Convergence assembly and battery module

Abstract

The invention discloses a confluence assembly and a battery module, the confluence assembly is used for series-parallel connection of battery cell bodies in a battery cell module, the confluence assembly comprises a current plate, an elastic sheet and a cooling fin, a circuit board comprises a metal substrate, a heat conduction insulating layer and a confluence layer which are sequentially arranged along the thickness direction, and the circuit board is provided with mounting holes which are in one-to-one correspondence with the battery cell bodies. At least one elastic sheet is arranged at each mounting hole, the elastic sheets are fixedly connected and conducted with the confluence layer, and the elastic sheets are not in contact with the metal substrate. The cooling fins extend in the thickness direction of the circuit board along at least part of the edge of the substrate, gaps are reserved between the cooling fins and the battery cell modules, and the cooling fins make contact with the cooling module to conduct heat. According to the confluence assembly, welding-free of the battery module is realized, efficient heat dissipation can be realized, and the safety of the battery module is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a busbar assembly and a battery module. Background Art

[0002] A battery module combines battery cells in series and parallel within multiple cell modules to provide a suitable voltage and capacity for a load. Therefore, multiple cell modules need to be assembled into a battery module to supply power to the load. Quality defects such as de-soldering, solder penetration, excessive heat-affected areas, and stress concentration during the welding and grouping process of the battery module seriously affect the secondary utilization of the battery module. Therefore, in the prior art, a welding-free grouping technique is generally used to splice the battery module. As recorded in the Chinese invention patent document (CN106654135A), adjacent cell modules are connected through a busbar assembly. The existing busbar assembly only considers the electrical connection problem of the battery cells in the cell module. However, a large amount of heat is generated during the operation of the battery cells. If the heat is not dissipated in time, it will affect the safety of the battery module. Summary of the Invention

[0003] To overcome the above disadvantages, the purpose of the present invention is to provide a busbar assembly and a battery module, which can achieve welding-free of the battery module, efficiently dissipate heat, and improve the safety of the battery module.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is: A busbar assembly for series and parallel connection of battery cells in a cell module, the busbar assembly includes: A circuit board, the circuit board includes a metal substrate, a thermally conductive insulating layer, and a busbar layer arranged in sequence along the thickness direction, and mounting holes corresponding to the battery cells one by one are opened on the circuit board; Elastic pieces, at least one elastic piece is arranged at each mounting hole, the elastic piece is fixedly connected and conducted with the busbar layer, and the elastic piece does not contact the metal substrate; A heat sink, the heat sink extends along at least part of the edge of the metal substrate in the thickness direction of the circuit board, and there is a gap between the heat sink and the cell module, and the heat sink contacts the heat dissipation module for heat conduction. The beneficial effects of the present invention are as follows: By using the elastic piece as a contact conductive element to contact the battery cell, the conduction of the power of the battery cell is realized, and it is convenient for disassembly and repair after the subsequent formation of the battery module, without re-welding. The circuit board serves as a support component for the elastic piece, and at the same time, the parallel or series connection between different battery cells is realized through the setting of the busbar layer.

[0005] The circuit board fixes a heat sink on the metal substrate. The heat generated by the battery cell body is conducted to the elastic piece, and the elastic piece is conducted to the metal substrate through the thermally conductive insulating layer. Finally, the heat on the metal substrate is exported through the heat sink to achieve heat dissipation of the battery cell. Since there is a gap between the heat sink and the battery cell module, the heat sink does not contact the battery cell module and will not conduct the heat on the wire module back to the battery cell module. Instead, it contacts the external heat dissipation module and conducts the heat to the heat dissipation module for rapid heat dissipation.

[0006] Furthermore, the surface of the heat sink close to the heat dissipation module is an uneven surface, and the area of the uneven surface is large, which is convenient for heat dissipation.

[0007] Thermally conductive silicone is applied on the uneven surface, and the thermally conductive silicone adheres the heat sink and the heat dissipation module. While the thermally conductive silicone adheres and fixes the heat sink and the heat dissipation module, it conducts heat between the two.

[0008] Furthermore, the busbar assemblies are arranged at both ends in the thickness direction of one battery cell module, and the heat sinks of the two busbar assemblies can cover the battery cell module in the thickness direction. The space in the thickness direction is fully utilized, and the area of the heat sink is maximized to improve the heat dissipation effect.

[0009] Furthermore, the heat sink and the metal substrate are of an integral structure, and a part of the metal substrate is bent to form the heat sink. The integral structure has high strength, and the formed circuit board structure is more stable. At the same time, it is convenient for processing. Only by bending can a part of the metal substrate form a heat sink.

[0010] Furthermore, two layers of the thermally conductive insulating layer and the busbar layer are provided. The two busbar layers and the thermally conductive insulating layer are symmetrically arranged relative to the metal substrate in the thickness direction. Two elastic pieces are symmetrically arranged at each mounting hole, and the two elastic pieces are respectively fixedly connected and conducted with the two busbar layers. At this time, the busbar assembly is located between the two battery cell modules and connects the two battery cell modules on both sides in series.

[0011] Furthermore, the elastic piece includes a first annular disk, a second annular disk and a plurality of cantilevers. The first annular disk and the second annular disk are arranged at intervals in the thickness direction. The second annular disk is fixedly connected to the busbar layer by welding, and the inner circle of the second annular disk is connected to the inner circle of the first annular disk; the plurality of cantilevers are evenly arranged along the circumference of the first annular disk, and one end of each cantilever is fixedly connected to the inner circle of the first annular disk, and the other end is suspended.

[0012] The first annular disk serves as a supporting structure for the cantilevers. One end of the cantilever is suspended, allowing each cantilever to deform separately to form independent contact points. Even if the battery cell body in the battery cell module is inclined or offset during installation, at least some of the cantilevers will contact the electrode end of the battery cell body.

[0013] Furthermore, the cantilever includes a connecting portion and an abutting portion. One end of the connecting portion is fixed to the inner ring of the first annular disc, and the other end is fixed to the abutting portion. A through hole penetrating the cantilever in the thickness direction is formed in the connecting portion, reducing the internal resistance of the elastic piece while not affecting the connection strength. The abutting portion is parallel to the first annular disc, increasing the contact area between the elastic arm and the battery cell body. Furthermore, a fusing fuse is connected in series between the elastic piece directly abutting against the positive end of the battery cell body and the busbar layer, and the fusing fuse is fixed on the circuit board. The fusing fuse protects each battery cell body.

[0014] The present invention also discloses a battery module, which includes a plurality of the above-mentioned busbar assemblies arranged at intervals in the thickness direction. A battery cell module is arranged between adjacent busbar assemblies. The battery module further includes: An end plate assembly, which includes a first end plate and a second end plate located on the outer sides of the busbar assemblies at both ends in the thickness direction; A locking member, which penetrates through the end plate assembly, the busbar assembly, and the battery cell module in the thickness direction and is threadedly connected to the end plate assembly, the busbar assembly, and the battery cell module.

[0015] The busbar assembly realizes the solderless connection between battery cell modules. A heat sink is arranged on the busbar assembly, allowing the heat generated by the battery cell body to be conducted to the heat sink through the circuit board for heat dissipation, improving the heat dissipation effect of the battery module.

[0016] Furthermore, a BMS control board is fixed on the first end plate. The busbar assembly further includes sampling pins fixed on the circuit board, and the sampling pins are communicatively connected to the BMS control board through a collection wire harness. Description of the Drawings

[0017] Figure 1 is a three-dimensional structural diagram of a busbar assembly in an embodiment of the present invention; Figure 2 is a three-dimensional structural diagram of an intermediate busbar assembly in an embodiment of the present invention; Figure 3 is a cross-sectional view of an intermediate busbar assembly in an embodiment of the present invention; Figure 4 is a three-dimensional structural diagram of a second-end busbar assembly in an embodiment of the present invention; Figure 5 is a cross-sectional view of a second-end busbar assembly in an embodiment of the present invention; Figure 6 is a top view of a busbar assembly in an embodiment of the present invention; Figure 7Schematic three-dimensional structure diagram of the shrapnel in an embodiment of the present invention; Figure 8 Explosion diagram of the battery module in an embodiment of the present invention; Figure 9 Explosion diagram of the battery cell module in an embodiment of the present invention; Figure 10 Schematic three-dimensional structure diagram of the acquisition line in an embodiment of the present invention; Figure 11 Cross-sectional view of the battery module in an embodiment of the present invention; Figure 12 Schematic three-dimensional structure diagram of the battery module in an embodiment of the present invention; Figure 13 Cross-sectional view and partial enlarged view of the battery module including a metal housing in an embodiment of the present invention; Figure 14 Temperature acquisition spectrogram during discharge of the battery module in the prior art; Figure 15 Temperature acquisition spectrogram during discharge of the battery module in an embodiment of the present invention.

[0018] In the figure: 1. Busbar assembly; 1a. Intermediate busbar assembly; 1b. First-end busbar assembly; 1c. Second-end busbar assembly; 11. Circuit board; 111. Metal substrate; 112. Busbar layer; 1121. First region; 1122. Second region; 12. Shrapnel; 121. First annular disk; 122. Second annular disk; 123. Cantilever; 1231. Contact portion; 1232. Connection portion; 12321. Through hole; 124. Sinking step; 13. Heat sink; 131. Concave-convex surface; 14. Mounting hole; 15. Fuse; 16. Sampling pin; 17. Positioning hole; 18. Threaded hole; 2. Battery cell module; 21. Battery cell body; 22. First bracket; 221. Positioning post; 23. Second bracket; 3. BMS control board; 31. Acquisition wire harness; 311. Sleeve; 312. Wire harness body; 313. Terminal; 4. Locking member; 5. First end plate; 6. Second end plate.

[0019] 8. Metal housing; 9. Gap. Detailed implementation manners The following elaborates on the preferred embodiments of the present invention in conjunction with the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0020] In the following figures, the thickness direction of the circuit board 11 is the X direction in the figures. It can be understood that in this application, for the sake of unified reference benchmarks, each component uses itself as a reference to ensure that the descriptions of all structures and components are based on the same coordinate system, so as to improve the accuracy and consistency of the descriptions.

[0021] A busbar assembly 1 of the present invention is used for the series and parallel connection of the battery cell bodies 21 in the battery cell module 2.

[0022] See the attached Figure 1 As shown in the figure, the busbar assembly 1 includes a circuit board 11, a spring piece 12, and a heat sink 13. The circuit board 11 is used to support and fix the spring pieces 12 and realize the series or parallel connection of these spring pieces 12. The spring piece 12 is used to contact the battery cell body 21 to realize the electrical connection of the battery cell bodies 21 within the same battery cell module 2 or between adjacent battery cell modules 2. The heat sink 13 is used for heat dissipation of the circuit board 11.

[0023] See the attached Figure 2 and the attached Figure 4 As shown in the figure, the circuit board 11 includes a metal substrate 111, a thermally conductive insulating layer (not shown in the figure), and a busbar layer 112 arranged in sequence along the thickness direction. The circuit board 11 is provided with mounting holes 14 corresponding to the battery cell bodies 21 one by one, and the mounting holes 14 penetrate through the circuit board 11 along the thickness direction. At least one spring piece 12 is arranged at each mounting hole 14, and the spring piece 12 is fixedly connected and conducted with the busbar layer 112. At this time, the spring pieces 12 realize series and parallel connection through the busbar layer 112, and the spring pieces 12 do not contact the metal substrate 111 to ensure that the spring pieces 12 are not conducted with the metal substrate 111. The heat sink 13 extends along at least part of the edge of the metal substrate 111 towards the thickness direction, and there is a gap 9 between the heat sink 13 and the battery cell module 2, and the heat sink 13 contacts the heat dissipation module for heat conduction.

[0024] In this embodiment, the spring piece 12 is used as a contact conductive element to contact the battery cell body 21 to replace the current welding process, realize the conduction of the power of the battery cell body 21, and facilitate the disassembly and repair after the subsequent formation of the battery module. The circuit board 11 is used as a support component for the spring pieces 12, and at the same time, the parallel or series connection between different battery cell bodies 21 is realized through the setting of the busbar layer 112.

[0025] The circuit board 11 adopts a multi-layer structure. A heat sink 13 is fixed on the metal substrate 111. The heat generated by the cell body 21 is conducted to the elastic sheet 12, and the elastic sheet 12 is conducted to the metal substrate 111 through the thermally conductive insulating layer. Finally, the heat on the metal substrate 111 is exported through the heat sink 13 to achieve heat dissipation of the cell. Since there is a gap between the heat sink 13 and the cell module 2, the heat sink 13 does not contact the cell module 2 and will not conduct the heat on the cell module 2 back to the cell module 2. Instead, it contacts the external heat dissipation module and conducts the heat to the heat dissipation module for rapid heat dissipation.

[0026] In this embodiment, a heat sink 13 corresponding to the circuit board 11 is provided, so that the heat generated by the cell body 21 is conducted to the heat sink 13 through the circuit board 11 for heat dissipation, improving the heat dissipation effect of the cell module 2.

[0027] Exemplarily, see the appendix Figure 13 As shown, the heat dissipation module is a metal shell 8 sleeved outside all the cell modules 2. The metal shell 8 protects the assembled cell modules 2 from being damaged by collision. And the metal shell has a large contact area with the external space and can be quickly cooled.

[0028] Of course, the heat dissipation module can also be a heat dissipation structure such as a water-cooled plate, as long as it can achieve the cooling of the heat sink 13.

[0029] In one embodiment, the heat sink 13 and the metal substrate 111 are of an integral structure, and a part of the metal substrate 111 is bent to form the heat sink 13. This integral structure has high strength, and it is not easy for the heat sink 13 and the metal substrate 111 to break and deform. At the same time, it has good heat conduction performance, and the heat on the heat sink 13 and the metal substrate 111 is balanced. Only by bending a part of the metal substrate 111 can the heat sink 13 be formed, and there is no busbar layer 112 and thermally conductive insulating layer on the heat sink 13.

[0030] In order to improve the heat conduction speed, the metal substrate 111 is generally made of a material with good heat conduction performance. In one embodiment, the metal substrate 111 is an aluminum substrate or a copper substrate. When the cell body 21 generates heat, the heat can be quickly and evenly conducted to the metal substrate 111 and the heat sink 13.

[0031] The thermally conductive insulating layer is a layer of low thermal resistance thermally conductive insulating material, which conducts the heat on the busbar layer 112 to the metal substrate 111 and at the same time blocks the electrical connection between the metal substrate 111 and the busbar layer 112. Exemplarily, the thermally conductive insulating layer is composed of a special polymer filled with special ceramics. The busbar layer 112 is generally made of electrolytic copper foil and is used to realize the assembly and connection of the elastic sheet 12.

[0032] In one embodiment, a heat-conducting silicone is applied to the side of the heat sink 13 close to the heat dissipation module. While bonding and fixing the heat sink 13 and the heat dissipation module, the heat-conducting silicone conducts heat between the two.

[0033] In one embodiment, the side of the heat sink 13 close to the heat dissipation module is the first side, and a plurality of parallel grooves are formed on the first side. At this time, the first side is a concave-convex surface 131, and the concave-convex structure increases the area of this surface, facilitating heat dissipation.

[0034] The second side of the heat sink 13 away from the heat dissipation module faces the battery cell module 2. The second side is a flat surface or a concave-convex surface 131 the same as the first side. When both the first side and the second side are concave-convex surfaces, the heat dissipation effect is better. However, due to the limitation of the thickness of the heat sink, in this embodiment, the second side is a flat surface.

[0035] The larger the area of the heat sink 13, the better the heat dissipation effect. The heat sink 13 can be arranged around the metal substrate 111. In this embodiment, considering the space limitation and the structure of the battery cell module 2, the heat sink 13 is only arranged in the straight-edge area of the metal substrate 111, which is convenient for bending the metal substrate 111 to form the heat sink 13, and the processing is convenient.

[0036] The shape of the heat sink 13 can be variable. Exemplarily, in this embodiment, the heat sink 13 is square.

[0037] The gap between the heat sink 13 and the battery cell module 2 prevents heat from being conducted to the battery cell module, and at the same time forms a heat dissipation channel. Within the allowable space, the larger the gap 9, the better the heat dissipation performance. In this embodiment, the gap is 1 mm.

[0038] See Appendix Figure 8 and Appendix Figure 13 As shown, the battery cell modules 2 are stacked in the X direction. In order to maximize the use of the space in the X direction to increase the area of the heat sink. The heat sinks of the busbar assemblies 1 at both ends of a battery cell module 2 can cover the battery cell module 2 in the X direction.

[0039] Exemplarily, when multiple battery cell modules 2 are stacked, among two adjacent busbar assemblies 1, the length of the heat sink 13 of one busbar assembly 1 in the X direction is the same as the length of the battery cell module 2 in the X direction, and extends towards the battery cell module 2 between the two busbar assemblies 1. At this time, the heat sink 13 of the other busbar assembly 1 extends towards another adjacent battery cell module 2. Or for a battery cell module 2 at one end, the heat sinks 13 of the busbar assemblies 1 on both sides both extend towards the battery cell module 2 between the two, and the ends of the two heat sinks 13 abut against each other. At this time, the total length of the two heat sinks 13 in the X direction is equal to the length of the battery cell module 2 in the X direction.

[0040] See Appendix Figure 5 and Appendix Figure 7As shown, the elastic sheet 12 includes a first annular disk 121, a second annular disk 122, and a plurality of cantilevers 123. The second annular disk 122 is fixedly welded to the busbar layer 112, and the cantilevers 123 are in contact with the electrodes of the battery cell body 21. The first annular disk 121 and the second annular disk 122 are spaced apart in the X direction, and the inner ring of the second annular disk 122 is connected to the outer ring of the first annular disk 121. The plurality of cantilevers 123 are uniformly arranged along the circumference of the first annular disk 121. One end of the cantilever 123 is fixedly connected to the inner ring of the first annular disk 121, and the other end is suspended.

[0041] In this embodiment, the elastic sheet 12 is used to contact the electrodes of the battery cell body 21 to ensure the current transfer between the battery cell body 21 and other components. The first annular disk 121 serves as the support structure for the cantilevers 123. One end of the cantilever 123 is suspended, allowing each cantilever 123 to deform separately to form independent contact points. Even if the battery cell body 21 in the battery cell module 2 is tilted or offset during installation, at least some of the cantilevers 123 will be in contact with the electrode ends of the battery cell body 21.

[0042] The second annular disk 122 is a welding disk for being fixedly welded to the busbar layer 112 of the circuit board 11. A sinking step 124 is formed at the connection between the first annular disk 121 and the second annular disk 122. The first annular disk 121 is embedded in the mounting hole 14, but the first annular disk 121 does not contact the side wall of the mounting hole 14. Before welding, the sinking step 124 preliminarily positions the elastic sheet 12, improving the welding accuracy. At the same time, the diameter of the mounting hole 14 is slightly larger than the diameter of this sinking step 124, and the sinking step 124 does not contact the side wall of the mounting hole 14, thereby ensuring that the elastic sheet 12 is only electrically connected to the busbar layer 112.

[0043] Exemplarily, the number of the cantilevers 123 is six, and the six cantilevers 123 are centrosymmetric. The number of the cantilevers 123 is variable.

[0044] The cantilever 123 is in an S-shaped bent shape, enabling the stress to be evenly distributed when the cantilever 123 is stressed. One end of the cantilever 123 away from the first annular disk 121 is an abutting portion 1231 parallel to the first annular disk 121. The abutting portion 1231 abuts against the battery cell body 21, and the setting of the abutting portion 1231 increases the contact area between the elastic arm and the battery cell body 21.

[0045] When the elastic sheet 12 abuts against the battery cell body 21, the abutting portions 1231 of the plurality of cantilevers 123 jointly abut against the battery cell, and drive the plurality of cantilevers 123 to elastically deform, thereby increasing the elastic force and the over-current capacity. The internal resistance of the elastic sheet 12 is reduced, and at the same time, the reliability of the connection with the battery cell is increased. Even if the battery cell body 21 and the elastic sheet 12 are not aligned and one of them is tilted, there will still be some elastic arms abutting against the battery cell body 21, reducing the short circuit caused by the installation error.

[0046] The cantilever 123 further includes a connecting portion 1232 located between the abutting portion 1231 and the first annular disc 121. The connection is inclined toward the axis of the mounting hole 14 along the X direction. A through hole 12321 penetrating the cantilever 123 along the X direction is further provided on the side of the connecting portion 1232 close to the first annular disc 121. The provision of the through hole 12321 reduces the internal resistance of the elastic sheet 12 while not affecting the connection strength.

[0047] The elastic sheet 12 is made of an elastic conductive material, usually processed from a metal sheet to meet the comprehensive requirements of the elastic sheet 12 in terms of high elasticity, high conductivity, and mechanical stability. Exemplarily, the elastic conductive material can be copper, silver, aluminum, and copper alloys, etc. Among them, copper alloys have excellent electrical conductivity, thermal conductivity, elasticity, and fatigue resistance and corrosion resistance, and are more suitable for the structure of the elastic sheet 12.

[0048] A battery cell module 2 usually includes a plurality of battery cell bodies 21 arranged side by side. The positive and negative electrode directions of the battery cell bodies 21 are different, that is, some elastic sheets 12 on the current collecting component 1 are connected to the positive electrode end, and some elastic sheets 12 are connected to the negative electrode end. When it is necessary to connect the positive electrode end and the negative electrode end in series, see the appendix Figure 4 As shown, the current collecting layer 112 of the elastic sheet 12 connected to the positive electrode end and the current collecting layer 112 of the elastic sheet 12 connected to the negative electrode end are electrically connected. At this time, the current collecting layer 112 on the current collecting component 1 is an interconnected area. When it is necessary to separate the positive electrode end and the negative electrode end, see the appendix Figure 2 As shown, the current collecting layer 112 of the elastic sheet 12 connected to the positive electrode end and the current collecting layer 112 of the elastic sheet 12 connected to the negative electrode end are not electrically connected. At this time, the current collecting layer 112 on the current collecting component 1 is two non-conductive first regions 1121 and second regions 1122. The first region 1121 is electrically connected to the elastic sheet 12 connected to the positive electrode end, and the second region 1122 is electrically connected to the elastic sheet 12 connected to the negative electrode end.

[0049] In one embodiment, see the appendix Figure 6 As shown, a fusing fuse 15 is connected in series between the elastic sheet 12 directly abutting against the positive electrode end of the battery cell body 21 and the current collecting layer 112. The fusing fuse 15 is fixed on the circuit board 11. One end of the fusing fuse 15 is welded to the second annular disc 122 of the elastic sheet 12, and the other end is welded to the current collecting layer 112. After the battery module is assembled, the current, as shown by the arrow in the appendix Figure 6 flows from the elastic sheet 12 connected to the positive electrode end of the battery cell body 21 to the fusing fuse 15. When this battery cell body 21 has a short circuit, the current flowing through the fusing fuse 15 will suddenly increase, and the fusing fuse 15 will fuse, disconnecting this circuit and realizing the protection of the battery cell body 21.

[0050] In this embodiment, by providing the fusing fuse 15, the circuit can be automatically physically disconnected during a short circuit, improving the use safety.

[0051] In one embodiment, the busbar assembly 1 sometimes needs to be located between two battery cell modules 2. The busbar assembly 1 located between two battery cell modules 2 is the intermediate busbar assembly 1a, and the intermediate busbar assembly 1a needs to be electrically connected to the two battery cell modules 2 on both sides in the X direction. Refer to the attached Figure 3 As shown, at this time, the circuit board 11 of the intermediate busbar assembly 1a is a double-sided circuit board 11, that is to say, the circuit board 11 includes two insulating and heat-conducting layers and two busbar layers 112, and the two insulating and heat-conducting layers and the two busbar layers 112 are symmetrically arranged in the X direction relative to the metal base plate. Elastic pieces 12 are welded on both busbar layers 112, and the elastic pieces 12 on the two busbar layers 112 are symmetrically arranged.

[0052] In one embodiment, the busbar assembly 1 further includes sampling pins 16, and the sampling pins 16 correspond to the areas of the busbar layer 112 one by one. Exemplarily, refer to the attached Figure 4 As shown, when there is only one area in a busbar layer 112, one sampling pin 16 is provided. Refer to the attached Figure 2 As shown, when there are two areas in a busbar layer 112, two sampling pins 16 are provided.

[0053] When the battery cell bodies 21 are connected in parallel, the voltages at both ends are the same. Therefore, the sampling pins 16 correspond to the areas of the busbar layer 112 one by one. The sampling pins 16 perform voltage sampling. Cooperating with the detection circuit on the BMS control board 3, the sampling pins 16 can trigger an active open circuit action to effectively protect the battery cell module 2. The sampling pins 16 are welded and fixed on the circuit board 11. On the one hand, it is convenient to fix with the circuit board 11, and on the other hand, it is convenient to plug with the acquisition wire harness. Refer to the attached Figure 10 As shown, sleeves that can be sleeved with the sampling pins 16 are provided on the acquisition wire harness.

[0054] In one embodiment, refer to the attached Figure 1 As shown, positioning holes 17 are also provided on the circuit board 11. Refer to the attached Figure 9 As shown, positioning posts 221 that can be inserted into the positioning holes 17 are provided on the battery cell module 2. The positioning rod and the positioning posts 221 cooperate to preliminarily position the relative positions of the two when the busbar assembly 1 and the battery cell module 2 are assembled, so as to improve the accuracy during the assembly of the two.

[0055] Exemplarily, the model of the battery cell body is 18650, the diameter of the battery cell body is 18.4 mm, and the length is 65 mm. At this time, one busbar assembly 1 is connected in series and parallel with eight battery cell bodies, the maximum length of the circuit board in the busbar assembly 1 is 78 mm, the maximum width is 60.1 mm, and the heat sink is a rectangle of 40 mm * 21 mm.

[0056] The model of the battery cell body is 21700, the diameter of the battery cell body is 21.3 mm, and the length is 70.6 mm. At this time, a busbar assembly 1 is connected in series and parallel with eight battery cell bodies. The maximum length of the circuit board in the busbar assembly 1 is 90 mm, and the maximum width is 64.1 mm. The heat sink is a rectangle of 50 mm * 35 mm.

[0057] The model of the battery cell body is 26700, the diameter of the battery cell body is 26 mm, and the length is 70.6 mm. At this time, a busbar assembly 1 is connected in series and parallel with eight battery cell bodies. The maximum length of the circuit board in the busbar assembly 1 is 108 mm, and the maximum width is 76.9 mm. The heat sink is a rectangle of 60 mm * 35 mm.

[0058] It can be seen that the sizes of the heat sink and the circuit board are positively correlated with the size of the battery cell body, that is, the larger the size of the battery cell body, the larger the sizes of the heat sink and the circuit board adopted. The sizes of the heat sink and the circuit board are flexibly adjusted according to the size of the battery cell, the size of the gap between the battery cell arrangements, and the magnitude of the battery discharge current.

[0059] In this embodiment, the busbar assembly can greatly enhance the heat dissipation effect of the battery cell body. Attached Figure 14 and attached Figure 15 , the abscissa is time, and the ordinate is temperature, where T1 - T6 are temperature sensors attached to battery cell bodies at different positions. However, in the prior art, the temperature sensors with the same number in the battery module and the battery module in this application are located on the same battery cell body. Among them, attached Figure 15 is the temperature curve during discharge of the battery module formed by assembling the battery cell body of model 26700 and the busbar assembly in this embodiment. Among them, attached Figure 14 is the temperature curve during discharge of the battery module formed by welding the battery cell body of model 26700 and nickel strips in the prior art.

[0060] Combined with attached Figure 14 and attached Figure 15 it can be seen that at the beginning of the discharge of the battery module, the temperature collected by the temperature sensor T6 of the battery module in the prior art is 22.3 °C, which is greater than the temperature of 20.2 °C collected by the temperature sensor T6 of the battery module with the busbar assembly of this application. After the two battery modules are discharged for 30 minutes, the temperature collected by the temperature sensor T1 of the battery module in the prior art is 56.8 °C, which is greater than the temperature of 45.7 °C collected by the temperature sensor T1 of the battery module with the busbar assembly of this application. The temperature difference between the two reaches 10.1 °C. It can be seen that the busbar assembly in this application has a good heat dissipation function and improves the safety of the battery module.

[0061] In one embodiment, the present invention discloses a battery module. Refer to attached Figure 8As shown in the figure, it includes a plurality of the above-mentioned busbar components 1 arranged at intervals along the X direction. Two adjacent busbar components 1 are provided with a battery cell module 2 electrically connected thereto. The busbar component 1 does not need to be welded to the battery cell module 2, and the electrical connection between the battery modules is directly realized by using the elastic sheet 12, achieving welding-free between the battery modules.

[0062] For the battery module of this embodiment, a busbar component 1 that can connect the battery modules without welding is adopted. A heat sink is arranged on the busbar component 1, so that the heat generated by the battery cell body 21 is conducted to the heat sink 13 through the circuit board 11 for heat dissipation, improving the heat dissipation effect of the battery module.

[0063] The battery module further includes a metal shell. A cavity is formed inside the metal shell, and the stacked battery cell modules 2 are placed in the cavity. The heat sink 13 is fixed to the metal shell through thermal conductive silicone, and the heat is conducted to the metal shell for heat dissipation. Of course, a cooling plate (through which a cooling medium flows) can also be arranged inside the metal shell, and rapid heat dissipation of the heat sink 13 can also be achieved.

[0064] See the appendix Figure 9 As shown in the figure, the battery cell module 2 includes a first bracket 22 and a second bracket 23 that are snap-connected. After the first bracket 22 and the second bracket 23 are snap-fitted, a plurality of placement cavities are formed, and each placement cavity contains a battery cell body 21. The modular framework of the battery cell module 2 in this embodiment is fixed by snap-fastening, which is convenient for assembly.

[0065] See the appendix Figure 8 As shown in the figure, the battery module further includes a plurality of locking members 4. The locking members 4 are bolts. Among them, threaded holes 18 corresponding to the bolts are provided on the circuit board 11, the first bracket 22, and the second one, so that the screw can sequentially penetrate through the battery cell module 2 and the circuit board 11 along the X direction, and the bolt is threadedly connected to the threaded hole 18 to fix the battery cell module 2 and the busbar component 1. The battery cell module 2 and the busbar component 1 are pressed tightly by the locking member 4, so that the elastic arm is in close contact with the battery cell body 21. While ensuring the mechanical strength of the connection between the battery cell module 2 and the busbar component 1, the locking member 4 simplifies the overall assembly process, reduces the production cost, and reduces the subsequent disassembly difficulty.

[0066] The battery module further includes a first end plate 5 and a second end plate 6. The battery cell module 2 and the busbar component 1 are located between the first end plate 5 and the second end plate 6, and the first end plate 5 and the second end plate 6 are also fixed by the locking member 4. The two end plates protect the busbar components 1 at both ends.

[0067] A BMS control board 3 is fixed inside the first end plate 5. The BMS control board 3 is communicatively connected to the sampling pin 16 through the acquisition wire harness 31. See the appendix Figure 10As shown, the acquisition wire harness 31 includes a plurality of wire harness bodies 312 and terminals 313 that are commonly connected to all the wire harness bodies 312. The terminals 313 are plugged into the sockets on the BMS control board 3. A sleeve is also fixed on the wire harness body 312, and the sleeve is sleeved with the sampling pin 16.

[0068] The two busbar assemblies 1 at both ends in the X direction are the first-end busbar assembly 1b and the second-end busbar assembly 1c respectively. The circuit boards 11 of the first-end busbar assembly 1b and the second-end busbar assembly 1c are all three-layer structures, and elastic pieces 12 are fixed on only one side. See the appendix Figure 11 As shown, the arrows in the figure indicate the flow of current. Among them, the first-end busbar assembly 1b realizes the output busbar connection of the total positive and total negative of the battery cell module 2, and the second-end busbar assembly 1c is used to connect in series the battery cell bodies 21 installed reversely in the end battery cell modules 2. The middle busbar assembly 1a located between the two battery cell modules 2 is used for the series-parallel connection of the battery cell bodies 21 in the two end battery cell modules 2. The middle busbar assembly 1a connects in parallel the battery cell bodies 21 installed in the same direction in the same battery cell module 2, and then connects in series the battery cell bodies 21 installed in the same direction in the two battery cell modules 2.

[0069] This application does not limit the number of battery cell modules 2. Exemplarily, five battery cell modules 2 are provided in this embodiment, but the combination of the battery cell modules 2 and the busbar assemblies 1 is fixed, that is, the busbar assemblies 1 necessarily include the first-end busbar assembly 1b and the second-end busbar assembly 1c located at both ends in the X direction, and the middle busbar assembly 1a.

[0070] When assembling the battery module, the first-end busbar assembly 1b is plugged into the first end plate 5 on which the BMS control board 3 is installed, and then the battery cell module 2 is placed on the first-end busbar assembly 1b. Then the middle busbar assemblies 1a and the middle busbar assemblies 1a are alternately placed in the X direction until the last battery cell module 2 is placed. The second-end busbar assembly 1c is placed on the last battery cell module 2, and then the second end plate 6 is placed. So far, the end plates, the busbar assemblies 1 and the battery cell modules 2 have been stacked and are fixed by the locking member 4. After the fixing is completed, the end plates, the busbar assemblies 1 and the battery cell modules 2 form an integral structure. Then the terminals 313 of the acquisition wire harness 31 are inserted into the ports of the BMS control board 3, and then the sleeves 311 of the acquisition wire harness 31 are sleeved with each sampling pin 16 to form Figure 12 the battery module as shown. Guide grooves for guiding the acquisition wire harness 31 are provided on the first bracket 22 and the second bracket 23, and the guide grooves position the acquisition wire harness 31.

[0071] After the battery module is assembled, it is placed in a metal housing, and at least one battery module is placed in the metal housing.

[0072] The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it. It is not intended to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A busbar assembly for series and parallel connection of battery cell bodies in a battery cell module, characterized in that: The busbar assembly includes: A circuit board, which includes a metal substrate, a thermally conductive insulating layer, and a busbar layer sequentially arranged in the thickness direction. Mounting holes corresponding to the battery cell bodies one by one are formed on the circuit board; Elastic pieces, at least one elastic piece is arranged at each mounting hole. The elastic piece is fixedly connected and electrically connected to the busbar layer, and the elastic piece is not in contact with the metal substrate; A heat sink, the heat sink extends along at least part of the edge of the metal substrate in the thickness direction of the circuit board. There is a gap between the heat sink and the battery cell module, and the heat sink is in contact with the heat dissipation module for heat conduction.

2. The busbar assembly according to claim 1, wherein: The surface of the heat sink close to the heat dissipation module is an uneven surface, and thermally conductive silicone is applied on the uneven surface. The thermally conductive silicone adheres the heat sink and the heat dissipation module.

3. The busbar assembly according to claim 1, wherein: The busbar assemblies are arranged at both ends of one battery cell module in the thickness direction. The heat sinks of the two busbar assemblies can cover the battery cell module in the thickness direction.

4. The bus bar assembly according to claim 1, characterized in that: The heat sink and the metal substrate are of an integral structure, and part of the metal substrate is bent to form the heat sink.

5. The busbar assembly according to any one of claims 1-4, characterized in that: Both the thermally conductive insulating layer and the busbar layer are provided with two layers. The two busbar layers and the thermally conductive insulating layer are symmetrically arranged relative to the metal substrate in the thickness direction. Two elastic pieces are symmetrically arranged at each mounting hole, and the two elastic pieces are respectively fixedly connected and electrically connected to the two busbar layers.

6. The busbar assembly according to any one of claims 1-4, characterized in that: The elastic piece includes a first annular disk, a second annular disk, and a plurality of cantilevers. The first annular disk and the second annular disk are arranged at intervals in the thickness direction. The second annular disk is welded and fixed to the busbar layer, and the inner ring of the second annular disk is connected to the inner ring of the first annular disk; the plurality of cantilevers are uniformly arranged along the circumferential direction of the first annular disk. One end of each cantilever is fixedly connected to the inner ring of the first annular disk, and the other end is suspended.

7. The busbar assembly according to claim 6, wherein: The cantilever includes a connecting portion and an abutting portion. One end of the connecting portion is fixed to the inner ring of the first annular disk, and the other end is fixed to the abutting portion. A through hole penetrating the cantilever in the thickness direction is formed on the connecting portion; the abutting portion is parallel to the first annular disk.

8. The busbar assembly according to claim 1, wherein: A fusing fuse is connected in series between the elastic piece directly abutting against the positive electrode end of the battery cell body and the busbar layer, and the fusing fuse is fixed on the circuit board.

9. A battery module, characterized in that: Including a plurality of busbar assemblies according to any one of claims 1-8 arranged at intervals in the thickness direction, a battery cell module is arranged between adjacent busbar assemblies. The battery module further includes: An end plate assembly, which includes a first end plate and a second end plate located outside the busbar assemblies at both ends in the thickness direction; A locking member, the locking member penetrates the end plate assembly, the busbar assembly, and the battery cell module in the thickness direction and is threadedly connected to the end plate assembly, the busbar assembly, and the battery cell module.

10. The battery module according to claim 9, wherein: A BMS control board is fixed on the first end plate. The busbar assembly further includes a sampling pin fixed on the circuit board, and the sampling pin is communicatively connected to the BMS control board through a collection wire harness.

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