Battery pack

Abstract

The invention relates to a battery pack. The battery pack comprises a shell; the at least two battery cells are accommodated in the shell; the signal acquisition assembly comprises an insulating support, a circuit board arranged on the insulating support, a plurality of connecting pieces and a plurality of connecting pieces, the two ends of each connecting piece are connected with the circuit board and the connecting pieces respectively, the insulating support is provided with a plurality of open grooves correspondingly containing the connecting pieces, and the connecting pieces are arranged in the open grooves. The connecting piece comprises two hard rows which are connected through a flexible part in the length direction, the two hard rows are respectively connected with the pole columns of the two adjacent battery cells, the flexible part is bent towards one side deviating from the battery cells, and the top of the flexible part extends out of the open slot. The insulation support is used for bearing and arranging other elements in the signal acquisition assembly, and the structure of the signal acquisition assembly is simplified. The connecting piece adopts a mode of combining the hard bar and the flexible part, so that the reliability of the connection with the pole of the battery cell is ensured, a buffer space is provided for the battery cell, and the damage to the connection position of the hard bar and the pole of the battery cell is avoided.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery pack. Background Art

[0002] Battery energy storage module is a key technology in the field of new energy. In the prior art, battery energy storage module is usually implemented by battery pack. Battery pack usually contains several battery modules. Battery module is composed of a frame structure and several batteries arranged in the frame structure. The batteries in the battery module are connected by a connecting component. The battery pack BMS system collects the voltage and temperature of each battery in the battery module through the collection line in the connecting component.

[0003] The acquisition circuit in the prior art usually includes an aluminum bar, a circuit board, and a connecting piece connecting the aluminum bar and the circuit board. After the aluminum bar and the pole are welded, the battery pole voltage can be transmitted to the PCB board through the aluminum bar and the connecting piece, thereby completing the sampling of the battery pole voltage by the external circuit.

[0004] During the recycling of the battery pack, the battery cells have the characteristics of deformation and expansion. At the same time, during the installation, transportation and use, they will inevitably vibrate, which will cause the collection line to be easily damaged and pose a safety hazard. Summary of the invention

[0005] Based on this, it is necessary to provide a battery pack to address the potential safety hazards in the acquisition line.

[0006] A battery pack comprises a shell; at least two battery cells accommodated in the shell; and a signal acquisition component, wherein the signal acquisition component comprises an insulating bracket, a circuit board, a plurality of connectors and a plurality of connecting plates arranged on the insulating bracket, wherein the two ends of the connecting plates are respectively connected to the circuit board and the connectors, wherein the insulating bracket is provided with a plurality of slots corresponding to the connectors, wherein the connector comprises two hard rows connected by a flexible portion in the length direction, wherein the two hard rows are respectively connected to poles of two adjacent battery cells, and the flexible portion is bent toward a side away from the battery cell and the top extends out of the slot.

[0007] In some embodiments, two ends of the flexible portion are respectively welded to the upper surfaces of the two rigid rows.

[0008] In some embodiments, the effective width of the rigid row is L1, the effective width of the flexible portion is L2, the thickness of the connector is t1, the thickness of the flexible portion is t2, and the size of the connector satisfies L1*t1≥L2*t2.

[0009] In some embodiments, the flexible portion is provided with a fuse zone arranged along the width direction of the connector, the width of the fuse zone is the same as the width of the flexible portion, and the melting point of the fuse zone is lower than the melting points of the two hard rows.

[0010] In some embodiments, the connecting piece is connected to the flexible portion.

[0011] In some embodiments, a groove is provided on the upper surface of the flexible portion, the connecting piece is accommodated in the groove, and the connecting piece is not higher than the upper surface of the flexible portion.

[0012] In some embodiments, the connecting piece is S-shaped as a whole, and the connecting piece includes a hollow portion, and the hollow portion has a plurality of hollow portions arranged side by side.

[0013] In some embodiments, the hollowing extends from above the circuit board to above the slot.

[0014] In some embodiments, it further includes insulating glue covering the hollow portion and bonding to the connector, wherein the insulating glue is embedded in the hollow portion.

[0015] In some embodiments, a first buffer layer is provided between the insulating support and the battery core.

[0016] In some embodiments, a cover plate matched with the shell is further included, the cover plate is located on the side of the signal acquisition component facing away from the battery cell, and a second buffer layer is provided between the circuit board and the cover plate.

[0017] The present application utilizes an insulating bracket to carry and set other components in the signal acquisition assembly, thereby simplifying the architecture of the signal acquisition assembly. The connector adopts a combination of a hard row and a flexible portion, which not only ensures the reliability of the connection with the pole of the battery cell, but also provides a buffer space for the battery cell, so that the battery expansion force is released in the flexible portion, avoiding damage to the connection position between the hard row and the pole of the battery cell. In addition, the flexible portion bends toward the side away from the battery cell and the top extends out of the slot. In this way, when adjacent battery cells move relative to each other, the top of the flexible portion is deformed in the space outside the slot, and the top of the flexible portion does not occupy the space inside the slot when deformed, so there is no need to reserve a large space in the slot, which makes the battery pack compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the structure of a battery pack according to an embodiment of the present application.

[0019] Figure 2 This is a schematic diagram of the structure of a battery pack with a hidden cover according to an embodiment of the present application.

[0020] Figure 3 This is a schematic diagram of the structure of a signal acquisition circuit according to an embodiment of the present application.

[0021] Figure 4 This is a schematic structural diagram of an insulating bracket according to an embodiment of the present application.

[0022] Figure 5This is a schematic structural diagram of a connector according to one embodiment of the present application.

[0023] Figure 6 for Figure 5 A top view of the connector shown.

[0024] Figure 7 for Figure 5 Side view of the connector shown.

[0025] Figure 8 This is a schematic structural diagram of a connecting piece according to another embodiment of the present application.

[0026] Fig. 9 This is a schematic structural diagram of a connecting piece according to one embodiment of the present application.

[0027] Fig.10 This is a schematic structural diagram of a connecting piece according to another embodiment of the present application.

[0028] Fig.11 for Figure 1 Schematic diagram of a top view of a battery pack.

[0029] Fig.12 for Fig.11 Sectional view along AA direction.

[0030] Fig.13 for Fig.12 Enlarged view of part B.

[0031] Reference numerals:

[0032] 100, battery pack; 10, shell; 110, box; 120, cover; 20, battery cell; 210, pole; 30, signal acquisition component; 310, insulating bracket; 311, slot; 312, through hole; 320, circuit board; 330, connector; 331, hard row; 3311, welding hole; 3312, missing corner; 332, flexible part; 333, welding point; 340, connecting piece; 341, first welding end; 3411, opening; 3142, protective sheet; 342, hollow part; 343, second welding end; 344, reinforcing rib; 350, insulating glue; 40, first buffer layer; 50, second buffer layer. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0034] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0035] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0036] See also Figures 1 to 5 The present application proposes a battery pack 100, including a housing 10, at least two battery cells 20, and a signal acquisition component 30. Figures 2 to 5 The signal acquisition component 30 includes an insulating bracket 310, a circuit board 320, a plurality of connectors 330 and a plurality of connecting sheets 340 arranged on the insulating bracket 310, wherein the two ends of the connecting sheet 340 are respectively connected to the circuit board 320 and the connector 330, wherein the insulating bracket 310 is provided with a plurality of slots 311 corresponding to accommodating the connector 330, and the connector 330 includes two hard rows 331 connected by a flexible portion 332 in the length direction, and the two hard rows 331 are respectively connected to the poles 210 of two adjacent battery cells 20, and the flexible portion 332 is bent toward a side away from the battery cell 20 and the top extends out of the slot 311.

[0037] In the present application, the housing 10 is a frame structure for accommodating at least two battery cells 20. The frame structure is fully or partially enclosed in the circumferential direction. Optionally, the housing 10 may include a box body 110 having a receiving cavity and a cover body 120.

[0038] In the present application, the battery cell 20 is specifically a secondary battery, and can be a pouch-type secondary battery, a square secondary battery or a cylindrical secondary battery. At least two battery cells 20 can be arranged in series, parallel or mixed in the shell 10; or at least two battery cells 20 are combined into a plurality of battery cell 20 modules, and then placed in the shell 10. The battery cell 20 is filled with an electrolyte, which contains electrolytes and is a carrier for ion transmission in the battery. It is generally composed of lithium salts and organic solvents. During the charging and discharging process of the lithium battery, lithium ions move back and forth between the positive and negative electrodes, and the electrolyte is the medium for the back and forth migration and transmission of lithium ions, which creates a potential difference between the positive and negative electrodes of the battery, thereby generating current, and thus enabling the battery to work normally.

[0039] The signal acquisition component 30 is used to connect the battery cell 20 and the BMS system of the battery pack 100 , so that the BMS system can collect information such as voltage and temperature of each battery cell 20 in the battery pack 100 .

[0040] As described in the background technology, during the cycle of the battery pack 100, the battery cell 20 has the characteristic of deformation and expansion. At the same time, during use, due to the influence of environmental factors, the battery pack 100 will inevitably be vibrated, which may cause the signal acquisition circuit to be easily damaged, posing a safety hazard.

[0041] In view of the above problems, the present application improves the signal acquisition component 30. Specifically, refer to Figures 2 to 5 The signal acquisition component 30 includes an insulating bracket 310, a circuit board 320, a plurality of connectors 330 and a plurality of connecting sheets 340 arranged on the insulating bracket 310, wherein the two ends of the connecting sheet 340 are respectively connected to the circuit board 320 and the connector 330, wherein the insulating bracket 310 is provided with a plurality of slots 311 corresponding to accommodating the connector 330, and the connector 330 includes two hard rows 331 connected by a flexible portion 332 in the length direction, and the two hard rows 331 are respectively connected to the poles 210 of two adjacent battery cells 20, and the flexible portion 332 is bent toward a side away from the battery cell 20 and the top extends out of the slot 311.

[0042] Combined with reference Figures 2 to 4 , used to carry and set other components in the signal acquisition component 30, and to isolate the circuit board 320 from the pole 210 of the battery cell 20. The insulating bracket 310 is provided with a plurality of slots 311, each of which is used to accommodate a connector 330. The insulating bracket 310 can be prepared by an injection molding process, and a plurality of slots 311 are formed at the same time as the injection molding. The insulating bracket 310 is, for example, a PC (polycarbonate) board, which has the characteristics of being lightweight.

[0043] refer to Figure 1 , Figure 2 , Figure 4In the battery pack 100, in the height direction of the battery pack 100, i.e., the Z direction, the battery cell 20 is located below the signal acquisition component 30, and the pole 210 of the battery cell 20 can be connected to the connector 330. Among them, the slot 311 is provided on the upper surface of the insulating bracket 310, and two through holes 312 are provided at the bottom of the slot 311. When the connector 330 is accommodated in the slot 311, the bottom of the connector 330 can be connected to the pole 210 of the battery cell 20 through the through hole 312.

[0044] In this embodiment, the plurality of battery cells 20 are arranged in a matrix. Specifically, along the X direction, a plurality of rows of battery cells 20 ( Figure 2 There are three rows in the figure); multiple columns of battery cells 20 are arranged along the Y direction. Each battery cell 20 has two poles 210. Among them, the poles 210 in two adjacent battery cells 20 in the same column are connected by a connector 330; the poles 210 in two adjacent battery cells 20 in the same row are also connected by a connector 330. For each battery cell 20 in the leftmost and rightmost rows in the X direction, one of its two poles 210 is connected to the pole 210 of another battery cell 20 in the same row through a connector 330, and the other pole 210 is connected to the pole 210 of another battery cell 20 in the same column through another connector 330. For each battery cell 20 in the middle row in the X direction, its two poles 210 are connected to the pole 210 of another battery cell 20 in the same column through a connector 330.

[0045] It can be understood that the number and arrangement of the slots 311 should meet the connection requirements of the battery cells 20 when the battery cells 20 are arranged in a matrix as described above. Specifically in this embodiment, the slots 311 are arranged in a matrix. Three rows of slots 311 are arranged along the X direction; and multiple columns of slots 311 are arranged along the Y direction.

[0046] The circuit board 320 is specifically arranged between two adjacent rows of slots 311. In this embodiment, two circuit boards 320 are arranged in the X direction. The circuit board 320 can be a hard circuit board, a flexible circuit board (FPC) or a flexible wiring harness, or a combination of a hard circuit board and a flexible circuit board.

[0047] refer to Figure 2 , Figure 5 The connector 330 in the present application includes two hard rows 331 connected by a flexible portion 332 in the length direction, the two hard rows 331 are respectively connected to the poles 210 of two adjacent battery cells 20, and the flexible portion 332 is bent toward the side away from the battery cell 20 and the top extends out of the slot 311. The connector 330 connects the poles 210 of two adjacent battery cells 20 along its length direction, and is connected to the circuit board 320 through the connecting piece 340. The material of the connector 330 is, for example, aluminum alloy, copper alloy, nickel alloy, or a non-metallic material including a coating of alloy material.

[0048] Specifically, when the connector 330 connects two adjacent cells 20 in the X direction, the length direction of the connector 330 is along the X direction. The two hard rows 331 and the flexible portion 332 are arranged along the X direction. One of the hard rows 331 of the connector 330 is connected to one pole 210 of one cell 20, and the other hard row 331 is connected to one pole 210 of another cell 20. At the same time, each connector 330 is connected to the adjacent circuit board 320 through a connecting piece 340.

[0049] When the connector 330 connects two adjacent cells 20 in the Y direction, the length direction of the connector 330 is along the Y direction. The two hard rows 331 and the flexible portion 332 are arranged along the Y direction. One of the hard rows 331 of the connector 330 is connected to one pole 210 of one cell 20, and the other hard row 331 is connected to one pole 210 of another cell 20. At the same time, each connector 330 is connected to the adjacent circuit board 320 through a connecting piece 340.

[0050] The hard row 331 and the pole 210 of the battery cell 20 may be connected by welding, for example. Figure 5 The hard bar 331 is provided with a through welding hole 3311, and the pole 210 can be inserted into the connection hole and then welded with the hard bar 331. The hard bar 331 can ensure a firm connection with the pole 210.

[0051] refer to Figure 2 and Figure 6 When the two adjacent cells 20 bridged by the connector 330 expand, the two hard rows 331 are subjected to stresses F1 and F2 respectively, and the directions of F1 and F2 are opposite. The flexible portion 332 is deformed by the force F1 and F2, providing a buffer space for the cell 20, thereby offsetting the expansion and deformation of the cell 20 and preventing damage to the connection between the hard row 331 and the pole 210 of the cell 20. This greatly improves the reliability of the electrical connection, improves the safety of the overall battery pack 100, and further increases the life of the product.

[0052] Optionally, the flexible portion 332 is configured to deform when subjected to a force of 10N to 40N. In this way, the stress generated during normal use of the battery cell 20 can be offset in time by the flexible portion 332. Optionally, the flexible portion 332 can be U-shaped, V-shaped, Z-shaped or other structural shapes, which are more likely to deform when subjected to force.

[0053] In the present application, an insulating bracket 310 is used to carry and set other components in the signal acquisition component 30, which simplifies the architecture of the signal acquisition component 30. The connector 330 adopts a combination of a hard row 331 and a flexible portion 332, which not only ensures the reliability of the connection with the pole 210 of the battery cell 20, but also provides a buffer space for the battery cell 20, so that the battery expansion force is released at the flexible portion 332, avoiding damage to the connection position between the hard row 331 and the pole 210 of the battery cell 20. In addition, the flexible portion 332 bends toward the side away from the battery cell 20 and the top extends out of the slot 311. In this way, when adjacent battery cells 20 move relative to each other, the top of the flexible portion 332 is deformed in the space outside the slot 311, and the top of the flexible portion 332 does not occupy the space in the slot 311 when deformed, so there is no need to reserve a large space in the slot 311, which makes the battery pack 100 compact.

[0054] Further, refer to Figure 5 and Figure 6 The two ends of the flexible portion 332 are respectively welded to the upper surfaces of the two rigid rows 331. Figure 5 As shown, a plurality of welding points 333 are provided between the end of the flexible portion 332 and the upper surface of the hard row 331. The welding method may be resistance welding, ultrasonic welding, laser welding, hot melt welding, etc.

[0055] With this arrangement, on the one hand, the entire flexible portion 332 is located above the hard row 331, and in the Y direction, the flexible portion 332 does not occupy the lateral dimension of the slot 311 at all, the distance between the two hard rows 331 can be very small, and the battery pack 100 is compact in the Y direction. On the other hand, the two ends of the flexible portion 332 are in contact with the surface between the two hard rows 331, and there is a large overlapping area between the two, which facilitates the welding of the flexible portion 332 and the hard row 331.

[0056] In some embodiments, reference Figure 6 and Figure 7 , the size of the connecting member 330 satisfies the following rule: assuming that the effective width of the rigid row 331 is L1, the effective width of the flexible portion 332 is L2, the thickness of the connecting member 330 is t1, the thickness of the flexible portion 332 is t2, and the size of the connecting member 330 satisfies L1*t1≥L2*t2.

[0057] The effective width is the effective width dimension when the rigid row 331 or the flexible portion 332 acts as a conductor to participate in the transmission of the conductive current. Figures 5 to 7When the connector 330 is used to connect two adjacent cells 20 in the same row, the effective width of the connector 330 is the effective dimension along the X direction. The thickness t1 is the dimension of the connector 330 along the Z direction. The connector 330 must meet a sufficient overcurrent value. The overcurrent capacity of the connector 330 is generally proportional to the cross-sectional area of ​​the electrical connector 330 in the overcurrent direction. For this reason, in this application, the overcurrent capacity is designed based on the cross-sectional area L1*t1 of the hard row 331, and then the size of the connector 330 satisfies L1*t1≥L2*t2.

[0058] In the present application, the size of the connector 330 is designed based on the cross-sectional area of ​​the hard row 331, which can effectively ensure the overcurrent capacity of the connector 330. When designing the size of the connector 330, the reference standard is simple and unique, thereby simplifying the design process. In addition, such a design also makes it possible that when L1*t1>L2*t2, the overcurrent capacity of the flexible portion 332 is less than the overcurrent capacity of the hard row 331, so that when the current passing through is too large, the flexible portion 332 is first fused, disconnecting the physical connection between the flexible portion 332 and the hard row 331, so that the connector 330 has a safety function.

[0059] In addition, when the flexible portion 332 is connected to the hard row 331, in the X direction, the edge contour of the flexible portion 332 is within the contour range of the hard row 331. Figure 5 , the width of the flexible portion 332 may be smaller than the width of the rigid row 331; Figure 8 , the width of the flexible portion 332 may also be equal to the width of the rigid row 331 .

[0060] like Figure 5 As shown, in some embodiments, the hard row 331 is a rectangular structure with a missing corner 3312. The rectangular structure with the missing corner 3312 plays a fool-proof role.

[0061] In order to make the connector 330 have a safety function, in other embodiments, a fuse zone is provided on the flexible portion 332 along the width direction of the connector 330 , the width of the fuse zone is the same as the width of the flexible portion 332 , and the melting point of the fuse zone is lower than the melting points of the two hard rows 331 .

[0062] In a specific configuration, the length of the fusing zone is smaller than the length of the flexible portion 332, and the width is the same as the width of the flexible portion 332. The melting point of the fusing zone is smaller than the melting points of the two hard bars 331. Thus, when the current passing through is too large, the fusing zone of the flexible portion 332 is fused, and the physical connection with the hard bar 331 is disconnected, so that the connector 330 has a safety function.

[0063] Optionally, the fuse area is provided at the end or the middle of the flexible portion 332. Optionally, more than two fuse areas are provided, so as to ensure that the physical connection between the flexible portion 332 and the hard row 331 can be quickly disconnected when the current is too large.

[0064] Optionally, the material of the fusing area is different from the material of the remaining part of the flexible portion 332. For example, the material of the fusing area is aluminum, and the material of the remaining part of the flexible portion 332 is copper.

[0065] Optionally, a first coating is provided on the flexible portion 332, and a second coating is provided on the hard row 331. The flexible portion 332 conducts the two hard rows 331 through the connection between the first coating and the second coating. The melting point of the first coating is lower than that of the second coating, and the first coating constitutes a fuse area. When the current passing through is too large, the first coating is melted, and the physical connection with the hard row 331 is disconnected, so that the connector 330 has a safety function.

[0066] For example, the first coating is specifically an aluminum coating, and the second coating is specifically a copper coating. When the current is too large, the temperature of the first coating rises and the first coating is melted into droplets, so that the first coating, which was originally a continuous conductive area, is no longer continuous, and at least one disconnected area appears, so that the two hard rows 331 on both sides are no longer electrically connected, thereby reducing the probability of the entire battery having a risk when a certain battery cell has thermal runaway.

[0067] For example, the first coating may cover the entire surface of the flexible portion 332 ; or may be in the shape of a long strip with a width smaller than that of the flexible portion 332 and disposed along the length direction of the connector 330 .

[0068] Furthermore, the flexible portion 332 is provided with a blocking area. The first coating is arranged in the blocking area. Taking the first coating as a strip as an example, the blocking area has a blocking wall surrounding the first coating. When the first coating is melted into droplets, the droplets are blocked by the blocking wall and will not drip onto the hard row 331, thereby avoiding contamination of the battery cell.

[0069] In some embodiments, the hard row 331 is fixed to the insulating bracket 310 by a plurality of screws. By adding fixing screws to the connecting member 330, the influence of vibration on the connecting member 330 can be effectively reduced.

[0070] Specifically, the fixing screws divide the connector 330 into multiple shorter segments, each of which is a fixing point, so that the stress generated by the vibration of the battery pack 100 is dispersed to multiple fixing points, and the stress amplitude of each segment of the connector 330 is significantly reduced, and the fatigue life is extended. In addition, the setting of the fixing screws changes the natural frequency of the connector 330, preventing it from resonating with the external vibration frequency, thereby reducing the vibration amplification effect.

[0071] Exemplarily, the end of the hard row 331 is provided with a plurality of holes and screws fixed to the insulating bracket 310 are installed in the holes. The screw spacing is controlled to be 20 mm-30 mm. The screws firmly fix the connector 330 on the insulating bracket 310 to limit its free vibration amplitude. And the vibration energy is dispersed to multiple fixed points instead of being concentrated on a certain section of the connector 330, thereby reducing local stress.

[0072] In other embodiments, the hard row 331 can also be riveted to the insulating bracket 310 by multiple rivets. The rivets form multiple riveting points to disperse the vibration energy and reduce local stress. The rivet material can be compatible with the material of the connector 330. For example, the connector 330 and the rivet material can both be selected from aluminum alloy or stainless steel.

[0073] In the present application, in the X direction, one end of the connecting sheet 340 is connected to the connecting member 330, and the other end is connected to the circuit board 320. The connecting sheet 340 is, for example, a nickel sheet with good conductivity, but is not limited thereto.

[0074] When the battery cell 20 expands and deforms, the connection between the connecting piece 340 and the circuit board 320 and the connecting member 330 will also be pulled by stress, resulting in certain safety hazards of the connecting piece 340.

[0075] In view of the above problems, in some embodiments, the connecting piece 340 is connected to the flexible portion 332. Specifically, the end of the connecting piece 340 is connected to the upper surface of the flexible portion 332. In this way, when the battery cell 20 expands and deforms, the stress is released when the flexible portion 332 deforms, so that the pulling force transmitted to the connecting piece 340 is reduced, thereby preventing the connecting piece 340 from falling off.

[0076] Furthermore, in order to ensure reliable connection between the connecting piece 340 and the flexible part 332, in some embodiments, the material of the flexible part 332 is specifically polyimide (PI) or polyester (PET), with a thickness of 25μm-50μm; the surface of the flexible part 332 is provided with a copper foil layer or a nickel foil layer with a thickness of 18μm-35μm as a conductive layer, and the surface of the copper foil layer is also provided with a 0.5μm-2μm anti-corrosion layer. The material of the anti-corrosion layer can be a nickel-plated layer or a gold-plated layer. The connecting piece 340 is specifically a nickel strip with a thickness of 0.5μm-2μm, and the overlapping length of the nickel strip and the flexible part 332 is 5mm-10mm.

[0077] In the above manner, the flexible portion 332 and the connecting piece 340 each have good flexibility while having a certain strength, and there is a large contact area between the flexible portion 332 and the connecting piece 330. After the two are connected, they are not easily corroded by external impurities, thereby ensuring the reliability of the connection between the two. The copper foil layer or the nickel foil layer is used as the intermediate layer to facilitate the connection of the flexible portion 332 and the connecting piece 340 by welding.

[0078] Of course, it should be pointed out that in other embodiments, the connecting piece 340 can also be connected to the hard row 331 .

[0079] Furthermore, a groove is provided on the upper surface of the flexible portion 332 , and the connecting piece 340 is accommodated in the groove. The connecting piece 340 is not higher than the upper surface of the flexible portion 332 .

[0080] By embedding one end of the connecting piece 340 into the flexible part 332, one end of the connecting piece 340 can be physically limited by the groove of the flexible part 332, and the two can be regarded as an integral structure, thereby reducing the risk of separation. In addition, one end of the connecting piece 340 is not higher than the upper surface of the flexible part 332, so that the size of the connecting member 330 in the Z direction is not increased.

[0081] When specifically configured, the shape of one end of the connecting piece 340 embedded in the flexible portion 332 matches the groove of the flexible portion 332. For example, the end of the connecting piece 340 embedded in the flexible portion 332 is rectangular, and the groove is a rectangular groove.

[0082] In some embodiments, a transition region is provided between the rigid row 331 and the flexible portion 332, wherein the thickness of the transition region gradually decreases from the rigid row 331 to the flexible portion 332, and the length of the transition region is 10 mm to 20 mm. The transition region may be a step-like transition, or the slope may be less than 1 / 10.

[0083] In one example, the thickness of the transition area gradually decreases from 0.5 mm to 0.2 mm, and the length is 15 mm. The transition area specifically includes 3 steps, each with a thickness difference of 0.1 mm, and a transition length of 5 mm. In another example, the thickness of the transition area gradually decreases from 0.5 mm to 0.2 mm, and the length is 15 mm. The slope of the transition area is 0.08.

[0084] By setting a stepped transition area or a transition area with a slope less than 1 / 10, the risk of interface peeling caused by a sudden change in stiffness during soft-hard connection can be avoided.

[0085] In addition, a stepped transition area or a transition area with a slope less than 1 / 10 can reduce the stress concentration factor. According to calculations, the stress concentration factor can be reduced by 30-40%. The stepped transition area and the thickness mutation from the hard row 331 to the flexible part 332 are decomposed into multiple small steps, so that the thickness change amplitude is reduced each time, so that the cross-sectional size mutation is small, so the stress concentration coefficient is small, thereby avoiding uneven stress distribution caused by cross-sectional mutation. By setting the slope of the transition area to less than 1 / 10, on the one hand, the thickness of the transition area has a gradual trend but the cross-sectional size mutation is small, so that the stress concentration coefficient is small, and on the other hand, it can also ensure that the current distribution is reasonable and the temperature gradient in the transition area is small. When manufacturing the hard row 331 with a transition area, for example, 3D printing technology can be used to form a structure with complex thickness.

[0086] Furthermore, in some embodiments, the material of the hard row 331 is a copper alloy with a nickel-plated layer on the surface; the material of the flexible portion 332 is a flexible copper foil. The material of the transition area is a copper-stainless steel composite material. The difference in stiffness of different materials is used to achieve a natural stress transition, avoiding stress concentration between the hard row 331 and the flexible portion 332.

[0087] In one example, the hard row 331 is 0.5 mm thick C1100 copper with a 2 μm-5 μm thick nickel-plated layer on the surface. The material of the flexible portion 332 is a 25 μm thick polyimide or polyester substrate with a 0.2 mm thick rolled copper layer on the substrate surface. The transition area is 0.5 mm thinning gradually to 0.2 mm, and the length is 15 mm.

[0088] During the use of the battery, the flexible portion 332 may need to be bent or vibrated frequently, and the fatigue resistance of the flexible portion 332 itself is an issue that needs to be considered.

[0089] To address the above problem, in some embodiments, the upper surface of the flexible portion 332 is provided with protrusions with a corrugated structure; the extension direction of the corrugated texture is perpendicular to the Z direction.

[0090] The protrusions of the corrugated structure can absorb vibration energy, reduce peak stress, and improve fatigue resistance of the flexible portion 332. The texture extension direction of the corrugated structure is perpendicular to the Z direction, which can enhance the ability to resist vibration in the horizontal direction.

[0091] In order to further reduce the pulling effect of the flexible portion 332 on the connecting piece 340 when it is deformed, in some embodiments, Fig. 9 The connecting piece 340 is generally S-shaped, and includes a hollow portion 342, and the hollow portion 342 has a plurality of hollow portions arranged side by side.

[0092] Specifically, the connecting piece 340 includes a first welding end 341, a hollow portion 342, and a second welding end 343 along its length. The first welding end 341 and the second welding end 343 are respectively welded to the circuit board 320 and the connecting member 330. The welding method of the first welding end 341 and the second welding end 343 to the circuit board 320 or the connecting member 330 is preferably laser welding, ultrasonic welding, resistance welding, etc.

[0093] The hollow portion 342 is S-shaped and includes a plurality of hollows. The first welding end 341 and the second welding end 343 are respectively located at two ends of the hollow portion 342, so that the connecting piece 340 is S-shaped as a whole.

[0094] When the two cells 20 bridged by the connecting piece 340 expand and deform, the forces F3 and F4 act on the first welding end 341 and the second welding end 343 respectively, and the directions of F3 and F4 are opposite. When two forces in opposite directions act on the acquisition nickel sheet, the nickel sheet is prone to breakage. At this time, the hollow portion 342 of the S-shaped structure can buffer and release the forces acting on the first welding end 341 and the second welding end 343, offsetting the expansion stress of the cell 20, greatly improving the reliability of the acquisition signal, improving the structural safety of the overall signal acquisition component 30, and thus improving the life of the product.

[0095] In addition, the multiple hollow settings make the connecting piece 340 have good flexible stretching characteristics, and have a strong ability to offset the expansion stress of the battery cell 20, ensuring that the connection between the connecting piece 340 and the flexible part 332 is not stressed or is very stressed, thereby preventing the two from detaching.

[0096] In other embodiments, the connecting piece 340 can be connected to the hard row 331, and the connecting piece 340 is also S-shaped as a whole, and the connecting piece 340 includes a hollow portion 342, and the hollow portion 342 is provided with a plurality of hollow portions arranged side by side. At this time, when the battery expands and deforms, the hard row 331 directly drives the connecting piece 340 to deform, and since the hollow portions 342 of the connecting piece 340 form a multi-S-shaped structure and have a plurality of buffer spaces, the battery expansion stress can be effectively offset.

[0097] In some embodiments, reference Fig. 9 and Fig.10 A reinforcing rib 344 is provided on the connecting piece 340 to strengthen the structural strength of the connecting piece 340, facilitate the manufacturing, transportation, assembly and other operations of the connecting piece 340, and avoid damage due to insufficient strength.

[0098] Specifically, Fig. 9 As shown, in one embodiment, the reinforcing rib 344 is disposed on the hollow portion 342, which can be understood as the reinforcing rib 344 being located inside the S-shaped hollow portion 342. Fig.10As shown, in another embodiment, the reinforcing rib 344 is disposed between the hollow portion 342 and the first welding end 341 , which can be understood as the reinforcing rib 344 being located outside the S-shaped hollow portion 342 .

[0099] In some embodiments, the first welding end 341 is provided with an opening 3411. Protective sheets 3142 protrude from two oppositely disposed hole walls of the opening 3411. The circuit board 320 may be provided with a thermistor at the corresponding opening 3411. The protective sheet 3142 may prevent the thermistor from being crushed by the components above.

[0100] In some embodiments, reference Figure 2 , Fig. 9 and Fig.10 , the hollowing extends from the top of the circuit board 320 to the top of the slot 311. Specifically, the connecting piece 340 has the above-mentioned hollowing in the remaining area between the first welding end 341 and the second welding end 343, so that the connecting piece 340 has a larger local hollowing area, so that the flexible stretching ability is stronger.

[0101] After the hollow portion 342 is opened, the connecting piece 340 has good flexible stretching characteristics, but to a certain extent, it brings the risk of weakening the strength of the new connecting piece 340.

[0102] For the above problems, refer to Figure 2 In some embodiments, the battery pack 100 further includes an insulating adhesive 350 covering the hollow portion 342 and bonding to the connector 330 , and the insulating adhesive 350 is embedded in the hollow portion.

[0103] Specifically, insulating glue 350 is applied on the connecting piece 340 between each hollowing, and the insulating glue 350 also penetrates into the hollowing. In this way, a layer of insulating glue 350 is formed on the connecting piece 340, and the hollowing is also filled with insulating glue 350. The insulating glue 350 can increase the strength of the hollowing part 342. When subjected to battery expansion stress, the S-shaped connecting piece 340 is deformed, and the collision stress will first overcome the glue deformation and then transfer the force to the S-shaped part, thereby releasing the battery expansion stress. The glue application enhances the deformation reliability of the S-shaped connecting piece 340, prevents a large force from tearing the S-shaped structure apart, protects the acquisition signal from being interrupted, and extends the service life of the product.

[0104] In some embodiments, reference Figure 2 , Figure 3 and Fig. 9 The hollowing extends from the top of the circuit board 320 to the top of the slot 311 , and the battery pack 100 also includes an insulating glue 350 covering the hollowing portion 342 and bonding to the connector 330 , and the insulating glue 350 is embedded in the hollowing and connected to the circuit board 320 or the connector 330 .

[0105] In this way, the hollowed-out portion above the circuit board 320 is filled with insulating glue 350, and the insulating glue 350 of this portion is bonded to the circuit board 320. In this way, the transition between the hollowed-out portion 342 and the first welding end 341 is not easily torn off. The hollowed-out portion above the slot 311 is filled with insulating glue 350, and the insulating glue 350 of this portion is bonded to the connector 330. In this way, the transition between the hollowed-out portion 342 and the second welding end 343 is not easily torn off.

[0106] In some embodiments, reference Figure 2 , Figures 11 to 13 A first buffer layer 40 is disposed between the insulating support 310 and the battery cell 20 . In the height direction of the battery pack 100 , that is, in the Z direction, the first buffer layer 40 is located below the insulating support 310 and above the battery cell 20 .

[0107] The first buffer layer 40 is made of a flexible material with buffering ability. Optionally, the first buffer layer 40 includes one or more layers of foam.

[0108] The first buffer layer 40 allows the circuit board 320 , the connecting piece 340 and other structures in the signal acquisition component 30 to be effectively buffered in the Z direction, thereby reducing the breakage of the connecting piece 340 caused by the stress concentration in the Z direction.

[0109] In some embodiments, reference Figure 1 , Figures 11 to 13 , and also includes a cover plate that cooperates with the shell 10, the cover plate is located on the side of the signal acquisition component 30 facing away from the battery cell 20, and a second buffer layer 50 is provided between the circuit board 320 and the cover plate. The second buffer layer 50 is made of a flexible material with buffering capacity. Optionally, the second buffer layer 50 includes one or more layers of foam. The second buffer layer 50 allows the circuit board 320, the connecting piece 340 and other structures in the signal acquisition component 30 to be effectively buffered in the Z direction, thereby reducing the breakage of the connecting piece 340 caused by the stress concentration in the Z direction.

[0110] In some embodiments, the first buffer layer 40 and the second buffer layer 50 are provided simultaneously to form a sandwich structure, which buffers the signal acquisition component 30 in the Z direction, thereby achieving a better buffering effect.

[0111] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0112] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0113] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0114] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0115] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A battery pack, characterized in that: include case; at least two battery cells, contained in the housing; A signal acquisition component, the signal acquisition component includes an insulating bracket, a circuit board, multiple connectors and multiple connecting plates arranged on the insulating bracket, the two ends of the connecting plates are respectively connected to the circuit board and the connectors, wherein the insulating bracket is provided with multiple slots corresponding to accommodating the connectors, the connector includes two hard rows connected by a flexible portion in the length direction, the two hard rows are respectively connected to the poles of two adjacent battery cells, and the flexible portion is bent to the side away from the battery cell and the top extends out of the slot.

2. The battery pack according to claim 1, characterized in that: The two ends of the flexible part are respectively welded to the upper surfaces of the two rigid rows.

3. The battery pack according to claim 1, characterized in that: The effective width of the rigid row is L1, the effective width of the flexible portion is L2, the thickness of the connecting member is t1, the thickness of the flexible portion is t2, and the size of the connecting member satisfies L1*t1≥L2*t2.

4. The battery pack according to claim 1, characterized in that: The flexible portion is provided with a fuse zone arranged along the width direction of the connector, the width of the fuse zone is the same as the width of the flexible portion, and the melting point of the fuse zone is lower than the melting points of the two hard rows.

5. The battery pack according to claim 1, characterized in that: The connecting piece is connected to the flexible portion.

6. The battery pack according to claim 5, characterized in that: The upper surface of the flexible portion is provided with a groove, the connecting piece is accommodated in the groove, and the connecting piece is not higher than the upper surface of the flexible portion.

7. The battery pack according to claim 1 or 5, characterized in that: The connecting piece is generally S-shaped, and includes a hollow portion, wherein the hollow portion is provided with a plurality of hollow portions arranged side by side.

8. The battery pack according to claim 7, characterized in that: The hollowing extends from the top of the circuit board to the top of the slot.

9. The battery pack according to claim 7, characterized in that: It also includes insulating glue covering the hollow portion and bonding to the connecting piece, wherein the insulating glue is embedded in the hollow portion.

10. The battery pack according to claim 1, characterized in that: A first buffer layer is provided between the insulating support and the battery cell; a cover plate matched with the shell is also included, the cover plate is located on the side of the signal acquisition component facing away from the battery cell, and a second buffer layer is provided between the circuit board and the cover plate.

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