Assembly process of soft package battery cell and soft package battery cell

Abstract

The invention discloses an assembly process of a soft package battery cell and the soft package battery cell, relates to the technical field of assembly of the soft package battery cell, and aims to solve the problem of low yield caused by the existing assembly process of the soft package battery cell. The assembling process of the soft package battery cell comprises the following steps: S1, stacking a plurality of battery cells along the same direction to form a battery cell group, wherein a tab extends from each of two ends of each battery cell; a plurality of confluence plates are arranged in an array mode and fixed to a confluence support to form a busbar, the arrangement direction of the confluence plates corresponds to the distribution direction of the battery cells, and therefore one end of each battery cell corresponds to the corresponding confluence plate; electrically connecting the plurality of wire harnesses with the plurality of nickel sheets to form a nickel sheet-wire harness connector; s2, the busbar is horizontally placed on a welding tool, a nickel sheet-wire harness connector is arranged on each busbar plate of the busbar, and the nickel sheets and the busbar plates are welded to form a busbar assembly; and S3, arranging a confluence assembly on each of the two sides of the battery cell group with the tabs.

Description

Technical Field

[0001] The present application relates to the technical field of assembly of soft-pack battery cells, and in particular to an assembly process of soft-pack battery cells and a soft-pack battery cell. Background Art

[0002] Soft-pack batteries refer to batteries that use aluminum-plastic film as packaging material, which together with metal-shell batteries form a power battery pack. The soft-pack batteries include a busbar, a battery module and a nickel sheet. A tab extends from each end of the battery module and is fixedly connected to the busbar at the corresponding end. Then the nickel sheet is welded to the busbar to energize the battery cell.

[0003] However, the existing assembly process usually fixes the bus and the battery cell first, and then fixes the tab and the bus bar. At this time, the common module volume of the battery cell and the bus bar is large, and the nickel sheet can only be welded vertically. At this time, the nickel sheet needs to be attached to the bus bar in the horizontal direction. This welding method is more troublesome and has high requirements for tooling. The tab needs to be pressurized on the bus bar surface during bending and welding, which may also cause the bus bar bracket to tilt, resulting in an uneven surface of the bus bar, so that the nickel sheet and the bus bar are not tightly fitted during welding, and gaps appear, which will reduce the yield rate of the soft-pack battery cell after assembly. Summary of the Invention

[0004] The present application provides an assembly process for a soft-pack battery cell and a soft-pack battery cell, which are used to solve the problem of low yield rate caused by the existing assembly process for soft-pack battery cells.

[0005] The present application provides an assembly process for a soft-pack battery cell, including S1, S2 and S3.

[0006] S1: Stack multiple battery cells in the same direction to form a battery cell group, with a pole ear extending from both ends of each battery cell; arrange and fix multiple busbar arrays on a busbar bracket to form a busbar, and the arrangement direction of the multiple busbars corresponds to the distribution direction of the multiple battery cells, so that one end of each battery cell corresponds to a busbar; electrically connect multiple wiring harnesses to multiple nickel sheets respectively to form a nickel sheet-wiring harness connector.

[0007] S2: Place the busbar horizontally on a welding fixture, set a nickel sheet-wiring harness connector on each busbar board, and weld the nickel sheet to the busbar board to form a busbar assembly.

[0008] S3: A bus assembly is set on both sides of the battery cell group with tabs, and the bus bracket in the bus assembly is fixed relatively to the battery cell group. The tabs extend to the side of the bus plate away from the battery cells, and the ends of the tabs are bent and attached to the corresponding bus plate.

[0009] The battery cell group, busbar and nickel sheet-wiring harness connector in this application can be pre-assembled in step S1 respectively, and then the busbar and nickel sheet-wiring harness connector are welded in step S2, and finally the busbar and the tabs on the battery cell group are bent and welded.

[0010] When this process is used for production, when welding the busbar and the nickel sheet-wiring harness connector in step S2, the busbar can be flattened and installed on a horizontal support tooling. At this time, the busbar is an independent part with a small volume. Compared with the welding process of the nickel sheet-wiring harness connector and the busbar in the existing solution, the volume of the support tooling can be reduced and welding can be made more convenient.

[0011] In this solution, the busbar and nickel sheet-wiring harness connector welding process S2 is located before the tab and busbar connection process S3, avoiding the relative offset between the busbar and the busbar bracket caused by the pressing of the busbar when the tab and busbar are connected, avoiding the cold solder joints and welding gaps caused by the uneven surface of the busbar, improving the welding quality between the busbar and the nickel sheet, and improving the yield rate of the soft-pack battery cell.

[0012] In some embodiments of the present application, the assembly process of the soft-pack battery cell also includes S4: setting a flexible circuit board outside the battery cell group, and distinguishing the wiring harnesses on multiple nickel sheet-wiring harness connectors by positive and negative poles and connecting them to the flexible circuit board to form a soft-pack battery cell, and then performing EOL testing on the soft-pack battery cell.

[0013] After the overall assembly of the soft-pack battery cell is completed, EOL testing is performed to ensure that the circuit connection of the soft-pack battery cell is normal and to prevent defective products without power from flowing into the next process.

[0014] In some embodiments of the present application, after S2 is completed, the nickel sheets and busbars in the busbar assembly are visually inspected, and the welds are inspected. The visual inspection can ensure a certain level of weld quality between the nickel sheets and the busbars, and detect weld leaks and poor welds. Furthermore, a brute force test can be performed on the welds by sampling to verify the weld quality of the nickel sheets in that batch.

[0015] In some embodiments of the present application, the nickel sheet and the bent portion of the tab are spaced apart and distributed on the busbar surface. The bent portion and the nickel sheet are located in different areas of the busbar, so that when the bent portion is pressed onto the busbar, it does not affect the weld of the nickel sheet, thereby preventing the quality of the weld between the nickel sheet and the busbar in S2 from being affected.

[0016] In some embodiments of the present application, along the distribution direction of multiple battery cells, two adjacent tabs form a tab group, and a tab group corresponds to a busbar. The two tabs in a tab group are respectively located on the upper and lower sides of the corresponding busbar, and the two tabs in a tab group are bent in opposite directions. The two tabs in a tab group are connected to the same busbar, which can reduce the number of busbars connected to the battery cell group, thereby reducing the number of nickel sheets, facilitating the overall process difficulty and reducing production costs.

[0017] In some embodiments of the present application, the bent portions of two tabs in a tab group at least partially mate. The partial mate of the two tabs can reduce the width of the busbar while the bent portions of the tabs are fixed, and can press-fit the two tabs together, making the press-fitting effect between the tabs and the busbar more stable.

[0018] In some embodiments of the present application, the tabs located at the edge of the multiple tabs are independent tabs, and the independent tabs are correspondingly arranged with an independent busbar. This approach can facilitate the design and layout of an odd number of battery cells.

[0019] In some embodiments of the present application, the busbar also includes a connecting plate. Along the distribution direction of multiple battery cells, two adjacent busbars form a busbar group. Each busbar group is provided with a connecting plate. The connecting plate is fixedly connected to the two busbars. The nickel sheet is welded to the connecting plate, and the bent part of the pole ear is crimped onto the busbar.

[0020] The connecting plate allows a group of busbar groups to be configured with only one nickel sheet, that is, only one set of nickel sheet-wiring harness connectors is required, thereby reducing the number of nickel sheet-wiring harness connectors and improving assembly convenience; at the same time, this method can create a larger gap between the nickel sheet and the tab, reducing the possibility of mutual influence between the two.

[0021] In some embodiments of the present application, the busbars located at the edge of the multiple busbars are independent busbars, and the tabs and nickel sheets corresponding to the independent busbars are arranged at intervals on the independent busbars. Independent busbars can facilitate the arrangement and design of odd-numbered busbars.

[0022] A soft-pack battery cell includes a battery cell, a busbar, a nickel sheet, and a wiring harness. Tabs extend from both ends of the battery cell. The battery cell, busbar, nickel sheet, wiring harness, and tabs are assembled using the aforementioned soft-pack battery cell assembly process. This process achieves a higher yield rate and reduces the difficulty of assembling the nickel sheet and busbar. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0024] Figure 1 A schematic diagram of a soft-pack battery cell formed by an assembly process of a soft-pack battery cell provided in an embodiment of the present application.

[0025] Figure 2 A schematic diagram of the connection relationship between the nickel plate and the busbar formed by the assembly process of a soft-pack battery cell provided in an embodiment of the present application.

[0026] Figure 3 This is an intentional description of the positional relationship between a cell group and a busbar assembly formed by an assembly process of a soft-pack cell provided in an embodiment of the present application.

[0027] Figure 4 A schematic diagram of the positional relationship between the tabs and the busbar formed by an assembly process of a soft-pack battery cell provided in an embodiment of the present application.

[0028] Figure 5 A schematic diagram of a soft-pack battery cell provided in an embodiment of the present application.

[0029] Figure 6 A schematic diagram of the position of an independent busbar in a soft-pack battery cell provided in an embodiment of the present application.

[0030] Figure markings: 1-battery cell group; 11-battery cell; 12-electrode ear; 2-busbar; 21-busbar; 22-busbar bracket; 23-connecting plate; 24-busbar group; 25-independent busbar; 3-nickel sheet-wiring harness connector; 31-wiring harness; 32-nickel sheet; 4-busbar assembly; 5-flexible circuit board. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0032] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0033] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0034] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "connected" and "connect" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances. Furthermore, when describing pipelines, the terms "connected" and "connected" used in this application have the meaning of conducting electricity. The specific meanings need to be understood in the context.

[0035] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0036] A soft-pack battery cell refers to a battery cell that uses aluminum-plastic film as packaging material, which together with a metal shell forms a power battery pack. The soft-pack battery cell includes a busbar, a battery module and a nickel sheet. A pole ear extends from each end of the battery module and is fixedly connected to the busbar at the corresponding end. Then the nickel sheet is welded to the busbar to energize the battery cell.

[0037] However, the existing assembly process usually fixes the bus and the battery cell first, and then fixes the tab and the bus. At this time, the common module volume of the battery cell and the bus is large, and the nickel sheet can only be welded vertically. At this time, the nickel sheet needs to be attached to the bus in the horizontal direction. This welding method is more troublesome and has high requirements for tooling; the tab needs to be pressurized on the bus surface during bending welding (when the bent part of the tab is pressed onto the bus, the pressure is transferred to the bus, and the bus is installed on the battery cell, and is only supported at both ends of the bus, and there is a lack of support in the middle), which will cause the bus bracket to tilt, resulting in a partially uneven surface of the bus.

[0038] However, at this time, the busbar has been assembled with the tabs, and the overall process parts are large, so the busbar cannot be leveled. Therefore, the nickel sheet needs to be set vertically and fit horizontally on the busbar. There is a local tilt on the surface of the busbar, and the positioning tooling and pressure tooling in the horizontal direction will also have a certain amount of pressure, which will cause some of the nickel sheet and the busbar to not fit tightly when welding, and gaps will appear, which will reduce the quality of the welding between the busbar and the nickel sheet after the soft-pack battery cell is assembled, thereby affecting the overall yield of the soft-pack battery cell.

[0039] To do this, please refer to Figure 1 The present application provides a new assembly process for soft-pack battery cells, including step S1, step S2 and step S3.

[0040] Please refer to Figure 1 , S1: stack multiple battery cells 11 in the same direction to form a battery cell group 1, and a pole ear 12 extends from both ends of each battery cell 11; arrange multiple busbars 21 in an array and fix them on a busbar bracket 22 to form a busbar 2, and the arrangement direction of the multiple busbars 21 is set corresponding to the distribution direction of the multiple battery cells 11, so that one end of each battery cell 11 corresponds to a busbar 21; electrically connect multiple wiring harnesses 31 to multiple nickel sheets 32 respectively to form a nickel sheet-wiring harness connector 3.

[0041] Please refer to Figure 1 The number of battery cells 11 can be designed as needed. Multiple battery cells 11 can be stacked in the thickness direction to form an array in the height direction. In this case, a tab 12 is provided at each end of the battery cell 11 in the length direction. The tab 12 is fixedly connected to the battery cell 11 and has a plate shape. The battery cells 11 can also be arranged in multiple groups in the width direction. In this case, the battery cell group 1 can be arranged in multiple groups in the width direction, and there can be gaps between adjacent groups.

[0042] Please refer to Figure 1 A shell for fixing the battery cells 11 can be provided on the outside of the battery cell group 1 to fix the position of the battery cells 11 and avoid deformation or displacement of the battery cell group 1 with a thick array arrangement.

[0043] Please refer to Figure 1 The busbar 21 may be a metal plate with good electrical conductivity. The busbar 21 may be uniform along its thickness. The busbar bracket 22 may serve as a frame to support and fix the busbar 21. The busbar bracket 22 and the busbar 21 may be relatively fixed. The material of the busbar bracket 22 may be selected as needed, and may be a conductive material or an insulating material.

[0044] Please refer to Figure 1The bus bracket 22 may have a positioning hole, and the bus plate 21 may be installed at the predetermined positioning hole on the bus bracket 22 and fixedly connected by rivets or other connecting parts; both ends of the bus bracket 22 may also be provided with a structure for fixed connection with the battery cell group 1.

[0045] Please refer to Figure 1 The wire harness 31 and the nickel sheet 32 can be electrically connected through a conventional press-fitting process, so that one end of the wire harness 31 is electrically connected and fixedly connected to a side wall of the nickel sheet 32.

[0046] Please refer to Figure 2 , S2: Place the busbar 2 horizontally on the welding fixture, set one on each busbar plate 21 of the busbar 2, and weld the nickel sheet 32 to the busbar plate 21 to form a busbar assembly 4.

[0047] Please refer to Figure 2 The bus 2 may have a specific tooling that can completely accommodate the bus 2, and the tooling may have multiple support points to provide stable support for each bus plate 21 of the bus 2, thereby avoiding the deflection of the bus 2 caused by large differences in local support forces within the bus 2.

[0048] Please refer to Figure 2 The nickel sheet 32 in the nickel sheet-wiring harness connector 3 has two side panels, wherein the side panel on which the wiring harness 31 is not installed should be in contact with the busbar 21 on the busbar 2 .

[0049] Please refer to Figure 1 The bus assembly 4 can be the above-mentioned combination of a bus bracket 22, multiple bus plates 21 and multiple nickel sheet-wiring harness connectors 3. The combination, i.e., the bus assembly 4, is only a semi-finished product of a part of the process and is not the final product required.

[0050] Please refer to Figure 3 , S3: A bus assembly 4 is respectively arranged on both sides of the battery cell group 1 having the pole tab 12, and the bus bracket 22 in the bus assembly 4 is fixed relatively to the battery cell group 1, the pole tab 12 extends to the side of the bus plate 21 away from the battery cell 11, and the end of the pole tab 12 is bent and fitted on the corresponding bus plate 21.

[0051] Please refer to Figure 3 There are tabs 12 on both sides of the battery cell group 1. In order to ensure complete current transmission of the battery cells 11 in the battery cell group 1, the tabs 12 at both ends of the battery cell group 1 need to be press-fitted separately, that is, the tabs 12 at both ends of the battery cell group 1 are connected to the two bus assemblies 4 respectively.

[0052] Please refer to Figure 1When connecting, it is necessary to first fix the bus assembly 4 to the battery cell group 1. At this time, the tab 12 will extend along the gap reserved on the bus 2 to the outside of the bus 2, and be positioned, bent, and pressed through specific tooling (the installation process of the tab 12 belongs to the existing process, and the tooling is also conventional tooling, which will not be described here). Then, the bent part of the tab 12 is fixed to the bus 2 by welding to complete the installation of the tab 12.

[0053] Please refer to Figure 1 The battery cell group 1, busbar 2 and nickel sheet-wiring harness connector 3 in this application can be pre-assembled in step S1 respectively, and then the busbar 2 and the nickel sheet-wiring harness connector 3 are welded in step S2, and finally the busbar 2 and the tabs 12 on the battery cell group 1 are bent and welded.

[0054] Please refer to Figure 2 When this process is used for production, when welding the busbar 2 and the nickel sheet-wiring harness connector 3 in step S2, the busbar 2 can be flattened and installed on a horizontal support tooling. At this time, the busbar 2 is an independent part with a small volume. Compared with the welding process of the nickel sheet-wiring harness connector 3 and the busbar 2 in the existing solution, the volume of the supporting tooling can be reduced and welding can be made more convenient.

[0055] Please refer to Figure 1 In this solution, the welding process S2 of the busbar 2 and the nickel sheet-wiring harness connector 3 is located before the connection process S3 of the tab 12 and the busbar 2, avoiding the relative offset between the busbar 21 and the busbar bracket 22 caused by the press-fitting of the busbar 2 when the tab 12 and the busbar 2 are connected, avoiding the cold solder joints and welding gaps caused by the uneven surface of the busbar 2, improving the welding quality between the busbar 2 and the nickel sheet 32, and improving the yield rate of the soft-pack battery cell.

[0056] Please refer to Figure 2 It can be added that, since the nickel sheet 32 is horizontally welded to the bus 2, and the bus 2 is small in size, it can be supported at multiple points to ensure that when the bus 2 is subjected to greater pressure, the surface of the bus 2 is guaranteed to be flat by the tooling supporting the bus 2. That is, welding the nickel sheet 32 and the bus 2 first will not cause the bus plate 21 in the bus 2 to tilt, that is, it will not cause bumps on the surface of the bus 2, and can make the surface of the bus 2 flat when the tab 12 is welded, and the welding quality of the tab 12 will not be reduced due to the welding of the nickel sheet 32.

[0057] Please refer to Figure 1In the prior art, the process of welding the tab 12 first causes the busbar 21 on the surface of the busbar 2 to tilt slightly due to the huge pressure during the welding of the tab 12. At this time, the nickel sheet 32 is pressurized by a horizontal tool, and the welding is achieved using a specific tool. This existing specific tool cannot achieve pressure welding, resulting in empty welds or local gaps between the nickel sheet 32 and the busbar 2. Therefore, the process provided by this solution can significantly improve the yield rate of the nickel sheet 32 and the busbar 2.

[0058] Please refer to Figure 1 It can be explained that the process of the battery cell group 1, the busbar 2 and the nickel sheet-wiring harness connector 3 in step S1 can be three steps. There is no particular order for these three steps, that is, they can be carried out simultaneously or any one step can be carried out first.

[0059] Please refer to Figure 4 In some examples, the following supplements are made regarding the welding process of the tab 12 .

[0060] First, use a clamp or a positioning jig to fix the battery cell 11 and the busbar 2 to ensure that the welding positions of the tabs 12 and the busbar 2 are accurately aligned.

[0061] The tabs 12 are welded to the busbar 2 by laser welding or ultrasonic welding.

[0062] After welding is completed, check the quality of the welding points, such as the firmness of the welding points, whether the appearance is good, etc. If there are any problems, repair or rework them in time.

[0063] Please refer to Figure 1 In some examples, when the battery cell groups 1 are arranged into multiple groups and distributed along the width direction of the battery cell 11, the busbar 21 should be arranged corresponding to the battery cell group 1, that is, there can be multiple busbars 2, or the busbar 21 distributed in an array can be arranged in the same busbar 2, so as to facilitate the installation of the tab 12.

[0064] That is, the battery cells 11 in the battery cell group 1 can be arranged and distributed, or can be distributed in an array, and can be designed and laid out as needed.

[0065] Please refer to Figure 5 In some examples, the assembly process of the soft-pack battery cell also includes S4: placing the flexible circuit board 5 outside the battery cell group 1, and distinguishing the wiring harnesses 31 on the multiple nickel sheet-wiring harness connectors 3 by positive and negative poles and connecting them to the flexible circuit board 5 to form a soft-pack battery cell, and then performing EOL testing on the soft-pack battery cell.

[0066] After the overall assembly of the soft-pack battery cell is completed, EOL testing is performed to ensure that the circuit connection of the soft-pack battery cell is normal and to prevent defective products without power from flowing into the next process.

[0067] Please refer to Figure 5 In some examples, the flexible circuit board 5 is a common circuit structure in soft-pack batteries. The same soft-pack battery can have multiple semi-finished products after the S3 step. For example, the same flexible circuit board 5 can be configured with two groups of semi-finished products after the S3 step, or three groups or four groups.

[0068] The flexible circuit board 5 may have positive and negative electrodes, so that the wiring harnesses 31 on different bus assemblies 4 on the same battery cell group 1 are connected to different electrodes, thereby facilitating the transmission of electrical energy of the battery cells 11 .

[0069] EOL test is a type of electrical test. EOL, or End of Line Test, usually includes but is not limited to circuit testing, as well as sampling strength testing, appearance inspection of all finished products, etc.

[0070] Please refer to Figure 2 In some examples, after S2 is completed, the nickel sheets 32 and busbars 21 in the busbar assembly 4 are visually inspected, and the welds are inspected. The visual inspection can ensure a certain level of weld quality between the nickel sheets 32 and the busbars 21, and detect weld leaks and poor welds. Destructive shear and peel tests can also be performed on the welds by sampling to verify the weld quality of the nickel sheets 32 in that batch.

[0071] Please refer to Figure 1 and Figure 2 In some examples, the busbar 2 is difficult to repair after being installed with the battery cell group 1. Therefore, after the nickel sheet 32 and the busbar 2 are welded, an appearance inspection and a sampling strength test are performed to ensure that the busbar assembly 4 installed on the battery cell group 1 has a high yield rate, thereby improving the yield rate of the soft-pack battery after the process is completed.

[0072] In some examples, the appearance inspection includes not only the inspection of the busbar 2 , but also the inspection of the weld seam and the nickel sheet 32 .

[0073] Please refer to Figure 4 In some examples, the nickel sheet 32 and the bent portion of the tab 12 are spaced apart and distributed on the surface of the busbar 21. The bent portion and the nickel sheet 32 are located in different areas of the busbar 21. This can prevent the bent portion from affecting the weld of the nickel sheet 32 when it is press-fitted onto the busbar 21, thereby preventing the welding quality between the nickel sheet 32 and the busbar 21 in S2 from being affected.

[0074] In some examples, the nickel sheet 32 and the bent portion of the tab 12 are spaced apart to prevent the tab 12 from being welded and affecting the connection between the nickel sheet 32 and the busbar 2 in the previous step.

[0075] Please refer to Figure 4When the tab 12 is press-fitted and welded, the bent portion of the tab 12 needs to be pressed against the corresponding busbar 21 on the busbar 2. The pressure is usually more than 200N. In addition, the connection and support effect of the battery cell on the busbar 2's busbar bracket 22 are limited, which can easily cause local deflection of the busbar 21, that is, form a certain angle between the busbar 21 and the vertical direction.

[0076] At this time, the welded nickel sheet 32 will deflect along with the busbar 21 on the busbar 2. Since the wiring harness 31 is flexible, the deflection will not cause damage to the weld between the nickel sheet 32 and the busbar 2 or the nickel sheet 32. The gap between the bent part of the tab 12 and the nickel sheet 32 can also avoid direct impact on the busbar 2 when the tab 12 is pressed.

[0077] Please refer to Figure 4 In some examples, along the distribution direction of the multiple battery cells 11, two adjacent tabs 12 form a tab group. Each tab group corresponds to a busbar 21. The two tabs 12 in a tab group are located on the upper and lower sides of the corresponding busbar 21, and the two tabs 12 in a tab group are bent in opposite directions. Connecting the two tabs 12 in a tab group to the same busbar 21 can reduce the number of busbars 21 connected to the battery cell group 1, thereby reducing the number of nickel sheets 32, facilitating overall process complexity and reducing production costs.

[0078] Please refer to Figure 4 In some examples, two adjacent tabs 12 can be grouped adjacently in this direction, for example, the first tab 12 and the second tab 12 can constitute one tab group, and the third tab 12 and the fourth tab 12 can constitute another tab group.

[0079] Please refer to Figure 4 The two tabs 12 in a tab group are bent in opposite directions, and the bent portion of the lower tab 12 is bent upward, and the bent portion of the upper tab 12 is bent downward.

[0080] Please refer to Figure 4 In some examples, the bent portions of two tabs 12 in a tab group at least partially fit together. Partially fitting the two tabs 12 can reduce the width of the busbar 21 while the bent portions of the tabs 12 are fixed, and can press-fit the two tabs 12 against each other, making the press-fitting effect between the tabs 12 and the busbar 21 more stable.

[0081] In some examples, the bent portions of two tabs 12 in a tab group may only partially fit together, that is, a gap is left between the edge of one tab 12 and the unbent portion of the other tab 12 to avoid affecting the assembly effect.

[0082] In some examples, the tabs 12 located at the edge of the plurality of tabs 12 are independent tabs 12 , and the independent tabs 12 are disposed corresponding to an independent busbar 21 . This approach can facilitate the design and arrangement of an odd number of battery cells 11 .

[0083] In some examples, when the number of multiple pole tabs 12 arranged along the thickness direction of the pole tab 12 is an even number, the battery cell group 1 may not have the above-mentioned independent pole tab 12; when the number of multiple pole tabs 12 arranged along the thickness direction of the pole tab 12 is an odd number, the pole tab 12 on one side edge of the battery cell group 1 may be the above-mentioned independent pole tab 12.

[0084] Alternatively, the independent tabs 12 may also be located in the middle, and each tab 12 may be press-fitted onto a busbar 21 as needed.

[0085] Please refer to Figure 2 In some examples, the busbar 2 also includes a connecting plate 23. Along the distribution direction of the multiple battery cells 11, two adjacent busbar groups 24 form a busbar group 24. Each busbar group 24 is provided with a connecting plate 23. The connecting plate 23 is fixedly connected to the two busbars 21. The nickel sheet 32 is welded to the connecting plate 23, and the bent part of the tab 12 is crimped onto the busbar 2.

[0086] Please refer to Figure 2 The connecting plate 23 can make it necessary to configure only one nickel sheet 32 in a group of busbar groups 24, that is, only one group of nickel sheet-wiring harness connectors 3 is required, thereby reducing the number of nickel sheet-wiring harness connectors 3 and improving assembly convenience; at the same time, this method can create a larger gap between the nickel sheet 32 and the tab 12, reducing the possibility of mutual influence between the two.

[0087] In some examples, the connecting plate 23 can be welded or integrally formed with the busbar 21 connected thereto. The connecting plate 23 can be located at the end of the busbar 21, that is, the connecting plate 23 and the two busbars 21 can form a U-shaped structure.

[0088] At this time, when two busbars 2 are press-fitted onto one busbar 21 , four tabs 12 , ie, four battery cells 11 , can be configured on one busbar assembly 24 , thereby greatly reducing the number of nickel sheets 32 .

[0089] Please refer to Figure 6 In some examples, the busbars 21 at the edge of the plurality of busbars 2 are independent busbars 25, and the tabs 12 and nickel sheets 32 corresponding to the independent busbars 25 are spaced apart and arranged on the independent busbars 25. The independent busbars 25 can facilitate the arrangement and design of odd-numbered busbars 2.

[0090] Please refer to Figure 6In some examples, the independent busbar 25 may or may not be present, and may be designed accordingly based on the number of battery cells 11. When the tabs 12 can be configured on each busbar group 24 in the manner described above, and there are no excess tabs 12, the independent busbar 25 may not be present.

[0091] When there are one or two surplus tabs 12 , one independent busbar 25 may be provided; when there are three surplus tabs 12 , two independent busbars 25 are required.

[0092] Please refer to Figure 5 A soft-pack battery cell includes a battery cell 11, a busbar 2, a nickel sheet 32, and a wiring harness 31. Tabs 12 extend from both ends of the battery cell 11. The battery cell 11, busbar 2, nickel sheet 32, wiring harness 31, and tabs 12 are assembled using the aforementioned soft-pack battery cell assembly process. This process achieves a higher yield rate and reduces the difficulty of assembling the nickel sheet 32 and busbar 2.

[0093] The structure of the soft-pack battery cells is formed by the above-mentioned process, so the shape and structure of the soft-pack battery cells can be obtained by the above-mentioned process.

[0094] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0095] The above is only a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A soft-pack battery cell assembly process, characterized in that: include: S1: stacking multiple battery cells in the same direction to form a battery cell group, wherein each of the battery cells has a tab extending from both ends; Arrange and fix a plurality of busbars in an array on a busbar bracket to form a busbar, wherein the arrangement direction of the plurality of busbars corresponds to the distribution direction of the plurality of battery cells, so that one end of each battery cell corresponds to the busbar; electrically connecting the plurality of wire harnesses to the plurality of nickel sheets respectively to form a nickel sheet-wire harness connection body; S2: placing the busbar horizontally on a welding tool, arranging a nickel sheet-wiring harness connector on each busbar on the busbar, and welding the nickel sheet to the busbar to form a busbar assembly; S3: A bus assembly is respectively arranged on both sides of the battery cell group having the pole ear, and the bus bracket in the bus assembly is fixed relative to the battery cell group, the pole ear extends to the side of the bus plate away from the battery cell, and the end of the pole ear is bent and attached to the corresponding bus plate.

2. The assembly process of the soft-pack battery cell according to claim 1, characterized in that: Also includes: S4: Place the flexible circuit board outside the battery cell group, and distinguish the wiring harnesses on multiple nickel sheet-wiring harness connectors by positive and negative poles and connect them to the flexible circuit board to form a soft-pack battery cell, and then perform EOL testing on the soft-pack battery cell.

3. The assembly process of the soft-pack battery cell according to claim 1, characterized in that: After S2 is completed, the nickel sheet and the busbar in the busbar assembly are visually inspected, and the welds are inspected.

4. The assembly process of the soft-pack battery cell according to claim 1, characterized in that: The nickel sheets and the bent portions of the tabs are spaced apart and distributed on the surface of the busbar.

5. The assembly process of the soft-pack battery cell according to any one of claims 1 to 4, characterized in that: Along the distribution direction of the multiple battery cells, two adjacent pole ears form a pole ear group, a group of pole ears corresponds to one busbar, the two pole ears in a group of pole ears are respectively located on the upper and lower sides of the corresponding busbar, and the two pole ears in a group of pole ears are bent in opposite directions.

6. The assembly process of the soft-pack battery cell according to claim 5, characterized in that: The bent portions of two of the tabs in a group of the tabs are at least partially in contact with each other.

7. The assembly process of the soft-pack battery cell according to claim 5, characterized in that: The pole lugs located at the edge of the plurality of pole lugs are independent pole lugs, and the independent pole lugs are correspondingly arranged with an independent busbar.

8. The assembly process of the soft-pack battery cell according to any one of claims 1 to 4, characterized in that: The busbar further includes a connecting plate. Along the distribution direction of the plurality of battery cells, two adjacent busbars form a busbar group. Each busbar group is provided with a connecting plate, and the connecting plate is fixedly connected to the two busbars. The nickel sheet is welded to the connecting plate, and the bent portion of the tab is pressed onto the busbar.

9. The assembly process of the soft-pack battery cell according to claim 8, characterized in that: The busbars located at the edge of the plurality of busbars are independent busbars, and the tabs and nickel sheets corresponding to the independent busbars are arranged on the independent busbars at intervals.

10. A soft-pack battery cell, characterized in that: include: A battery cell, a busbar, a nickel sheet, and a wiring harness, wherein tabs extend from both ends of the battery cell, and the battery cell, the busbar, the nickel sheet, the wiring harness, and the tabs are assembled and formed using the assembly process of the soft-pack battery cell according to any one of claims 1 to 9.

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