Battery cell preparation method, battery cell, energy storage device, and electronic device

Abstract

Embodiments of the present application provide a kind of electric core preparation method and electric core, energy storage device and electronic equipment.Electric core preparation method includes: the bare electric core is formed after winding pole piece and separator;Along the axial direction of bare electric core, uncoated part is cut, and multiple pre-bent tab groups arranged along the circumference of bare electric core are formed;Multiple pre-bent tab groups include at least one first pre-bent tab close to the center part of bare electric core and multiple second pre-bent tabs away from the center part of bare electric core;The first part of first pre-bent tab is processed by first jig;Second pre-bent tab and the second part of first pre-bent tab are processed by second jig to form tab group;Wherein second pre-bent tab and second part are flat and arranged overlapping each other, and the partial projection of second part in the axial direction of bare electric core overlaps with first part;Lead-out part is arranged on bare electric core, lead-out part is covered on tab group and connected with tab group to form electric core.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a method for preparing a battery cell, as well as a battery cell, an energy storage device, and an electronic device. Background Technology

[0002] Lithium-ion batteries, with their high energy density, high power density, good cycle performance, no memory effect, and environmental friendliness, have become energy storage tools for portable office equipment and are widely used in various electronic products such as mobile phones, mobile cameras, laptops, and smartphones. They are also expected to become the power supply system for future electric vehicles.

[0003] A battery cell includes electrodes. During electrode coating, a blank foil area (also known as a tab) is reserved at the edge of the current collector. There are two ways to form the tab: one is to cut the blank foil area at the edge of the current collector before winding to form the tab; the other is to cut the blank foil area at the edge of the current collector after winding to form the tab. In the latter case, the tab is more likely to block the center of the battery cell, affecting the normal use of the battery cell. Summary of the Invention

[0004] The purpose of this application is to provide a method for manufacturing battery cells and new technological solutions for battery cells, energy storage devices and electronic devices.

[0005] In a first aspect, this application provides a method for manufacturing a battery cell. The battery cell includes an electrode and a separator, wherein the electrode has an uncoated portion at its width-direction end;

[0006] The cell manufacturing method includes:

[0007] The electrode sheet and the separator are wound together to form a bare battery cell, the bare battery cell having a central portion;

[0008] The uncoated portion is cut along the axial direction of the bare battery cell to form a plurality of pre-bent tabs arranged circumferentially along the bare battery cell;

[0009] The uncoated portion is located on one side of the bare cell in the axial direction; the plurality of pre-bent tabs include at least one first pre-bent tab near the center of the bare cell and a plurality of second pre-bent tabs away from the center of the bare cell;

[0010] The first part of the first pre-bent electrode tab is processed using the first fixture;

[0011] A group of electrodes is formed by processing the second pre-bent electrode tab and the second part of the first pre-bent electrode tab using a second fixture;

[0012] The second pre-bent tab and the second part are flat and overlap each other, and the projection of the second part in the axial direction of the bare cell overlaps with the first part.

[0013] A lead-out portion is provided on the bare battery cell, and the lead-out portion is covered on the electrode group and connected to the electrode group to form the battery cell.

[0014] Optionally, cutting the uncoated portion along the axial direction of the bare battery cell specifically includes:

[0015] The uncoated portion is cut at least three times along the axial direction of the bare cell to form a first cutting line, a second cutting line, and a third cutting line; the first cutting line and the second cutting line are parallel, and the third cutting line is adjacent to and intersects the second cutting line; the first cutting line, the second cutting line, and the third cutting line all extend to the circumferential edge of the bare cell.

[0016] Optionally, the multiple pre-bent electrode groups include a first pre-bent electrode group and a second pre-bent electrode group;

[0017] The first pre-bent tab group is defined between the first cutting line and the second cutting line;

[0018] The second pre-bent tab group is defined between the third cutting line and the first cutting line.

[0019] Optionally, the processing of the second pre-bent electrode tab and the second part of the first pre-bent electrode tab using the second fixture specifically includes:

[0020] First, the second pre-bent electrode and the second part of the first pre-bent electrode in the first pre-bent electrode group are processed to form the first electrode group;

[0021] Then, the second pre-bent electrode and the second part of the first pre-bent electrode in the second pre-bent electrode group are processed to form the second electrode group.

[0022] Optionally, the first electrode group and the second electrode group partially overlap.

[0023] Optionally, the processing of the second pre-bent electrode tab and the second part of the first pre-bent electrode tab using the second fixture specifically includes:

[0024] A second fixture applies force to the second pre-bent electrode tab and the second part of the first pre-bent electrode tab, causing the second pre-bent electrode tab and the second part of the first pre-bent electrode tab to be laid down towards the center of the bare cell, thereby forming an electrode tab group.

[0025] Optionally, processing the first portion of the first pre-bent electrode tab using the first fixture specifically includes:

[0026] The first fixture applies a force to the first pre-bent tab, causing the first portion to be oriented away from the center of the bare cell.

[0027] Optionally, the bare cell has a central hole, and before processing the first portion of the first pre-bent tab with the first fixture, the method further includes: placing the first fixture inside the central hole.

[0028] Optionally, placing the first fixture within the central hole specifically includes:

[0029] The first fixture includes a column and a cover connected to the column, the column extending into the central hole, and the first portion located below the cover.

[0030] Secondly, a battery cell is provided. The battery cell is manufactured using the battery cell manufacturing method described in the first aspect.

[0031] Optionally, the battery cell has an end face, and the end face has a plurality of the electrode groups, which are arranged along the circumference of the battery cell;

[0032] Each of the electrode groups includes at least one first electrode and multiple second electrodes, wherein the first electrode is disposed closer to the center of the cell than the second electrode;

[0033] The first electrode includes a first part and a second part, wherein the projection of the second part in the axial direction of the battery cell overlaps with the first part;

[0034] Multiple second electrodes are flatly disposed on the end face, and adjacent second electrodes overlap each other in the radial direction of the battery cell;

[0035] The first electrode and the second electrode, which are arranged adjacently, overlap each other;

[0036] The battery cell also includes a lead-out portion, which covers the electrode group and is connected to the electrode group.

[0037] Thirdly, an energy storage device is provided. The energy storage device includes a battery cell and a housing as described in the second aspect, and the lead-out portion is connected to the housing.

[0038] Fourthly, an electronic device is provided. The electronic device includes the energy storage device as described in the third aspect.

[0039] According to an embodiment of this application, a method for manufacturing a battery cell is provided. A first fixture processes a first portion of a first pre-bent electrode tab, and a second fixture processes a second portion of both a second pre-bent electrode tab and a second portion of the first pre-bent electrode tab. This ensures that the first electrode tab is positioned away from the center of the battery cell, preventing it from obstructing the center of the end face and thus not affecting the normal use of the battery cell.

[0040] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0041] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0042] Figure 1 The diagram shown is a structural schematic of the first electrode provided in an embodiment of this application.

[0043] Figure 2 The diagram shown is a structural schematic of the second electrode provided in an embodiment of this application.

[0044] Figures 3-5 The diagram shown is a schematic diagram of the manufacturing process of the battery cell provided in the embodiment of this application.

[0045] Figures 6-8 The diagram shown is a schematic representation of the battery cell provided in an embodiment of this application. Figure 1 .

[0046] Figure 9 The diagram shown is a structural schematic of the energy storage device provided in an embodiment of this application. Figure 1 .

[0047] Figures 10-12 The diagram shown is a schematic representation of the battery cell provided in an embodiment of this application. Figure 2 .

[0048] Figure 13 The diagram shown is a structural schematic of the energy storage device provided in an embodiment of this application. Figure 2 .

[0049] Figure 14 The diagram shown is a schematic diagram of the structure of a battery cell with a lead-out portion provided in an embodiment of this application.

[0050] Figure 15 The diagram shows a flowchart of the battery cell manufacturing method provided in an embodiment of this application.

[0051] Explanation of reference numerals in the attached figures:

[0052] 1. Electrode; 10. First electrode; 101. First coated portion; 102. First uncoated portion; 11. Second electrode; 111. Second coated portion; 112. Second uncoated portion; 100. Cell; 100a. Bare cell;

[0053] 20. First electrode tab; 20a. First pre-bent electrode tab; 201. First part; 202. Second part;

[0054] 21. Second electrode tab; 21a. Second pre-bent electrode tab;

[0055] 23. First tab group; 231. First side surface; 232. Second side surface;

[0056] 24. Second pole ear group; 241. Third lateral surface; 242. Fourth lateral surface;

[0057] 25. First pre-bent tab group; 26. Second pre-bent tab group; 271. First cutting line; 272. Second cutting line; 273. Third cutting line;

[0058] 3a. First end face; 3b. Second end face;

[0059] 4. Central part;

[0060] 5. Lead-out section; 51. Cover plate; 52. Lead-out plate; 5a. First lead-out section; 5b. Second lead-out section;

[0061] 6. Sleeve; 61. Column; 62. Cover;

[0062] 200. Shell. Detailed Implementation

[0063] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0064] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0065] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0066] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0067] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0068] This application provides a method for preparing a battery cell, specifically, a method for preparing a multi-tab battery cell.

[0069] Reference Figures 1-15 The battery cell 100 includes an electrode 1 and a separator, wherein the electrode 1 has an uncoated portion at its end in the width direction.

[0070] Reference Figure 1 and Figure 2 The battery cell 100 includes a first electrode 10, a second electrode 11, and a separator. The first electrode 10 can be a positive electrode and the second electrode 11 can be a negative electrode, or the first electrode 10 can be a negative electrode and the second electrode 11 can be a positive electrode.

[0071] The first electrode 10 includes a first uncoated portion 102 and a first coated portion 101, with the first uncoated portion 102 located at the upper end of the first electrode 10 in the width direction. The second electrode 11 includes a second uncoated portion 112 and a second coated portion 111, with the second uncoated portion 112 located at the lower end of the second electrode 11 in the width direction.

[0072] Reference Figure 15 and Figures 3-8 and Figure 14 The method for manufacturing the battery cell 100 includes:

[0073] Step 1: The electrode 1 and the separator are wound together to form a bare cell 100a, the bare cell 100a having a central portion 4;

[0074] Step 2: Refer to Figure 3 The uncoated portion is cut along the axial direction of the bare cell 100a to form a plurality of pre-bent tabs arranged circumferentially along the bare cell 100a.

[0075] The uncoated portion is located on one side of the bare cell 100a in the axial direction; the plurality of pre-bent tabs include at least one first pre-bent tab 20a near the center portion 4 of the bare cell 100a and a plurality of second pre-bent tabs 21a away from the center portion 4 of the bare cell 100a.

[0076] Step 3: Refer to Figure 4 The first part 201 of the first pre-bent electrode tab 20a is processed by the first fixture;

[0077] Step 4: Refer to Figure 5 and Figure 6The second pre-bent electrode tab and the second part 202 of the first pre-bent electrode tab 20a are processed by the second fixture to form an electrode tab group;

[0078] The second pre-bent tab 21a and the second part 202 are flat and overlap each other, and the projection of the second part 202 in the axial direction of the bare cell 100a overlaps with the first part 201.

[0079] Step 5: Refer to Figure 14 A lead-out portion 5 is provided on the bare battery cell 100a. The lead-out portion 5 is covered on the electrode group and connected to the electrode group to form the battery cell 100.

[0080] In step 1, the first electrode 10, the separator, and the second electrode 11 are placed into a winding needle and wound to form a bare battery cell 100a. In this bare battery cell 100a structure, the first uncoated portion 102 of the first electrode 10 is located on one side of the bare battery cell 100a in the axial direction, and the second uncoated portion 112 of the second electrode 11 is located on the other side of the bare battery cell 100a in the axial direction.

[0081] In step 1, neither the first electrode 10 nor the second electrode 11 is die-cut with tabs before winding. Instead, after winding, the first uncoated portion 102 and the second uncoated portion 112 are processed to form a tab group. Therefore, in this embodiment, compared with the prior art where the electrode 1 is die-cut to form tabs before winding, the tab group formed after winding in this application can be arranged in separate areas, and the tabs in the tab group can be neatly arranged, avoiding the phenomenon of tabs being randomly arranged on the end face of the cell 100.

[0082] In step 1, a bare battery cell 100a is formed by winding the electrode 1 and the separator film. The bare battery cell 100a has a central portion 4. This central portion 4 is formed during the winding process of the battery cell 100. The central portion 4 can be a hollow central portion 4, a solid central portion 4, or a central portion 4 forming an axis. In the axial direction of the battery cell 100, the central portion 4 penetrates the battery cell 100, and its end is located on the end face of the battery cell 100. When the central portion 4 is hollow, the battery cell 100 forms a central hole.

[0083] In step 2, the first uncoated portion 102 is cut along the axial direction of the bare cell 100a to form a plurality (at least two) of first pre-bent electrode groups. The plurality of first pre-bent electrode groups are arranged circumferentially along the bare cell 100a. The first uncoated portion 102 is cut along the axial direction of the bare cell 100a to the junction of the first uncoated portion 102 and the first coated portion 101.

[0084] The second uncoated portion 112 is cut along the axial direction of the bare cell 100a to form a plurality of (at least two) second type of pre-bent electrode groups, which are arranged circumferentially along the bare cell 100a. The second uncoated portion 112 can be cut along the axial direction of the bare cell 100a to the junction of the second uncoated portion 112 and the second coated portion 111.

[0085] The difference between the first type of pre-bent tab group and the second type of pre-bent tab group is that their polarities are opposite.

[0086] Both the first type of pre-bent tab group and the second type of pre-bent tab group include at least one first pre-bent tab 20a near the center portion 4 of the bare cell 100a and a plurality of second pre-bent tabs 21a away from the center portion 4 of the bare cell 100a.

[0087] The first type of pre-bending tab group is processed to form a first type of tab group, which is arranged along the circumference of the battery cell 100; the second type of pre-bending tab group is processed to form a second type of tab group, which is arranged along the circumference of the battery cell 100.

[0088] In steps 3 and 4, the first pre-bent electrode tab 20a and the second pre-bent electrode tab 21a are processed using two fixtures.

[0089] Specifically, the first pre-bent electrode tab 20a is first processed by the first fixture, and then the second pre-bent electrode tab 21a is processed by the second fixture. Finally, the second pre-bent electrode tab 21a and the second part 202 of the first pre-bent electrode tab 20a are flat and overlap each other, and the projection of the second part 202 of the first pre-bent electrode tab 20a in the axial direction of the bare cell 100a overlaps with the first part 201 of the first pre-bent electrode tab 20a.

[0090] Specifically, the first pre-bent electrode tab 20a is processed by the first fixture and the second fixture, and the first pre-bent electrode tab 20a is bent to form the first electrode tab 20. The first electrode tab 20 includes two parts, namely a first part 201 and a second part 202, and the projection of the second part 202 in the axial direction of the cell 100 overlaps with the first part 201.

[0091] In this way, a portion of the first tab 20 is positioned relative to the first pre-bent tab 20a in the axial space of the cell 100, thus shortening the length of the first tab 20 relative to the first pre-bent tab 20a. Even in subsequent operations (e.g., step 4), the first tab 20 will not obstruct the center portion 4 of the cell 100. For example, in step 4, when the second pre-bent tab 21a and the second portion 202 of the first pre-bent tab 20a are processed by the second fixture to make the second portion 202 flat, the first tab 20 will not obstruct the center portion 4 of the cell 100.

[0092] The second pre-bent electrode tab 21a is processed by a second fixture to form the second electrode tab 21. The second electrode tab 21 is arranged along the radial direction of the cell 100, avoiding the scattered and irregular distribution of multiple second electrode tabs 21 on the end face of the cell 100. In this step, the uncoated portion is uniformly cut, and then the cut uncoated portion is uniformly processed, so that the final second electrode tab 21 is evenly distributed on the end face of the cell 100, and is flat and overlapping each other.

[0093] Furthermore, the first tab 20 and the second tab 21 arranged adjacent to each other overlap, which facilitates the connection of multiple tabs in the same tab group, making it easier to draw current from the same side in the axial direction of the cell 100.

[0094] In step 5, a lead-out portion 5 is provided on the bare cell 100a. The lead-out portion 5 is covered on the tab group and connected to the tab group to form the cell 100. Current is drawn out through the lead-out portion 5.

[0095] Therefore, in this embodiment of the application, the first part 201 of the first pre-bent electrode tab 20a is processed by the first fixture, and the second part 202 of the second pre-bent electrode tab 21a and the first pre-bent electrode tab 20a is processed by the second fixture, so that the first electrode tab 20 is set away from the center part 4 of the cell 100, the first electrode tab 20 will not block the center part 4 of the end face, and will not affect the normal use of the cell 100.

[0096] Furthermore, the tab group is formed by winding the electrode sheet 1 and the separator. In this way, the first tab 20 and the second tab 21 in each tab group can be arranged along the radial direction of the cell 100, avoiding misalignment of multiple tabs during the winding process and facilitating the connection of multiple tabs.

[0097] In one embodiment, refer to Figure 3 Cutting the uncoated portion along the axial direction of the bare battery cell 100a specifically includes:

[0098] The uncoated portion is cut at least three times along the axial direction of the bare cell 100a to form a first cutting line 271, a second cutting line 272, and a third cutting line 273; wherein the first cutting line 271 and the second cutting line 272 are parallel, and the third cutting line 273 is adjacent to and intersects the second cutting line 272; the first cutting line 271, the second cutting line 272, and the third cutting line 273 all extend to the circumferential edge of the bare cell 100a.

[0099] Specifically, the uncoated portion can be cut with a cutting blade; after cutting the uncoated portion once along the axial direction of the bare cell 100a, the position of the cutting blade is moved. During the second cut, the blade setting direction of the cutting blade is parallel to the direction of the first cutting line 271 formed during the first cut. Thus, after the second cut, the first cutting line 271 and the second cutting line 272 are parallel.

[0100] After the second cut is completed, the position of the cutting blade is moved again. During the third cut, the blade direction of the cutting blade is set to intersect with the direction of the second cutting line 272 formed during the second cut. Thus, after the third cut, the third cutting line 273 intersects with the second cutting line 272.

[0101] In this embodiment, multiple pre-bent tab groups are formed by repeatedly cutting the uncoated portion, with each pre-bent tab having a different shape. This facilitates the differentiation of the multiple pre-bent tab groups, allowing for the corresponding processing of a specific pre-bent tab group.

[0102] In one embodiment, refer to Figure 3 Multiple pre-bent electrode groups include a first pre-bent electrode group 25 and a second pre-bent electrode group 26;

[0103] The first pre-bent tab group 25 is defined between the first cutting line 271 and the second cutting line 272;

[0104] The second pre-bent tab group 26 is defined between the third cutting line 273 and the second cutting line 272.

[0105] Specifically, the first cutting line 271 and the second cutting line 272 are arranged parallel to each other, and the first pre-bent tab group 25 defined between the first cutting line 271 and the second cutting line 272 is rectangular.

[0106] The third cutting line 273 and the second cutting line 272 are intersected and the second pre-bent tab group 26 defined between the third cutting line 273 and the second cutting line 272 is fan-shaped.

[0107] The first pre-bent electrode lug group 25 is rectangular. After being processed by the first fixture and the second fixture, the first pre-bent electrode lug group 25 forms the first electrode lug group 23, which is also rectangular in structure. The second pre-bent electrode lug group 26 is fan-shaped. After being processed by the first fixture and the second fixture, the second pre-bent electrode lug group 26 forms the second electrode lug group 24, which is also fan-shaped in structure.

[0108] In this embodiment, multiple pre-bent tab groups of different shapes are formed by repeatedly cutting the uncoated portion. This facilitates the overlap of the first tab group 23 and the second tab group 24 during subsequent operations. When the first tab group 23 and the second tab group 24 are overlapped, a lead-out portion 5 is provided on the bare cell 100a. The lead-out portion 5 can be soldered to one or more tab groups. It is not necessary to solder the lead-out portion 5 to each tab group, which facilitates the soldering of the lead-out portion 5 to the tab groups.

[0109] Specifically, refer to Figure 6 After being processed, the first pre-bent tab group 25 forms the first tab group 23. The first tab group 23 has a first side surface 231 and a second side surface 232, which are parallel to each other.

[0110] After the second pre-bent tab group 26 is processed, a second tab group 24 is formed. The second tab group 24 has a third side surface 241 and a fourth side surface 242, and the extended surface of the third side surface 241 and the extended surface of the fourth side surface 242 intersect.

[0111] In one embodiment, refer to Figure 5 and Figure 6 The processing of the second pre-bent electrode tab and the second part 202 of the first pre-bent electrode tab 20a by the second fixture specifically includes:

[0112] First, the second pre-bent electrode in the first pre-bent electrode group 25 and the second part 202 of the first pre-bent electrode 20a are processed to form the first electrode group 23;

[0113] Then, the second pre-bent electrode in the second pre-bent electrode group 26 and the second part 202 of the first pre-bent electrode 20a are processed to form the second electrode group 24.

[0114] In this embodiment, the processing order of the first pre-bent electrode group 25 and the second pre-bent electrode group 26 is defined. The first pre-bent electrode group 25, which has a rectangular structure, is processed first. Specifically, the second pre-bent electrode and the second portion 202 of the first pre-bent electrode 20a in the first pre-bent electrode group 25 are processed to form the first electrode group 23. In the first electrode group 23, the first pre-bent electrode 20a is processed to form the first electrode 20, and the second pre-bent electrode 21a is processed to form the second electrode 21.

[0115] Then, the second pre-bent tab group 26 of the fan-shaped structure is processed. Specifically, the second pre-bent tab and the second part 202 of the first pre-bent tab 20a in the second pre-bent tab group 26 are processed to form the second tab group 24. In the second tab group 24, the second pre-bent tab 21a is processed to form the first tab 20, and the second pre-bent tab 21a is processed to form the second tab 21.

[0116] In this embodiment, after processing the first pre-bent tab group 25 and the second pre-bent tab group 26 in sequence, a portion of the second tab group 24 can be located above the first tab group 23. For example, by adjusting the flattening angle of the first pre-bent tab group 25 and the second pre-bent tab group 26, a portion of the second tab group 24 can be located above the first tab group 23.

[0117] In one embodiment, refer to Figures 6-8 ,as well as Figures 10-12 The first electrode group 23 and the second electrode group 24 partially overlap.

[0118] In this embodiment, after processing the first pre-bent electrode group 25 and the second pre-bent electrode group 26 in sequence, a first electrode group 23 and a second electrode group 24 are formed respectively. The first electrode group 23 and the second electrode group 24 partially overlap each other, which facilitates the lead-out portion 5 to be welded together with at least one of the electrode groups.

[0119] In an optional embodiment, the width of the second tab group 24 gradually decreases in the radial direction from away from the center portion 4 to near the center portion 4. For example, the second tab group 24 has a fan-shaped structure.

[0120] In this embodiment, the structure of the second tab group 24 is defined, and the width of the second tab group 24 gradually changes to facilitate contact between the second tab group 24 and the first tab group 23.

[0121] In one embodiment, refer to Figure 5 and Figure 6 ,as well as Figures 10-11The processing of the second pre-bent electrode tab and the second part 202 of the first pre-bent electrode tab 20a by the second fixture specifically includes:

[0122] A force is applied to the second pre-bent electrode tab and the second part 202 of the first pre-bent electrode tab 20a by the second fixture, so that the second pre-bent electrode tab and the second part 202 of the first pre-bent electrode tab 20a are laid down toward the center 4 of the bare cell 100a, thereby forming an electrode tab group.

[0123] Specifically, the second fixture applies a pressing force to the second pre-bent electrode tab, causing the second pre-bent electrode tab to be laid down towards the center 4 of the bare cell 100a to form the second electrode tab 21, which is then flattened towards the center 4. Each second electrode tab 21 is pressed in the same direction, resulting in a more uniform shape for the processed electrode tab group.

[0124] Specifically, the second fixture applies a pressing force to the second part 202 of the first pre-bent electrode tab 20a. The second part 202 is flattened toward the center 4, so that the partial projection of the second part 202 in the axial direction of the bare cell 100a overlaps with the first part 201.

[0125] In one embodiment, refer to Figure 4 The processing of the first portion 201 of the first pre-bent electrode tab 20a using the first fixture specifically includes:

[0126] The first fixture applies a force to the first pre-bent tab 20a, causing the first portion 201 to be oriented away from the center portion 4 of the bare cell 100a.

[0127] In this embodiment, a pressing force is applied to the first pre-bent tab 20a by the first fixture, so that the first part 201 of the first pre-bent tab 20a is set away from the center 4 of the bare cell 100a. The processed first tab 20 will not block the center 4 of the cell 100 and will not affect the normal use of the cell 100.

[0128] Specifically, the first electrode 20 includes a first part 201 and a second part 202. One end of the first part 201 is connected to the electrode 1, and the other end of the first part 201 is connected to the second part 202. One end of the second part 202 is connected to the first part 201, and the other end of the second part 202 is a free end.

[0129] The first part 201 is oriented toward the direction away from the center of the end face 4. For example, the end of the first part 201 away from the end face is oriented toward the direction away from the center of the end face 4. The second part 202 is oriented toward the direction close to the center of the end face 4. For example, the free end of the second part 202 is oriented toward the direction close to the center of the end face 4.

[0130] In one example, the first part 201 is inclined toward the direction away from the center of the end face 4, and the second part 202 is inclined toward the direction close to the center of the end face 4. In this case, the first part 201 and the second part 202 may not be attached together. Or in another example, the first part 201 is inclined toward the direction away from the center of the end face 4, and the second part 202 is inclined toward the direction close to the center of the end face 4. The first part 201 and the second part 202 are attached together.

[0131] In this embodiment, by limiting the bending direction of the first part 201 of the first tab 20, the bent first tab 20 will not block the center part 4 of the end face, and will not affect the normal use of the battery cell 100.

[0132] In one embodiment, the bare cell 100a has a central hole, and before processing the first portion 201 of the first pre-bent tab 20a by the first fixture, the method further includes: placing the first fixture inside the central hole.

[0133] Figures 6-8 The provided structural diagram of the battery cell is consistent with... Figures 10-12 The differences in the provided cell structure diagrams are as follows: Figures 6-8 The first fixture was not removed from the central part 4, and Figures 10-12 The first fixture was removed from the central part 4.

[0134] Specifically, refer to Figure 7 The first fixture is placed inside the central hole, and then the first pre-bent tab 20a is processed through the first fixture. In this way, under the continuous force of the first fixture, it can be ensured that the shape of the first tab 20 does not change.

[0135] In an optional embodiment, refer to Figure 12 Other tooling fixtures can be used to bend the first pre-bent tab 20a, and then the other tooling fixtures can be removed. Although the tooling fixtures are removed, because the first tab 20a has been bent, even if the second part 202 is set towards the center part 4 under the action of the external force of the second fixture, the second part 202 will not block the center part 4.

[0136] In one embodiment, refer to Figure 9 Setting the first fixture within the central hole specifically includes:

[0137] The first fixture includes a column 61 and a cover 62 connected to the column 61, the column 61 extending into the central hole, and the first portion 201 located below the cover 62.

[0138] In this embodiment, the first electrode 20 includes a first part 201 and a second part 202, wherein one end of the first part 201 is connected to the electrode 1, the other end of the first part 201 is connected to the second part 202, one end of the second part 202 is connected to the first part 201, and the other end of the second part 202 is a free end.

[0139] The first part 201 is oriented toward the direction away from the center of the end face 4. For example, the end of the first part 201 away from the end face is oriented toward the direction away from the center of the end face 4. The second part 202 is oriented toward the direction close to the center of the end face 4. For example, the free end of the second part 202 is oriented toward the direction close to the center of the end face 4.

[0140] This creates an opening between the first part 201 and the second part 202, with the opening end facing the center of the end face 4.

[0141] The opening defines a bending area, within which the cover 62 is located. In this embodiment, the first tab 20 is processed so that it does not obstruct the central hole.

[0142] Specifically, a first fixture is fitted into the center hole of the battery cell 100. The first fixture is a sleeve 6. The sleeve 6 presses the first pre-bent electrode tab 20a outward (towards the direction away from the center portion 4) to form a pre-bent structure. The pre-bent structure includes a first part 201 and a second part 202. The first part 201 is pressed under the sleeve 6, and the second part 202 is inclined towards the direction away from the center portion 4.

[0143] Then, the second tab 21 and the second part 202 are pressed towards the center part 4. At this time, under the action of external force, the second part 202 is attached to the upper surface of the sleeve 6. In this embodiment, the first pre-bent tab 20a is processed by the sleeve 6, which shortens the length of the first tab 20, so that the first tab 20 will not block the center hole.

[0144] In an optional embodiment, the second portion 202 is disposed away from the end face relative to the first portion 201; in the radial direction of the cell 100, the second portion 202 extends out of the first portion 201, wherein there is a blank area between the second portion 202 and the center portion 4 of the end face.

[0145] In this embodiment, one end of the first portion 201 is connected to the electrode 1, the other end of the first portion 201 is connected to the second portion 202, one end of the second portion 202 is connected to the first portion 201, and the other end of the second portion 202 is a free end. Therefore, in the axial direction of the cell 100, the second portion 202 is positioned away from the end face relative to the first portion 201.

[0146] In this embodiment, the free end of the second part 202 is positioned toward the center of the end face 4, and there is a blank area between the free end of the second part 202 and the center of the end face 4, so that the first tab 20 will not block the center of the end face 4.

[0147] In an optional embodiment, the first pre-bent electrode tab 20a is bent using a sleeve 6 or a tooling fixture, aligning the two sides of the first part 201 and the two sides of the second part 202, resulting in a neat structure after bending. The second pre-bent electrode tab 21a is then pressed using other fixtures, ensuring that the second electrode tab 21 is neatly and flatly positioned on the end face.

[0148] Alternatively, without considering the neatness of the first tab 20 being pressed down, a tooling fixture can be used to randomly press down the first pre-bent tab 20a (for example, the first part 201 and the second part 202 are misaligned in the circumferential direction of the cell 100), and then the second tab group 24 can be randomly pressed down, for example, adjacent second tabs 21 are misaligned in the circumferential direction of the cell 100.

[0149] Secondly, a battery cell 100 is provided. The battery cell 100 is manufactured using the battery cell 100 manufacturing method described in the first aspect.

[0150] In one embodiment, refer to Figures 6-8 and Figures 10-12 The battery cell 100 has an end face, and the end face has a plurality of electrode groups, which are arranged along the circumference of the battery cell 100.

[0151] Each of the electrode groups includes at least one first electrode 20 and a plurality of second electrodes 21, wherein the first electrode 20 is disposed closer to the center portion 4 of the cell 100 relative to the second electrode 21;

[0152] The first tab 20 includes a first part 201 and a second part 202, wherein the projection of the second part 202 in the axial direction of the cell 100 overlaps with the first part 201.

[0153] Multiple second electrode tabs 21 are flatly disposed on the end face, and adjacent second electrode tabs 21 overlap each other in the radial direction of the cell 100;

[0154] The first electrode 20 and the second electrode 21, which are arranged adjacently, overlap each other;

[0155] The battery cell 100 also includes a lead-out portion 5, which covers the electrode group and is connected to the electrode group.

[0156] Specifically, the battery cell 100 has end faces, including a first end face 3a and a second end face 3b. Both the first end face 3a and the second end face 3b of the battery cell 100 have multiple groups of tabs, which are arranged circumferentially along the battery cell 100. For example, the first end face 3a and the second end face 3b may be completely covered with tab groups.

[0157] In this embodiment, each electrode group includes a first electrode 20 and a second electrode 21, wherein the first electrode 20 is formed by a first pre-bent electrode 20a, and the second electrode 21 is formed by a second pre-bent electrode 21a. The first electrode 20 is positioned closer to the center portion 4 than the second electrode 21.

[0158] In this embodiment of the application, the first pre-bent electrode tab 20a located on the inner side is processed to form the first electrode tab 20, which shortens the length of the first electrode tab 20 after it is flattened. The first electrode tab 20 is disposed on the end face, which avoids the phenomenon that the first electrode tab 20 blocks the center part 4 of the end face.

[0159] Specifically, refer to Figures 6-8 and reference Figures 10-12 The first tab 20 includes a first part 201 and a second part 202. The projection of the second part 202 in the axial direction of the cell 100 overlaps with the first part 201. This shortens the length of the first tab 20, and the first tab 20 will not block the center part 4 of the end face.

[0160] The second tabs 21 are arranged along the radial direction of the cell 100, avoiding the scattered and irregular distribution of multiple second tabs 21 on the end face of the cell 100. For example, in the embodiment of this application, multiple second tabs 21 are arranged regularly on the end face, and are flat and overlapping each other, which is beneficial to connecting multiple second tabs 21 in the same second sub-tab group, and facilitates the extraction of current from the same side in the axial direction of the cell 100.

[0161] Furthermore, the first tab 20 and the second tab 21, which are arranged adjacent to each other, overlap each other, which is beneficial for connecting multiple tabs in the same tab group and making it easier to draw current from the same side in the axial direction of the cell 100.

[0162] The battery cell 100 also includes a lead-out section 5, which is disposed on the end face of the battery cell 100 and welded to the tab group on the end face, through which current is led out.

[0163] Therefore, in this embodiment, the first tab 20 in the first sub-tab group is bent so that the first sub-tab group is located away from the center of the end face 4. The first tab 20 of the first sub-tab group will not block the center of the end face 4 and will not affect the normal use of the cell 100.

[0164] In addition, the tab group is formed by winding the electrode sheet 1 and the separator. In this way, the multiple tabs included in each tab group can be arranged along the radial direction of the cell 100, avoiding misalignment of multiple tabs during the winding process and facilitating the connection of multiple tabs.

[0165] In an optional embodiment, the first end face 3a has a group of tabs connected to the first electrode 10, and the group of tabs has an insulating portion between it and the second electrode 11.

[0166] In this embodiment, the first end face 3a of the battery cell 100 has a group of tabs, including a first group of tabs 23 and a second group of tabs 24. The tabs included in the first group of tabs 23 and the second group of tabs 24 are disposed on the first end face 3a. Both the first group of tabs 23 and the second group of tabs 24 have an insulating portion between them and the second electrode 11 to prevent the tabs connected to the first electrode 10 from directly contacting the second electrode 11 and causing a short circuit in the battery cell 100. For example, the insulating portion can be a separator film disposed between the first electrode 10 and the second electrode 11.

[0167] For example, refer to Figure 1 and Figure 2 When the first electrode 10, the separator, and the second electrode 11 are stacked and wound, the upper end of the second electrode 11 in the width direction does not overlap with the upper end of the first electrode 10 in the width direction. The first electrode 10 has a first uncoated portion 102 at its upper end in the width direction.

[0168] The upper end of the second electrode 11 in the width direction does not overlap with the upper end of the first electrode 10 in the width direction. Specifically, the upper end of the second electrode 11 in the width direction is lower than the upper end of the first electrode 10 in the width direction. Meanwhile, the upper end of the separator between the first electrode 10 and the second electrode 11 is higher than the upper end of the second electrode 11. For example, the upper end of the second electrode 11 in the width direction is lower than the boundary between the first uncoated portion 102 and the first coated portion 101 in the first electrode 10. The upper end of the separator is higher than the boundary between the first uncoated portion 102 and the first coated portion 101 in the first electrode 10.

[0169] After winding, the first uncoated portion 102 is cut along the axial direction of the cell 100 to the junction of the first uncoated portion 102 and the first coated portion 101. Then the first uncoated portion 102 is flattened, and the separator is also flattened. The first uncoated portion 102 and the second electrode 11 are separated by the separator to prevent the first uncoated portion 102 and the second electrode 11 from contacting each other.

[0170] Similarly, when the first electrode 10, the separator, and the second electrode 11 are stacked and wound, the lower end of the first electrode 10 in the width direction does not overlap with the lower end of the second electrode 11 in the width direction. Specifically, the lower end of the first electrode 10 in the width direction is higher than the lower end of the second electrode 11 in the width direction, while the lower end of the separator between the first electrode 10 and the second electrode 11 is lower than the lower end of the first electrode 10. For example, the lower end of the first electrode 10 in the width direction is higher than the junction of the second uncoated portion 112 and the second coated portion 111 in the second electrode 11. The lower end of the separator is lower than the lower end of the first electrode 10.

[0171] In an optional embodiment, refer to Figure 14 The lead-out portion 5 includes a cover plate 51 and a lead-out plate 52, with the lead-out plate 52 disposed on the cover plate 51; the cover plate 51 covers the first electrode group 23 and the second electrode group 24.

[0172] Specifically, a cover plate 51 is disposed on the end face of the battery cell 100, covering the first tab group 23 and the second tab group 24. The cover plate 51 is welded to at least one of the first tab group 23 and the second tab group 24. Thus, a welding point is formed between the first tab group 23 and the cover plate 51, and / or between the second tab group 24 and the cover plate 51. Optionally, the cover plate 51 is welded to each tab group on the end face of the battery cell 100.

[0173] The lead-out section 5 includes a cover plate 51 and a lead-out plate 52, which can be an integral structure. The lead-out plate 52 is used to connect to the housing 200.

[0174] It should be noted that when the cover plate 51 is welded to the first tab group 23 or the second tab group 24, the first tab group 23 and the adjacent second tab group 24 are partially overlapped, ensuring the normal current output of the cell 100. For example, if the cover plate 51 is welded to the first tab group 23, and the second tab group 24 and the first tab group 23 are partially overlapped, it is equivalent to the cover plate 51 and the second tab group 24 being indirectly connected, thus ensuring the normal current output of the cell 100.

[0175] Thirdly, an energy storage device is provided. (Refer to...) Figure 9 and Figure 13 The energy storage device includes a housing 200 and a battery cell 100 as described in the second aspect;

[0176] The lead-out part 5 is connected to the housing 200.

[0177] For example, the energy storage device is a battery. The battery includes a casing 200, and the lead-out portion 5 of the cell 100 is electrically connected to the casing 200. For example, the casing 200 includes a casing body and a cap assembly, and the lead-out portion 5 of the cell 100 can be electrically connected to the casing body, or the lead-out portion 5 of the cell 100 can also be electrically connected to the cap assembly.

[0178] Reference Figure 9 and Figure 13 A group of tabs is provided on the upper end face (first end face 3a) of the battery cell 100. The group of tabs includes a first group of tabs 23 and a second group of tabs 24. A first lead-out portion 5a is covered on the upper end face of the battery cell 100. The first lead-out portion 5a is welded to the first group of tabs 23 and / or the second group of tabs 24. The first lead-out portion 5a is connected to the cap assembly of the housing 200.

[0179] The lower end face (second end face 3b) of the battery cell 100 is also provided with a group of tabs, including a first group of tabs 23 and a second group of tabs 24. The second lead-out portion 5b is covered on the lower end face of the battery cell 100. The second lead-out portion 5b is welded to the first group of tabs 23 and / or the second group of tabs 24. The second lead-out portion 5b is connected to the shell body of the housing 200.

[0180] Fourthly, an electronic device is provided. The electronic device includes the energy storage device described in the third aspect. For example, the electronic device may be a mobile phone, tablet computer, watch, or other types of smart wearable devices.

[0181] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0182] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A method for manufacturing a battery cell, characterized in that, The battery cell includes an electrode and a separator. The electrode has an uncoated portion at its width end. The uncoated portion is provided with a length equal to the length of the electrode along its length direction. The cell manufacturing method includes: The electrode and the separator are wound together to form a bare cell, the bare cell having a central portion, wherein the uncoated portion is located on one side of the bare cell in the axial direction; The uncoated portion is cut along the axial direction of the bare battery cell to form a plurality of pre-bent tabs arranged circumferentially along the bare battery cell; The plurality of pre-bent tab groups include at least one first pre-bent tab (20a) near the center of the bare cell and a plurality of second pre-bent tabs away from the center of the bare cell; The bare battery cell has a central hole. The first part (201) of the first pre-bent tab (20a) is processed by a first fixture. The first fixture includes a column (61) and a cover (62). The cover (62) is located on the periphery of the column (61) and connected to the column (61). The column (61) extends into the central hole. The cover (62) acts on the first part (201) of the first pre-bent tab (20a) so that the first part (201) is disposed away from the center of the bare battery cell and is located under the cover (62). Then, the second pre-bent tab (21a) and the second part (202) of the first pre-bent tab (20a) are pressed toward the center (4) by the second fixture, so that the second pre-bent tab (21a) and the second part (202) of the first pre-bent tab (20a) are laid down toward the center (4) of the bare cell, and at least part of the second part (202) of the first pre-bent tab (20a) after being pressed covers the cover (62). The first part (201) of the first pre-bent electrode (20a) after processing, and the second part (202) of the second pre-bent electrode (21a) and the first pre-bent electrode (20a) after processing form an electrode group; The second pre-bent tab (21a) and the second part (202) are flat and overlap each other, and the projection of the second part (202) in the axial direction of the bare cell overlaps with the first part (201); A lead-out portion (5) is provided on the bare battery cell. The lead-out portion (5) is covered on the tab group and connected to the tab group to form the battery cell.

2. The cell manufacturing method according to claim 1, characterized in that, Cutting the uncoated portion along the axial direction of the bare battery cell specifically includes: The uncoated portion is cut at least three times along the axial direction of the bare cell to form a first cutting line (271), a second cutting line (272), and a third cutting line (273). The first cutting line (271) and the second cutting line (272) are parallel, and the third cutting line (273) is adjacent to and intersects the second cutting line (272); the first cutting line, the second cutting line and the third cutting line all extend to the circumferential edge of the bare cell.

3. The cell manufacturing method according to claim 2, characterized in that, Multiple pre-bent electrode groups include a first pre-bent electrode group (25) and a second pre-bent electrode group (26); The first pre-bent tab group (25) is defined between the first cutting line and the second cutting line. The second pre-bent tab group (26) is defined between the third cutting line and the first cutting line.

4. The cell manufacturing method according to claim 3, characterized in that, The processing of the second pre-bent electrode tab (21a) and the second part (202) of the first pre-bent electrode tab (20a) using the second fixture specifically includes: First, the second pre-bent electrode (21a) in the first pre-bent electrode group (25) and the second part (202) of the first pre-bent electrode (20a) are processed to form the first electrode group (23). Then, the second pre-bent electrode (21a) in the second pre-bent electrode group (26) and the second part (202) of the first pre-bent electrode (20a) are processed to form the second electrode group (24).

5. The cell manufacturing method according to claim 4, characterized in that, The first electrode group (23) and the second electrode group (24) partially overlap.

6. A battery cell, characterized in that, The battery cell is prepared using the battery cell preparation method as described in any one of claims 1-5.

7. The battery cell according to claim 6, characterized in that, The battery cell has an end face, and the end face has a plurality of electrode groups, which are arranged circumferentially along the battery cell; wherein, the battery cell includes an electrode sheet and a separator film, the electrode sheet has an uncoated portion at its width end, and the uncoated portion is provided with a length equal to the length of the electrode sheet along its length direction; Each of the electrode groups includes at least one first electrode (20) and a plurality of second electrodes (21), wherein the first electrode (20) is disposed closer to the center of the cell than the second electrode (21); The first tab (20) includes a first part (201) and a second part (202), wherein the first part (201) is disposed facing away from the center of the battery cell; the second part (202) is partially projected in the axial direction of the battery cell and overlaps with the first part (201); Multiple second tabs (21) are flatly disposed on the end face, and adjacent second tabs overlap each other in the radial direction of the cell; The first electrode (20) and the second electrode, which are arranged adjacent to each other, overlap each other; The battery cell also includes a lead-out portion, which covers the electrode group and is connected to the electrode group.

8. An energy storage device, characterized in that, The energy storage device includes a battery cell and a housing (200) as described in claim 6 or claim 7, wherein the lead-out portion (5) is connected to the housing (200).

9. An electronic device, characterized in that, The electronic device includes the energy storage device as described in claim 8.

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