Manufacturing method of pole piece, pole piece, battery cell and vehicle

Abstract

The invention relates to a manufacturing method of a pole piece, the pole piece, a battery cell and a vehicle. The manufacturing method comprises the step of adding the insulating filler to the thinned area of the pole piece coated with the slurry. According to the method, the lithium precipitation phenomenon of the battery cell caused by the thinned area is improved.

Description

Technical Field

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

[0002] At present, new energy products including new energy vehicles are developing rapidly, among which lithium-ion batteries are widely used. In the processing of lithium-ion batteries, in order to avoid the edge bulging of the pole piece, the edge of the pole piece is thinned. For example, when coating the pole piece, the amount of dressing on the edge of the pole piece is reduced, which makes it inevitable that the edge of the pole piece will have a thinning area. However, due to the poor control of the consistency of the thinning area size, the positive and negative pole pieces and the diaphragm are not well fitted, which affects the balance of lithium insertion and extraction of the positive and negative electrodes, resulting in lithium precipitation. Summary of the invention

[0003] The present application provides a method for manufacturing a pole piece, a pole piece, a battery cell and a vehicle, which can improve the lithium plating phenomenon.

[0004] A method for manufacturing a pole piece, comprising:

[0005] Add insulating filler to the thinned area of ​​the pole piece after the slurry is applied.

[0006] Optionally, adding insulating filler to the thinned area of ​​the pole piece after the slurry is applied comprises:

[0007] A plurality of paths of the insulating filler are added side by side to the thinned area along a vertical direction from the tab to the slurry area.

[0008] Optionally, adding a plurality of insulating fillers in parallel to the thinned area comprises:

[0009] Multiple paths of the insulating filler are added side by side to the skived area in a manner that the amount added becomes smaller as it is closer to the slurry area.

[0010] Optionally, adding a plurality of paths of the insulating filler to the skived area in parallel comprises:

[0011] Multiple paths of the insulating filler are added side by side to the skived area in a manner that there is no gap between each path of the insulating filler, so that the multiple paths of the insulating filler are connected to each other.

[0012] Optionally, adding insulating filler to the thinned area of ​​the pole piece after the slurry is applied includes:

[0013] The insulating filler is added to the thinned area of ​​the surface of the pole piece on the side facing away from the isolation membrane after the slurry is coated.

[0014] Optionally, the manufacturing method further comprises: hot pressing the insulating filler in the thinned area.

[0015] Optionally, the manufacturing method further comprises:

[0016] Obtaining parameters of the thinned area of ​​the pole piece after the slurry is applied;

[0017] The step of adding insulating filler to the thinned area of ​​the pole piece after the slurry is applied comprises:

[0018] The injection gun is controlled according to the parameters to add the insulating filler into the thinned area of ​​the pole piece.

[0019] A pole piece, manufactured by the pole piece manufacturing method as described in any one of the above, the pole piece comprising:

[0020] A current collector, comprising a slurry area and a hollow foil area, wherein the hollow foil area forms a pole ear of the pole piece;

[0021] An active slurry is applied to the slurry area;

[0022] The insulating filler is arranged in the coating starting area of ​​the slurry area.

[0023] Optionally, the insulating filler is provided in the coating starting area on the surface of the pole piece on the side facing away from the isolation membrane.

[0024] A battery cell comprises a positive electrode sheet, a negative electrode sheet and a separation film for separating the positive electrode sheet from the negative electrode sheet, wherein the positive electrode sheet and / or the negative electrode sheet adopts any one of the electrode sheets described above.

[0025] A vehicle comprises a battery module, wherein the battery module comprises the battery cell described above.

[0026] The present application provides a method for manufacturing a pole piece, a pole piece, a battery cell and a vehicle, wherein the insulating filler added to the thinned area of ​​the pole piece can fill the thickness of the thinned area, thereby preventing the battery cell from becoming soft at the thinned area or from not fitting tightly at the location, thereby improving the polarization at the thinned area, reducing the diffusion rate of lithium ions and the amount of lithium desorption during charging, and improving lithium plating caused by mismatched coating amounts of positive and negative pole pieces and mismatched lithium desorption rates. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a top view of the existing pole piece;

[0028] Figure 2 is a cross-sectional view of an existing pole piece;

[0029] Figure 3 is a flow chart of a method for manufacturing a pole piece according to an exemplary embodiment of the present application;

[0030] Figure 4 It is a schematic diagram of adding multiple insulating fillers side by side in the skived area;

[0031] Figure 5 This is the front view with multiple insulating fillers added to the skived area;

[0032] Figure 6 is a top view of a pole piece processed by the pole piece manufacturing method of the present application;

[0033] Figure 7 yes Figure 6 A cross-sectional view of the pole piece shown in FIG.

[0034] Figure 8 is a flow chart of a method for manufacturing a battery cell according to an exemplary embodiment of the present application;

[0035] Fig. 9 is another flow chart of a method for manufacturing a battery cell according to an exemplary embodiment of the present application;

[0036] Fig.10 It is a flow chart of a method for manufacturing a laminated battery cell;

[0037] Fig.11 is a cross-sectional view of a pole piece shown in an embodiment of the present application;

[0038] Fig.12 It is a cross-sectional view of part of the structure of a laminated battery cell.

[0039] Description of reference numerals:

[0040] Pole piece 1; pole ear 11; slurry area 12; thinning area 13; empty foil area 14; current collector 1a; active slurry 1b; coating start area 120; injection gun 2; insulating filler 20; positive electrode piece 1'; negative electrode piece 1"; separator 3; first filler area 30; second filler area 31. DETAILED DESCRIPTION

[0041] Here, the technical solutions in the embodiments (or "implementations") of the present application will be described clearly and completely in conjunction with the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0042] If there are terms involving directional indications or positional relationships in the embodiments of the present application (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings); if the specific posture changes, the directional indication or positional relationship will also change accordingly. In addition, the terms "first", "second", etc. involved in the embodiments of the present application are only used for the purpose of convenience of description and cannot be understood as indicating or implying relative importance.

[0043] Please refer to Figure 1 and Figure 2 , Figure 1 It is a top view of the existing pole piece 1. Figure 2 It is a cross-sectional view of the existing pole piece 1.

[0044] In order to avoid the battery cell from bulging at the edge, the pole piece 1 reduces the amount of coating in the coating starting area during coating, and this area is called the thinning area 13. The pole piece 1 includes a pole ear 11, which is an empty foil area on the current collector where the slurry is not coated. The area on the pole piece 1 where the standard amount of slurry is coated is the slurry area 12, and the thinning area 13 is located between the pole ear 11 and the slurry area 12.

[0045] Please refer to Figure 3 , Figure 3 It is a flow chart of a method for manufacturing a pole piece shown in an exemplary embodiment of the present application.

[0046] In order to improve the lithium plating phenomenon of the battery cell, the present application provides a method for manufacturing a pole piece (hereinafter referred to as the manufacturing method), and the manufacturing method may include step S10.

[0047] Step S10, adding insulating filler to the thinned area of ​​the pole piece after applying the slurry. For example, the insulating filler can be injected into the thinned area of ​​the pole piece by an injection gun. The insulating filler can be a polymer with a viscosity of 500-25000mPa.s (tested at 25°C) and an insulating metal oxide, including but not limited to a mixture of one or more of PVDF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene), PMMA (polymethyl methacrylate), and alumina. Of course, it is not limited to this. In some other embodiments, a solid insulating filler can also be used, and the insulating filler is bonded to the thinned area of ​​the pole piece.

[0048] According to the above description, the insulating filler added to the thinned area fills the thickness of the thinned area, avoids the battery cell from becoming soft or not fitting tightly at the thinned area, improves the polarization at the thinned area, reduces the diffusion rate and amount of lithium ions removed during charging, and improves lithium plating caused by mismatched coating amounts of the positive and negative electrodes and mismatched lithium insertion and extraction rates.

[0049] When the battery cell is configured as a laminated battery cell, an insulating filler may be added to the thinned area of ​​the electrode sheet after each electrode sheet is placed. The amount of addition may be determined based on the coating parameters of the thinned area 13 of the electrode sheet. The insulating filler may be added to the thinned area of ​​the positive electrode sheet and / or the thinned area of ​​the negative electrode sheet.

[0050] exist Figure 3 In the flowchart shown, the manufacturing method may further include step S20.

[0051] Step S20, hot pressing the insulating filler in the skived area. In one embodiment, when a mixture of one or more of PVDF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene), PMMA (polymethyl methacrylate), and alumina is used, the hot pressing temperature can be set between 25°C-150°C, and the pressure value can be set between 0.1Mpa-1.1Mpa. When the battery cell is a laminated battery cell, all the laminates can be stacked and then hot pressed as a whole, but it is not limited to this. With this arrangement, the insulating filler can penetrate into the active slurry coating in the skived area after being hot pressed, and can be more closely combined with the active slurry coating.

[0052] It should be noted that hot pressing can be performed using hot pressing tooling, which usually uses rigid materials. Since rigid materials have good thermal conductivity, they will not deform or crack within the hot pressing temperature and pressure range. In addition, the flatness tolerance of the upper and lower pressing plates of the hot pressing tooling is not greater than 0.15mm, and the parallelism tolerance of the upper and lower pressing plates is not greater than 0.15mm to ensure the hot pressing effect.

[0053] Please refer to Figure 4 , Figure 4 It is a schematic diagram of adding multiple insulating fillers side by side in the thinned area 13 of the pole piece.

[0054] In one embodiment, step S10 may specifically be to: Figure 1 In the S direction of the pole ear 11, a plurality of insulating fillers are added side by side into the thinning area 13. For example, in the embodiment of injecting the insulating filler into the thinning area 13, the insulating filler can be injected into the thinning area 13 in the direction of the pole ear 11 ( Figure 4 A plurality of injection guns 2 are arranged side by side in the L direction (in the L direction in the figure), and the plurality of injection guns 2 are also configured to be able to move along the S direction during the injection process, so that multiple paths of the insulating filler can be injected side by side in the thinning area 13. This method can improve the injection efficiency and ensure that the injection amount at each part of the thinning area 13 is more uniform. It should be noted that the specific number of injection guns 2 is not limited, and can be two or more, and the plurality of injection guns 2 can be arranged at intervals or arranged closely together. The number of injection guns 2 includes but is not limited to Figure 4 Five are shown.

[0055] In one embodiment, step S10 may specifically include adding multiple paths of the insulating filler into the skived area 13 side by side along the S direction in a manner that there is no gap between each path of the insulating filler, so that the multiple paths of the insulating filler are connected to each other. That is, when the insulating filler is added to the skived area 13, any two adjacent paths of the insulating filler are connected to each other without a gap, so that defects such as poor filling effect of the skived area 13 caused by uneven filler can be avoided.

[0056] For example, still taking the injection of insulating filler as an example, multiple injection guns 2 can be placed next to each other, so that the insulating fillers from each injection gun 2 can be connected to each other. Figure 4 In the embodiment shown, in the direction from the pole ear 11 to the thinned area 13 ( Figure 4 In the middle L direction), the size of the thinning zone 13 is W2, and the overall size of the multiple injection guns 2 arranged side by side in this direction is W1. W2 can be set equal to W1 to ensure that sufficient liquid is injected into the thinning zone 13. Of course, W2 can also be set larger than W1.

[0057] Please refer to Figures 5 to 7 , Figure 5 It is a front view of the multiple insulating fillers 20 in the skived area 13. Figure 6 FIG. 1 is a top view of multiple insulating fillers in the skived area 13 . Figure 7 It is a cross-sectional view of the pole piece 1 after hot pressing.

[0058] In one embodiment, step S10 may also be to add multiple paths of the insulating filler 20 in parallel into the thinning zone 13 along the S direction with different addition amounts, and the closer to the slurry zone 12, the smaller the addition amount.

[0059] like Figure 5 and Figure 6 As shown in the figure, the amount of filler added can be gradually reduced from the position of the left pole ear 11 to the direction of the right slurry area 12, and the volume of the filler gradually decreases. Since the thickness of each part of the thinning area 13 is different, different amounts of filler are added to fill the thinning area 13 at different parts of the thinning area 13, so that the thinning area 13 after filling can be more uniform. In addition, in the hot pressing step, the hot pressed filler can be more evenly infiltrated into the active slurry. The pole piece after hot pressing is as shown in the figure. Figure 7 As shown, after the thinning area 13 is filled, the thickness is substantially equal to that of the slurry area 12. In the embodiment of injecting insulating filler, injection guns 2 with different diameters can be used, thereby injecting different injection amounts at different positions.

[0060] In one embodiment, step S10 may specifically be to obtain the parameters of the thinned area 13 of the pole piece after the slurry is applied, and control the injection gun to add the insulating filler to the thinned area 13 of the pole piece according to the parameters. In this step, a corresponding filling scheme may be adopted according to the specific situation of the thinned area 13 of each pole piece, so that the filler amount is more accurate, and thus the thinned area 13 of each pole piece is well filled with the filler. This step is applicable not only to positive pole pieces, but also to negative pole pieces.

[0061] There is no limit to the method of obtaining the parameters of the thinning area 13 of each pole piece. For example, an image of the thinning area 13 of each pole piece can be collected, and the parameters of the thinning area 13 can be determined after image analysis. Alternatively, the parameters of the thinning area 13 are determined according to the coating parameters of the pole piece. For another example, the parameters of the thinning area 13 are determined based on the image and the coating parameters. The parameters of the thinning area 13 include but are not limited to the thickness at different parts of the thinning area 13, the amount of dressing during coating, the flow rate of the dressing amount, and the like.

[0062] In one embodiment, step S10 may specifically include adding the insulating filler to the thinned area on the side of the electrode sheet facing away from the isolation membrane after the slurry is applied. This arrangement can simplify the manufacturing method of the electrode sheet, and the insulating filler is added only to the thinned area on one side of the electrode sheet, while the thinned area on the other side can be filled by adding filler on the isolation membrane, so that the electrode sheet can be avoided from being turned over during the manufacturing process.

[0063] Please refer to Figure 8 , Figure 8 is a flow chart of a method for manufacturing a battery cell according to an exemplary embodiment of the present application.

[0064] The manufacturing method includes step S5, step S11, and step S21.

[0065] Step S5, adding the insulating filler to the area of ​​the separator facing the positive electrode sheet and directly opposite to the thinned area 13 of the positive electrode sheet. In this step, by adding the insulating filler to the separator, the thinned area 13 on one side of the positive electrode sheet can be filled.

[0066] Step S11, adding the insulating filler to the thinned area 13 on the side of the positive electrode sheet facing away from the separator. In this step, the insulating filler is added only to the thinned area 13 on one side of the positive electrode sheet.

[0067] In this manufacturing method, the insulating filler on the isolation membrane can be used to fill the thinned area 13 on the side of the positive electrode sheet facing away from the isolation membrane. In this way, there is no need to add the insulating filler to the thinned areas 13 on both sides of the positive electrode sheet. During the manufacturing process, flipping the positive electrode sheet can be avoided, thereby ensuring that the filler in the thinned area 13 of the positive electrode sheet is stable and improving processing efficiency.

[0068] exist Figure 8 The flowchart shown also includes step S21.

[0069] Step S21 , hot pressing the filler area of ​​the isolation film and the thinned area 13 of the positive electrode sheet.

[0070] By adopting this step, the filler after hot pressing is more mixed with the active slurry, the position of the filler is more stable and the filling effect is better.

[0071] The filler amount of the separator can be selected according to the parameters of the thinning area 13 of the positive electrode. In one embodiment, from the tab 11 to the slurry area 12, as the slurry thickness of the thinning area 13 gradually increases, the thickness of the material layer of the filler area of ​​the separator can gradually decrease.

[0072] In the embodiment using the injection of insulating filler, the positive electrode sheet and the separator can be injected with the insulating filler separately and then hot pressed separately, or the insulating filler can be injected while the sheets are stacked and then hot pressed as a whole after the sheets are stacked.

[0073] Please refer to Fig. 9 , Fig. 9 It is another flow chart of a method for manufacturing a battery cell according to an exemplary embodiment of the present application.

[0074] The manufacturing method includes step S6, step S12 and step S22.

[0075] Step S6, adding the insulating filler to a region of the separator facing the negative electrode sheet and directly opposite to the thinned region 13 of the negative electrode sheet.

[0076] Step S12, adding the insulating filler to the thinned area 13 on the surface of the negative electrode sheet facing away from the separator.

[0077] In this manufacturing method, the insulating filler on the isolation membrane can be used to fill the thinned area 13 on the side of the negative electrode sheet facing away from the isolation membrane. In this way, there is no need to inject the insulating filler into the thinned areas 13 on both sides of the negative electrode sheet. During the manufacturing process, flipping the negative electrode sheet can be avoided, thereby ensuring the stability of the slurry in the thinned area 13 of the negative electrode sheet and improving the processing efficiency.

[0078] exist Figure 8 The flowchart shown also includes step S22.

[0079] Step S22 , hot pressing the filler area of ​​the isolation film and the thinned area 13 of the negative electrode sheet.

[0080] By adopting this step, the filler after hot pressing is more mixed with the active slurry, the position of the filler is more stable and the filling effect is better.

[0081] Please refer to Fig.10 , Fig.10 The present invention is a flow chart of a method for manufacturing a laminated battery cell.

[0082] In a specific embodiment, the method for manufacturing a laminated battery cell includes step S7, step S8, step S13 and step S23.

[0083] Step S7, injecting the insulating filler into the upper surface of the currently stacked isolation film on the stacking machine in sequence.

[0084] Step S8, stacking the pole piece on the upper layer of the isolation membrane so that the thinned area of ​​the pole piece facing the isolation membrane is opposite to the injection area of ​​the isolation membrane.

[0085] Step S13, injecting the insulating filler into the thinned area on the upper surface of the currently stacked pole piece on the stacking machine in sequence.

[0086] Step S23, after the positive electrode sheet, the negative electrode sheet and the isolation film are all stacked, the injection area of ​​the isolation film and the thinning areas of the positive electrode sheet and the negative electrode sheet are integrally hot pressed.

[0087] This manufacturing method achieves the simultaneous stacking and material injection. Neither the positive electrode sheet nor the negative electrode sheet needs to be flipped over. Instead, the material is injected onto the isolation membrane to fill the thinned area of ​​the positive electrode sheet and the negative electrode sheet facing the isolation membrane, making the manufacturing process of the battery cell more convenient and efficient.

[0088] Please refer to Fig.11 , Fig.11 A cross-sectional view of a pole piece shown as an exemplary embodiment of the present application.

[0089] The present application also provides a pole piece 1, which can be manufactured by using the above-mentioned pole piece manufacturing method, and the pole piece 1 can be a positive pole piece 1' or a negative pole piece 1".

[0090] The pole piece 1 includes a current collector 1a, an active slurry 1b and an insulating filler 20. Among them, the current collector 1a is provided with a slurry area 12 and an empty foil area 14, the active slurry 1b is coated on the slurry area 12, and the empty foil area 14 is not coated with the active slurry 1b, and serves as the pole ear of the pole piece 1. The insulating filler 20 is arranged in the coating starting area 120 of the slurry area 12, and is used to increase the thickness at the coating starting area 120. In this way, the coating starting area 120 of the pole piece 1 (equivalent to the thinning area 13 mentioned above) is filled with the insulating filler 20, which prevents the battery cell from becoming soft at this position or the fitting is not tight, improves the polarization at this position, reduces the diffusion rate and lithium removal amount of lithium ions during charging, and improves the lithium precipitation caused by the mismatch of the coating amount of the positive and negative pole pieces and the mismatch of the lithium insertion and removal speed.

[0091] In one embodiment, the coating start region 120 on the side surface of the pole piece 1 facing away from the isolation film is provided with the insulating filler 20. In this way, the insulating filler 20 can be provided only in the coating start region 120 on the single side surface of the pole piece 1, thereby reducing the processing difficulty of the pole piece 1 and improving the processing efficiency.

[0092] Of course, in some other embodiments, the insulating filler 20 may also be provided in the coating start area 120 on both side surfaces of the pole piece 1 , and the specific setting may be selected according to actual needs.

[0093] Please refer to Fig.12 , Fig.12 It is a cross-sectional view of part of the structure of a laminated battery cell.

[0094] The present application also provides a battery cell, which includes a positive electrode sheet 1', a negative electrode sheet 1" and a separator 3 separating the positive electrode sheet 1' and the negative electrode sheet 1". At least one of the positive electrode sheet 1' or the negative electrode sheet 1" adopts the electrode sheet 1 as described above.

[0095] In one embodiment, one side of the separator 3 faces the positive electrode sheet 1', and the other side faces the negative electrode sheet 1", and a first filler area 30 is provided on the side of the separator 3 facing the positive electrode sheet 1'. The first filler area 30 is used to add the insulating filler 20. The first filler area 30 is opposite to the coating starting area 120 of the positive electrode sheet 1'. The thickness of the material layer added in the first filler area 30 gradually decreases in the direction from the pole ear 11 to the slurry area 12, so that the thickness size after filling is more uniform.

[0096] A second filling area 31 is provided on the side of the isolation film 3 facing the negative electrode sheet 1", and the second filling area 31 is used to add the insulating filler 20. The second filling area 31 is opposite to the coating starting area 120 of the negative electrode sheet 1", and the thickness of the material layer added in the second filling area 31 gradually decreases in the direction from the pole ear 11 to the slurry area 12, so that the thickness size after filling is more uniform.

[0097] By adopting the above scheme, the coating starting area 120 on the side of the positive electrode sheet 1' or the negative electrode sheet 1" facing the isolation film 3 can be filled by adding an insulating filler 20 on the isolation film 3. The insulating filler 20 can be added only on one side of the positive electrode sheet 1' or the negative electrode sheet 1", thereby simplifying the processing technology of the positive electrode sheet 1' or the negative electrode sheet 1".

[0098] The present application also provides a vehicle, which includes a battery module, the battery module includes a plurality of battery cells, and at least one battery cell includes the battery cell described above.

[0099] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for manufacturing a pole piece, characterized in that: include: Add insulating filler to the thinned area of ​​the pole piece after the slurry is applied.

2. The method for manufacturing a pole piece according to claim 1, characterized in that: The step of adding insulating filler to the thinned area of ​​the pole piece after the slurry is applied comprises: A plurality of paths of the insulating filler are added side by side to the thinned area along a vertical direction from the tab to the slurry area.

3. The method for manufacturing a pole piece according to claim 2, characterized in that: The step of adding a plurality of insulating fillers in parallel to the thinned area comprises: Multiple paths of the insulating filler are added side by side to the skived area in a manner that the amount added becomes smaller as it is closer to the slurry area.

4. The method for manufacturing a pole piece according to claim 2, characterized in that: The step of adding a plurality of paths of the insulating filler to the skived area in parallel comprises: Multiple paths of the insulating filler are added side by side to the skived area in a manner that there is no gap between each path of the insulating filler, so that the multiple paths of the insulating filler are connected to each other.

5. The method for manufacturing a pole piece according to any one of claims 1 to 4, characterized in that: Adding insulating fillers to the thinned area of ​​the pole piece after the slurry is applied includes: The insulating filler is added to the thinned area of ​​the surface of the pole piece on the side facing away from the isolation membrane after the slurry is coated.

6. The method for manufacturing a pole piece according to any one of claims 1 to 4, characterized in that: The manufacturing method further comprises: hot pressing the insulating filler in the skived area.

7. The method for manufacturing a pole piece according to any one of claims 1 to 4, characterized in that: The manufacturing method further comprises: Obtaining parameters of the thinned area of ​​the pole piece after the slurry is applied; The step of adding insulating filler to the thinned area of ​​the pole piece after the slurry is applied comprises: The injection gun is controlled according to the parameters to add the insulating filler into the thinned area of ​​the pole piece.

8. A pole piece, characterized in that: The pole piece is manufactured by the manufacturing method of the pole piece according to any one of claims 1 to 7, and the pole piece comprises: A current collector, comprising a slurry area and a hollow foil area, wherein the hollow foil area forms a pole ear of the pole piece; An active slurry is applied to the slurry area; The insulating filler is arranged in the coating starting area of ​​the slurry area.

9. The pole piece according to claim 8, characterized in that: The insulating filler is provided in the coating starting area on the surface of the pole piece on the side facing away from the isolation membrane.

10. A battery cell, characterized in that: It comprises a positive electrode sheet, a negative electrode sheet and a separation film for isolating the positive electrode sheet from the negative electrode sheet, and the positive electrode sheet and / or the negative electrode sheet adopts the electrode sheet as described in any one of claims 8 to 9.

11. A vehicle, characterized in that: It comprises a battery module, wherein the battery module comprises the battery cell according to claim 10.

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