Battery cell, battery cell manufacturing method, and battery

Abstract

This application discloses a battery cell, a method for manufacturing a battery cell, and a battery, wherein the battery cell includes a first electrode, a second electrode, and a separator. The width of the separator is less than or equal to the width of the second main body and does not extend into the area where the first and second electrodes are located. During the manufacturing process of the battery cell using a winding-then-cutting method, the separator is not cut when the electrodes are cut on the wound battery cell prototype. Therefore, it can avoid the situation of wrinkling and damage to the separator caused by cutting the separator and the first and second electrodes at the same time, which can improve the yield, increase production efficiency, and reduce production costs. After the first electrode, the second electrode, and the separator are stacked, the insulating layer and the separator jointly isolate the first and second main bodies, so the first and second electrodes can still be kept insulated from each other, avoiding internal short circuits in the battery cell and ensuring the safety performance of the battery cell.

Description

Technical Field

[0001] This application relates to the field of lithium-ion battery technology, and in particular to a battery cell, a battery cell manufacturing method, and a battery. Background Technology

[0002] The production process of wound battery cells usually involves die-cutting the edges of the electrode sheets to form tabs, and then stacking the electrode sheets and separators and winding them. Due to equipment fluctuations, the position of the tabs may be misaligned after the electrode sheets are wound, which will prevent the tabs from being properly led out in subsequent processes, affecting the production yield. In order to improve the production yield, multiple adjustments are required, resulting in low production efficiency and high labor, time, and material costs.

[0003] In related technologies, the electrode sheets and separators can be overlapped and wound to form a prototype of a battery cell with a full tab structure. Then, the tabs are made to ensure that the tabs in the finished battery cell are accurately positioned. However, in order to avoid short circuits between the positive and negative electrodes, the width of the separator must be greater than the width of the positive and negative electrodes to ensure that the positive and negative electrodes are completely insulated from each other. This means that in the prototype of a battery cell with a full tab structure formed after winding, the tab position includes the separator. When the tabs are cut later, the separator and the electrode sheets are cut at the same time, which can easily cause the separator to wrinkle or break, resulting in substandard product quality, low yield, and consequently reduced production efficiency and increased production costs. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a battery cell in which the separator does not extend into the area where the electrode tab is located, thereby improving yield, increasing production efficiency, and reducing production costs.

[0005] This application also proposes a method for manufacturing the aforementioned battery cells.

[0006] This application also proposes a battery that includes the aforementioned battery cells.

[0007] The battery cell provided in the first aspect of this application includes: a first electrode, comprising a first body portion, a first tab, and an insulating layer, wherein the first tab is connected to the edge of the first body portion, and the insulating layer covers one end of the first tab near the first body portion and the edge of the first body portion near the first tab; a second electrode, comprising a second body portion and a second tab, wherein the second tab is connected to the edge of the second body portion; and a separator, located between the first body portion and the second body portion, wherein the width of the separator is less than or equal to the width of the second body portion; wherein the first electrode, the second electrode, and the separator are stacked and wound, and the separator and the insulating layer together isolate the first body portion and the second body portion; the first electrode and the second electrode are configured such that, after the first electrode, the second electrode, and the separator are stacked and wound, they are cut to form the first tab and the second tab.

[0008] The battery cell provided in the first aspect of this application has at least the following beneficial effects: the width of the separator is less than or equal to the width of the second main body, so the separator will not extend into the area where the first and second electrodes are located. During the manufacturing process of the battery cell using the method of winding and then cutting, the separator will not be cut when cutting the electrodes on the wound battery cell prototype. Therefore, it is possible to avoid the situation of separator wrinkling and damage caused by cutting the separator and the first and second electrodes at the same time, which can improve the yield, increase production efficiency, and reduce production costs. After the first electrode, the second electrode and the separator are stacked, the first electrode of the battery cell is provided with an insulating layer covering the end of the first electrode near the first main body and the edge of the first main body near the first electrode. The insulating layer and the separator together isolate the first main body and the second main body, so it is still possible to ensure that the first electrode and the second electrode are mutually insulated, avoid internal short circuits in the battery cell, and ensure the safety performance of the battery cell.

[0009] In some embodiments of this application, the width of the first main body portion is smaller than the width of the second main body portion.

[0010] In some embodiments of this application, the width of the insulating layer is 3 mm to 5 mm.

[0011] The battery cell manufacturing method provided in the second aspect of this application is used to manufacture the battery cell provided in any embodiment of the first aspect of this application. The battery cell manufacturing method includes the following steps: Prepare an uncut first electrode, an uncut second electrode, and a diaphragm. The uncut first electrode includes a first main body, a first empty foil area, and an insulating layer covering the connection between the first main body and the first empty foil area. The uncut second electrode includes a second main body and a second empty foil area. The width of the diaphragm is less than or equal to the width of the second main body. The first electrode, the second electrode, and the separator are stacked and then wound to form a basic battery cell shape, so that the separator and the insulating layer together isolate the first main body and the second main body; A first tab is fabricated on the battery cell prototype, such that the width of the first tab is equal to the first design width; A second tab is fabricated on the battery cell prototype, such that the width of the second tab is equal to the second design width.

[0012] The battery cell manufacturing method provided in the second aspect of this application has at least the following beneficial effects: In manufacturing the battery cell provided in any embodiment of the first aspect of this application, the width of the separator of the battery cell is less than or equal to the width of the second main body. Therefore, the separator will not extend into the area where the first electrode and the second electrode are located. In the process of manufacturing the battery cell by first winding and then cutting, when cutting the electrode on the wound battery cell prototype, the separator will not be cut. Therefore, it can avoid the situation of separator wrinkling and damage caused by cutting the separator and the electrode at the same time, which can improve the yield, improve production efficiency, and reduce production costs. The first electrode of the battery cell is provided with an insulating layer covering the end of the first electrode near the first main body and the edge of the first main body near the first electrode. After the first electrode, the second electrode and the separator are stacked, the insulating layer and the separator jointly isolate the first main body and the second main body. Therefore, it can still ensure that the first electrode and the second electrode are mutually insulated, avoid the battery cell from internal short circuit, and ensure the safety performance of the battery cell.

[0013] In some embodiments of this application, the cell manufacturing method further includes the step of: Before the first electrode, the second electrode and the separator are stacked and wound to form a basic battery cell shape, the first empty foil area is cut to form a basic first electrode tab connected to the edge of the first main body. The width of the basic first electrode tab is greater than the first design width. Before the first electrode, the second electrode, and the separator are stacked and wound to form a basic battery cell shape, the second empty foil area is cut to form a basic second electrode tab connected to the edge of the second main body. The width of the basic second electrode tab is greater than the second design width. The process of fabricating the first tab on the prototype battery cell includes the following steps: The first electrode ear prototype is cut into the first electrode ear; The process of fabricating a second tab on the battery cell prototype includes the following steps: The second electrode ear prototype is cut into the second electrode ear.

[0014] In some embodiments of this application, the step of cutting the first empty foil area to form a first tab prototype connected to the edge of the first main body includes the following steps: The first empty foil area is cut to form a plurality of first tab prototypes connected to the edge of the first main body; The step of cutting the second empty foil area to form a second electrode ear prototype connected to the edge of the second main body includes: The second empty foil area is cut to form a plurality of second electrode tab prototypes connected to the edge of the second main body; The step of stacking and winding the first electrode, the second electrode, and the separator to form a preliminary battery cell includes the following steps: The first electrode, the second electrode, and the diaphragm are stacked and wound to form a basic battery cell shape. Multiple first electrode tab shapes are at least partially overlapped to form a first electrode tab group, and multiple second electrode tab shapes are at least partially overlapped to form a second electrode tab group. The step of cutting the first electrode ear prototype into the first electrode ear includes the following steps: The first electrode group is cut so that each first electrode prototype is cut into a first electrode, the width of the first electrode is equal to the first design width, and multiple first electrodes overlap and are aligned. The step of cutting the second electrode ear prototype into the second electrode ear includes the following steps: The second electrode group is cut so that each second electrode prototype is cut into a second electrode, the width of the second electrode is equal to the second design width, and multiple second electrodes overlap and align.

[0015] In some embodiments of this application, in the first electrode group, the width of the overlapping portion of all the first electrode prototypes is greater than or equal to the first design width; in the second electrode group, the width of the overlapping portion of all the second electrode prototypes is greater than or equal to the second design width.

[0016] In some embodiments of this application, the width of the first electrode prototype is less than twice the first design width; the width of the second electrode prototype is less than twice the second design width.

[0017] In some embodiments of this application, the width of the first tab prototype and the width of the second tab prototype are both less than half the width of the battery cell prototype.

[0018] The battery provided in the third aspect of this application includes: a battery cell provided in any embodiment of the first aspect of this application; and a housing, wherein the battery cell is housed in the housing.

[0019] The battery provided in the third aspect of this application has at least the following beneficial effects: When using the battery cell provided in the first aspect of this application, the separator will not extend into the area where the tab is located. During the process of manufacturing the battery cell by first winding and then cutting, the separator will not be cut when cutting the tab on the wound battery cell prototype. Therefore, it can avoid the situation of separator wrinkling and damage caused by cutting the separator and the first and second electrodes at the same time. The yield rate of the battery cell is high, the production efficiency is high, and the production cost is low. Therefore, it can improve the yield rate and production efficiency of the battery and reduce the production cost of the battery.

[0020] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0021] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 A front view of a battery cell provided for some embodiments of the first aspect of this application; Figure 2 for Figure 1 A top view of the battery cell shown; Figure 3 for Figure 1 The diagram shows the unfolded shape of the battery cell; Figure 4 for Figure 1 The image shown is an exploded view of the battery cell after it has been unfolded. Figure 5 Flowcharts of a cell manufacturing method provided for some embodiments of the second aspect of this application; Figure 6 for Figure 5 A schematic diagram of the uncut first electrode sheet in step S100 of the battery cell manufacturing method shown; Figure 7 for Figure 5 A schematic diagram of the uncut second electrode sheet in step S100 of the battery cell manufacturing method shown; Figure 8 for Figure 5 A schematic diagram showing the completion of step S200 in the battery cell manufacturing method shown; Figure 9 for Figure 5 A schematic diagram showing the completion of step S300 in the battery cell manufacturing method shown; Figure 10 for Figure 5 An exploded view of the first electrode, the second electrode, and the separator in step S400 of the battery cell manufacturing method shown. Figure 11 for Figure 5A schematic diagram of the first electrode, second electrode, and separator after being stacked in step S400 of the battery cell manufacturing method shown; Figure 12 for Figure 5 A top view of the prototype battery cell after step S400 of the battery cell manufacturing method shown is completed; Figure 13 for Figure 5 A front view of the prototype battery cell after step S400 of the battery cell manufacturing method shown is completed.

[0022] Figure label: First electrode 100, first main body 110, first electrode tab prototype 120, first electrode tab 130, insulating layer 140, first empty foil area 150, second electrode 200, second main body 210, second electrode tab prototype 220, second electrode tab 230, second empty foil area 240, diaphragm 300, battery cell prototype 400, first electrode tab group 410, second electrode tab group 420, battery cell 500. Detailed Implementation

[0023] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0024] In the description of this application, it should be understood that the orientation descriptions, such as up, down, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not 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.

[0025] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0026] In the description of this application, the reference to terms such as "one embodiment," "some embodiments," etc., means that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0027] The production process of wound battery cells usually involves die-cutting the edges of the electrode sheets to form tabs, and then stacking the electrode sheets and separators and winding them. Due to equipment fluctuations, the position of the tabs may be misaligned after the electrode sheets are wound, which will prevent the tabs from being properly led out in subsequent processes, affecting the production yield. In order to improve the production yield, multiple adjustments are required, resulting in low production efficiency and high labor, time, and material costs.

[0028] In related technologies, the electrode sheets and separators can be overlapped and wound to form a prototype of a battery cell with a full tab structure. Then, the tabs are made to ensure that the tabs in the finished battery cell are accurately positioned. However, in order to avoid short circuits between the positive and negative electrodes, the width of the separator must be greater than the width of the positive and negative electrodes to ensure that the positive and negative electrodes are completely insulated from each other. This means that in the prototype of a battery cell with a full tab structure formed after winding, the tab position includes the separator. When the tabs are cut later, the separator and the electrode sheets are cut at the same time, which can easily cause the separator to wrinkle or break, resulting in substandard product quality, low yield, and consequently reduced production efficiency and increased production costs.

[0029] Based on this, refer to Figures 1 to 4 The battery cell 500 provided in the first aspect embodiment of this application includes a first electrode 100, a second electrode 200, and a separator 300. The first electrode 100 includes a first main body portion 110, a first tab 130, and an insulating layer 140. The first tab 130 is connected to the edge of the first main body portion 110, and the insulating layer 140 covers the end of the first tab 130 near the first main body portion 110 and the edge of the first main body portion 110 near the first tab 130. The second electrode 200... The first body portion 210 and the second electrode tab 230 are connected to the edge of the second body portion 210. The diaphragm 300 is located between the first body portion 110 and the second body portion 210, and the width H3 of the diaphragm 300 is less than or equal to the width H2 of the second body portion 210. The first electrode 100, the second electrode 200 and the diaphragm 300 are stacked and wound together, and the diaphragm 300 and the insulating layer 140 together isolate the first body portion 110 and the second body portion 210.

[0030] The width H3 of the separator 300 is less than or equal to the width H2 of the second main body 210. Therefore, the separator 300 does not extend into the area where the first electrode tab 130 and the second electrode tab 230 are located. During the manufacturing process of the battery cell 500 using the method of winding and then cutting, the separator 300 will not be cut when the electrode tabs are cut on the wound battery cell 500 prototype. Therefore, it is possible to avoid the separator 300 wrinkling or breaking caused by cutting the separator 300 at the same time as the first electrode 100 and the second electrode 200, which can improve the yield, increase production efficiency, and reduce production costs. The first electrode 100 of the battery cell 500 is provided with a cover for the first electrode tab. The insulating layer 140 at one end of the first main body 110 and at the edge of the first main body 110 near the first electrode tab 130, after the first electrode 100, the second electrode 200 and the separator 300 are stacked, the insulating layer 140 and the separator 300 together isolate the first main body 110 and the second main body 210, so that the first electrode 100 and the second electrode 200 can still be kept insulated from each other, avoiding internal short circuits in the cell 500 and ensuring the safety performance of the cell 500; in addition, it can also reduce the concentrated area of ​​the separator 300, thereby reducing the lithium plating phenomenon at the head of the cell 500 and improving the safety performance of the cell 500.

[0031] It is understandable that the insulation layer 140 can be made of ceramic; the thickness of the insulation layer 140 can be set according to actual needs. Specifically, factors such as the design thickness of the battery cell 500 and the flatness of the battery cell 500 can be considered.

[0032] Furthermore, referring to Figure 4 The width H1 of the first main body 110 is smaller than the width H2 of the second main body 210, which can further improve the reliability of the insulation of the diaphragm 300 to the first electrode 100 and the second electrode 200, thereby further improving the safety performance of the cell 500.

[0033] The width of the insulating layer 140 can be set according to actual needs. It is necessary to ensure that after the first electrode 100 is cut, the insulating layer 140 covers the end of the first electrode tab prototype 120 near the first main body 110 and the edge of the first main body 110 near the first electrode tab prototype 120. It is also necessary to ensure that after the first electrode 100, the second electrode 200 and the diaphragm 300 are stacked, the insulating layer 140 and the diaphragm 300 can jointly isolate the first main body 110 and the second main body 210. For example, it can be set to 3mm to 5mm.

[0034] Reference Figure 5 The battery cell manufacturing method provided in the second aspect of this application is used to manufacture the battery cell 500 provided in any embodiment of the first aspect of this application. The battery cell manufacturing method includes the following steps: S100, prepare the uncut first electrode 100, the uncut second electrode 200, and the diaphragm 300, as per reference. Figure 6 The uncut first electrode 100 includes a first main body portion 110, a first empty foil area 150, and an insulating layer 140 covering the connection between the first main body portion 110 and the first empty foil area 150, as shown in the figure. Figure 7 The uncut second electrode 200 includes a second main body 210 and a second empty foil area 240, as shown in the figure. Figure 8 The width H3 of the diaphragm 300 is less than or equal to the width H2 of the second main body 210; S200, refer to Figures 10 to 13 The first electrode 100, the second electrode 200, and the separator 300 are stacked and wound to form a preliminary battery cell 400. The separator 300 and the insulating layer 140 together isolate the first main body 110 and the second main body 210. Specifically, to ensure complete insulation between the first electrode 100 and the second electrode 200, refer to... Figure 10 There are two diaphragms 300, which are stacked in the order of first electrode 100, one diaphragm 300, second electrode 200, and another diaphragm 300. S300, refer to Figure 12 , Figure 13 , Figure 1 and Figure 2 The first tab 130 is fabricated on the battery cell prototype 400, and the width of the first tab 130 is equal to the first design width d1. S400, refer to Figure 12 , Figure 13 , Figure 1 and Figure 2 A second tab 230 is fabricated on the battery cell prototype 400, with the width of the second tab 230 equal to the second design width d2.

[0035] In manufacturing the battery cell 500 provided in any embodiment of the first aspect of this application, the width H3 of the separator 300 of the battery cell 500 is less than or equal to the width H2 of the second main body portion 210. Therefore, the separator 300 does not extend into the area where the first electrode tab 130 and the second electrode tab 230 are located. During the manufacturing process of the battery cell 500 by winding and then cutting, when cutting the electrode tabs on the wound battery cell 500 prototype, the separator 300 will not be cut. Therefore, it is possible to avoid the situation where the separator 300 is wrinkled or damaged due to simultaneous cutting of the separator 300 and the first electrode 100 and the second electrode 200, thereby improving the efficiency of battery cell manufacturing. The yield rate is improved, production efficiency is increased, and production costs are reduced. The first electrode 100 of the battery cell 500 is provided with an insulating layer 140 covering the end of the first electrode tab 130 near the first main body 110 and the edge of the first main body 110 near the first electrode tab 130. After the first electrode 100, the second electrode 200 and the separator 300 are stacked, the insulating layer 140 and the separator 300 together isolate the first main body 110 and the second main body 210. Therefore, the first electrode 100 and the second electrode 200 can still be kept insulated from each other, avoiding internal short circuits in the battery cell 500 and ensuring the safety performance of the battery cell 500.

[0036] Based on this, refer to Figure 5 The cell manufacturing method also includes the following steps: S500, refer to Figure 8 The first empty foil area 150 is cut. Specifically, the first empty foil area 150 can be cut by die cutting to form a first electrode tab prototype 120 connected to the edge of the first main body 110. The width D1 of the first electrode tab prototype 120 is greater than the first design width d1. S600, refer to Figure 9 The second empty foil area 240 is cut. Specifically, the second empty foil area 240 can be cut by die cutting to form a plurality of second electrode ear prototypes 220 connected to the edge of the second main body 210. The width D2 of the second electrode ear prototypes 220 is greater than the second design width d2. Furthermore, in S300, the first tab 130 is fabricated on the battery cell prototype 400, including the following steps: Reference Figure 12 , Figure 13 , Figure 1 and Figure 2 ,along Figures 12 to 13 The dotted lines shown indicate that the first electrode ear prototype 120 is cut into the first electrode ear 130. Specifically, the first electrode ear prototype 120 can be cut by die cutting or laser cutting. In S400, the second tab 230 is fabricated on the battery cell prototype 400, including the following steps: Reference Figure 12 , Figure 13 , Figure 1 and Figure 2 ,along Figures 12 to 13 The dotted line shown indicates that the second electrode ear prototype 220 is cut into the second electrode ear 230. Specifically, the second electrode ear prototype 220 can be cut by die-cutting or laser cutting.

[0037] Before winding begins, a first electrode tab prototype 120 with a width greater than the first design width d1 is cut from the first electrode 100, and a second electrode tab prototype 220 with a width greater than the second design width d2 is cut from the second electrode 200. Then, the first electrode 100, the second electrode 200, and the separator 300 are wound. First, in the battery cell prototype 400 formed after winding, the part that needs to be processed for the first electrode tab 130 does not have the second electrode 200, and the part that needs to be processed for the second electrode tab 230 does not have the first electrode 100. Therefore, only cutting is needed to form the final first electrode tab 130 and the final second electrode tab 230. It is not necessary to remove the part of the second electrode 200 that overlaps with the position of the first electrode tab 130 and the part of the first electrode 100 that overlaps with the position of the second electrode tab 230 after cutting, which helps to reduce the complexity of the production process. Furthermore, the first electrode tab prototype 120, with a width greater than the first design width d1, and the second electrode tab prototype 220, with a width greater than the second design width d2, can tolerate a certain range of equipment fluctuations. Even after winding, if the axial position of the first electrode tab prototype 120 is misaligned compared to the designed axial position of the first electrode tab 130, and / or the axial position of the second electrode tab prototype 220 is misaligned compared to the designed axial position of the second electrode tab 230, as long as the first electrode tab prototype 120 still covers the designed position of the first electrode tab 130... If the second tab prototype 220 still covers the designed position of the second tab 230, the first tab prototype 120 can be cut into the first tab 130 with the first designed width d1, and the second tab prototype 220 can be cut into the second tab 230 with the second designed width d2. This ensures that the first tab 130 and the second tab 230 of the cell 500 are both located in the designed position, thereby avoiding tab misalignment of the cell 500, improving production yield, reducing equipment debugging time, increasing production efficiency, and reducing labor costs, time costs, and material costs.

[0038] Winded battery cells have various structural forms, such as conventional structures, center-mounted tab structures, and multi-tab structures. It is understood that the battery cell manufacturing method provided in the first aspect of this application can be applied to various different structural forms of wound battery cells. For example, it can be applied to a conventional structure with only a single first tab 130 and a single second tab 230, so that the first tab 130 and the second tab 230 are precisely located in the designed position; it can also be applied to a three-tab structure, so that all three tabs are precisely located in the designed position; it can also be applied to a multi-tab structure with multiple first tabs 130 and multiple second tabs 230, so that the first tabs 130 and the second tabs 230 are precisely located in the designed position, while the multiple first tabs 130 are aligned and the multiple second tabs 230 are aligned.

[0039] When the battery cell manufacturing method provided in the first aspect of this application is applied to a multi-tab structure, it specifically is as follows: S500 includes the following steps: Reference Figure 8 The first electrode 100 is cut to form a first main body 110 and a plurality of first electrode ear prototypes 120 connected to the edge of the first main body 110. S600 includes the following steps: Reference Figure 9 The second electrode 200 is cut to form a second main body 210 and a plurality of second electrode ear prototypes 220 connected to the edge of the second main body 210. S200 includes the following steps: Reference Figure 10 and Figure 11 The first electrode 100, the second electrode 200 and the separator 300 are stacked and wound to form a battery cell prototype 400, and multiple first electrode prototypes 120 overlap at least partially to form a first electrode group 410, and multiple second electrode prototypes 220 overlap at least partially to form a second electrode group 420. In S300, the first electrode prototype 120 is cut into the first electrode 130, including the following steps: Reference Figures 12 to 2 The first electrode group 410 is cut so that each first electrode prototype 120 is cut into a first electrode 130. The width of the first electrode 130 is the first design width d1. Multiple first electrodes 130 overlap and are aligned. In S400, the second electrode ear prototype 220 is cut into a second electrode ear 230, including the following steps: Reference Figures 12 to 2 The second electrode group 420 is cut so that each second electrode prototype 220 is cut into a second electrode 230. The width of the second electrode 230 is the second design width d2. Multiple second electrodes 230 overlap and are aligned.

[0040] In related technologies, during the manufacturing process of a multi-tab battery cell 500, to ensure the alignment of the tabs, the center line of the first tab can be found as a reference line, and then the width of the tabs in each layer can be adjusted. This method is relatively complex and cumbersome, and inconsistent tab widths may affect subsequent packaging processes. Alternatively, the number of winding turns and the length of each turn can be calculated to select the position of the first tab, and the position of each tab can be calculated sequentially. However, this method is only theoretically feasible, and in practice, due to equipment fluctuations, it is impossible to achieve precise alignment of the tabs, making it impractical. The multi-tab battery cell 500 manufactured by the battery cell manufacturing method provided in the first aspect of this application has more precise positions of the first tab 130 and the second tab 230, and multiple first tabs 130 and multiple second tabs 230 can be aligned, which is conducive to the smooth progress of subsequent processes. Furthermore, the method steps are relatively simple and easy to implement. Moreover, the battery cell 500 has more tabs and a more uniform distribution, enabling higher charging and discharging rates, lower charging and discharging temperature rise, and reduced impedance of the battery cell 500, which is beneficial to improving battery performance.

[0041] Furthermore, referring to Figure 12 In the first electrode group 410, the width d3 of the overlapping portion of all first electrode prototypes 120 is greater than or equal to the first design width d1; in the second electrode group 420, the width d4 of the overlapping portion of all second electrode prototypes 220 is greater than or equal to the second design width d2. Thus, after steps S300 and S400 are completed, the width of each first electrode 130 is the first design width d1, and the width of each second electrode 230 is the second design width d2.

[0042] The larger the width D1 of the first electrode prototype 120 and the width D2 of the second electrode prototype 220, the larger the allowable error range of equipment fluctuations, but at the same time, it will also cause more material waste. Based on this, referring to Figure 12 The width D1 of the first electrode prototype 120 is less than twice the first design width d1, and the width D2 of the second electrode prototype 220 is less than twice the second design width d2, thereby reducing material waste while ensuring that a sufficient error range can be tolerated.

[0043] If the width D1 of the first tab prototype 120 and the width D2 of the second tab prototype 220 are too large, it may result in overlapping first tab prototype 120 and second tab prototype 220 in the cell prototype 400 after step S200. This could lead to situations where, after steps S300 and S400, the cut-off portion of the first tab prototype 120 remains on the second tab 230, or the cut-off portion of the second tab prototype 220 remains on the first tab 130, affecting the quality of the cell 500. Based on this, referring to... Figure 12The width D1 of the first tab prototype 120 and the width D2 of the second tab prototype 220 are both less than half the width D of the cell prototype 400, so as to avoid the first tab prototype 120 and the second tab prototype 220 overlapping in the cell prototype 400 after step S200. This also prevents the part of the first tab prototype 120 that was cut off after steps S300 and S400 from remaining on the second tab 230, or the part of the second tab prototype 220 that was cut off from the first tab 130, thus ensuring the quality of the cell 500.

[0044] The battery provided in the third aspect of this application includes a battery cell 500 and a casing provided in any embodiment of the first aspect of this application, with the battery cell 500 housed in the casing. Using the battery cell 500 provided in the second aspect of this application, the separator 300 does not extend into the area where the electrode tabs are located. During the manufacturing process of the battery cell 500 using a winding-then-cutting method, the separator 300 is not cut when the electrode tabs are cut from the wound battery cell prototype. Therefore, it is possible to avoid wrinkling or damage to the separator 300 caused by simultaneous cutting of the separator 300 with the first electrode 100 and the second electrode 200. The battery cell 500 has a higher yield, higher production efficiency, and lower production cost, thus improving the battery yield and production efficiency while reducing the battery production cost.

[0045] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

Claims

1. A battery cell, characterized in that, include: The first electrode includes a first main body, a first electrode tab, and an insulating layer. The first electrode tab is connected to the edge of the first main body, and the insulating layer covers the end of the first electrode tab near the first main body and the edge of the first main body near the first electrode tab. The second electrode includes a second main body and a second electrode tab, wherein the second electrode tab is connected to the edge of the second main body; A diaphragm is located between the first main body portion and the second main body portion, and the width of the diaphragm is less than or equal to the width of the second main body portion; The first electrode, the second electrode, and the diaphragm are stacked and wound together, and the diaphragm and the insulating layer together isolate the first main body and the second main body. The first electrode and the second electrode are configured such that after the first electrode, the second electrode, and the diaphragm are stacked and wound together, they are cut to form the first electrode tab and the second electrode tab.

2. The battery cell according to claim 1, characterized in that, The width of the first main body is smaller than the width of the second main body.

3. The battery cell according to claim 1, characterized in that, The width of the insulating layer is 3mm to 5mm.

4. A method for manufacturing battery cells, characterized in that, The method for manufacturing a battery cell according to any one of claims 1 to 3 includes the following steps: Prepare an uncut first electrode, an uncut second electrode, and a diaphragm. The uncut first electrode includes a first main body, a first empty foil area, and an insulating layer covering the connection between the first main body and the first empty foil area. The uncut second electrode includes a second main body and a second empty foil area. The width of the diaphragm is less than or equal to the width of the second main body. The first electrode, the second electrode, and the separator are stacked and then wound to form a basic battery cell shape, so that the separator and the insulating layer together isolate the first main body and the second main body; A first tab is fabricated on the battery cell prototype, such that the width of the first tab is equal to the first design width; A second tab is fabricated on the battery cell prototype, such that the width of the second tab is equal to the second design width.

5. The cell manufacturing method according to claim 4, characterized in that, The battery cell manufacturing method further includes the following steps: Before the first electrode, the second electrode and the separator are stacked and wound to form a basic battery cell shape, the first empty foil area is cut to form a basic first electrode tab connected to the edge of the first main body. The width of the basic first electrode tab is greater than the first design width. Before the first electrode, the second electrode, and the separator are stacked and wound to form a basic battery cell shape, the second empty foil area is cut to form a basic second electrode tab connected to the edge of the second main body. The width of the basic second electrode tab is greater than the second design width. The process of fabricating the first tab on the prototype battery cell includes the following steps: The first electrode ear prototype is cut into the first electrode ear; The process of fabricating a second tab on the battery cell prototype includes the following steps: The second electrode ear prototype is cut into the second electrode ear.

6. The cell manufacturing method according to claim 5, characterized in that, The step of cutting the first empty foil area to form a first tab prototype connected to the edge of the first main body includes: The first empty foil area is cut to form a plurality of first tab prototypes connected to the edge of the first main body; The step of cutting the second empty foil area to form a second electrode ear prototype connected to the edge of the second main body includes: The second empty foil area is cut to form a plurality of second electrode tab prototypes connected to the edge of the second main body; The step of stacking and winding the first electrode, the second electrode, and the separator to form a preliminary battery cell includes the following steps: The first electrode, the second electrode, and the diaphragm are stacked and wound to form a basic battery cell shape. Multiple first electrode tab shapes are at least partially overlapped to form a first electrode tab group, and multiple second electrode tab shapes are at least partially overlapped to form a second electrode tab group. The step of cutting the first electrode ear prototype into the first electrode ear includes the following steps: The first electrode group is cut so that each first electrode prototype is cut into a first electrode, the width of the first electrode is equal to the first design width, and multiple first electrodes overlap and are aligned. The step of cutting the second electrode ear prototype into the second electrode ear includes the following steps: The second electrode group is cut so that each second electrode prototype is cut into a second electrode, the width of the second electrode is equal to the second design width, and multiple second electrodes overlap and align.

7. The cell manufacturing method according to claim 6, characterized in that, In the first electrode group, the width of the overlapping portion of all the first electrode prototypes is greater than or equal to the first design width; in the second electrode group, the width of the overlapping portion of all the second electrode prototypes is greater than or equal to the second design width.

8. The cell manufacturing method according to claim 5, characterized in that, The width of the first electrode prototype is less than twice the width of the first design; the width of the second electrode prototype is less than twice the width of the second design.

9. The cell manufacturing method according to claim 5, characterized in that, The width of the first tab prototype and the width of the second tab prototype are both less than half the width of the battery cell prototype.

10. A battery, characterized in that, include: The battery cell according to any one of claims 1 to 3; The battery cell is housed within the housing.

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