strip for fixing the connecting aluminum sheet and the plastic frame is arranged at the outer end of the fixing film, and the extension strip is located above or below the junction of the connecting aluminum sheet and the plastic frame.

6. The busbar for a battery module according to claim 1, characterized in that: The connecting aluminum sheet and the circuit board are electrically connected via a nickel strip, one end of the nickel strip is connected to the connecting aluminum sheet, and the other end of the nickel strip is connected to the circuit board.

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