Battery cell and preparation method thereof, battery and electronic equipment

Abstract

The invention discloses a battery cell and a preparation method thereof, a battery and electronic equipment, and the preparation method of the battery cell comprises the following steps: obtaining a pole piece which is provided with a main body area and a first empty foil area which are distributed along the length direction of the pole piece; the first empty foil area is located at the ending end of the main body area, the first empty foil area comprises a first leading-out section and a second leading-out section, the first leading-out section is connected with the main body area, and the second leading-out section is used for being connected with a first pole piece; folding the second leading-out section of the first empty foil area to one side of the width direction of the pole piece; winding the pole piece by taking the ending end of the main body area as a terminal to obtain a winding core; first adhesive paper is pasted to the side face of the roll core, so that the first adhesive paper covers the ending end of the roll core, and part of the first adhesive paper is located on the side, close to the center of the roll core, of the first leading-out section; and folding the second leading-out section to one side, deviating from the center of the roll core, of the first gummed paper to obtain the battery core.

Description

Technical Field

[0001] The present invention belongs to the technical field of batteries, and in particular relates to a battery cell and a preparation method thereof, a battery and an electronic device. Background Art

[0002] In the traditional battery cell manufacturing process, the end of the winding core of the wound battery cell is usually fixed by adhesive tape. However, in the related art, when the pole lug is led out from the side of the winding core, the adhesive tape often needs to avoid the part where the pole piece connects to the pole lug in the width direction of the pole piece, so only narrow adhesive tape can be used for bonding. This method limits the fixing range of the adhesive tape, and the stability of the battery cell structure is low. Summary of the invention

[0003] The first objective of the present invention is to provide a new technical solution for a battery cell preparation method, which can at least solve the technical problem of insufficient structural stability of the existing battery cells due to the tabs being led out from the side of the winding core.

[0004] The second object of the present invention is to provide a new technical solution for battery cells.

[0005] The third object of the present invention is to provide a new technical solution for batteries.

[0006] A fourth object of the present invention is to provide a new technical solution for electronic equipment.

[0007] According to a first aspect of the present invention, there is provided a method for preparing a battery cell, comprising: obtaining a pole piece, the pole piece having a main body area and a first empty foil area distributed along its length direction; the first empty foil area is located at the tail end of the main body area, the first empty foil area comprises a first lead-out section and a second lead-out section, the first lead-out section is connected to the main body area, and the second lead-out section is used to connect to the first pole piece; folding the second lead-out section of the first empty foil area to one side in the width direction of the pole piece; winding the pole piece with the tail end of the main body area as the terminal end to obtain a winding core; sticking a first adhesive tape to the side of the winding core so that the first adhesive tape covers the tail end of the winding core and a portion of the first adhesive tape is located on a side of the first lead-out section close to the center of the winding core; folding the second lead-out section to a side of the first adhesive tape away from the center of the winding core to obtain a battery cell.

[0008] Optionally, the first lead-out section and the second lead-out section are distributed along the length direction or the width direction of the pole piece.

[0009] Optionally, the step of obtaining the electrode sheet includes: obtaining a base material, the base material being provided with a main body area and a first empty foil area distributed along its length direction, the first empty foil area being located at the tail end of the main body area, the first empty foil area including a first lead-out section and a second lead-out section; cutting a connection between the main body area and the first empty foil area from one side in the width direction of the base material.

[0010] Optionally, the battery cell preparation method further includes: welding the first end of the first pole lug to the second lead-out section before winding the pole piece; or, welding the first end of the first pole lug to the second lead-out section after pasting the first adhesive tape.

[0011] Optionally, the battery cell preparation method further includes: sticking a second adhesive tape to a side of the first adhesive tape away from the center of the winding core, and making the second adhesive tape cover the second lead-out section and the first end of the first electrode tab.

[0012] Optionally, the main body area has two tail ends, and the two tail ends are respectively connected to the first empty foil area, and the step of winding the pole piece with the tail end of the main body area as the terminal includes: folding the pole piece in half along the length direction of the pole piece so that the two first empty foil areas are aligned; and winding the folded pole piece with the tail end of the main body area as the terminal.

[0013] Optionally, the battery cell preparation method further includes: before bonding the second adhesive tape, welding the first pole pieces corresponding to the two tail ends together.

[0014] Optionally, the main area includes a plurality of active areas and a second empty foil area distributed along the length direction of the pole piece, the second empty foil area is connected between the two active areas, the second empty foil area includes a third lead-out segment and a fourth lead-out segment, the third lead-out segment is connected to the active area, and the fourth lead-out segment is used to connect the second pole ear. The battery cell preparation method also includes: before winding the pole piece, folding the fourth lead-out segment of the second empty foil area to one side in the width direction of the pole piece; after pasting the first adhesive tape, folding the fourth lead-out segment of the second empty foil area to the side of the winding core.

[0015] Optionally, the step of obtaining the electrode piece further includes: cutting the connection between the active area and the second empty foil area from one side in the width direction of the base material.

[0016] Optionally, the battery cell preparation method further includes: welding the first end of the second pole piece to the fourth lead-out section before winding the pole piece; or, welding the first end of the second pole piece to the fourth lead-out section after affixing the first adhesive tape.

[0017] Optionally, the second pole tab is stacked with the first pole tab, and the battery cell preparation method further includes: welding the second pole tab and the first pole tab together after pasting the first adhesive tape.

[0018] Optionally, the winding core is configured to be flat, the length of the winding core is greater than the width of the winding core, the width direction of the winding core is the same as the width direction of the pole piece, and the first pole piece is arranged on the side of the length direction of the winding core.

[0019] According to a second aspect of the present invention, a battery cell is provided. The battery cell is manufactured by any of the above battery cell manufacturing methods.

[0020] According to a third aspect of the present invention, a battery is provided, comprising the above-mentioned battery cell.

[0021] According to a fourth aspect of the present invention, there is provided an electronic device comprising the above-mentioned battery.

[0022] According to the battery cell preparation method of the present invention, the second lead-out section of the electrode sheet is folded to the side and then wound into a core, so that when the tail end of the core is fixed, the second lead-out section and the first pole ear will not interfere with the winding of the first adhesive tape in the winding direction, which can improve the pasting efficiency of the first adhesive tape, and thus can increase the production efficiency of the battery cell; and the first adhesive tape can fix the tail position of the first lead-out section corresponding to the core and the remaining tail positions of the core, which can improve the stability of the battery cell structure, reduce the risk of disintegration, and ensure the performance and safety of the battery; after the first adhesive tape is bonded, the first empty foil area can be folded again to fold the second lead-out section to the side of the core, so that the first electrode sheet can be led out from the side of the core.

[0023] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0025] Figure 1 is a schematic structural diagram of an electrode sheet of a battery cell in step S10 according to an embodiment of the present invention;

[0026] Figure 2 is a schematic structural diagram of an electrode sheet of a battery cell in step S10 according to another embodiment of the present invention;

[0027] Figure 3 is a schematic structural diagram of an electrode sheet of a battery cell in step S10 according to another embodiment of the present invention;

[0028] Figure 4 is a schematic structural diagram of an electrode sheet of a battery cell in step S20 according to an embodiment of the present invention;

[0029] Figure 5 is a schematic structural diagram of an electrode sheet of a battery cell in step S20 according to another embodiment of the present invention;

[0030] Figure 6 is a schematic structural diagram of an electrode sheet of a battery cell in step S20 according to another embodiment of the present invention;

[0031] Figure 7 is a schematic structural diagram of an electrode sheet of a battery cell in step S20 according to another embodiment of the present invention;

[0032] Figure 8 is a schematic structural diagram of a battery cell in step S40 according to an embodiment of the present invention;

[0033] Fig. 9 It is a schematic diagram of the structure of a battery cell according to an embodiment of the present invention.

[0034] Reference numerals:

[0035] 100. Battery cell;

[0036] 10, pole piece; 11, first empty foil area; 11a, first lead-out section; 11b, second lead-out section; 12, active area; 13, second empty foil area; 13a, third lead-out section; 13b, fourth lead-out section;

[0037] 20. first electrode tab; 30. first adhesive tape; 40. second adhesive tape. DETAILED DESCRIPTION

[0038] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0039] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0040] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0041] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0042] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0043] The method for preparing a battery cell according to an embodiment of the present invention is described in detail below with reference to the accompanying drawings.

[0044] like Figures 1 to 9 As shown, the method for preparing a battery cell according to an embodiment of the present invention includes: S10 to S50.

[0045] S10, obtain the electrode 10, the electrode 10 has a main body area and a first empty foil area 11 distributed along its length direction, the first empty foil area 11 is located at the tail end of the main body area, the first empty foil area 11 includes a first lead-out section 11a and a second lead-out section 11b, the first lead-out section 11a is connected to the main body area, and the second lead-out section 11b is used to connect to the first electrode 10.

[0046] It should be noted that the obtained electrode sheets 10 include positive electrode sheets 10 and negative electrode sheets 10, each of which has a main body area and a first empty foil area 11 distributed along its own length direction. When the electrode sheet 10 is a positive electrode sheet 10, the first electrode ear 20 is a positive electrode ear, and when the electrode sheet 10 is a negative electrode sheet 10, the first electrode ear 20 is a negative electrode ear.

[0047] S20, folding the second lead-out section 11b of the first empty foil area 11 to one side in the width direction of the electrode sheet 10;

[0048] In detail, Figures 3 to 6 As shown, the second lead-out section 11b is folded to one side of the width direction of the electrode sheet 10 by folding the first empty foil area 11, so that the second lead-out section 11b and the main area are staggered in the width direction of the electrode sheet 10. In this embodiment, the second lead-out section 11b of the positive electrode sheet 10 and the second lead-out section 11b of the negative electrode sheet 10 are in opposite directions, that is, the second lead-out section 11b of the positive electrode sheet 10 is located on the first side of the width direction of the electrode sheet 10, and the second lead-out section 11b of the negative electrode sheet 10 is located on the second side of the width direction of the electrode sheet 10.

[0049] S30, winding the pole piece 10 with the tail end of the main body region as the terminal to obtain a winding core;

[0050] Specifically, the positive electrode sheet 10, the first separator, the negative electrode sheet 10 and the second separator are first stacked in sequence, and then the stacked positive electrode sheet 10, the first separator, the negative electrode sheet 10 and the second separator are wound together using a winding device with the tail end of the main area as the terminal to form a winding core.

[0051] S40, sticking the first adhesive tape 30 to the side of the reel core, so that the first adhesive tape 30 covers the tail end of the reel core, and a portion of the first adhesive tape 30 is located on a side of the first lead-out section 11a close to the center of the reel core;

[0052] In detail, Figure 8 As shown, the first portion of the first adhesive tape 30 is first adhered to the outer side surface of the tail end of the core, and then the first adhesive tape 30 is continued to be wrapped around the side of the core along the winding direction of the core, so that the first adhesive tape 30 covers the tail end of the core, and a portion of the first adhesive tape 30 is located on the side of the first lead-out section 11a close to the center of the core, so that the first lead-out section 11a corresponding to the tail position of the core and the remaining tail positions of the core can be fixed in the winding direction of the core, thereby increasing the fixing range and ensuring the tightening effect.

[0053] S50 , fold the second lead-out section 11 b to the side of the first adhesive tape 30 away from the center of the winding core to obtain the battery cell 100 .

[0054] Specifically, Fig. 9 As shown, after the first adhesive tape 30 is pasted, the second lead section 11b is folded to the side of the first adhesive tape 30 away from the center of the winding core by folding the first empty foil area 11 again, so that the second lead section 11b of the first pole piece 10 is located on the side of the winding core, thereby obtaining the desired battery cell 100.

[0055] Therefore, according to the battery cell preparation method of the embodiment of the present invention, by folding the second lead-out section 11b of the pole piece 10 to the side and then winding it into a core, when fixing the tail end of the core, the second lead-out section 11b and the first pole ear 20 will not interfere with the winding of the first adhesive tape 30 in the winding direction, which can improve the pasting efficiency of the first adhesive tape 30, and thus can provide the production efficiency of the battery cell 100; and the first adhesive tape 30 can fix the tail position of the first lead-out section 11a corresponding to the core and the other tail positions of the core, which can improve the structural stability of the battery cell 100, reduce the risk of disintegration, and ensure the battery performance and safety; after the first adhesive tape 30 is bonded, the first empty foil area 11 can be folded again to fold the second lead-out section 11b to the side of the core, so that the first pole piece 10 can be led out from the side of the core.

[0056] According to one embodiment of the present invention, the first lead-out section 11 a and the second lead-out section 11 b are distributed along the length direction or the width direction of the pole piece 10 .

[0057] That is to say, the distribution directions of the first lead-out section 11a and the second lead-out section 11b include but are not limited to the following situations:

[0058] Case 1: The first lead-out section 11a and the second lead-out section 11b are distributed along the length direction of the pole piece 10. When the first empty foil area 11 is folded for the first time, the first empty foil area 11 is folded ninety degrees to fold the second lead-out section 11b to one side in the width direction of the main area. In this case, the first lead-out section 11a is formed into a triangle.

[0059] Case 2: The first lead-out section 11a and the second lead-out section 11b are distributed along the width direction of the electrode 10. When the first empty foil area 11 is folded for the first time, the first empty foil area 11 is folded 180 degrees (i.e., folded along a straight line extending in its width direction) to fold the second lead-out section 11b to one side in the width direction of the main area. In this case, the first lead-out section 11a is formed into a rectangle.

[0060] In some specific embodiments of the present invention, the step of obtaining the pole piece 10 includes: S11 and S12.

[0061] S11, obtaining a mother material, wherein the mother material is provided with a main body area and a first empty foil area 11 distributed along its length direction, wherein the first empty foil area 11 is located at the end of the main body area, and the first empty foil area 11 includes a first lead-out section 11a and a second lead-out section 11b;

[0062] It should be noted that the mother material includes the negative electrode sheet 10 mother material and the positive electrode sheet 10 mother material. The mother material is a sheet structure with uniform width. The mother material has the main area and the first empty foil area 11 required for the electrode sheet 10 distributed along its length.

[0063] S12, cutting the connection between the main body area and the first empty foil area 11 from one side in the width direction of the base material.

[0064] Specifically, when the first lead-out section 11a and the second lead-out section 11b are distributed along the width direction of the pole piece 10, the connection between the main area and the first empty foil area 11 can be cut from one side of the width direction of the base material, so that the second lead-out section 11b can be disconnected from the main area, and the connection length between the first lead-out section 11a and the main area can be adjusted, so that the second lead-out section 11b can be folded to one side of the width direction of the main area, and the connection length between the first lead-out section 11a and the main area can be controlled according to actual needs, for example, the connection length between the first lead-out section 11a and the main area is controlled to be less than the width of the pole piece 10, so that the connection between the first lead-out section 11a and the main area forms an overcurrent protection point. When the current in the battery increases abnormally and exceeds its design tolerance range, the overcurrent protection point will fuse and cause a short circuit, thereby effectively avoiding thermal runaway of the battery and effectively improving the safety of the battery.

[0065] When the first lead-out section 11a and the second lead-out section 11b are distributed along the length direction of the pole piece 10, the connection between the main body area and the first empty foil area 11 (i.e., the connection between the main body area and the first lead-out section 11a) is cut from one side in the width direction of the base material, so that the connection length between the first lead-out section 11a and the main body area can be reduced, so that the connection between the first lead-out section 11a and the main body area forms an overcurrent protection point. When the current in the battery increases abnormally and exceeds its design tolerance range, the overcurrent protection point will fuse and cause a short circuit, thereby effectively avoiding thermal runaway of the battery and effectively improving the safety of the battery.

[0066] In some optional examples of the present invention, the battery cell preparation method also includes: before winding the pole piece 10, welding the first end of the first pole ear 20 to the second lead-out section 11b; or, after pasting the first adhesive tape 30, welding the first end of the first pole ear 20 to the second lead-out section 11b.

[0067] That is, the timing of welding the first electrode tab 20 includes but is not limited to the following situations:

[0068] Case 1: Before winding the pole piece 10, the first end of the first pole tab 20 is welded to the second lead-out section 11b. For example, the first pole tab 20 can be welded to the second lead-out section 11b before the first empty foil area 11 is folded for the first time, or the first pole tab 20 can be welded to the second lead-out section 11b after the first empty foil area 11 is folded for the first time.

[0069] Case 2: After winding the pole piece 10, the first end of the first pole ear 20 is welded to the second lead-out section 11b. For example, after pasting the first adhesive tape 30, the first end of the first pole ear 20 is welded to the second lead-out section 11b. In this case, since the structure of the battery cell 100 is relatively fixed after winding and pasting the adhesive tape, it is easier to determine the exact welding position of the first pole ear 20 and the second lead-out section 11b, which helps to avoid deviations in the welding process and improve the preparation quality of the battery cell 100.

[0070] According to one embodiment of the present invention, the battery cell preparation method further includes: sticking the second adhesive tape 40 to the side of the first adhesive tape 30 away from the center of the winding core, and making the second adhesive tape 40 cover the second lead section 11b and the first end of the first electrode tab 20.

[0071] That is to say, in order to improve the reliability of the battery cell 100, the second adhesive tape 40 can be adhered to the side of the first adhesive tape 30 away from the center of the winding core, and the adhered second adhesive tape 40 covers the second lead-out section 11b and the first end of the first pole lug 20, so that the position of the second lead-out section 11b and the first end of the first pole lug 20 can be fixed, thereby effectively avoiding the movement of the second lead-out section 11b and the first end of the first pole lug 20, and further avoiding the first empty foil area 11 from breaking, which can effectively improve the reliability of the battery cell 100.

[0072] In some specific embodiments of the present invention, the main body region has two tail ends, the two tail ends are respectively connected to the first empty foil region 11, and the step of winding the pole piece 10 with the tail ends of the main body region as the terminals includes: S31 and S32.

[0073] S31, folding the electrode sheet 10 in half along the length direction of the electrode sheet 10 so that the two first empty foil areas 11 are aligned;

[0074] S32, winding the folded electrode sheet 10 with the tail end of the main body region as the terminal.

[0075] In other words, the two ends of the main body area in the length direction are two tail ends, and the two tail ends are connected to the first empty foil area 11. Before winding the electrode sheet 10, the positive electrode sheet 10, the first separator, the negative electrode sheet 10 and the second separator are stacked in sequence, and then the folded positive electrode sheet 10, the first separator, the negative electrode sheet 10 and the second separator are aligned along the length direction of the electrode sheet 10, so that the first empty foil area 11 connected to the two tail ends of the main body area is aligned, and then the folded positive electrode sheet 10, the first separator, the negative electrode sheet 10 and the second separator are wound together to form a winding core. Thus, a high-power battery cell 100 can be prepared, which can effectively improve the charging and discharging efficiency of the battery.

[0076] According to an embodiment of the present invention, the method for preparing a battery cell further includes: before bonding the second adhesive tape 40 , welding together the first pole pieces 10 corresponding to the two end ends.

[0077] Specifically, the first pole pieces 10 corresponding to the two tail ends can be welded together before the second adhesive tape 40 is adhered. For example, the first pole pieces 10 corresponding to the two tail ends are stacked and welded together before the folded pole piece 10 is wound. In this case, the two first pole pieces 10 can be reliably welded together, and the misalignment of the two first pole pieces 10 during the winding process can be avoided, thereby ensuring the production quality of the battery cell 100. Alternatively, the second connecting section can be folded to the side of the first adhesive tape 30 away from the center of the winding core, and then the first pole pieces 10 corresponding to the two tail ends are welded together. This can avoid the second adhesive tape 40 interfering with the welding of the two first pole pieces 10, thereby ensuring the current capacity of the battery cell 100.

[0078] In some specific embodiments of the present invention, the main area includes a plurality of active areas 12 and a second empty foil area 13 distributed along the length direction of the electrode sheet 10, the second empty foil area 13 is connected between the two active areas 12, the second empty foil area 13 includes a third lead-out segment 13a and a fourth lead-out segment 13b, the third lead-out segment 13a is connected to the active area 12, and the fourth lead-out segment 13b is used to connect the second pole ear. The battery cell preparation method also includes: before winding the electrode sheet 10, folding the fourth lead-out segment 13b of the second empty foil area 13 to one side in the width direction of the electrode sheet 10; after pasting the first adhesive tape 30, folding the fourth lead-out segment 13b of the second empty foil area 13 to the side of the winding core.

[0079] That is to say, the main body area includes a plurality of active areas 12 and a second empty foil area 13 distributed along the winding direction thereof, wherein the active area 12 refers to a current collector coated with positive / negative active materials, and the second empty foil area 13 refers to a current collector not coated with positive / negative active materials, and a second empty foil area 13 is provided between two adjacent active areas 12. The second empty foil area 13 is mainly composed of a third lead-out section 13a and a fourth lead-out section 13b, and the third lead-out section 13a and the fourth lead-out section 13b are distributed along the width direction of the pole piece 10, and the third lead-out section 13a is connected to the two active areas 12 on both sides of the pole piece 10 in the length direction. Before winding the electrode sheet 10, the fourth lead-out segment 13b of the second empty foil area 13 is folded to one side in the width direction of the electrode sheet 10 by folding the second empty foil area 13, so that the fourth lead-out segment 13b will not be wound into the winding core. After pasting the first adhesive tape 30, the fourth lead-out segment 13b of the second empty foil area 13 is folded to the side of the winding core by folding the second empty foil area 13, so that the second pole ear can be led out from the side of the winding core, which can further improve the power of the battery cell 100.

[0080] According to one embodiment of the present invention, the step of obtaining the pole piece 10 further includes: S13.

[0081] S13, cutting the connection between the active area 12 and the second empty foil area 13 from one side in the width direction of the base material.

[0082] Specifically, the mother material is a sheet structure with uniform width, and the mother material has a second empty foil area 13 required for the pole piece 10. The second empty foil area 13 is mainly composed of a third lead-out section 13a and a fourth lead-out section 13b. The third lead-out section 13a and the fourth lead-out section 13b are distributed along the width direction of the mother material. By cutting the connection between the active area 12 and the second empty foil area 13 from one side in the width direction of the mother material, the fourth lead-out section 13b can be disconnected from the active area 12, and the connection length between the third lead-out section 13a and the active area 12 can be adjusted, so that the fourth lead-out section 13b can be folded to one side in the width direction of the pole piece 10, and the connection length between the third lead-out section 13a and the active area 12 can be controlled according to actual needs. For example, the connection length between the third lead-out section 13a and the active area 12 is controlled to be less than the width of the pole piece 10, so that the connection between the third lead-out section 13a and the active area 12 forms an overcurrent protection point. When the current in the battery increases abnormally and exceeds its designed tolerance range, the overcurrent protection will melt and cause a short circuit, which can effectively prevent the battery from thermal runaway and effectively improve the safety of the battery.

[0083] In some specific embodiments of the present invention, the battery cell preparation method further includes: before winding the pole piece 10, welding the first end of the second pole piece 10 to the fourth lead-out section 13b; or, after pasting the first adhesive tape 30, welding the first end of the second pole piece 10 to the fourth lead-out section 13b.

[0084] That is to say, the timing of welding the second tab includes but is not limited to the following situations:

[0085] Case 1: Before winding the pole piece 10, the first end of the second pole tab is welded to the fourth lead-out section 13b. For example, the second pole tab can be welded to the fourth lead-out section 13b before the second empty foil area 13 is folded for the first time, or the second pole tab can be welded to the fourth lead-out section 13b after the second empty foil area 13 is folded for the first time.

[0086] Case 2: After winding the pole piece 10, the first end of the second pole ear is welded to the fourth lead-out segment 13b. For example, after pasting the first adhesive tape 30, the first end of the second pole ear is welded to the fourth lead-out segment 13b. In this case, since the structure of the battery cell 100 is relatively fixed after winding and pasting the adhesive tape, it is easier to determine the exact welding position of the second pole ear and the fourth lead-out segment 13b, which helps to avoid deviations in the welding process and improve the preparation quality of the battery cell 100.

[0087] According to an embodiment of the present invention, the second pole tab and the first pole tab 20 are stacked, and the battery cell preparation method further includes: after pasting the first adhesive tape 30 , welding the second pole tab and the first pole tab 20 together.

[0088] Specifically, when winding the pole piece 10, it is necessary to ensure that the position of the second pole ear corresponds to the first pole ear 20, so that the first pole ear 20 and the second pole ear can be stacked on one side of the winding core, and after pasting the first adhesive tape 30, the second pole ear can be welded together with the two first pole ears 20, so as to ensure the current capacity of the battery cell 100 and the production efficiency at the same time.

[0089] In some specific embodiments of the present invention, the winding core is configured to be flat, the length of the winding core is greater than the width of the winding core, the width direction of the winding core is the same as the width direction of the pole piece 10, and the first pole piece 10 is arranged on the side of the length direction of the winding core.

[0090] In the related art, the wound battery cell 100 used in the long strip battery is like a button battery. The tabs are generally led out from the end face of the winding core, and the short end face of the battery is used as the tab lead-out surface. However, such a winding core will result in low space utilization and reduce the battery capacity.

[0091] Based on this, the winding core of this embodiment is designed to be flat, the width direction of the winding core is the same as the width direction of the pole piece 10, and the length of the winding core is greater than the width of the winding core, which is conducive to preparing a longer winding core through a pole piece 10 with a smaller width. The first pole ear 20 can be arranged on one side of the winding core in the length direction, so that the first pole ear 20 can be led out from the end face in the length direction of the battery (i.e., the direction in which the long side extends), which is conducive to making full use of the internal space of the battery, and further conducive to increasing the battery capacity.

[0092] In summary, according to the battery cell preparation method of the embodiment of the present invention, by folding the second lead-out section 11b of the electrode sheet 10 to the side and then winding it into a core, when fixing the tail end of the core, the second lead-out section 11b and the first pole ear 20 will not interfere with the winding of the first adhesive tape 30 in the winding direction, which can improve the pasting efficiency of the first adhesive tape 30, and thus can provide the production efficiency of the battery cell 100; and the first adhesive tape 30 can fix the tail position of the first lead-out section 11a corresponding to the core and the remaining tail positions of the core, which can improve the structural stability of the battery cell 100, reduce the risk of disintegration, and ensure the battery performance and safety; after the first adhesive tape 30 is bonded, the first empty foil area 11 can be folded again to fold the second lead-out section 11b to the side of the core, so that the first electrode sheet 10 can be led out from the side of the core.

[0093] The embodiment of the present invention further provides a battery cell 100, which is made by the battery cell preparation method described in any of the above embodiments. Since the battery cell preparation method according to the embodiment of the present invention has the above technical effects, the battery cell 100 according to the embodiment of the present invention also has corresponding technical effects, which will not be described in detail in this embodiment.

[0094] The embodiment of the present invention further provides a battery, which may be a long strip battery or a curved battery, and the battery includes the battery cell 100 described in any of the above embodiments. Since the battery cell preparation method and the battery cell 100 according to the embodiment of the present invention have the above technical effects, the battery according to the embodiment of the present invention also has the corresponding technical effects, which will not be described in detail in this embodiment.

[0095] The embodiment of the present invention further provides an electronic device, such as, but not limited to, a mobile phone, a car, an electric car, etc., and the electronic device includes the above-mentioned battery. Since the battery cell preparation method and the battery cell 100 according to the embodiment of the present invention have the above-mentioned technical effects, the electronic device according to the embodiment of the present invention also has the corresponding technical effects, which will not be described in detail in this embodiment.

[0096] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A method for preparing a battery cell, characterized in that: include: Obtaining a pole piece (10), wherein the pole piece (10) has a main body region and a first empty foil region (11) distributed along its length direction; The first empty foil area (11) is located at the end of the main body area, and the first empty foil area (11) comprises a first lead-out section (11a) and a second lead-out section (11b), the first lead-out section (11a) is connected to the main body area, and the second lead-out section (11b) is used to connect to the first pole piece (10); Folding the second lead-out section (11b) of the first empty foil area (11) to one side in the width direction of the pole piece (10); Winding the pole piece (10) with the tail end of the main body region as the terminal to obtain a winding core; Pasting the first adhesive tape (30) on the side of the winding core, so that the first adhesive tape (30) covers the tail end of the winding core, and a portion of the first adhesive tape (30) is located on the side of the first lead-out section (11a) close to the center of the winding core; The second lead-out section (11b) is folded to the side of the first adhesive tape (30) away from the center of the winding core to obtain a battery core.

2. The method for preparing a battery cell according to claim 1, characterized in that: The first lead-out section (11a) and the second lead-out section (11b) are distributed along the length direction or the width direction of the pole piece (10).

3. The method for preparing a battery cell according to claim 1, characterized in that: The step of obtaining the pole piece (10) comprises: Obtaining a mother material, the mother material being provided with a main body area and a first empty foil area (11) distributed along its length direction, the first empty foil area (11) being located at the end of the main body area, and the first empty foil area (11) comprising a first lead-out section (11a) and a second lead-out section (11b); The connection between the main body area and the first hollow foil area (11) is cut from one side in the width direction of the base material.

4. The method for preparing a battery cell according to claim 1, characterized in that: Also includes: Before winding the pole piece (10), welding the first end of the first pole tab (20) to the second lead-out section (11b); Alternatively, after the first adhesive tape (30) is pasted, the first end of the first electrode tab (20) is welded to the second lead-out section (11b).

5. The method for preparing a battery cell according to claim 4, characterized in that: Also includes: The second adhesive tape (40) is pasted on the side of the first adhesive tape (30) away from the center of the winding core, and the second adhesive tape (40) covers the second lead-out section (11b) and the first end of the first electrode tab (20).

6. The method for preparing a battery cell according to claim 5, characterized in that: The main body region has two tail ends, the two tail ends are respectively connected to the first empty foil region (11), and the step of winding the pole piece (10) with the tail ends of the main body region as terminals comprises: Folding the pole piece (10) in half along the length direction of the pole piece (10) so that the two first empty foil areas (11) are aligned; The pole piece (10) is folded in half and wound with the tail end of the main body region as a terminal.

7. The method for preparing a battery cell according to claim 6, characterized in that: Also includes: Before bonding the second adhesive tape (40), the first pole pieces (10) corresponding to the two tail ends are welded together.

8. The method for preparing a battery cell according to claim 3, characterized in that: The main body area comprises a plurality of active areas (12) and a second empty foil area (13) distributed along the length direction of the pole piece (10), the second empty foil area (13) being connected between two of the active areas (12), the second empty foil area (13) comprising a third lead-out section (13a) and a fourth lead-out section (13b), the third lead-out section (13a) being connected to the active area (12), and the fourth lead-out section (13b) being used to connect to a second pole lug, and the battery cell preparation method further comprises: Before winding the pole piece (10), the fourth lead-out section (13b) of the second empty foil area (13) is folded to one side in the width direction of the pole piece (10); After the first adhesive tape (30) is pasted, the fourth lead-out section (13b) of the second empty foil area (13) is folded to the side of the winding core.

9. The method for preparing a battery cell according to claim 8, characterized in that: The step of obtaining the pole piece (10) further comprises: The connection between the active area (12) and the second hollow foil area (13) is cut from one side in the width direction of the base material.

10. The method for preparing a battery cell according to claim 8, characterized in that: Also includes: Before winding the pole piece (10), welding the first end of the second pole piece (10) to the fourth lead-out section (13b); Alternatively, after the first adhesive tape (30) is pasted, the first end of the second pole piece (10) is welded to the fourth lead-out section (13b).

11. The method for preparing a battery cell according to claim 10, characterized in that: The second pole tab and the first pole tab (20) are stacked, and the battery cell preparation method further comprises: After the first adhesive tape (30) is pasted, the second pole tab and the first pole tab (20) are welded together.

12. The battery cell according to claim 1, characterized in that: The winding core is configured to be flat, the length of the winding core is greater than the width of the winding core, the width direction of the winding core is the same as the width direction of the pole piece (10), and the first pole piece (10) is arranged on the side of the length direction of the winding core.

13. A battery cell, characterized in that: The battery cell is made by the battery cell preparation method according to any one of claims 1 to 12.

14. A battery, characterized in that: Comprising the battery cell as claimed in claim 13.

15. An electronic device, characterized in that: Comprising the battery of claim 14.

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