Square-shell lithium ion battery module

Abstract

The utility model discloses a square shell lithium ion battery module, which comprises an aluminum row and a battery core stacking structure composed of a plurality of battery cores, the aluminum row comprises a plurality of welding connection parts welded with the battery cores and a plurality of buffering bosses connected with the welding connection parts and protruding towards the outer sides of the welding connection parts, and the buffering bosses are arranged on the aluminum row. The buffering bosses are arranged between every two adjacent welding connecting parts. According to the square-shell lithium ion battery module disclosed by the utility model, the aluminum row structure is optimized, so that the square-shell lithium ion battery module can be conveniently welded with the battery cell, and the welding performance of the battery cell can be improved.

Description

Technical Field

[0001] This utility model belongs to the field of lithium-ion battery energy storage application technology. Specifically, this utility model relates to a square-shell lithium-ion battery module. Background Technology

[0002] Currently, most new energy vehicle power batteries use lithium-ion batteries, which offer better safety and cost performance. Most lithium iron phosphate lithium-ion prismatic cells have a capacity of less than 280Ah. To achieve higher capacity and overcurrent capability, cells are connected in parallel. Due to the high requirements for cell assembly and welding, the current parallel assembly method for prismatic lithium-ion batteries is 2P. The welding requirements for 3P and 4P cells and aluminum busbars are also high.

[0003] Currently, the prismatic lithium-ion battery packs mainly adopt a vertical stacking method for the cells, with buffer pads supporting the large surfaces of the cells. They are wrapped by welding aluminum end plates and side plates, resulting in high overall structural strength. However, the welding equipment for the module end plates and side plates requires high precision. If a problem occurs with a cell in the module, rework is extremely difficult and in most cases, it will lead to the scrapping of the entire module. In addition, because the cells are wrapped by aluminum sheet metal end plates, the overall heat dissipation performance is poor, and the insulation performance of the module is required to be high. The blue film of the module cells cannot be damaged, and the aluminum end plates and side plates also need to be covered with an insulation film. If the insulation film is damaged, it will lead to poor insulation and, in severe cases, the scrapping of the module. Currently, for high-voltage connections and low-voltage data acquisition in modular battery cells, a higher degree of integration is often achieved by using an aluminum bar + FPC (Flexible Printed Circuit) + molded carrier to form a CCS (Cells Contact System) assembly. The CCS assembly has high integrity, and the welding process during module welding requires strict control. If the aluminum bar is over-welded, welded through, or the FPC is broken, it cannot be repaired and must be reworked and the CCS welding operation repeated. This places extremely high demands on production process control and after-sales quality. In addition, during the cycle of use, the expansion and deformation of the square-shell battery cell will become increasingly larger. Due to the design characteristics of the FPC, its resistance to cell deformation is limited, and there is a risk that the FPC body or the circuit of the welding point may be pulled and broken. The current mainstream battery cell temperature acquisition is more reflected in the aluminum bar welded to the battery cell, usually with nickel sheet welding. No matter which acquisition method is used, it is impossible to completely acquire the true temperature of the battery cell. More often, it relies on experiments and temperature field simulation and temperature acquisition software compensation. The current module assembly method with higher capacity and overcurrent requirements is 1P structure, and a few are 2P structure. Due to factors such as the flatness requirements of the welding between the battery cell and the aluminum busbar, the 3P and 4P parallel structures are more difficult to control.

[0004] Chinese Patent Application No. 202023164102.7 discloses a square lithium-ion battery module assembly structure, which mainly includes several batteries (1). A plastic insulating sheet I (4) is provided between every two batteries (1). The plastic insulating sheet I (4) bonds adjacent batteries (1) together. A battery connection device is provided between every two batteries (1). The battery connection device connects several batteries (1) together in series. After the several batteries (1) are bonded by the plastic insulating sheet I (4) and connected in series by the battery connection device, they are arranged to form a battery module. Plastic end plates I (2) and plastic end plates II (3) are provided on both sides of the battery module. The battery module is fixed together with plastic end plates I (2) and plastic end plates II (3). This utility model can not only adapt to different battery installation spaces, but also has a simple structure, is easy to install, and has low manufacturing cost.

[0005] The aim is to provide an improved prismatic lithium-ion battery module, particularly regarding how to facilitate cell welding and improve cell welding performance. Utility Model Content

[0006] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention provides a square-shell lithium-ion battery module, the purpose of which is to facilitate the welding of battery cells and improve the welding connection strength of the battery cells.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a square-shell lithium-ion battery module, including an aluminum busbar and a cell stacking structure composed of multiple cells. The aluminum busbar includes a welding connection part that is welded to the cell and a buffer boss that is connected to the welding connection part and protrudes outward toward the welding connection part. Multiple welding connection parts are provided, and the buffer boss is provided between two adjacent welding connection parts.

[0008] The aluminum busbar is made of AL1060-O state pure aluminum plate.

[0009] The aforementioned prismatic lithium-ion battery module further includes two aluminum end plates disposed at both ends of the cell stacking structure, and a first and a second binding strap for binding and fixing the cell stacking structure and the aluminum end plates. The first binding strap is made of PET plastic steel strapping, and the second binding strap is made of stainless steel. Compressed silicone rubber is disposed between the cell stacking structure and the aluminum end plates.

[0010] An end-plate side insulating film is provided between the cell stacking structure and the compressed silicone rubber, a cell side insulating film is provided on the side of the cell stacking structure, and a cell bottom insulating film is provided on the bottom surface of the cell stacking structure.

[0011] The aluminum end plate is provided with an output electrode base mating groove for assembling the output electrode base assembly, an output electrode base I-shaped nut insert for connecting, fixing and protecting the output electrode, and an output electrode base protective cover.

[0012] The top surface of the battery cell stacking structure is provided with a busbar support, and a top insulating film cover plate is provided on the busbar support. The thickness of the top insulating film cover plate is 0.5mm.

[0013] The top insulating film cover is made of insulating and flame-retardant polycarbonate insulating film.

[0014] The busbar bracket is equipped with a module acquisition harness assembly, which includes a voltage acquisition point for acquiring cell voltage values ​​and a temperature acquisition point for acquiring cell temperature values.

[0015] A temperature switch for collecting temperature values ​​is installed on the top insulating film cover plate, and the temperature switch is electrically connected to the temperature switch wiring harness.

[0016] The top insulating film cover is equipped with a nameplate label, a positive electrode marking, and a negative electrode marking.

[0017] The thickness of the welded joint is 1.0mm to 1.5mm.

[0018] The square-shell lithium-ion battery module of this invention optimizes the aluminum busbar structure, making it easier to weld to the battery cell and improving the battery cell welding performance. Attached Figure Description

[0019] This manual includes the following figures, which illustrate the following:

[0020] Figure 1 This is a schematic diagram of the overall external structure of a high-current square-shell lithium-ion battery module according to this utility model;

[0021] Figure 2 This is a schematic diagram of the overall exploded structure of a high-current square-shell lithium-ion battery module according to this utility model;

[0022] Figure 3 This is a schematic diagram of a high-current square-shell lithium-ion battery module cell stacking structure according to the present invention.

[0023] Figure 4 This is a schematic diagram of the end plate and steel strip structure of a high-current square-shell lithium-ion battery module according to this utility model.

[0024] Figure 5 This is a schematic diagram of a high-current square-shell lithium-ion battery module busbar bracket and connecting structure according to the present invention.

[0025] Figure 6This is a schematic diagram of the acquisition harness structure of a high-current square-shell lithium-ion battery module according to this utility model;

[0026] Figure 7 This is a schematic diagram of the structure of a high-current square-shell lithium-ion battery module CCS component according to this utility model;

[0027] Figure 8 This is a schematic diagram of a temperature switch and wiring harness for a high-current square-shell lithium-ion battery module according to this utility model.

[0028] Figure 9 This is a schematic diagram of the insulating protective component for a high-current square-shell lithium-ion battery module according to this utility model.

[0029] Figure 10 This is a detailed structural diagram of a high-current square-shell lithium-ion battery module connection bar according to this utility model. Detailed Implementation

[0030] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of this utility model, and to facilitate its implementation.

[0031] like Figures 1 to 10 As shown, this utility model provides a square-shell lithium-ion battery module, including an aluminum busbar, a cell stacking structure, two aluminum end plates 4 disposed at both ends of the cell stacking structure, and a first binding strap 6 and a second binding strap 7 for binding and fixing the cell stacking structure and the aluminum end plates 4. The first binding strap 6 is made of PET plastic steel strapping, and the second binding strap 7 is made of stainless steel. A compression silicone rubber 17 is disposed between the cell stacking structure and the aluminum end plates 4. The cell stacking structure is composed of multiple cells 21 stacked together. The aluminum busbar includes a welding connection portion 48 welded to the cell 21 and a buffer boss 49 connected to the welding connection portion 48 and protruding outward toward the welding connection portion 48. Multiple welding connection portions 48 and multiple buffer bosses 49 are provided. Each buffer boss 49 is disposed between each two adjacent welding connection portions 48, and the buffer boss 49 connects two adjacent welding connection portions 48.

[0032] Specifically, in this utility model, a combination of stainless steel strip and plastic steel strip, along with compressed silicone foam and two-component polyurethane structural adhesive, replaces the traditional module structure (laser welding of aluminum module end side plates, use of compressed foam to fill between single sides of the battery cells, and use of structural adhesive to bond the narrow side of the battery cells to the side plates). The side plates (with insulating film covering) are eliminated, and the bottom and sides of the module are protected by ultra-thin PC insulating film adhesive bonding. This greatly reduces procurement and production costs and the high requirements for end side plate welding equipment, while improving the overall heat dissipation and insulation performance of the module. The CCS module adopts a distributed assembly method, using aluminum busbars, wire harnesses, and plastic carriers for separate packaging. During module welding, aluminum busbars and wire harnesses can be replaced or repaired individually. Due to the design characteristics of FPC, its resistance to cell deformation is limited, posing a risk of breakage from the FPC body or welded circuitry. The wire harness acquisition points and main wire harness length are designed with allowances to mitigate the impact of module expansion and deformation on the acquisition wires after repeated use. Furthermore, the cell voltage and temperature acquisition points are secured using standard components, ensuring reliable connections and avoiding the serious risk of power interruption due to poor welding caused by welding methods. A separate temperature acquisition point is added to collect the actual temperature of the cell cover plate plus the cell aluminum busbar temperature, ensuring that the temperature is not affected by aluminum busbar temperature acquisition deviations. Simultaneously, the temperature switch, in conjunction with the control system, can quickly disconnect and protect the system in case of abnormalities. The top insulating film cover is fixed with 0.5mm PC (insulating flame-retardant polycarbonate) insulating film, ensuring insulation protection while effectively reducing production costs and meeting the module's lightweight requirements. The problem of welding multiple parallel cells was solved by locally thinning the aluminum busbar, thinning the welding area, adding stamped welding bosses to the welding area, and using AL1060-O state pure aluminum plate material.

[0033] As a preferred option, such as Figure 10 As shown, one side surface of the welded connection part 48 is a welded contact surface 50 that contacts the cell electrode post. The cell electrode posts provided on the cell include the positive electrode post 28 and the negative electrode post 29. The buffer boss 49 has an arc-shaped structure, and the welded contact surface 50 is a plane parallel to the axis of the buffer boss 49. The two ends of the buffer boss 49 in the arc length direction are fixedly connected to the two welded connection parts 48 on both sides. The aluminum busbar is made of AL1060-O state pure aluminum plate. The buffer boss 49 is used to absorb the expansion deformation of the cell after the 4P4S module assembly 2 is used repeatedly. The thickness of the welded connection part 48 is 1.0mm~1.5mm, forming a weld thinning area.

[0034] like Figure 1The diagram shows the overall external structure of a high-current prismatic lithium-ion battery module. Its main components include: a nameplate label 11 for identifying and tracing the 4P4S module assembly 2; positive electrode markings 12 and 13 for distinguishing the positive and negative electrode positions, which are affixed to the top insulating film cover; a first binding strap 6 and a second binding strap 7 for connecting the aluminum end plate 4, the battery cell 21, and the aluminum end plate 4; and a top insulating film cover 1 and a bottom layer for insulating and protecting the battery cell 21 of the 4P4S module assembly 2. The battery cell bottom insulation film 3 is made of PC (insulating and flame-retardant polycarbonate) insulation film and has a thickness of 0.175mm; it includes M4*10 plastic rivets 10 for connecting the top insulation film cover 1 and the busbar bracket 18; it includes a module acquisition harness assembly 8 for acquiring module voltage and temperature; it includes an output pole base assembly 5 for fixing and supporting the output pole connection busbar; and it includes a temperature switch for acquiring the temperature of the top insulation film cover 1 and a temperature switch harness 9 connected to the temperature switch.

[0035] like Figure 1 and Figure 3 As shown, in this embodiment, two first strapping straps 6 are provided, and one second strapping strap 7 is provided. The second strapping strap 7 is located between the two first strapping straps 6. Three strapping strap limiting grooves 23 are provided on the aluminum end plate 4 to allow the first strapping strap 6 and the second strapping strap 7 to be embedded respectively, so as to prevent the strapping straps from moving.

[0036] like Figure 2 The diagram shows an exploded view of the external structure of a high-current prismatic lithium-ion battery module. The module also includes a top insulating film cover 1, a bottom insulating film 3, an end-plate side insulating film 16, and a side insulating film 15 for external protection of the battery cell 21. The side insulating film 15 is made of PC (insulating and flame-retardant polycarbonate) and has a thickness of 0.175 mm. The module also includes aluminum end plates 4, compressed silicone rubber 17, end-plate side insulating films 16, and battery cell 21 extrusion stacking. The first and second cable ties are included; the module acquisition harness assembly 8 and temperature switch harness 9 are used for voltage and temperature acquisition of the 4P4S module assembly 2; the M4*10 plastic rivets 10 are used to fix the top insulating film cover plate 1 and busbar bracket 18; the output pole base assembly 5 and M6*20 hexagonal head assembly 19 are used to fix the first aluminum busbar 33 and the third aluminum busbar 35; the nameplate label 11, positive pole label 12 and negative pole label 13 are used to indicate the traceability and positive and negative pole identification of the 4P4S module assembly 2.

[0037] like Figure 3As shown, a schematic diagram of a high-current square-shell lithium-ion battery module cell stacking structure is shown. The structure mainly includes a positive electrode post 28 and a negative electrode post 29 for the positive and negative electrode output of the cell 21; a cell explosion-proof valve 27 for pressure relief protection when the cell 21 is abnormal; and a cell large surface 26 for applying glue and extruding the cells in the stacking direction.

[0038] like Figure 4 The diagram shows a schematic of a high-current prismatic lithium-ion battery module end plate and steel strip structure. The high-current prismatic lithium-ion battery module end plate includes an aluminum end plate 4 for extruding and bundling the 4P4S module assembly 2, a first bundling strap 6, and a second bundling strap 7; it includes an output electrode base mating groove 25 for assembling the output electrode base assembly 5, and an output electrode base M6 I-shaped nut insert 20 for connecting, fixing, and protecting the output electrode; it includes a module lifting hole 24 and a module end plate fixing hole 31 for lifting and fixing the 4P4S module assembly 2; and it includes a module end plate cell surface 32 for the glued contact surface between the battery cell 21 of the 4P4S module assembly 2 and the aluminum end plate 4.

[0039] like Figure 5 , Figure 7 As shown, a schematic diagram of a busbar bracket and connecting structure for a high-current prismatic lithium-ion battery module, and a schematic diagram of a CCS component structure for a high-current prismatic lithium-ion battery module are presented. The high-current prismatic lithium-ion battery module includes a busbar bracket cover fixing hole 38 and an M4*10 plastic rivet 10 on the busbar bracket 18 for the top insulating film cover 1; a wire harness slot 36 for fixing the routing of the module acquisition wire harness assembly 8 and the temperature switch wire harness 9; and a slot for engaging the first aluminum busbar 33, the second aluminum busbar 34, and the third aluminum busbar 35. The aluminum busbar slot 41 is a limiting device; it includes an aluminum busbar fixing hole 39 for fixing the output aluminum busbar and an M6*20 hexagonal head assembly 19; it includes an aluminum busbar welding surface 40 for welding the first aluminum busbar 33, the second aluminum busbar 34, the third aluminum busbar 35 and the battery cell 21; it includes an M4*10 press-fit screw 37 and an M4 hexagonal flange nut 44 for fixing the voltage acquisition point 42 and temperature acquisition point 43 of the module acquisition harness assembly 8; and it includes a busbar bracket temperature harness through hole 45 on the busbar bracket 18 for the output of the temperature switch harness 9.

[0040] like Figure 6 , Figure 8 As shown, a schematic diagram of a high-current square-shell lithium-ion battery module acquisition harness structure and a schematic diagram of a high-current square-shell lithium-ion battery module temperature switch and harness are provided. The structure mainly includes voltage acquisition point 42 and temperature acquisition point 43 for sampling of the module acquisition harness assembly 8; and temperature switch 46 and temperature switch harness 9 for acquiring the temperature of the upper cover plate of the cell 21.

[0041] like Figure 9As shown, a schematic diagram of a high-current square-shell lithium-ion battery module acquisition harness structure is provided. The structure mainly includes compressed silicone rubber 17 for compression buffering of the 4P4S module assembly 2; a top insulating film cover 1, a bottom insulating film 3, a side insulating film 15, and an end-plate side insulating film 16 for insulating protection of the battery cell 21, aluminum end plate 4, and second binding strap 7; and a nameplate label 11, a positive electrode label 12, and a negative electrode label 13 for tracing the 4P4S module assembly 2 and identifying the positive and negative electrodes.

[0042] like Figure 10 The diagram shows a detailed structural schematic of a high-current prismatic lithium-ion battery module cell connection strip, including M4*10 rivet screws 37 for fixing voltage acquisition points 42 and temperature acquisition points 43 of the module acquisition harness assembly 8; and aluminum busbar welding positioning holes 51 for welding and positioning the cell 21 to the connection strip. Three aluminum busbars are provided for welding and connecting the cell 21, namely the first aluminum busbar 33, the second aluminum busbar 34, and the third aluminum busbar 35.

[0043] The high-current prismatic lithium-ion battery module with the above-described structure has the following advantages:

[0044] The structure is simple, assembly and repair processes are convenient, and equipment requirements and dependencies are low. The square-shell battery cells are stacked on their large surfaces, bonded together with a two-component polyurethane structural adhesive. This ensures the overall strength and rigidity of the assembled cells, meeting various operating conditions. An insulating film is added to the end plate sides for enhanced insulation and protection. Compressible silicone pads on both sides of the end plate meet the compressive pressure requirements of the assembled cells and absorb the influence of dimensional tolerances of the cells and other components on the assembly of the stainless steel strip and the module's fixing points. A combination of stainless steel strips and plastic-coated steel strips ensures the compressive pressure requirements after module stacking, as well as the expansion force and stress relaxation after cell cycle durability. The bottom and sides of the module are bonded with a 0.175mm ultra-thin PC insulating film, ensuring insulation protection for the module cells while minimizing the impact on cell heat dissipation. The insulating film provides insulation and scratch protection while facilitating replacement and repair.

[0045] The CCS module is composed of an aluminum busbar, a wire harness, and a plastic carrier. The aluminum busbar is inserted and secured by clips on the plastic parts, and can be installed and removed independently. The wire harness is also inserted and secured by grooves on the plastic parts, and can also be installed and removed independently. After the aluminum busbar is welded, the wire harness is assembled with fasteners to connect the cell voltage and temperature acquisition points. The acquisition points are reliably installed, avoiding quality problems caused by poor welding or over-welding due to welding methods. The acquisition points can be installed and removed independently. At the same time, the length of the wire harness acquisition points and the main body of the wire harness is reserved to ensure that the expansion and deformation of the module after repeated use will not affect the pulling of the acquisition wire.

[0046] In addition to temperature acquisition on the aluminum busbar, a separate temperature acquisition device is added to the top cover of the battery cell. By using thermally conductive adhesive, the contact surface of the temperature sensor is completely bonded to the top cover of the battery cell, and the temperature harness is led out separately for separate acquisition, calibration, and control. This avoids the errors caused by acquiring temperature only on the aluminum busbar and adds protection against temperature control disconnection.

[0047] To enable more battery cells to be connected in series and parallel, the current-carrying area of ​​the welded aluminum busbar is adjusted by increasing its width and reducing its thickness. While maintaining the basic current-carrying thickness at the output electrode position, the welding area is thinned. Considering the current-carrying capacity of individual battery cells and the strength requirements of the welded connection, the aluminum busbar cannot be further thinned, typically around 2mm to 2.5mm in thickness. To improve welding performance (the optimal thickness for welding aluminum busbars using laser welding machines is generally 1.0 to 1.5mm), the welding area is further thinned to a thickness of 1.0mm to 1.5mm. This utility model relates to a high-current prismatic lithium-ion battery module device. For the 4P4S assembly structure, the aluminum busbar can simultaneously weld up to 8 battery cell terminals. Due to deviations in the aluminum busbar processing and module assembly process, it is impossible to guarantee that the aluminum busbar welding surface and the battery cell terminal are in complete contact (if the aluminum busbar and the battery cell terminal are not completely in contact during welding, it will cause the aluminum busbar to have a false weld or a burst weld, resulting in the scrapping of the module or serious quality problems after sales). Therefore, based on the overall thinning of the welding surface of the aluminum busbar, the overall planar contact between the aluminum busbar and the battery cell terminal is changed to the combination of stamped protrusions on the aluminum busbar. At the same time, a softer O-state material is used for welding the aluminum busbar to achieve point-to-point contact welding between the welding area on the aluminum busbar and the battery cell terminal, avoiding the influence of the flatness of the aluminum busbar and the assembly height of the module on the welding.

[0048] like Figures 1 to 10 As shown, the assembly process of the above-described prismatic lithium-ion battery module includes the following steps:

[0049] S1: Take battery cell 21 and place it on the workbench according to the positive and negative requirements.

[0050] S2: Peel off the adhesive backing of the compressed silicone rubber 17, and paste it onto the cell surface 32 of the module end plate as required. Apply two-component structural adhesive to the groove after pasting.

[0051] S4: Place the coated aluminum end plate 4 into the extrusion limiting fixture, and perform the end plate side insulation film 16 pasting operation on the contact side of the first cell 21 with the cell surface 32 of the module end plate.

[0052] S5: Adhere the battery cell 21 with the insulating film 16 on the end plate to the aluminum end plate 4 with glue. Take the battery cell 21 and apply glue to it in sequence. Stack and bond the cells according to the placement order. Repeat the operation requirements of S2 and S4 for the last battery cell.

[0053] S6: The stacked modules are extruded by the tooling until the extrusion pressure or stroke reaches the operation requirements and the extrusion is stopped. The second strapping 7 is then put on the module until it stops at the strapping limit groove 23 on the aluminum end plate 4, and the tooling pressure is released.

[0054] S7: Remove the adhesive backing from the insulating film 15 on the side of the battery cell and stick it to the side of the stacked length of the 2 battery cells in the 4P4S module assembly.

[0055] S8: After the module is flipped in the S7 process, remove the backing adhesive from the bottom insulating film 3 of the battery cell and attach protective adhesive to the bottom of the battery cell 21.

[0056] S9: After the module is flipped in the flipping process S8, take two first strapping straps 6 and place them in the strapping strap limiting grooves 23 on the aluminum end plate 4, and use a hot melt packaging machine to pack and bundle them.

[0057] S10: Take the output electrode base assembly 5 and insert it into the output electrode base mating groove 25 on the aluminum end plate 4, and open the output electrode base protective cover 30 of the output electrode base assembly 5.

[0058] S11: Place the busbar bracket 18 on the 4P4S module assembly 2, and fix the first aluminum busbar 33, the second aluminum busbar 34, and the third aluminum busbar 35 through the aluminum busbar slot 41 on the busbar bracket 18.

[0059] S12: Take two M6*20 hexagonal head assemblies 19, and fix the first aluminum busbar 33 and the third aluminum busbar 35 to the output pole base M6 I-shaped nut insert 20 on the output pole base assembly 5 through the aluminum busbar fixing hole 39.

[0060] S13: Using a laser welding machine, the first aluminum busbar 33, the second aluminum busbar 34, and the third aluminum busbar 35 are fixed and limited by the busbar bracket 18, and are welded to the battery cell 21 by pressing and bonding the aluminum busbar welding surface 40 and the welding boss 47 together.

[0061] S14: The temperature switch 46 is bonded to the top cover of the battery cell 21 and the busbar bracket 18 using thermally conductive structural adhesive.

[0062] S15: Arrange and fix the module acquisition harness assembly 8 through the harness slot 36 on the busbar bracket 18.

[0063] S16: Use M4 hexagonal flange nuts 44 to fix the M4 voltage acquisition point 42 and M4 temperature acquisition point 43 on the module acquisition harness assembly 8 with M4*10 press-fit screws 37 on the first aluminum busbar 33, the second aluminum busbar 34 and the third aluminum busbar 35. After torque operation, confirm the painting.

[0064] S17: Connect one end of the temperature switch harness 9 to the terminal on the temperature switch 46, and pass the other end through the busbar bracket temperature harness through hole 45 on the busbar bracket 18.

[0065] S18: Use M4*10 plastic rivets 10 to snap into the busbar bracket cover plate fixing holes 38 on the busbar bracket 18 through the top insulating film cover plate fixing holes 14 on the top insulating film cover plate 1.

[0066] S19: Reinstall the output terminal base protective cover 30 back onto the output terminal base assembly 5.

[0067] S20: Affix the nameplate label 11 to the top insulating film cover plate 1 and the aluminum end plate 4 as required.

[0068] S21: Test the voltage, temperature, and internal resistance of the 4P4S module assembly 2. If it passes the test, package it into the warehouse.

[0069] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A prismatic lithium-ion battery module, characterized in that: The device includes an aluminum busbar and a battery cell stack structure consisting of multiple battery cells. The aluminum busbar includes a welded connection portion that is welded to the battery cells and a buffer boss that is connected to the welded connection portion and protrudes outward toward the welded connection portion. Multiple welded connection portions are provided, and the buffer boss is provided between two adjacent welded connection portions.

2. The prismatic lithium-ion battery module according to claim 1, characterized in that: The aluminum busbar is made of AL1060-O state pure aluminum plate.

3. The prismatic lithium-ion battery module according to claim 1, characterized in that: It also includes two aluminum end plates disposed at both ends of the battery cell stacking structure, and a first and a second binding strap for binding and fixing the battery cell stacking structure and the aluminum end plates. The first binding strap is made of PET plastic steel tape, and the second binding strap is made of stainless steel. Compressed silicone rubber is disposed between the battery cell stacking structure and the aluminum end plates.

4. The prismatic lithium-ion battery module according to claim 3, characterized in that: An end-plate side insulating film is provided between the cell stacking structure and the compressed silicone rubber, a cell side insulating film is provided on the side of the cell stacking structure, and a cell bottom insulating film is provided on the bottom surface of the cell stacking structure.

5. The prismatic lithium-ion battery module according to claim 3, characterized in that: The aluminum end plate is provided with an output electrode base mating groove for assembling the output electrode base assembly, an output electrode base I-shaped nut insert for connecting, fixing and protecting the output electrode, and an output electrode base protective cover.

6. The prismatic lithium-ion battery module according to any one of claims 3 to 5, characterized in that: The top surface of the battery cell stacking structure is provided with a busbar support, and a top insulating film cover plate is provided on the busbar support. The thickness of the top insulating film cover plate is 0.5mm.

7. The prismatic lithium-ion battery module according to claim 6, characterized in that: The top insulating film cover is made of insulating and flame-retardant polycarbonate insulating film.

8. The prismatic lithium-ion battery module according to claim 6, characterized in that: The busbar bracket is equipped with a module acquisition harness assembly, which includes a voltage acquisition point for acquiring cell voltage values ​​and a temperature acquisition point for acquiring cell temperature values.

9. The prismatic lithium-ion battery module according to claim 6, characterized in that: A temperature switch for collecting temperature values ​​is installed on the top insulating film cover plate, and the temperature switch is electrically connected to the temperature switch wiring harness.

10. The prismatic lithium-ion battery module according to claim 1, characterized in that: The thickness of the welded joint is 1.0mm to 1.5mm.

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