A method for assembling a battery module

Abstract

The present invention provides a method for assembling a battery module. The method for assembling a battery module includes the following steps: preparing battery cells; preparing a housing, the housing including a cover plate and a housing main body, and arranging a plurality of cavities in the housing main body; respectively installing the plurality of battery cells in the plurality of cavities of the housing main body, and welding the tabs of the plurality of battery cells to a plurality of first pole columns located inside the housing, and electrically connecting adjacent ones of the plurality of first pole columns through a plurality of second pole columns arranged outside the housing; welding the cover plate to the housing main body. This method for assembling a battery module can solve the problem that the assembly between battery cell monomers is required in the production of a battery module.

Description

Technical Field

[0001] This application relates to the technical field of battery pack assembly, and particularly to a method for assembling a battery module. Background Art

[0002] Facing the increasingly severe energy crisis and huge emission reduction pressure, it is an inevitable development trend for new energy vehicles that are energy-saving and environmentally friendly to replace traditional fuel vehicles. Lithium-ion batteries, with their excellent electrical performance and no environmental pollution, have become the most promising power batteries for electric vehicles and have broad market application prospects.

[0003] Generally, the production steps of vehicle lithium-ion batteries include the production of battery cell monomers and the welding and assembly of battery modules or battery packs. The battery cell monomers need to be welded and assembled through metal connecting pieces to form battery modules and battery packs. The assembly process between battery cell monomers requires workshops, equipment, tooling, and labor, etc., and its process is complex and the cost is high, which in turn leads to an increase in the cost of producing battery modules. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a method for assembling a battery module to solve the problem that the assembly between battery cell monomers is required for producing battery modules.

[0005] According to the present invention, a method for assembling a battery module is provided, wherein the method for assembling the battery module includes the following steps: preparing battery cells; preparing a housing, the housing includes a cover plate and a housing body, and a plurality of cavities are provided in the housing body; installing a plurality of the battery cells into the plurality of cavities of the housing body respectively, and welding the tabs of the plurality of battery cells to a plurality of first pole columns located inside the housing, and a plurality of adjacent first pole columns are electrically connected through a plurality of second pole columns provided outside the housing; welding the cover plate to the housing body.

[0006] Preferably, preparing the battery cells includes the following steps: manufacturing a pole group; installing end plates on the positive and negative electrodes of the pole group; installing an insulating film.

[0007] Preferably, manufacturing the pole group includes forming the pole group by winding or stacking pole pieces, and then performing tab shaping.

[0008] Preferably, the end plates include an upper end plate and a lower end plate that can be spliced together. Installing the end plates on the positive and negative electrodes of the pole group includes splicing the upper end plate and the lower end plate and then setting them on the positive and negative electrodes of the pole group, and extending the tabs of the pole group through the gap between the upper end plate and the lower end plate.

[0009] Preferably, installing the insulating film includes covering the insulating film on the pole group, and then thermally welding the two ends of the insulating film to the end plates.

[0010] Preferably, the preparation of the housing includes the following steps: stamping the housing into shape; assembling the second pole column with the second plastic for insulation, with a fusing device provided in the middle of a part of the second pole column and wrapping the fusing device inside the second plastic; installing the first pole column and the first plastic for insulation inside the housing, and installing the second pole column and the second plastic outside the housing; installing riveting posts to electrically connect the first pole column and the second pole column.

[0011] Preferably, after welding the tabs of multiple battery cells to multiple first pole columns located inside the housing, the battery module assembly method further includes applying adhesive protection or dispensing protection at the positions where the tabs of the battery cells are welded to the first pole columns.

[0012] Preferably, multiple cavities are arranged at intervals along the length direction inside the housing body, and a partition is provided between two adjacent cavities.

[0013] Preferably, welding the cover plate to the housing body includes the following steps: welding the outer periphery of the cover plate to the periphery of the opening side of the housing body; welding the middle part of the cover plate to the end face of the partition.

[0014] Preferably, after welding the cover plate to the housing body, the battery module assembly method further includes a process of injecting electrolyte and forming, which includes the following steps: injecting electrolyte into the housing through the injection hole; performing an opening pre-charge; sealing the injection hole; and performing grading on each battery cell.

[0015] The battery module assembly method according to the embodiment of the present invention first prepares battery cells and a housing. The housing includes a cover plate and a housing body, and multiple cavities are provided inside the housing body. Then, multiple battery cells are respectively installed in multiple cavities of the housing body, and the tabs of the multiple battery cells are welded to multiple first pole columns located inside the housing. The multiple first pole columns are electrically connected through multiple second pole columns provided outside the housing, thereby electrically connecting the battery cells located in the cavities, and further omitting the assembly process between the battery cell monomers. The battery module can be directly produced by producing the battery cells and the housing, reducing the manufacturing cost. Finally, the cover plate is welded to the housing body to complete the sealing of the battery cells. In this way, the problem that the assembly between the battery cell monomers is required for producing the battery module can be effectively solved.

[0016] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0018] Figure 1 is a schematic structural diagram of a battery module according to the present invention.

[0019] Figure 2 is a schematic structural diagram of another angle of the battery module according to the present invention.

[0020] Figure 3 is a schematic diagram of the battery module according to the present invention.

[0021] Figure 4 is a schematic diagram of the housing main body of the battery module according to the present invention.

[0022] Figure 5 is a schematic diagram of another angle of the housing main body of the battery module according to the present invention.

[0023] Figure 6 is a schematic structural diagram of the housing main body of the battery module according to the present invention.

[0024] Figure 7 is a schematic diagram of the housing of the battery module according to the present invention.

[0025] Figure 8 is a schematic diagram of yet another angle of the housing main body of the battery module according to the present invention.

[0026] Figure 9 is Figure 8 a cross-sectional view of part A in

[0027] Figure 10 is a schematic diagram of the battery cell according to the present invention.

[0028] Figure 11 is a schematic diagram of a partial structure of the battery cell according to the present invention.

[0029] Figure 12 is a schematic structural diagram of the end plate of the battery cell according to the present invention.

[0030] Reference numerals: 1 - electrode group; 11 - positive electrode tab; 12 - negative electrode tab; 21 - upper end plate; 210 - assembly pin; 22 - lower end plate; 220 - pin hole; 23 - gap; 24 - opening; 3 - insulating film; 30 - heat melting point; 4 - battery module; 5 - housing; 50 - cavity; 500 - step portion; 51 - housing body; 511 - liquid injection hole; 512 - explosion-proof valve; 52 - cover plate; 520 - welding mark; 53 - first pole column; 530 - first plastic; 54 - second pole column; 540 - second plastic; 541 - short pole column; 542 - long pole column; 5420 - fusing device; 55 - sealing ring; 56 - riveting column; 6 - battery cell. Detailed implementation manners

[0031] The following detailed implementation manners are provided to assist the reader in obtaining a comprehensive understanding of the methods, devices, and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein, but rather, changes that will be apparent after understanding the disclosure of the present application may be made, except for operations that must occur in a specific order. In addition, descriptions of features known in the art may be omitted for the sake of clarity and brevity.

[0032] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many possible ways of implementing the methods, devices, and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0033] Throughout the specification, when an element (such as, a layer, region, or substrate) is described as "on" another element, "connected to" another element, "bonded to" another element, "above" another element, or "covering" another element, it may be directly "on" another element, "connected to" another element, "bonded to" another element, "above" another element, or "covering" another element, or there may be one or more other elements therebetween. In contrast, when an element is described as "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly above" another element, or "directly covering" another element, there may be no other elements therebetween.

[0034] As used herein, the term "and / or" includes any one of the listed related items and any combination of any two or more of them.

[0035] Although terms such as "first", "second", and "third" may be used herein to describe various components, elements, regions, layers, or sections, these components, elements, regions, layers, or sections are not limited by these terms. Rather, these terms are only used to distinguish one component, element, region, layer, or section from another. Thus, a first component, element, region, layer, or section as referred to in the examples described herein may also be referred to as a second component, element, region, layer, or section without departing from the teachings of the examples.

[0036] For ease of description, spatial relationship terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another as shown in the drawings. Such spatial relationship terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the drawings is flipped, an element described as "above" or "upper" relative to another element will then be "below" or "lower" relative to the other element. Thus, the term "above" includes both the orientation of "above" and "below" depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relationship terms used herein will be interpreted accordingly.

[0037] The terms used herein are for the purpose of describing various examples only and are not intended to limit the examples. Unless the context clearly dictates otherwise, the singular forms are also intended to include the plural forms. The terms "comprises", "comprising", and "having" list the stated features, quantities, operations, components, elements, and / or combinations thereof that exist, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0038] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the drawings may occur. Thus, the examples described herein are not limited to the specific shapes shown in the drawings, but include changes in shape that occur during manufacturing.

[0039] The features of the examples described herein can be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have a variety of configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0040] The present invention provides a method for assembling a battery module, the method for assembling the battery module comprising the following steps:

[0041] Prepare the battery cell 6;

[0042] Prepare a housing 5, which includes a cover plate 52 and a housing body 51, and a plurality of cavities 50 are provided in the housing body 51;

[0043] Install a plurality of battery cells 6 in the plurality of cavities 50 of the housing body 51 respectively, and weld the tabs of the plurality of battery cells 6 to a plurality of first pole columns 53 located inside the housing 5. The adjacent plurality of first pole columns 53 are electrically connected through a plurality of second pole columns 54 provided outside the housing 5;

[0044] Weld the cover plate 52 to the housing body 51.

[0045] In the following description, reference will be made to the figures such as Figures 1 to 12 Specifically describe the above steps of the battery module assembly method.

[0046] Preferably, as Figures 10 to 12 shown, in the embodiment, prepare the battery cells 6, that is, produce the required number of battery cell monomers of the battery cells 6 for use in making the battery module 4. Preparing the battery cells 6 may include the following steps. First, make the electrode assembly 1, then install the end plates on the positive and negative electrodes of the electrode assembly 1, and finally install the insulating film 3.

[0047] Specifically, as Figure 11 shown, in the embodiment, making the electrode assembly 1 includes making the electrode plates into the electrode assembly 1 by winding or stacking, and then performing tab shaping. Preferably, the electrode plates can be made into an electrode assembly 1 in the shape of an approximate cuboid by an electrode plate winding machine or an electrode plate stacking device. Then shape the tabs of the electrode assembly 1 so that the positive tab 11 and the negative tab 12 are respectively located at the centers of both ends in the length direction of the electrode assembly 1, and the positive tab 11 and the negative tab 12 protrude from the end face of the electrode assembly 1.

[0048] Preferably, as Figures 10 to 12 shown, in the embodiment, the end plates include an upper end plate 21 and a lower end plate 22 that can be joined together. Installing the end plates on the positive and negative electrodes of the electrode assembly 1 includes joining the upper end plate 21 and the lower end plate 22 and then setting them on the positive and negative electrodes of the electrode assembly 1, and extending the tabs of the electrode assembly 1 through the gap 23 between the upper end plate 21 and the lower end plate 22.

[0049] Specifically, as Figure 10 and Figure 12As shown, in the embodiment, the upper end plate 21 and the lower end plate 22 can be formed in a strip shape. The lengths of the upper end plate 21 and the lower end plate 22 can be equal to the width of the electrode group 1, such that the upper end plate 21 and the lower end plate 22 can be exactly mounted at the ends of the electrode group 1. One of the upper end plate 21 and the lower end plate 22 can be provided with an assembly pin 210, and the other can be provided with a pin hole 220 that can cooperate with the assembly pin 210. Specifically, a downwardly protruding assembly pin 210 can be formed on the lower end surface of the upper end plate 21. A pin hole 220 that can cooperate with the assembly pin 210 can be formed at the corresponding position on the upper end surface of the lower end plate 22. Such that the assembly pin 210 can be inserted into the pin hole 220, thereby fitting the upper end plate 21 and the lower end plate 22 together. Preferably, the number of assembly pins 210 can be two, and the two assembly pins 210 can be spaced apart in the length direction of the upper end plate 21. The number of pin holes 220 corresponds to the number of assembly pins 210, such that the upper end plate 21 and the lower end plate 22 can be firmly clamped. After fitting two sets of upper end plates 21 and lower end plates 22 together, they can be respectively arranged at both ends (i.e., the positive electrode end and the negative electrode end) in the length direction of the electrode group 1.

[0050] In addition, as Figure 10 shown, in the embodiment, when the upper end plate 21 and the lower end plate 22 are clamped, a gap 23 is formed between the upper end plate 21 and the lower end plate 22. That is, after the upper end plate 21 and the lower end plate 22 are assembled together, a strip-shaped gap 23 still remains between the upper end plate 21 and the lower end plate 22. Thereby, the sheet-shaped positive electrode tab 11 and negative electrode tab 12 can be extended from the gap 23 between the two sets of end plates to realize shaping and fixing of the positive electrode tab 11 and the negative electrode tab 12.

[0051] Preferably, as Figure 12 shown, in the embodiment, openings 24 can also be formed on the upper end plate 21 and the lower end plate 22 for the electrolyte to flow through and for gas to be discharged during thermal runaway. Specifically, the number of openings 24 can be multiple, and the multiple openings 24 can be respectively formed at both ends in the length direction of the upper end plate 21 and the lower end plate 22. More preferably, rectangular grooves can also be formed at both ends in the length direction of the upper end plate 21 and the lower end plate 22, and the multiple openings 24 can be formed in the rectangular grooves.

[0052] Preferably, as Figure 10As shown, in the embodiment, installing the insulating film 3 includes wrapping the insulating film 3 around the electrode group 1, and then thermally welding the two ends of the insulating film 3 to the end plates. Preferably, the insulating film 3 can be made of polypropylene. The operator can wind and wrap the insulating film 3 around the outside of the electrode group 1. Specifically, the insulating film 3 can be wrapped around the end faces of the electrode group 1 except for the two ends in the length direction. The dimension of the insulating film 3 in the length direction of the electrode group 1 can be greater than that of the electrode group 1, so that the two ends of the insulating film 3 protrude from the two ends of the electrode group 1. Then, the two ends of the insulating film 3 in the length direction of the electrode group 1 are thermally welded to the peripheries of the upper end plate 21 and the lower end plate 22, thereby fixing the insulating film 3 to the electrode group 1 and fixing the upper end plate 21 and the lower end plate 22 to the electrode group 1. Preferably, a plurality of heat melting points 30 can surround the end of the electrode group 1 in the length direction.

[0053] Preferably, as Figures 1 to 9 As shown, in the embodiment, preparing the housing 5, the housing 5 includes a cover plate 52 and a housing main body 51, and a plurality of cavities 50 are arranged in the housing main body 51. Preferably, preparing the housing 5 can include the following steps. First, stamp the housing 5 into shape. Then, assemble the second pole column 54 with the second plastic 540 for insulation. A fuse device 5420 is arranged in the middle of a part of the second pole column 54, and the fuse device 5420 is wrapped inside the second plastic 540. Then, install the first pole column 53 and the first plastic 530 for insulation inside the housing 5, and install the second pole column 54 and the second plastic 540 outside the housing 5. Finally, install the riveting column 56 to electrically connect the first pole column 53 and the second pole column 54.

[0054] Preferably, in the embodiment, stamp the housing 5 into shape, that is, press the main structure of the housing 5 into shape. Stamping the housing 5 into shape includes pressing the cover plate 52 and pressing the housing main body 51. Among them, pressing the housing main body 51 includes stamping the outer shape of the housing main body 51, the cavities 50 and the partition between the cavities 50, and the partition can be integrally formed with the housing main body 51. Pressing the housing main body 51 also includes stamping the injection hole 511 and the installation hole of the explosion-proof valve 512. Further, after pressing the main structure of the housing 5 in the preparation of the housing 5, it also includes welding the explosion-proof sheet to the installation hole of the explosion-proof valve 512 to form the explosion-proof valve 512.

[0055] Specifically, as Figures 1 to 3As shown, in the embodiment, the shape of the compression-molded housing body 51 can be approximately a cuboid, and a plurality of cavities 50 are arranged in rows within the housing body 51 (i.e., arranged in rows within the housing 5). More preferably, the shape of the compression-molded cavity 50 can be approximately a cuboid, and the length direction of the cavity 50 can be perpendicular to the length direction of the housing body 51 to make full use of the internal space of the housing body 51. Preferably, a plurality of cavities 50 can be arranged at equal intervals along the length direction of the housing body 51 inside the housing body 51, and a partition can be formed by pressing between adjacent cavities 50 so that the battery cells 6 in each cavity 50 can be sealed relatively independently.

[0056] Preferably, as Figures 1 to 7 shown, the liquid injection hole 511 can be formed at the first end in the length direction of the cavity 50, and the explosion-proof valve 512 can be arranged at the second end in the length direction of the cavity 50. That is, each cavity 50 is provided with a corresponding liquid injection hole 511 and an explosion-proof valve 512, and the liquid injection hole 511 and the explosion-proof valve 512 are respectively arranged at both ends in the length direction of the cavity 50. The liquid injection hole 511 is used to inject electrolyte into the cavity 50, and the explosion-proof valve 512 is used to discharge gas when the battery module 4 is in thermal runaway.

[0057] Preferably, as Figures 1 to 9 shown, in the embodiment, step portions 500 can be formed at both ends of the housing body 51 in the length direction of the cavity 50. That is, the compression of the housing body 51 further includes stamping the step portions 500. The length of the step portion 500 can be less than the width of the cavity 50, and the step portion 500 can be located at the center of the end of the cavity 50.

[0058] Preferably, in the embodiment, the second pole column 54 is assembled with the second plastic 540 for insulation. A fusing device 5420 is arranged in the middle of a part of the second pole column 54, and the fusing device 5420 is wrapped inside the second plastic 540. Specifically, the second pole column 54 can include a short pole column 541 and a long pole column 542. Among them, a fusing device 5420 can be arranged in the middle of the long pole column 542 to prevent large current or short circuit of the battery module 4. Preferably, the second plastic 540 can be formed in a strip shape, and a through hole for the long pole column 542 to pass through can be opened inside it. Assembling the second pole column 54 with the second plastic 540 for insulation includes passing the long pole column 542 through the through hole of the second plastic 540 so that the fusing device 5420 can be wrapped inside the second plastic 540.

[0059] Preferably, as Figures 1 to 9As shown, in the embodiment, the first terminal post 53 and the first plastic 530 for insulation are installed inside the housing 5, and the second terminal post 54 and the second plastic 540 are installed outside the housing 5. Specifically, the first terminal post 53 can be installed on the side of the stepped portion 500 facing the inside of the housing main body 51, that is, the first terminal post 53 is installed at both ends of each cavity 50 in the length direction. Preferably, the first terminal post 53 can be in a sheet structure, and the first terminal post 53 can be installed on the tabletop of the stepped portion 500 facing the inside of the housing main body 51. In addition, the second terminal post 54 can be installed on the side of the stepped portion 500 facing the outside of the housing main body 51. Preferably, the second terminal post 54 can also be formed in a sheet structure, and the second terminal post 54 can be installed on the tabletop of the stepped portion 500 facing the outside of the housing main body 51, that is, the first terminal post 53 and the second terminal post 54 are respectively installed on both sides of the stepped portion 500.

[0060] In addition, in the embodiment, the first plastic 530 for insulation can be installed between the first terminal post 53 and the stepped portion 500. Preferably, the first plastic 530 and the first terminal post 53 can be overlapped. In addition, the second plastic 540 for insulation can be installed between the second terminal post 54 and the stepped portion 500. Preferably, the second plastic 540 and the short terminal post 541 in the second terminal post 54 can be overlapped, and the long terminal post 542 is partially wrapped in the second plastic 540. Preferably, the first plastic 530 and the second plastic 540 can be made of polypropylene material.

[0061] Preferably, as Figures 6 to 9 shown, in the embodiment, the riveting post 56 is installed to electrically connect the first terminal post 53 and the second terminal post 54. Specifically, a riveting hole (not shown) can be provided on the stepped portion 500. That is, the pressing of the housing main body 51 further includes stamping the riveting hole on the stepped portion 500. Preferably, as Figure 9 shown, the riveting post 56 can be successively passed through the first terminal post 53, the first plastic 530, the stepped portion 500, the second plastic 540, and the second terminal post 54 from left to right to achieve fixation. In addition, the riveting post 56 can electrically connect the first terminal post 53 and the second terminal post 54. Preferably, in the embodiment, one end of the riveting post 56 can be integrally formed with the first terminal post 53, and the other end of the riveting post 56 can be laser welded to the second terminal post 54. More preferably, a sealing ring 55 for sealing can be provided between the first plastic 530 and the stepped portion 500, and a sealing ring 55 for sealing can be provided between the second plastic 540 and the stepped portion 500 to ensure the sealing of the housing 5.

[0062] Preferably, as Figures 1 to 9As shown, in the embodiment, a plurality of battery cells 6 are respectively installed in a plurality of cavities 50 of the housing body 51, and the tabs of the plurality of battery cells 6 are welded to a plurality of first pole columns 53 located inside the housing 5. The plurality of first pole columns 53 are electrically connected through a plurality of second pole columns 54 arranged outside the housing 5. Specifically, after the battery cell 6 is installed in the cavity 50, the positive tab 11 and the negative tab 12 of the battery cell 6 respectively correspond to the positions of the first pole columns 53 at both ends of the cavity 50. Subsequently, the positive tab 11 and the negative tab 12 of the battery cell 6 can be welded to the first pole columns 53 to achieve the electrical connection between the battery cell 6 and the first pole columns 53.

[0063] As Figures 3 to 6 shown, in the embodiment, the short pole column 541 can be installed at the end in the length direction of the housing body 51, that is, corresponding to the cavity 50 located at the end of the housing body 51. One short pole column 541 is provided at each of the two ends of the housing body 51 in the length direction, and the short pole column 541 can be used for electrical connection with the motor of the vehicle. Each short pole column 541 is only electrically connected to a single first pole column 53, that is, the short pole column 541 is installed on a single stepped portion 500. Specifically, as Figure 5 shown, in the embodiment, when the number of cavities 50 is even, the two short pole columns 541 are installed at both ends on the same side of the housing body 51 (when the number of cavities 50 is odd, the two short pole columns 541 are installed at both ends on the opposite sides of the housing body 51).

[0064] In the embodiment, both ends of the long pole column 542 can be respectively electrically connected to the tabs of two adjacent battery cells 6. Specifically, both ends of the long pole column 542 can be respectively installed on two adjacent stepped portions 500, so that both ends of the long pole column 542 are respectively electrically connected to two adjacent first pole columns 53. Further, the long pole column 542 can electrically connect two adjacent battery cells 6 to achieve the series or parallel connection between the battery cells 6 (in this embodiment, it can be a series arrangement scheme, that is, the positive and negative poles of two adjacent battery cells 6 are arranged in reverse).

[0065] Preferably, in the embodiment, after welding the tabs (positive tab 11 and negative tab 12) of the plurality of battery cells 6 to the plurality of first pole columns 53 located inside the housing 5, it further includes applying glue protection or dispensing protection at the positions where the tabs of the battery cells 6 are welded to the first pole columns 53. Specifically, a tape made of PP material or PET material can be pasted at the welding marks of the tabs and the first pole columns 53, or liquid hot melt glue or epoxy resin can be used for dispensing protection to protect the welding positions of the tabs and the first pole columns 53.

[0066] In addition, preferably, as Figures 1 to 6As shown, in the embodiment, after the battery cell 6 is installed in the cavity 50, the dimension between the end plates at both ends of the battery cell 6 is less than or equal to the dimension of the cavity 50. And the upper end plate 21 and the lower end plate 22 can position the battery cell 6 in the length direction of the battery cell 6 to prevent the battery cell 6 from moving in the cavity 50. More preferably, when the battery cell 6 is installed in the cavity 50, the positions of the liquid injection hole 511 and the explosion-proof valve 512 on the housing main body 51 can be made to correspond to the positions of the openings 24 on the upper end plate 21 and the lower end plate 22, so as to facilitate the circulation of the electrolyte and the discharge of gas.

[0067] Preferably, as Figure 1 , Figure 2 and Figure 7 shown, in the embodiment, the cover plate 52 is welded to the housing main body 51. Specifically, welding the cover plate 52 to the housing main body 51 may include the following steps. Welding the outer periphery of the cover plate 52 to the periphery of the opening side of the housing main body 51, and welding the middle part of the cover plate 52 to the end face of the partition plate. Preferably, the press-formed housing main body 51 is formed with an opening side for placing the battery cell 6 (that is, as Figure 2 shown, the upper side face of the housing main body 51 is formed as the opening side). The shape of the press-formed cover plate 52 may be similar to the shape of the opening side of the housing main body 51, so that the cover plate 52 can be better welded to the opening side of the housing main body 51. Specifically, as shown by the position of the welding mark 520 in Figure 7 , the outer periphery of the cover plate 52 is laser welded to the periphery of the opening side of the housing main body 51, and the middle part of the cover plate 52 is laser welded to the upper end face of the partition plate, thereby realizing the independent sealing of each battery cell 6.

[0068] Preferably, in the embodiment, the battery module assembly method further includes a liquid injection and forming process after welding the cover plate 52 to the housing main body 51. The liquid injection and forming process may include the following steps. First, inject electrolyte into the housing 5 through the liquid injection hole 511; then perform an open precharge; then seal the liquid injection hole 511; and finally perform grading on each battery cell 6. Specifically, a liquid injection device can be used to inject electrolyte into each liquid injection hole 511 of the housing 5. Then perform an open precharge, and supplement the electrolyte after the precharge. Then seal the liquid injection hole 511, and finally perform grading (calibrating the capacity) on each battery cell 6. When sealing the liquid injection hole 511, a secondary seal can be used, that is, first block the liquid injection hole 511 with a glue nail, and then weld an aluminum cover outside the liquid injection hole 511 to ensure the sealing performance of the battery module 4.

[0069] During the processing, the battery module assembly method omits the assembly process between the monomers of the battery cell 6, directly produces the battery module 4 through the battery cell 6 and the housing 5, saves manpower and eliminates the tooling required for assembling the battery cell 6 monomers, and greatly reduces the manufacturing cost.

[0070] Finally, it should be noted that the above-described embodiments are only specific implementation manners of the present application, used to illustrate the technical solutions of the present application, rather than limiting it. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any person skilled in the technical field of the present application can still modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A battery module assembly method, characterized in that: The battery module assembly method comprises the following steps: preparing battery cells; Prepare a shell, the shell includes a cover plate and a shell body, and a plurality of cavities are arranged in the shell body; the preparation of the shell includes the following steps: stamping the shell; assembling the second pole and the second plastic for insulation together, a fuse device is arranged in the middle of part of the second pole, and the fuse device is wrapped inside the second plastic; installing the first pole and the first plastic for insulation inside the shell, and installing the second pole and the second plastic outside the shell; installing the riveting column to conductively connect the first pole and the second pole; The plurality of battery cells are respectively installed in the plurality of cavities of the shell body, and the tabs of the plurality of battery cells are welded to the plurality of first poles located inside the shell, and the plurality of adjacent first poles are conductively connected through the plurality of second poles arranged outside the shell; The cover plate is welded to the shell body.

2. The battery module assembly method according to claim 1, characterized in that: The preparation of the battery cell includes the following steps: Make a pole group; Installing end plates on the positive and negative electrodes of the electrode group; Install insulation film.

3. The battery module assembly method according to claim 2, characterized in that: The production of the electrode group includes winding or stacking the electrode sheets into an electrode group, and then shaping the electrode ears.

4. The battery module assembly method according to claim 2, characterized in that: The end plate includes an upper end plate and a lower end plate that can be assembled with each other. Installing the end plate on the positive and negative electrodes of the electrode group includes assembling the upper end plate and the lower end plate and then arranging them on the positive and negative electrodes of the electrode group, and extending the electrode ears of the electrode group through the gap between the upper end plate and the lower end plate.

5. The battery module assembly method according to claim 2, characterized in that: Installing the insulating film includes covering the insulating film on the pole group, and then hot-melting welding the two ends of the insulating film to the end plate.

6. The battery module assembly method according to claim 1, characterized in that: The battery module assembly method further comprises performing glue protection or glue spot protection at the welding positions of the electrode tabs of the battery cells and the first electrode posts after welding the electrode tabs of the battery cells to the first electrode posts located inside the shell.

7. The battery module assembly method according to claim 1, characterized in that: The plurality of cavities are arranged in the shell body at intervals along the length direction, and a partition is provided between two adjacent cavities.

8. The battery module assembly method according to claim 7, characterized in that: Welding the cover plate to the shell body comprises the following steps: Welding the outer periphery of the cover plate to the periphery of the opening side of the shell body; The middle portion of the cover plate is welded to the end surface of the partition plate.

9. The battery module assembly method according to claim 1, characterized in that: The battery module assembly method further comprises a liquid injection and formation process after welding the cover plate to the shell body, and the liquid injection and formation process comprises the following steps: injecting electrolyte into the shell through the injection hole; Carry out opening pre-filling; sealing the injection hole; The capacity of each battery cell is divided.

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