Bare cell, bare cell production device, and battery production line

Abstract

The present application relates to the technical field of battery production devices, and discloses a bare cell (200), a bare cell production device, and a battery production line. The bare cell production device comprises a screening mechanism (30); the screening mechanism (30) comprises a screening structure (32), a first discharge port (33), and a second discharge port (34); the screening structure (32) is used for measuring and determining whether a weight parameter of the bare cell (200) meets the standard; when the weight parameter of the bare cell (200) meets the standard, the bare cell (200) is outputted to the first discharge port (33); and when the weight parameter of the bare cell (200) meets the standard, the bare cell (200) is outputted to the second discharge port (34). The application of the present technical solution comprises, but is not limited to, solving the problem of poor battery capacity consistency among battery cells formed by assembling different bare cells from a batch of bare cells of the same model.

Description

A bare battery cell, bare battery cell production equipment and battery production line

[0001] This application claims priority to Chinese Patent Application No. 202422692311.0, filed on November 5, 2024, entitled "A Bare Battery Cell, Bare Battery Cell Production Equipment and Battery Production Line", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery production equipment technology, specifically to a bare battery cell, bare battery cell production equipment, and battery production line. Background Technology

[0003] Currently, the production process of bare battery cells in related technologies mainly focuses on how to precisely adjust the misalignment of the cathode tabs of the cathode sheet and the anode tabs of the anode sheet to achieve precise die-cutting of the cathode and anode sheets, thereby adjusting the accuracy of winding—that is, how to achieve good and accurate winding and forming of bare battery cells. However, the production process of bare battery cells in related technologies neglects the quality control of the consistency of cell performance, especially the quality control of the consistency of battery capacity of the assembled battery cells. This results in differences in battery capacity between different bare cells of the same model in a batch, with the difference exceeding the design tolerance range. Summary of the Invention

[0004] The purpose of this application is to provide a bare cell, bare cell production equipment, and battery production line, including but not limited to solving the problem of poor battery capacity consistency between battery cells assembled from different bare cells of the same model in a batch.

[0005] The technical solution adopted in the embodiments of this application is:

[0006] According to a first aspect of this application, a bare battery cell manufacturing apparatus is provided, comprising:

[0007] The screening mechanism includes a screening structure, a first discharge port, and a second discharge port. The screening structure is used to detect and determine whether the weight parameters of the bare battery cell are qualified. When the weight parameters of the bare battery cell are qualified, the bare battery cell is output to the first discharge port. When the weight parameters of the bare battery cell are unqualified, the bare battery cell is output to the second discharge port.

[0008] The bare cell production equipment provided in this application is used for the production and manufacturing of bare cells, and the produced bare cells are then used to assemble battery cells. The bare cells are inspected by a screening mechanism to determine whether their weight parameters are qualified. Bare cells with qualified weight parameters are then selected, and a batch of bare cells with qualified weight parameters are finally output from the first discharge port. Bare cells with unqualified weight parameters are output from the second discharge port and recycled. This process produces a batch of bare cells of the same model with high consistency in weight parameters, and these bare cells are then used to assemble battery cells, resulting in high consistency in the battery capacity of these battery cells.

[0009] In some embodiments of this application, the screening structure includes a control device, a weighing device, a first conveying device, and a second conveying device. The control device is electrically connected to the weighing device, the first conveying device, and the second conveying device. The weighing device is used to detect the weight parameters of the bare cells. The first conveying device is configured to correspond to the first discharge port to transport bare cells with qualified weight parameters to the first discharge port. The second conveying device is configured to correspond to the second discharge port to transport bare cells with unqualified weight parameters to the second discharge port. Based on the relationship between the weight parameters of the bare cells and the battery capacity of the battery cells assembled using these bare cells, the wound bare cells can be distinguished, thereby ultimately obtaining a batch of bare cells of the same model with high consistency in weight parameters. This improves the consistency of the battery capacity of the battery cells assembled using these bare cells and improves the quality of the battery cells.

[0010] In some embodiments of this application, the bare battery cell production equipment further includes a die-cutting mechanism and a feedback system. The die-cutting mechanism is used to die-cut the material strip into electrode sheets. The die-cutting mechanism includes a cutting device. The feedback system is electrically connected to both the control device and the cutting device. The material strip is input from the feed port of the die-cutting mechanism. In the bare battery cell production equipment, the material strip undergoes a die-cutting process by the die-cutting mechanism, a winding process by the winding mechanism, and a screening process by the screening mechanism, and is then wound into bare battery cells. The feedback system uses the current weighing result of the bare battery cell as reference data to control the cutting device to adjust the weight of the next bare battery cell to be wound, that is, to adjust the weight parameters of the next bare battery cell, thereby reducing the number of bare battery cells with unqualified weight parameters and improving the yield rate of bare battery cells.

[0011] In some embodiments of this application, the bare cell production equipment further includes a winding mechanism and a shaping mechanism. The winding mechanism is used to wind electrode sheets into bare cells, and the screening mechanism includes a screening inlet connected to the discharge port of the winding mechanism. The shaping mechanism is located between the winding mechanism and the screening mechanism. The winding bare cells are clamped and shaped by the shaping structure, thereby ensuring that all bare cells meet the density requirements.

[0012] In some embodiments of this application, the bare cell production equipment further includes a shaping mechanism located downstream of the first discharge port, thereby enabling the bare cells with qualified weight parameters to meet the density requirements.

[0013] In some embodiments of this application, the shaping mechanism includes a hot pressing device, which includes a shaping pressure plate and a heating structure, with the heating structure disposed on the shaping pressure plate. The hot pressing device integrates the two steps of heating the bare battery cell and clamping and shaping the bare battery cell into one process, reducing the structural composition of the bare battery cell production equipment and thus reducing the overall size of the integrated bare battery cell production machine, which is beneficial for reducing the footprint of the bare battery cell production equipment.

[0014] In some embodiments of this application, the shaping mechanism includes a tunnel furnace and a cold press arranged in sequence. The tunnel furnace is used to heat the bare battery cells, which helps to control the degree of heating of the bare battery cells and prevents overheating of the bare battery cells. The cold press includes a shaping plate, which clamps and shapes the bare battery cells output from the tunnel furnace. During the clamping and shaping process, some heat from the bare battery cells is absorbed, which helps to shorten the cooling time of the bare battery cells after pressure shaping.

[0015] In some embodiments of this application, the shaping mechanism includes a heating power supply and a cold press. The positive and negative terminals of the heating power supply are electrically connected to two cathode tabs and / or two anode tabs of the bare battery cell, respectively. The cold press includes a shaping plate that clamps and shapes the heated bare battery cell. This results in the bare battery cell being heated rapidly and uniformly, leading to higher heating efficiency, higher energy utilization, and better heating uniformity.

[0016] According to a second aspect of the embodiments of this application, a bare battery cell is provided, wherein the bare battery cell is a bare battery cell manufactured using the bare battery cell manufacturing equipment as described above.

[0017] According to a third aspect of the embodiments of this application, a battery production line is provided. This battery production line includes the bare cell production equipment described above. Using this bare cell production equipment to manufacture bare cells helps to improve the overall production efficiency of battery manufacturing. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or exemplary technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 is a top view of the cathode sheet according to an embodiment of this application;

[0020] Figure 2 is a cross-sectional view along the AA direction in Figure 1;

[0021] Figure 3 is a top view of a bare battery cell according to an embodiment of this application;

[0022] Figure 4 is a structural block diagram of a bare battery cell production equipment according to an embodiment of this application;

[0023] Figure 5 is a structural block diagram of another bare cell production equipment according to an embodiment of this application;

[0024] Figure 6 is a structural block diagram of another bare cell production equipment according to an embodiment of this application;

[0025] Figure 7 is a structural block diagram of another bare cell production equipment according to an embodiment of this application;

[0026] Figure 8 is a structural schematic diagram of a shaping mechanism of a bare battery cell production equipment according to an embodiment of this application, wherein the shaping mechanism includes a hot pressing device.

[0027] Figure 9 is a schematic diagram of another shaping mechanism of the bare cell production equipment according to an embodiment of this application, which clamps and shapes the bare cell. The shaping mechanism includes a tunnel furnace and a cold press.

[0028] Figure 10 is a logic block diagram of a method for preparing a bare battery cell according to an embodiment of this application;

[0029] Figure 11 is a logic block diagram of another method for preparing a bare battery cell according to an embodiment of this application;

[0030] Figure 12 is a logic block diagram of another method for preparing a bare battery cell according to an embodiment of this application;

[0031] Figure 13 is a logic block diagram of another method for preparing a bare battery cell according to an embodiment of this application.

[0032] The figures are labeled as follows: 10. Die-cutting mechanism; 11. Feed inlet; 12. Die-cutting unit; 121. Cutting device; 13. Die-cutting outlet; 20. Winding mechanism; 21. Winding inlet; 22. Winding unit; 23. Winding outlet; 30. Screening mechanism; 31. Screening inlet; 32. Screening structure; 321. Control device; 322. Weighing device; 323. First conveying device; 324. Second conveying device; 33. First outlet; 34. Second outlet; 40. Feedback system; 50. Shaping mechanism; 51. Hot pressing device; 52. Shaping platen; 521. First platen; 522. Second platen; 53. Heating structure; 54. Tunnel furnace; 55. Cold press. 100, Electrode; 110, Cathode plate; 120, Anode plate; 130, Cathode tab; 140, Anode tab; 150, Cathode active material; 160, Electrode substrate; 200, Bare cell; 301, First diaphragm; 302, Second diaphragm. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the scope of this application.

[0034] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly or indirectly attached to that other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to that other component. The terms "upper," "lower," "left," "right," etc., indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, and are for ease of description only, not to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. 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 technical features. "A plurality" means two or more, unless otherwise explicitly defined.

[0035] Currently, judging from market trends, the application of power batteries (including but not limited to lithium batteries and sodium batteries) is becoming increasingly widespread. Power batteries are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also widely applied in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in police equipment, military equipment, and aerospace. With the continuous expansion of power battery applications, market demand is also constantly increasing. Furthermore, users' quality requirements for power batteries are constantly rising, and battery quality is reflected in many aspects, including but not limited to long service life, high safety, and strong energy storage capacity.

[0036] Regarding the energy storage and range capabilities of power batteries, users often focus on battery capacity, a crucial reference data point. The smallest complete unit in a power battery that outputs electrical energy is the battery cell, and the capacity of a battery cell is closely related to the weight of the bare cell. However, current bare cell production processes neglect quality control to ensure the consistency of cell performance, especially the consistency of battery capacity after the bare cells are assembled into battery cells. This results in differences in battery capacity between different bare cells within a batch of the same model, exceeding the design tolerance range, indicating poor battery capacity consistency among battery cells.

[0037] Based on the above considerations, in order to solve the problem of poor battery capacity consistency among different bare cells of the same model in batch production of bare cells, embodiments of this application provide a bare cell production equipment, and apply this bare cell production equipment to manufacture bare cells on a battery production line. In this equipment, the wound bare cells are inspected by a screening mechanism to determine whether their weight parameters are qualified, and then bare cells with qualified weight parameters are screened out, resulting in a batch of bare cells of the same model with high weight parameter consistency. Bare cells with unqualified weight parameters are output from a second outlet and recycled. Correspondingly, embodiments of this application also provide a method for preparing bare cells to improve the consistency of bare cell weight parameters, and apply the manufactured bare cells to the assembly of battery cells, thereby improving the consistency of battery capacity of the battery cells.

[0038] To illustrate the technical solutions provided in this application, the following detailed description is provided in conjunction with specific drawings and embodiments.

[0039] According to a first aspect of the embodiments of this application, a bare battery cell production apparatus is provided. As shown in FIG4, the bare battery cell production apparatus includes a die-cutting mechanism 10, a winding mechanism 20, and a screening mechanism 30. The die-cutting mechanism 10 includes an inlet 11, a die-cutting unit 12, and a die-cutting outlet 13. The die-cutting unit 12 is used to die-cut the strip input from the inlet 11 into an electrode sheet 100. The electrode sheet 100 is output from the die-cutting outlet 13 and conveyed to the winding mechanism 20. The winding mechanism 20 includes a winding inlet 21, a winding unit 22, and a winding outlet 23. The winding inlet 21 is connected to the die-cutting outlet 13. The winding unit 22 is used to wind the electrode sheet 100 into a bare battery cell 200. The bare battery cell 200 is output from the winding outlet 23 and conveyed to the screening mechanism 30. The screening mechanism 30 includes a screening inlet 31, a screening structure 32, a first outlet 33, and a second outlet 34. The screening inlet 31 is connected to the winding outlet 23. The screening structure 32 is used to detect and determine whether the weight parameters of the bare battery cell 200 are qualified. When the weight parameters of the bare battery cell 200 are qualified, the bare battery cell 200 is output to the first outlet 33. When the weight parameters of the bare battery cell 200 are unqualified, the bare battery cell 200 is output to the second outlet 34.

[0040] The bare cell production equipment provided in this application is used to manufacture bare cells 200, and the produced bare cells 200 are used to assemble battery cells. A material strip is input from the feed port 11 of the die-cutting mechanism 10. The strip undergoes a die-cutting process by the die-cutting mechanism 10, a winding process by the winding mechanism 20, and a screening process by the screening mechanism 30 in the bare cell production equipment. The screened bare cells 200 are inspected by the screening mechanism 30 to determine whether their weight parameters are qualified. Bare cells 200 with qualified weight parameters are then screened out, and finally, a batch of bare cells 200 with qualified weight parameters are output from the first discharge port 33. Bare cells 200 with unqualified weight parameters are output from the second discharge port 34 and recycled. In this way, a batch of bare cells 200 of the same model with high consistency in weight parameters is produced, and these bare cells 200 are used to assemble battery cells, thereby ensuring that the battery cells have a consistently high battery capacity.

[0041] in:

[0042] The die-cutting process refers to cutting the strip into tabs to form tabs. Specifically, the cathode strip is cut into cathode tabs 130 to form cathode sheet 110, and the anode strip is cut into anode tabs 140 to form anode sheet 120.

[0043] The winding process refers to winding the electrode 100 (including the cathode 110 and the anode 120) and the separator (including the first separator 301 and the second separator 302) into a bare battery cell 200. At this time, the bare battery cell 200 is a semi-finished product.

[0044] The screening process refers to detecting and judging whether the weight parameters of the wound bare cells 200 are qualified, thereby screening out the bare cells 200 with qualified weight parameters.

[0045] As shown in Figures 3 and 8, the bare battery cell 200 is formed by sequentially stacking and winding a first separator 301, a cathode plate 110, a second separator 302, and an anode plate 120. As shown in Figures 1 and 2, the cathode plate 110 has a cathode active material 150 coated on its electrode substrate 160, and similarly, the anode plate 120 has an anode active material coated on its electrode substrate 160.

[0046] When bare cells 200 are assembled into a single battery cell, the actual battery capacity of the single cell depends largely on the amount of cathode active material 150 on the cathode plate 110 and the amount of anode active material on the anode plate 120. Therefore, the battery capacity of the single cell also depends largely on the weight of the bare cells 200. Generally, the cathode active material 150 is considered to be uniformly coated on the electrode substrate 160 of the cathode plate 110, and the anode active material is considered to be uniformly coated on the electrode substrate 160 of the anode plate 120.

[0047] The weight of the bare cell 200 comes from the sum of the weights of the cathode plate 110, cathode active material 150, anode plate 120, anode active material, first separator 301, and second separator 302. The weights of the first separator 301 and second separator 302 are relatively small and their impact on the total weight of the wound bare cell 200 is negligible. The two main factors affecting the weight of the wound bare cell 200 are the areas of the cathode plate 110 and anode plate 120, and the coating weights of the cathode active material 150 and anode active material. For a given model of bare cell, the electrode width error is also minimal; consequently, the lengths of the cathode plate 110 and anode plate 120 are essentially constant. Under varying conditions (within a batch of bare cells 200 of the same model, there may be length differences of a few millimeters to tens of millimeters between the cathode plates 110 and / or anode plates 120 of different bare cells 200; however, the proportion of the electrode substrate 160 in the weight differences caused by these length differences is relatively small, and the main source of the weight differences is the cathode active material 150 and / or anode active material in these length differences), the weight difference of the wound bare cell 200 originates from the difference in the coating weight of the cathode active material 150 on the electrode substrate 160 of the cathode plate 110 and the anode active material on the electrode substrate 160 of the anode plate 120 (affecting the weight parameters). Therefore, adjusting the length of the cathode plate 110 is equivalent to proportionally adjusting the weight of the cathode active material 150 on the electrode substrate 160 of the cathode plate 110, and adjusting the length of the anode plate 120 is equivalent to proportionally adjusting the weight of the anode active material on the electrode substrate 160 of the anode plate 120, ultimately equivalent to proportionally adjusting the weight of the bare cell 200.

[0048] Based on the relationship between the weight of the bare cell 200 and the battery capacity of the battery cell assembled using the bare cell 200, in some embodiments of this application, as shown in FIG5, the screening structure 32 includes a weighing device 322. The weighing device 322 weighs the wound bare cell 200, thereby determining whether the weight parameter of the bare cell 200 is qualified based on the weight of the bare cell 200. As shown in FIG5, the screening structure 32 also includes a control device 321, a first conveying device 323, and a second conveying device 324. The control device 321 is electrically connected to the weighing device 322, the first conveying device 323, and the second conveying device 324. Thus, when the weighing device 322 weighs the bare battery cell 200 to obtain its weight, it sends a weighing result signal to the control device 321. Then, the control device 321 controls the activation of either the first conveying device 323 or the second conveying device 324 based on the received weighing result signal. The first conveying device 323 is correspondingly configured with respect to the first discharge port 33, and the second conveying device 324 is correspondingly configured with respect to the second discharge port 34. When the weighing result signal received by the control device 321 indicates that the weight parameter of the bare battery cell 200 is acceptable, the control device 321 controls the first conveying device 323 to transport the bare battery cell 200 with acceptable weight parameters to the first discharge port 33; when the weighing result signal received by the control device 321 indicates that the weight parameter of the bare battery cell 200 is unacceptable, the control device 321 controls the second conveying device 324 to transport the bare battery cell 200 with unacceptable weight parameters to the second discharge port 34. In this way, the bare cells 200 output from the winding outlet 23 of the winding mechanism 20 are detected by the screening mechanism 30 to determine whether the weight parameters of the bare cells 200 are qualified. Then, the control device 321 controls the start of the first conveying device 323 to output the bare cells 200 with qualified weight parameters from the first outlet 33, or controls the start of the second conveying device 324 to output the bare cells 200 with unqualified weight parameters from the second outlet 34. This achieves the differentiation of the wound bare cells 200, thereby finally obtaining a batch of bare cells 200 of the same model with high consistency in weight parameters. This improves the consistency of battery capacity of battery cells assembled using these bare cells 200 and improves the quality of battery cells.

[0049] Although the cathode active material 150 is considered to be uniformly coated on the electrode substrate 160 of the cathode sheet 110, and the anode active material is considered to be uniformly coated on the electrode substrate 160 of the anode sheet 120, in reality, the cathode active material 150 coated on the electrode substrate 160 of the cathode sheet 110 and the anode active material coated on the electrode substrate 160 of the anode sheet 120 are both unevenly coated along the coating direction. Therefore, if the lengths of the cathode sheet 110 and anode sheet 120 of different bare cells 200 of the same model remain constant, the weight of the different bare cells 200 will always fluctuate, meaning the weight parameters of the different bare cells 200 will always fluctuate. To reduce the number of bare cells 200 with unqualified weight parameters and improve the yield rate of bare cells 200, as shown in Figures 4 to 7 and Figure 9, in some embodiments of this application, the bare cell production equipment further includes a feedback system 40, and the die-cutting unit 12 includes a cutting device 121. The feedback system 40 is electrically connected to the control device 321 and the cutting device 121. Thus, when the control device 321 receives the weighing result signal sent by the weighing device 322, the control device 321 simultaneously controls the start of the first conveying device 323 or the second conveying device 324 and forwards the weighing result signal to the feedback system 40. Furthermore, upon receiving the weighing result signal, the feedback system 40 compares and calculates the weighing result signal with the design data of the bare cells 200 preset in the feedback system 40, and then calculates the required new length of the cathode sheet 110 and / or the anode sheet 120. Then, the feedback system 40 controls the cutting device 121 to adjust the cutting length of the cathode plate 110 and / or the anode plate 120, that is, to adjust the weight of the next wound bare cell 200, that is, to adjust the weight parameter of the next bare cell 200, thereby reducing the number of bare cells 200 with unqualified weight parameters and improving the yield of bare cells 200.

[0050] The "design data of the bare cell 200 preset in the feedback system" includes, but is not limited to: the overall weight range of the bare cell 200, the length range of the cathode plate 110, and the length range of the anode plate 120.

[0051] The winding unit 22 winds the die-cut electrode sheets 100 into bare battery cells 200. Although the bare battery cell 200 is initially formed, its interior is still loose, and its shape and outline are not fixed. That is, the cathode sheet 110, anode sheet 120, first separator 301, and second separator 302 stacked inside the bare battery cell 200 are not dense. At this time, the volume of the bare battery cell 200 is relatively large. Furthermore, the relative positions of the cathode sheet 110 and anode sheet 120 in the bare battery cell 200 are prone to slippage and are not easy to assemble correctly into the battery casing, making it unsuitable for direct use in battery production. To achieve the required density, the wound bare battery cell 200 needs to be clamped and shaped. The bare battery cell production equipment also includes a shaping mechanism 50, which clamps and shapes the wound bare battery cell 200 to achieve the required density.

[0052] In some embodiments of this application, as shown in FIG6, the shaping mechanism 50 of the bare cell production equipment is disposed between the winding mechanism 20 and the screening mechanism 30. In this embodiment, after the wound bare cells 200 are output from the winding outlet 23 and before the bare cells 200 are conveyed into the screening mechanism 30 from the screening inlet 31, the shaping mechanism 50 clamps and shapes all the wound bare cells 200 to achieve the required density. All the clamped and shaped bare cells 200 are then sequentially conveyed into the screening mechanism 30 for screening, thereby obtaining a batch of bare cells 200 of the same model with high consistency in weight parameters.

[0053] In some other embodiments of this application, as shown in FIG7, the shaping mechanism 50 of the bare cell production equipment is located downstream of the first discharge port 33. In this embodiment, after the wound bare cells 200 are detected and determined to be qualified in terms of weight parameters and are output from the first discharge port 33, bare cells 200 with high consistency in weight parameters are then clamped and shaped by the shaping mechanism 50 to achieve the required density. For bare cells 200 whose weight parameters are determined to be unqualified from the second discharge port 34, clamping and shaping are not required, and these unqualified bare cells 200 are directly recycled.

[0054] The bare cell production equipment employs a hot-pressing forming process to clamp and shape the coiled, fluffy bare cell 200. The hot-pressing forming process includes, but is not limited to: heating the fluffy bare cell structure in a preheated tunnel furnace, then transferring the heated bare cell structure to a pressure plate for clamping and shaping; or, heating the pressure plate to a high temperature, transferring heat to the fluffy bare cell structure through the pressure plate to heat the bare cell structure, and then applying pressure to clamp the heated bare cell structure to achieve hot-pressing forming.

[0055] As shown in Figure 8, in some embodiments of this application, the shaping mechanism 50 includes a hot pressing device 51, which performs one-stop hot pressing shaping on the fluffy bare battery cell 200. The hot pressing device 51 includes a shaping pressure plate 52 and a heating structure 53. The heating structure 53 is disposed on the shaping pressure plate 52. As shown in Figure 8, the shaping pressure plate 52 includes a first pressure plate 521 and a second pressure plate 522, which are arranged vertically at intervals. Both the first pressure plate 521 and the second pressure plate 522 are provided with the heating structure 53. That is, in the hot pressing device 51, the shaping pressure plate 52 first contacts the bare battery cell 200 without applying pressure. The shaping pressure plate 52, heated by the heating structure 53, transfers heat to the bare battery cell 200, thereby heating the bare battery cell 200. Then, the shaping pressure plate 52 applies pressure to clamp and shape the heated bare battery cell 200. The hot pressing device 51 used in this embodiment integrates the two steps of heating the bare battery cell 200 and clamping and shaping the bare battery cell 200 into one, reducing the composition structure of the bare battery cell production equipment and reducing the overall volume of the bare battery cell production integrated machine. This helps to reduce the footprint of the bare battery cell production equipment, thereby freeing up effective space in the production workshop and improving the effective utilization rate of the production workshop space.

[0056] As shown in Figure 9, in some embodiments of this application, the shaping mechanism 50 includes a tunnel furnace 54 and a cold press 55 arranged in sequence. The tunnel furnace 54 is used to heat the bare battery cell 200, and the cold press 55 includes a shaping plate 52, which clamps and shapes the bare battery cell 200 output from the tunnel furnace 54. In this embodiment, the fluffy bare battery cell 200 is first heated by the tunnel furnace 54, and then the heated fluffy bare battery cell 200 is clamped and shaped by the cold press 55. That is, the two steps of heating the bare battery cell 200 and clamping and shaping the bare battery cell 200 are performed separately. The tunnel furnace 54 heats the bare battery cell 200, which helps to control the degree of heating of the bare battery cell 200, prevents overheating of the bare battery cell 200, and protects the integrity of the bare battery cell 200. The shaping plate 52 is specifically used to clamp and shape the heated bare battery cell 200, and absorbs some of the heat of the bare battery cell 200 during the clamping and shaping process, which helps to shorten the cooling time of the bare battery cell 200 after pressure shaping.

[0057] In other embodiments of this application, the shaping mechanism 50 includes a heating power supply (not shown) and a cold press 55. It utilizes the ohmic heat generated by the bare battery cell 200 itself when energized to heat itself, and then the cold press 55 clamps and shapes the heated bare battery cell 200. During the clamping and shaping of the fluffy bare battery cell 200, the positive and negative terminals of the heating power supply are electrically connected to two cathode tabs 130 of the cathode plate 110 of the bare battery cell 200 and / or two anode tabs 140 of the anode plate 120 of the bare battery cell 200, respectively, thereby heating the bare battery cell 200 itself. Then, the shaping plate 52 of the cold press 55 clamps and shapes the heated bare battery cell 200. One approach is to electrically connect the cathode tab 130 to the heating power source, thereby generating ohmic heat in the cathode plate 110 when current flows through it. Since the cathode plate 110, the diaphragm (including the first diaphragm 301 and the second diaphragm 302), and the anode plate 120 are in close contact with each other in the bare cell 200, the ohmic heat generated by the cathode plate 110 can quickly transfer heat to the diaphragm and the anode plate 120, thus rapidly and uniformly heating the entire bare cell 200 with high energy utilization. Alternatively, one approach is to electrically connect the anode tab 140 to the heating power source, thereby generating ohmic heat in the anode plate 120 when current flows through it. Since the cathode plate 110, the diaphragm, and the anode plate 120 are in close contact with each other in the bare cell 200, the ohmic heat generated by the anode plate 120 can quickly transfer heat to the diaphragm and the cathode plate 110, thus rapidly and uniformly heating the entire bare cell 200 with high energy utilization. Alternatively, both the cathode tab 130 and the anode tab 140 can be electrically connected to the heating power supply. In this case, both the cathode plate 110 and the anode plate 120 will generate ohmic heat due to overcurrent, thereby allowing the bare cell 200 to be heated rapidly and evenly as a whole. This results in higher heating efficiency, relatively higher energy utilization, and better heating uniformity.

[0058] "Overcurrent generation of ohmic heat in cathode plate 110" and "overcurrent generation of ohmic heat in anode plate 120" refer to the fact that cathode plate 110 and anode plate 120 themselves have ohmic resistance. Cathode plate 110 and anode plate 120 can be used as resistive heating devices. By electrically connecting cathode plate 110 to the positive and negative terminals of the heating power supply to form a circuit, and by electrically connecting anode plate 120 to the positive and negative terminals of the heating power supply to form another circuit, when a circuit current is generated, the current flows through cathode plate 110 and anode plate 120, and ohmic heat is generated in cathode plate 110 and anode plate 120.

[0059] Ohmic heat: According to Ohm's law, when an electric current flows through a conductor, heat is generated within the conductor due to its resistance. Ohmic heat, or the heat generated in a conductor, is directly proportional to the conductor's resistance, the intensity of the current, and the time the current flows. The formula is: Q = I²Rt, where Q represents the heat generated (in joules), I represents the intensity of the current (in amperes), R represents the resistance of the conductor (in ohms), and t represents the time the current flows (in seconds).

[0060] According to a second aspect of the embodiments of this application, a bare battery cell is provided. The bare battery cell is manufactured using the bare battery cell manufacturing equipment described above.

[0061] According to a third aspect of the embodiments of this application, a battery production line is provided. The battery production line includes the bare cell production equipment as described above.

[0062] In this battery production line, bare cell 200 is manufactured using the bare cell production equipment provided in the embodiments of this application, and the produced bare cell 200 is used to assemble and form battery cells. A strip is input from the feed port 11 of the die-cutting mechanism 10. The strip undergoes a die-cutting process by the die-cutting mechanism 10, a winding process by the winding mechanism 20, and a screening process by the screening mechanism 30 in the bare cell production equipment. The wound bare cell 200 is detected by the screening mechanism 30, which determines whether the weight parameters of the bare cell 200 are qualified. Bare cells 200 with qualified weight parameters are then screened out, and finally, a batch of bare cells 200 with qualified weight parameters are output from the first discharge port 33. Bare cells 200 with unqualified weight parameters are output from the second discharge port 34 and recycled. This allows for the production of a large batch of bare cells 200 of the same model with high consistency in weight parameters, improving the production efficiency of bare cells 200. These bare cells 200 are then used to assemble battery cells, resulting in a consistent and high battery capacity for these battery cells.

[0063] According to a fourth aspect of the embodiments of this application, a method for preparing a bare battery cell is provided. As shown in FIG10, the method for preparing the bare battery cell includes:

[0064] S10: Die-cut the strip into electrode 100, that is, perform a die-cutting process on the strip to obtain the required cathode 110 and anode 120;

[0065] S20: The electrode 100 is wound into a bare cell 200, that is, the cathode sheet 110, anode sheet 120 and separator (including the first separator 301 and the second separator 302) obtained by the winding process are carried out. The first separator 301, cathode sheet 110, second separator 302 and anode sheet 120 are sequentially stacked and wound to form a bare cell 200. The bare cell 200 obtained at this time is a semi-finished product.

[0066] S30: The bare battery cell 200 is inspected to determine whether its weight parameters are qualified, i.e., a screening process is performed to separate bare battery cells 200 with qualified weight parameters from those with unqualified weight parameters. Specifically: S31: When a bare battery cell 200 is determined to have qualified weight parameters, it is output to the next process; S32: When a bare battery cell 200 is determined to have unqualified weight parameters, it is recycled.

[0067] The bare cell manufacturing method provided in the embodiments of this application is used to produce bare cells 200. Starting from the raw material strip, the process includes die-cutting, winding, and screening. The screening process separates bare cells 200 with acceptable weight parameters from those with unacceptable weight parameters. Ultimately, a batch of bare cells 200 of the same model with high consistency in weight parameters is produced, and bare cells 200 with unacceptable weight parameters are recycled. These bare cells 200 are then used to assemble battery cells, resulting in a high and consistent battery capacity for these battery cells.

[0068] Referring to Figures 4 to 7 and Figure 9, the bare cell production equipment provided in the embodiments of this application is used to manufacture bare cells 200. The material strip sequentially passes through the die-cutting mechanism 10 for die-cutting, the winding mechanism 20 for winding, and the screening mechanism 30 for screening. The wound bare cells 200 are detected by the screening mechanism 30 to determine whether their weight parameters are qualified. Bare cells 200 with qualified weight parameters are then screened out, and a batch of bare cells 200 with qualified weight parameters are finally output from the first outlet 33. Bare cells 200 with unqualified weight parameters are output from the second outlet 34 and recycled. This process produces a batch of bare cells 200 of the same model with high consistency in weight parameters. These bare cells 200 are then used to assemble battery cells, resulting in a high and consistent battery capacity for these battery cells.

[0069] The phrase "recycling bare cells 200 that do not meet weight parameters" includes, but is not limited to: directly scrapping bare cells 200 that do not meet weight parameters; or, recycling and storing these bare cells 200 that do not meet weight parameters for use in the production of other models of bare cells with lower weight parameter requirements.

[0070] Based on the relationship between the weight of the bare cell 200 and the battery capacity of the battery cell assembled using the bare cell 200, in some embodiments of this application, during "S30: detecting and judging whether the weight parameter of the bare cell 200 is qualified", the bare cell 200 is weighed, and then the weight parameter of the bare cell 200 is judged to be qualified based on the relationship between the weight of the bare cell 200 and the weight parameter of the bare cell 200. That is, the screening structure 32 of the screening mechanism 30 in the aforementioned bare cell production equipment is a weighing device 322, which weighs the wound bare cell 200. Furthermore, a qualified weight range is preset in the control device 321 of the screening mechanism 30. When the weight of the bare cell 200 falls within the qualified weight range, the bare cell 200 is judged by the control device 321 to be qualified in terms of weight parameter; otherwise, it is judged by the control device 321 to be unqualified in terms of weight parameter. This makes the judgment process simple and direct, and improves the screening efficiency. When performing "S30: Detecting and judging whether the weight parameters of bare cell 200 are qualified" using the aforementioned bare cell production equipment, if the bare cell 200 is judged by the control device 321 to be qualified in terms of weight parameters, the control device 321 controls the first conveying device 323 to convey the bare cell 200 with qualified weight parameters to the first discharge port 33. If the bare cell 200 is judged by the control device 321 to be unqualified in terms of weight parameters, the control device 321 controls the second conveying device 324 to convey the bare cell 200 with unqualified weight parameters to the second discharge port 34.

[0071] To reduce the number of bare cells 200 with unqualified weight parameters and improve the yield rate of bare cells 200, when weighing the bare cells 200, if the weight of the bare cell 200 is greater than the upper threshold of the qualified weight range, the cutting length of the electrode 100 is reduced in the "die-cutting of the strip into electrode 100" process; if the weight of the bare cell 200 is less than the lower threshold of the qualified weight range, the cutting length of the electrode 100 is increased in the "die-cutting of the strip into electrode 100" process, i.e., operation S40 is performed, as shown in Figures 11 to 13. Thus, during the manufacturing process of bare cells 200, the weighing result of the currently weighed bare cell 200 serves as reference data for the next wound bare cell 200. This allows for adjustment of the required electrode length of the next bare cell 200 based on the current reference data during manufacturing, thereby improving the yield rate of die-cut and wound bare cells 200.

[0072] Referring to Figures 4 to 7 and Figure 9, the aforementioned bare cell production equipment is equipped with a feedback system 40 to achieve feedback correlation between the weighing device 322 and the cutting device 121 of the die-cutting mechanism 10. That is, the feedback system 40 feeds back the weighing result of the current bare cell 200 from the weighing device 322 to the cutting device 121. Then, the feedback system 40 controls the cutting device 121 to adjust the cutting length of the cathode sheet 110 and / or the anode sheet 120, which adjusts the weight of the next bare cell 200 to be wound. This achieves the adjustment of the weight parameters of the next bare cell 200, thereby reducing the number of bare cells 200 with unqualified weight parameters and improving the yield rate of bare cells 200.

[0073] In some embodiments of this application, in "reducing the cutting length of electrode 100", the cutting length of cathode sheet 110 and / or anode sheet 120 is reduced. Alternatively, in other embodiments of this application, in "increasing the cutting length of electrode 100", the cutting length of cathode sheet 110 and / or anode sheet 120 is increased. By adjusting the cutting length of cathode sheet 110 and / or anode sheet 120, the weight of the next wound bare cell 200 is also adjusted, that is, the weight parameter of the next bare cell 200 is adjusted, thereby reducing the number of bare cells 200 with unqualified weight parameters and improving the yield of bare cells 200.

[0074] As shown in Figures 12 and 13, the preparation method of the bare cell 200 also includes S50: clamping and shaping the bare cell 200. When the bare cell 200 is output after the winding process, the interior of the wound bare cell 200 is still in a loose state, and the shape and outline of the bare cell 200 are not fixed. That is, the cathode sheet 110, anode sheet 120, first separator 301 and second separator 302 stacked inside the bare cell 200 are not dense, the volume of the bare cell 200 is relatively large, and the relative positions between the cathode sheet 110 and anode sheet 120 in the bare cell 200 are easy to slip and are not easy to assemble correctly into the battery casing, so it is not suitable for direct application in the production of batteries. Therefore, the fluffy bare cell 200 needs to be clamped and shaped. As shown in Figures 6, 7 and 9, the aforementioned bare cell production equipment uses a shaping mechanism 50 to clamp and shape the fluffy bare cell 200, thereby obtaining a bare cell 200 with a smaller required shape and a denser internal structure.

[0075] In some embodiments of this application, as shown in FIG12, after completing the step "winding the electrode 100 into a bare cell 200", "S50: clamping and shaping the bare cell 200" is performed. Referring to FIGS. 6 and 9, in the aforementioned bare cell production equipment, the shaping mechanism 50 is located between the winding mechanism 20 and the screening mechanism 30. After the wound bare cell 200 is output from the winding outlet 23, and before the bare cell 200 is conveyed into the screening mechanism 30 from the screening inlet 31, the shaping mechanism 50 clamps and shapes all the wound bare cells 200 to ensure that the interior of all bare cells 200 meets the density requirement.

[0076] Alternatively, in some other embodiments of this application, as shown in FIG13, after completing the "inspection of bare cell 200" and before "outputting bare cell 200 to the next process", "S50: clamping and shaping bare cell 200" is performed. Referring to FIG7, in the aforementioned bare cell production equipment, the shaping mechanism 50 is located downstream of the first discharge port 33. Thus, the shaping mechanism 50 clamps and shapes bare cells 200 that meet the weight parameters, ensuring that the interiors of these bare cells 200 meet the density requirements. Bare cells 200 that do not meet the weight parameters do not require clamping and shaping and are directly recycled.

[0077] The above are merely optional embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A bare battery cell production equipment, characterized in that, include: The screening mechanism includes a screening structure, a first discharge port, and a second discharge port. The screening structure is used to detect whether the weight parameters of the bare battery cell are qualified. When the weight parameters of the bare battery cell are qualified, the bare battery cell is output to the first discharge port. When the weight parameters of the bare battery cell are unqualified, the bare battery cell is output to the second discharge port.

2. The bare cell production equipment according to claim 1, characterized in that, The screening structure includes a control device, a weighing device, a first conveying device, and a second conveying device. The control device is electrically connected to the weighing device, the first conveying device, and the second conveying device. The weighing device is used to detect the weight parameters of the bare battery cells. The first conveying device is configured to correspond to the first discharge port to convey bare battery cells with qualified weight parameters to the first discharge port. The second conveying device is configured to correspond to the second discharge port to convey bare battery cells with unqualified weight parameters to the second discharge port.

3. The bare cell production equipment according to claim 2, characterized in that, The bare cell production equipment also includes a die-cutting mechanism and a feedback system. The die-cutting mechanism is used to die-cut the material strip into electrode sheets. The die-cutting mechanism includes a cutting device. The feedback system is electrically connected to the control device and the cutting device.

4. The bare cell production equipment according to claim 3, characterized in that, The bare cell production equipment also includes a winding mechanism and a shaping mechanism. The winding mechanism is used to wind the electrode sheet into the bare cell. The screening mechanism also includes a screening inlet, which is connected to the winding outlet of the winding mechanism. The shaping mechanism is located between the winding mechanism and the screening mechanism.

5. The bare cell production equipment according to claim 3, characterized in that, The bare cell production equipment also includes a shaping mechanism, which is located downstream of the first discharge port.

6. The bare cell production equipment according to claim 4 or 5, characterized in that, The shaping mechanism includes a hot pressing device, which includes a shaping plate and a heating structure, wherein the heating structure is disposed on the shaping plate.

7. The bare cell production equipment according to claim 4 or 5, characterized in that, The shaping mechanism includes a tunnel furnace and a cold press arranged in sequence. The tunnel furnace is used to heat the bare battery cell, and the cold press includes a shaping plate that clamps and shapes the bare battery cell output from the tunnel furnace.

8. The bare cell production equipment according to claim 4 or 5, characterized in that, The shaping mechanism includes a heating power supply and a cold press. The positive and negative terminals of the heating power supply are electrically connected to two cathode tabs and / or two anode tabs of the bare battery cell, respectively. The cold press includes a shaping plate, which clamps and shapes the heated bare battery cell.

9. A bare battery cell, characterized in that, The bare cell is a bare cell manufactured using the bare cell production equipment as described in any one of claims 1-8.

10. A battery production line, characterized in that, Includes the bare cell production equipment as described in any one of claims 1-8.

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