Battery cell structure manufacturing method and battery cell structure

Abstract

The invention relates to a manufacturing method of a battery cell structure and the battery cell structure, the manufacturing method of the battery cell structure comprises two times of pre-welding processes, the connection strength of a tab and a switching piece is enhanced, the tab is matched with the width of a naked battery cell main body, and the tab of the naked battery cell is connected with a first pole body of a battery cell cover plate assembly through the switching piece after being pre-welded. The tab and the first pole body are respectively positioned on two adjacent sides of the naked battery cell, so that the current distribution is optimized. Besides, a pole in the battery cell cover plate assembly comprises a first pole body and a second pole body, the second pole body is divided into a main body part and an extension part, the extension part is used for connecting an external connecting piece, and a height difference exists between the top surface of the extension part and the top surface of the main body part; the design of the height difference provides the arrangement space of the connecting pieces, the volume utilization rate can be improved, and the module layout flexibility can be improved. According to the optimized manufacturing method and the battery cell structure, the reliability of the battery cell is improved, and the battery cell has a higher volume utilization rate.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method for manufacturing a battery cell structure and a battery cell structure. Background Art

[0002] Lithium-ion / sodium-ion batteries have become the core of energy storage due to their wide range of applications, such as electric vehicles, portable electronic devices and large-scale energy storage systems. This type of battery is mainly composed of core components such as positive electrode materials, negative electrode materials, diaphragms, electrolytes and shells. The packaging forms include square aluminum shells, square soft packs, cylindrical aluminum shells and cylindrical steel shells. Each form is designed for specific application scenarios, aiming to improve the battery's unit volume energy density, safety performance and cycle life.

[0003] Optimizing the battery structure is the key to improving space utilization. The assembly of the internal cells of square batteries usually adopts a winding or lamination process. The specific structure will directly determine the arrangement efficiency and space occupancy of the internal materials of the cell. The ear design, whether single-sided or double-sided, needs to ensure that the positive and negative electrodes can be effectively welded to the adapter or pole, thereby realizing the electrical connection between the cell and the external circuit. Current technological advances have improved the overall structural compactness and electrical connection efficiency of the battery to a certain extent by adjusting the pole configuration and the layout of the internal connecting plate, but the volume utilization of the cell structure still needs to be broken through.

[0004] On the basis of ensuring high performance and safety of the battery, further improving the space utilization of the battery cell, continuously optimizing the battery structure design, and enhancing the sealing performance and reliability are the current research and development focuses. In addition, with the growing market demand for electric vehicles and portable electronic devices, the performance requirements for batteries are becoming increasingly stringent. How to extend the cycle life and enhance safety while maintaining the battery volume has also become a focus in the field of battery technology. Summary of the invention

[0005] The purpose of the present application is to provide a method for manufacturing a battery cell structure and a battery cell structure, which can improve the space utilization rate of the battery cell in the module and the energy density per unit volume of the module. The purpose of the present application is achieved through the following technical solutions. The method for manufacturing the battery cell structure includes the following steps: Fold the tabs of the bare battery cell and perform the first pre-welding; Folding the tabs of the bare battery cell that has been pre-welded for the first time for the second pre-welding; Assembling the bare battery cell after the tabs are pre-welded with the aforementioned battery cell cover plate assembly; The assembly of the bare battery cell and the battery cover assembly is assembled with the battery casing.

[0006] In one of the embodiments, the assembly of the tab and the cell cover assembly specifically includes laser welding or ultrasonic welding the pre-welded tab assembly and the adapter.

[0007] In one embodiment, the first folding and the second folding are in opposite directions.

[0008] In one of the embodiments, the width of the tab assembly after secondary folding and pre-welding is less than or equal to the thickness of the bare battery cell.

[0009] In addition, the present application also provides a battery cell structure, which is obtained by the aforementioned battery cell structure manufacturing method, including a battery housing, a bare battery cell, and a battery cell cover assembly; The tabs of the negative electrode sheet and the positive electrode sheet in the bare battery cell are pre-welded together respectively; The adapter plate connects the pole in the battery cell cover plate assembly and the pre-welded pole lug.

[0010] In one of the embodiments, the pre-welded electrode tabs and the electrode posts in the cell cover assembly are respectively located on two adjacent sides of the bare cell.

[0011] In one embodiment, the pole includes a first pole body and a second pole body, the second pole body includes a main body and an extension, and a top surface of the main body and a top surface of the extension have a height difference.

[0012] In one of the embodiments, the connecting piece is connected to the extension portion of the second pole body in the battery cell cover plate assembly, and the height difference between the top surface of the extension portion and the top surface of the main body is equal to or greater than the thickness of the connecting piece.

[0013] In one of the embodiments, a liquid cooling structure is further included, and the liquid cooling structure is in thermal contact with the extension portion and the main body at the same time.

[0014] Compared with the prior art, this application has the following beneficial effects: The battery cell structure manufacturing method of the present application simplifies the manufacturing process of the battery cell and improves production efficiency through two pre-welding and precise assembly steps. The design of the second pole column allows the required function to be achieved by adjusting the structural design of the second pole column without changing other structural designs such as the first pole column in the prior art, thereby reducing manufacturing costs and complexity. The screw holes and the expanded area provided on the extension of the second pole column enable the battery cell to easily adapt to various external connection requirements, such as bus bars, connecting electrodes, and heat dissipation components, thereby improving the versatility and flexibility of the battery cell. It has advantages in improving space utilization, energy density per unit volume, heat dissipation performance, sealing and reliability, simplifying manufacturing processes, and enhancing applicability and flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a flow chart of a method for manufacturing a battery cell structure in an embodiment of the present application; Figure 2 is a schematic structural diagram of a battery cell structure according to an embodiment of the present application; Figure 3 is a schematic diagram of the cross-sectional structure of a battery cell structure at the position of the first pole column according to an embodiment of the present application; Figure 4 This is a schematic diagram of the structure of the bare battery cell after the first pre-welding in the embodiment of the present application; Figure 5 This is a schematic diagram of the structure of the bare battery cell after the second pre-welding in the embodiment of the present application; Figure 6 It is a schematic diagram of the top view of the structure of the bare battery cell after the second pre-welding in the embodiment of the present application; Figure 7 It is a schematic diagram of the structure after the bare battery cell and the battery cell cover plate assembly are assembled in the embodiment of the present application; Figure 8 is a schematic structural diagram of a battery cell module according to an embodiment of the present application; Fig. 9 It is a structural schematic diagram of a battery cell module including a cooling structure in an embodiment of the present application.

[0016] Explanation of the reference numerals: 100, cover plate; 110, battery casing; 200, first pole column; 300, second pole column; 310, main body; 320, extension portion; 321, screw hole; 400, sealing member; 410, upper plastic member; 420, sealing ring; 430, lower plastic member; 500, adapter; 600, bare cell; 610, pole ear; 700, connecting piece. DETAILED DESCRIPTION

[0017] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. It is to be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some structures related to the present application are shown in the accompanying drawings, rather than all structures. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0018] The terms "including" and "having" and any variations thereof in this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0019] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0020] As the core component of the battery system, the optimization of the structural design and manufacturing process of the battery cell is the key to improving the performance of the battery system. Figure 1 , Figure 1 It is a flow chart of the manufacturing method of the battery cell structure in the embodiment of the present application. The present application first provides a manufacturing method of the battery cell structure, including the following steps: folding the pole ear 610 of the bare battery cell 600 for the first pre-welding; folding the pole ear 610 of the bare battery cell 600 that has been pre-welded for the first time for the second time, and performing the second pre-welding; assembling the bare battery cell 600 after the pole ear 610 is pre-welded with the aforementioned battery cell cover assembly; assembling the assembly of the bare battery cell 600 and the battery cell cover assembly with the battery casing 110.

[0021] See also Figure 4 , Figure 4 It is a schematic diagram of the structure of the bare cell 600 after the first pre-welding in the embodiment of the present application. First, the tab 610 of the bare cell 600 is folded to ensure that the connection between the tab 610 and the body of the bare cell 600 is flat and tight. The folded tab 610 can be shaped to enhance the fit between the tab 610 and the body of the bare cell 600, providing a stable contact basis for subsequent welding. After the first folding of the tab 610 is completed, welding technology, such as laser welding or ultrasonic welding, is used to perform the first pre-welding of the tab 610. This step is intended to preliminarily fix the position of the tab 610, while ensuring that the electrical connection between the tabs 610 is reliable, providing a stable electrical performance basis for subsequent processes.

[0022] Please read further Figure 5 , Figure 5It is a schematic diagram of the structure of the bare cell 600 after the second pre-welding in the embodiment of the present application. After the first pre-welding is completed, the tab 610 is folded for the second time to reduce the space occupied by the tab, ensure that the multi-layer tab 610 is in full contact, and provide the best welding conditions for the second pre-welding. On the basis of the second folding and shaping, the tab 610 is pre-welded for the second time. In order to make rational use of space, the directions of the first folding and the second folding are opposite, and the width of the tab assembly after the second folding and pre-welding is less than or equal to the thickness of the bare cell, so that the tab assembly after pre-welding can be accommodated on one side of the bare cell, which is convenient for rational use of the space of the battery shell.

[0023] See also Figure 6 , Figure 6 It is a schematic diagram of the top view of the bare cell 600 after the second pre-welding in the embodiment of the present application. The first pre-welding position is at the position shown in the upper box, and the second pre-welding position is at the position shown in the lower box, wherein the area of ​​the first pre-welding position may be larger than the area of ​​the second pre-welding position. During specific welding, the welding path adopts a back-and-forth welding method in the width direction of the area, specifically adopting routing welding to form a linear track, and the tabs 610 in the corresponding area are welded together, and the area of ​​the area corresponding to the first pre-welding is larger than the area of ​​the area corresponding to the second pre-welding.

[0024] See also Figure 7 , Figure 7 It is a schematic diagram of the structure after the bare cell 600 and the cell cover assembly are assembled in the embodiment of the present application. The bare cell 600 that has undergone two pre-welding processes is precisely assembled with the aforementioned cell cover assembly. During the assembly process, positioning technology and clamping devices are used to ensure that the relative position between the cell cover assembly and the bare cell 600 is accurate, while ensuring that the electrical connection between the tab and the adapter is reliable. Finally, the assembly of the bare cell and the cell cover assembly is assembled with the battery housing 110. After the assembly is completed, the battery housing 110 is sealed and protected to ensure that the cell can maintain a stable working state in harsh environments.

[0025] The two folding and two pre-welding processes of the tabs 610 can effectively enhance the connection strength between the tabs 610 and improve the overall stability of the cell structure. The two pre-welding processes ensure the reliability and stability of the electrical connection of the tabs 610 of the cell, reduce the failure rate caused by poor connection, and the optimized cell structure manufacturing method improves the manufacturing quality of the cell, reduces the connection impedance inside the cell, and reduces the heating of the tabs.

[0026] Before the first and second pre-welding, the step of shaping the tab 610 can also be included. The shaping step makes the shape of the tab assembly after pre-welding more uniform, which can ensure the stability of the production process. After completing the assembly with the battery housing 110, the step of injecting electrolyte is also included.

[0027] Specifically, the assembly of the tab 610 and the cell cover assembly specifically includes laser welding or ultrasonic welding the pre-welded tab assembly and the adapter 500. During the assembly process, it is first necessary to accurately position and calibrate the pre-welded tab assembly and the adapter 500, and then weld the tab assembly and the adapter 500 using laser welding or ultrasonic welding technology. Laser welding uses the heat generated by a high-energy laser beam to quickly melt and fuse the contact surface of the tab assembly and the adapter 500 to form a high-strength welding structure, while ultrasonic welding uses the energy generated by ultrasonic vibrations to cause the contact surface of the tab assembly and the adapter 500 to undergo plastic deformation and metallurgical bonding at the microscopic level, thereby achieving a firm connection. Both welding technologies have the advantages of high precision, high efficiency and high reliability, and can ensure a stable and lasting electrical connection between the tab assembly and the adapter 500.

[0028] See also Figure 2 , the present application further provides a battery cell structure, including a battery housing 110, a bare battery cell 600, and a battery cell cover assembly, wherein the tabs 610 of the negative electrode sheet and the positive electrode sheet in the bare battery cell 600 are pre-welded together, and the adapter 500 connects the first pole column 200 in the battery cell cover assembly and the pre-welded tabs 610. Among them, the bare battery cell 600 is formed by processing the positive electrode sheet, the negative electrode sheet and the diaphragm through a precise stacking or winding process, and its form is flexible and diverse, and is not subject to specific restrictions. In the preparation process of the bare battery cell 600, the tabs 610 of the negative electrode sheet and the positive electrode sheet are first pre-welded together. This step ensures the reliability and stability of the electrical connection between the tabs 610. The pre-welding of the tabs 610 not only simplifies the subsequent assembly process, but also improves the overall structural strength of the battery cell, so that it can better resist the influence of external factors such as vibration and impact. The adapter 500 connects the first pole column 200 in the battery cell cover assembly and the pre-welded tabs 610.

[0029] Specifically, the pre-welded pole tab 610 and the first pole column 200 in the battery cover assembly are respectively located on two adjacent sides of the bare battery cell 600. Arranging the pole tab 610 and the first pole column 200 on two adjacent sides of the bare battery cell 600 can make full use of the area outside the pole tab 610 on the pole tab side, and the adapter 500 does not need to occupy too much space on the pole tab side. During the discharge or charging process of the battery cell, the current flows evenly from the first pole column 200 to the pole tab 610 through the adapter 500, and is then distributed and transmitted through the conductive structure inside the bare battery cell 600. The pole tabs 610 corresponding to the positive and negative poles can be set on opposite sides. This layout design helps to reduce the concentration of current and thermal effects inside the battery cell, and can improve the discharge efficiency and cycle life of the battery cell. After the pole ear 610 is welded, it will protrude relative to other positions, but the pole ear 610 only occupies a part. Assuming that the internal height of the battery cell is H and the width is W, if the pole ear is on the top, the required space height is M, then the effective area of ​​the pole piece S1=(HM)*W=HW-MW. When the pole ear 610 is arranged on both sides, the width required for the single-sided pole ear 610 is N, then the effective area of ​​the pole piece S2=H*(W-2N)=HW-2HN, the area difference is S1-S2=HW-MW-HW+2HN=2HN-MW, taking a large energy storage battery cell as an example, H=200, W=300, M≈10, N≈5 (unit: mm, H<W means short and wide battery cell), then S1-S2=2000-3000=-1000mm 2 , that is, when the tabs are arranged on both sides, the effective area is increased by 1000mm 2 , thereby increasing the proportion of the effective area of ​​the electrode piece. By optimizing the layout design and connection process of the electrode ear 610 and the first electrode column 200, the discharge efficiency, cycle life and overall performance of the battery cell can be improved. The battery cell structure proposed in the present application arranges the pre-welded electrode ear 610 and the first electrode column 200 in the battery cell cover assembly at the adjacent two sides of the bare battery cell 600, respectively, and can also expose the adapter 500 and the electrode ear 610 on the side, which is convenient for direct welding and other specific connection operations, thereby simplifying the assembly process.

[0030] The battery cell cover plate assembly of the present application specifically includes a cover plate 100 and a pole, and the pole includes a first pole column 200 and a second pole column 300. The cover plate 100 is designed with a mounting hole that runs through the entire cover plate 100. The first pole column 200 is inserted into the mounting hole to achieve electrical connection between the battery cell and the external circuit. In order to ensure the stability and safety of the connection, the second pole column 300 is arranged on the outside of the cover plate 100 and is fixedly connected to the first pole column 200 to improve the sealing performance and safety of the battery cell.

[0031] See also Figure 3 , Figure 3It is a schematic diagram of the cross-sectional structure of the battery cell structure at the pole position of an embodiment of the present application, and is a specific lead-out method of the first pole 200 under the plastic cover technical solution. The first pole 200 in the cover assembly is embedded in the plastic cover, and the two sides are respectively connected to the second pole 300 and the adapter 500, and sealed at the same time. The second pole 300 includes a main body 310 and an extension 320. The second pole 300 can be an integral structure, that is, the main body 310 and the extension 320 are as a whole, or they can be manufactured separately, for example, independent main bodies 310 and extensions 320 are made separately, and the independent main bodies 310 and extensions 320 are pressed together during assembly. Preferably, an integral structure is used. The main body 310 is used to be fixedly connected to the first pole 200. The fixed connection method includes welding, pressing, etc. The specific connection method is not specifically limited in this application. The extension portion 320 is used to connect the external connecting piece 700. The connecting piece 700 here refers to an external component used to electrically connect to the battery cell after the battery cell cover assembly is assembled to form a battery cell. It can also include other functions, such as heat transfer function, which can specifically be a bus, connecting electrodes, and heat dissipation components.

[0032] Since the second pole body 300 including the main body 310 and the extension part 320 is adopted, the external connecting piece 700 of the formed battery structure can be installed on the extension part 320, so that the components are no longer stacked at the position where the first pole body 200 is located, ensuring that the space occupied by the connecting parts is reduced on the basis of achieving efficient and stable connection through the second pole body 300, so that the area ratio of the pole piece in the bare battery cell 600 can be increased, and the pole ears 610 are arranged on both sides, which can maximize the use of the height space inside the battery cell, and after the side welding is completed, there is no need to fold the pole ears or adapters, and the width space is wasted is less, which is particularly suitable for short and wide batteries. If the positive and negative pole ears are on the top, they need to be welded first, and then the adapter and cover plate are turned over, which will cause a waste of height space, and the setting method of the present application can achieve an increase in energy density per unit volume. In addition, an explosion-proof valve is arranged on the battery housing 110 or the battery cover assembly.

[0033] See also Figure 8When forming a module, the connecting piece 700 is connected to the extension part 320 of the second pole column 300 in the cell cover plate assembly, and the height difference between the top surface of the extension part 320 and the top surface of the main body 310 is equal to or greater than the thickness of the connecting piece 700. When the cell structure is used as the basic unit, the connecting piece 700 is connected to the extension part 320 of the second pole column 300 in the cell cover plate assembly. This extension part 320 extends outward from the main body 310 of the second pole column 300, and is specially designed to have a certain height difference between its top surface and the top surface of the main body 310. When the thickness of the connecting piece 700 is less than or equal to the height difference between the extension part 320 and the main body 310, when the connecting piece 700 and the extension part 320 are attached, the top surface of the connecting piece 700 will not exceed the top surface of the main body 310, so there is no need to occupy the space at the height of the first pole column 200. This design helps to optimize the spatial layout of the battery module. By directly connecting the connecting piece 700 to the extension portion 320, the space inside the module can be more effectively utilized, reducing unnecessary space waste. Figure 8 In the technical solution, the connecting piece 700 can be a bus bar, connecting multiple battery cell structures in series to form a battery cell module.

[0034] See also Fig. 9 , Fig. 9 It is a schematic diagram of the structure of the battery cell module including the cooling structure in the embodiment of the present application, specifically, it also includes a liquid cooling structure, and the liquid cooling structure is in thermal contact with the extension portion 320 and the main body 310 at the same time. In the process of constructing the battery cell module, in addition to the battery cell structure, the connecting piece 700, and the extension portion 320 and the main body 310 of the second pole column 300 in the battery cell cover assembly, the second pole column 300 structure of the present application can better realize the assembly of the cooling structure and improve the cooling efficiency when the liquid cooling structure is applied. The liquid cooling structure can be designed to be in thermal contact with the extension portion 320 and the main body 310 of the second pole column 300 in the battery cell cover assembly at the same time, thereby realizing efficient thermal management of the battery cell module. Specifically, the liquid cooling structure can be attached to the surface of the extension part 320 and the main body 310 through a heat-conducting adhesive or a heat-conducting sheet. In particular, in the technical solution where a connecting sheet 700 has been set on the extension part 320, the liquid cooling structure can contact the first pole body 200 and the connecting sheet 700 at the same time. The setting of the heat-conducting adhesive or the heat-conducting sheet can better eliminate the height difference and ensure that the pole and the liquid cooling plate are in good contact, thereby maximizing the use of the heat conduction principle and quickly taking away the heat generated by the battery module during the charging and discharging process. Compared with the technical solution of setting the connecting sheet 700 on the first pole body 200, the technical solution of this application expands the heat conduction area and can make full use of the better thermal conductivity of metal. Since the extension part 320 and the main body 310 are the areas with higher heat in the battery module, and the heat is directly dissipated from the pole ear 610 to the pole, which belongs to the heat transfer between metal materials. Compared with the heat dissipation effect from the bare battery to the shell, the design of the liquid cooling structure can realize the cooling of key parts and ensure that the temperature rise of the battery module is lower during operation. The simultaneous thermal contact between the liquid cooling structure and the extension part 320 and the main body 310 also helps to achieve temperature balance inside the module. In the battery module, due to the uneven arrangement of the battery cells and the current distribution, the phenomenon of local temperature being too high or too low often occurs. The introduction of the liquid cooling structure can effectively reduce the temperature difference inside the module and improve the overall thermal management efficiency by quickly conducting and distributing the heat. By introducing the liquid cooling structure in the battery module and making it thermally contact with the extension part 320 and the main body 310 of the second pole 300 in the battery cover assembly at the same time, the thermal management efficiency can be improved, precise cooling and temperature balance can be achieved, thereby improving the overall performance and reliability of the battery module.

[0035] The cell structure in the present application can be formed into a cell module through the connecting sheet 700 . Due to the design and optimization of the structure of the second pole column 300 , the space of the cell module can be fully utilized.

[0036] In addition, in order to further enhance the stability and reliability of the electrical connection and effectively reduce the connection resistance to improve the energy transmission efficiency, in the technical solution of the present application, during the pre-welding process of the adapter 500 and the tab 610, the interconnected parts have highly matched geometric shapes. The contact surfaces of the adapter 500 and the tab 610 are physically matched to maximize the contact area, and are also beneficial to the positioning accuracy of the two before welding, so that a uniform and dense welding contact structure can be formed during the welding process. This matching shape design effectively avoids the problem of increased resistance caused by poor contact or uneven welds after welding, thereby ensuring smooth current transmission. By ensuring the height match between the connecting parts of the adapter 500 and the pole lug 610, the two can form a tight connection after welding. The matching shape design maximizes the contact area between the adapter 500 and the pole lug 610. Together, they significantly reduce the connection resistance, improve the energy transmission efficiency, and reduce energy loss. A good welding connection not only improves the electrical performance, but also enhances the structural strength between the adapter 500 and the pole lug 610, so that the entire battery module can maintain a more stable electrical connection state when subjected to external forces such as vibration and impact.

[0037] In addition, since the specific connection position of the external connection sheet 700 is expanded, and the first pole column 200 is connected through the main body 310, the expansion part does not need to be closely associated with the first pole column 200, which can not only maximize the use of space, but also can be adjusted through the extension part 320 to make it suitable for different scenarios such as welding and screw connection. In addition, the extension part 320 also expands the area of ​​the heat conduction part, so as to facilitate the improvement of heat dissipation efficiency. The second pole column 300 is arranged on the outside of the cover plate 100. The outside here refers to the side of the outer surface of the battery cell after the battery cell cover plate assembly is assembled to form a battery cell, which is fixedly connected to the first pole column 200. The fixed connection here refers to the whole without relative displacement between the first pole column 200, the cover plate 100 and the second pole column 300 after the installation is completed. It can be welded or screwed. The specific connection method can be selected according to needs.

[0038] On the basis that there is a height difference between the top surface of the extension portion 320 and the top surface of the main body 310, the area of ​​the extension portion 320 is larger than the area of ​​the main body 310, and the surface of the extension portion 320 can be further processed, and the surface is smoothed and a screw hole 321 is provided. The smooth surface can enable the extension portion 320 to be better connected to the connecting piece 700, including increasing the bonding force and making the contact more complete. In the technical solution of separately providing the main body 310 and the extension portion 320, only the structural design of the extension portion 320 of the second pole body 300 can be adjusted without changing the design of other structures such as the first pole body 200. In addition, in order to better realize the combination of the extension portion 320 and the cover plate 100, a receiving groove for accommodating the extension portion 320 can be provided in the cover plate 100, so that the extension portion 320 can be better fitted on the cover plate 100.

[0039] From the foregoing, it can be seen that the present application first proposes a method for manufacturing a battery cell structure and a battery cell structure. In the method for manufacturing the battery cell structure, two pre-welding processes are adopted to effectively enhance the connection strength between the pole ear and the bare battery cell body and the battery cell cover assembly. In addition, a liquid cooling structure is introduced, which is in thermal contact with the extension portion and the main body of the second pole body at the same time, thereby realizing efficient thermal management of the battery cell module, improving the thermal management efficiency, realizing precise cooling and temperature balance, and improving the overall performance and reliability of the battery cell module. In summary, the present application improves the space utilization, manufacturing quality, structural stability, and electrical connection performance of the battery cell through an optimized method for manufacturing the battery cell structure and an efficient thermal management solution.

[0040] In addition, the height difference design between the extension part and the main body of the second pole further optimizes the layout of the cell connection structure in the module. At the same time, the specific connection position of the external connection sheet is expanded, and the first pole is connected through the main body, so that the extension part and the first pole do not need to be completely corresponding, and the corresponding second pole can be selected as needed, which is suitable for different scenarios such as welding and screwing, and can maximize the expansion of the application scenarios of the battery.

[0041] The above is only a specific implementation of the present application, and any other improvements made based on the concept of the present application are deemed to be within the protection scope of the present application.

Claims

1. A method for manufacturing a battery core structure, characterized in that: The steps include: Folding the tab (610) of the bare battery cell (600) to perform the first pre-welding; Folding the tab (610) of the bare battery cell (600) that has been pre-welded for the first time for the second time, and performing pre-welding for the second time; Assembling the bare battery cell (600) after the tab (610) is pre-welded with the battery cell cover assembly; The assembly of the bare battery cell (600) and the battery cell cover plate assembly is assembled with the battery housing (110).

2. The method according to claim 1, characterized in that The assembly of the tab (610) and the cell cover assembly specifically includes laser welding or ultrasonic welding the pre-welded tab assembly and the adapter (500).

3. The method according to claim 1, characterized in that The directions of the first fold and the second fold are opposite.

4. The method according to claim 3, characterized in that The width of the tab assembly after secondary folding and pre-welding is less than or equal to the thickness of the bare battery cell.

5. A battery cell structure, obtained by the battery cell structure manufacturing method according to any one of claims 1 to 4, characterized in that: It comprises a battery housing (110), a bare battery cell (600), and a battery cell cover plate assembly; The tabs (610) of the negative electrode sheet and the positive electrode sheet in the bare battery cell (600) are pre-welded together respectively; The adapter plate (500) connects the pole in the cell cover plate assembly and the pre-welded pole lug (610).

6. The battery cell structure according to claim 5, characterized in that: The electrode tabs (610) pre-welded together and the electrode posts in the battery cell cover assembly are respectively located on two adjacent sides of the bare battery cell (600).

7. The battery cell structure according to claim 5, characterized in that: The pole comprises a first pole body (200) and a second pole body (300); the second pole body (300) comprises a main body (310) and an extension (320); a top surface of the main body (310) and a top surface of the extension (320) have a height difference.

8. The battery cell structure according to claim 7, characterized in that: The connecting piece (700) is connected to the extension part (320) of the second pole column (300) in the battery cover plate assembly, and the height difference between the top surface of the extension part (320) and the top surface of the main body (310) is equal to or greater than the thickness of the connecting piece (700).

9. The battery cell structure according to claim 7, characterized in that: It also includes a liquid cooling structure, wherein the liquid cooling structure is in thermal contact with the extension portion (320) and the main body portion (310) at the same time.

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