Cells and Batteries

Abstract

The utility model provides a battery cell and a battery, the battery cell comprises a wound first pole piece, a diaphragm and a second pole piece, the diaphragm is located between the adjacent first pole piece and the second pole piece; the first pole piece comprises a first current collector and a first active material layer coated on both sides of the first current collector, the first active material layer is provided with a pole ear groove and a groove, the pole ear groove is provided with a first pole ear electrically connected to the first current collector, and the pole ear groove is provided with a protective adhesive tape; along the width direction of the first pole piece, the pole ear groove and the groove are arranged oppositely at the edge of the first pole piece, and the protective adhesive tape covers the groove. The utility model can reduce the ineffective thickness of the pole piece; thereby reducing the ineffective thickness of the winding core and improving the energy density of the lithium-ion battery.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery cell and a battery. Background Art

[0002] With the advent of the 5G era and the rapid development of lithium-ion battery technology, people have put forward higher requirements on the energy density, fast charging capability and charge and discharge rate of lithium-ion batteries. Fast-charging lithium-ion batteries have become the development trend of consumer lithium-ion batteries.

[0003] At present, in order to improve the fast charging performance of batteries, the center-placed tab structure in lithium-ion batteries, that is, setting the tab in the middle of the pole piece, has been widely used. The tab is welded in the middle of the pole piece, which can effectively reduce the internal resistance of the battery and achieve the effect of fast charging.

[0004] However, the current solution requires affixing protective tape to the lug welding position in order to avoid the lug welding point from piercing the diaphragm and causing safety problems. Since both the lug and the protective tape have a certain thickness, this results in the lug after welding and the protective tape after installation having a greater thickness at the lug position, thereby increasing the ineffective thickness of the battery. Utility Model Content

[0005] The embodiments of the utility model provide a battery cell and a battery, which can improve the energy density of a lithium-ion battery.

[0006] The utility model provides a battery core, comprising a wound first pole piece, a diaphragm and a second pole piece, wherein the diaphragm is located between the adjacent first pole piece and the second pole piece;

[0007] The first pole piece includes a first current collector and a first active material layer coated on both sides of the first current collector, a pole lug groove and a groove are provided on the first active material layer, a first pole lug electrically connected to the first current collector is provided in the pole lug groove, and a protective tape is provided in the pole lug groove; along the width direction of the first pole piece, the pole lug groove and the groove are arranged opposite to each other at the edge of the first pole piece, and the protective tape covers the groove.

[0008] Through the above-mentioned setting, that is, through the setting of the pole ear groove, the thickness of the first pole ear and the protective tape can be hidden in the first active material layer of the first pole sheet to reduce the ineffective thickness of the first pole sheet, thereby reducing the ineffective thickness of the core, improving the energy density of the lithium-ion battery, improving the space utilization rate, and improving the endurance of electronic products; in addition, the setting of the protective tape is used to avoid burrs generated at the edge of the pole ear groove, and burrs generated at the welding point generated during the welding of the first pole ear piercing the diaphragm, causing the positive and negative pole sheets to contact and cause fire and explosion and other safety problems.

[0009] In some optional embodiments, an embedding groove is further provided on the first active material layer, and the embedding groove is connected to the pole lug groove along the thickness direction of the first pole piece and is located on a side away from the first current collector;

[0010] The protective tape is located in the embedding groove and covers the tab groove.

[0011] In some optional embodiments, a first protective adhesive tape is provided in the groove;

[0012] A second protective adhesive tape is arranged in the tab groove.

[0013] It should be noted that the second protective tape is provided on the tab slot to prevent burrs from being generated on the edge of the tab slot. The burrs generated at the welding points during the welding of the tabs may pierce the diaphragm, causing contact between the positive and negative electrodes and triggering safety issues such as fire and explosion.

[0014] In some optional embodiments, the width of the tab slot is M, wherein M satisfies: 5 mm ≤ M ≤ 20 mm;

[0015] The length of the tab slot is N, where N satisfies: 5mm≤N≤50mm;

[0016] The width of the groove is M', where M' satisfies: 5 mm ≤ M' ≤ 20 mm;

[0017] The length of the groove is R, where R satisfies: 1mm≤R≤10mm.

[0018] In some optional embodiments, the distance between the side wall of the first pole lug and the side wall of the pole lug groove is greater than 1 mm and less than 10 mm;

[0019] The distance between the bottom wall of the first pole lug and the bottom wall of the pole lug groove is greater than 1 mm and less than 10 mm;

[0020] The distance between the top of the welding section of the first pole tab and the bottom of the insulating pad of the first pole tab is greater than or equal to 0.5 mm and less than or equal to 5 mm.

[0021] When it is greater than 1mm, it can reduce the manufacturing difficulty and avoid the overlap of the first pole ear with the first active material layer during welding, resulting in cold welding and increased internal resistance of the battery; when it is less than 5mm, it is to avoid excessive loss of the first active material layer, resulting in capacity loss and ultimately energy density loss; the distance between the top of the welding section of the first pole ear and the bottom of the insulating pad of the first pole ear is between 0.5mm-5mm, so as to avoid the insulating pad of the first pole ear piercing the first current collector and causing the first pole sheet to break.

[0022] In some optional embodiments, the relationship between the width K of the second protective tape and the width M of the tab groove satisfies: M<K<M+15mm;

[0023] The relationship between the length T of the second protective tape and the length N of the tab groove satisfies: N<T<N+20MMmm;

[0024] The distance between the top of the second protective tape and the bottom of the insulating pad of the first electrode tab is greater than or equal to 1 mm and less than or equal to 10 mm.

[0025] The purpose of doing this is to reduce the difficulty of manufacturing and avoid the risk of the second protective tape covering the lug misaligned, which may lead to the burrs on the edge of the lug groove being exposed and piercing the diaphragm. At the same time, the coverage area cannot be too large to avoid too much active material being covered and failing, resulting in capacity loss and ultimately energy density loss.

[0026] In some optional embodiments, the relationship between the width M' of the groove and the width K' of the first protective tape satisfies: M'<K'<M'+10mm;

[0027] The relationship between the length T' of the first protective glue and the length R of the groove satisfies: R<T'<R+15mm;

[0028] The distance between the top of the first protective glue and the top of the groove is greater than 1 mm, and the distance between the bottom of the first protective glue and the bottom of the first pole piece is greater than or equal to 0.5 mm and less than or equal to 10 mm.

[0029] It should be noted that the purpose of doing so is to reduce the difficulty of manufacturing and avoid the risk of the first protective tape covering the surface misaligned, which may lead to the burrs on the edge of the groove being exposed and piercing the diaphragm. At the same time, the coverage area cannot be too large to avoid too much active material being covered and failing, resulting in capacity loss and ultimately energy density loss.

[0030] In some optional embodiments, the embedding slot includes a first embedding slot;

[0031] The relationship between the width K of the second protective tape and the width E of the first embedding groove satisfies: K<E<K+10mm;

[0032] And / or, the relationship between the length T of the second protective tape and the length F of the first embedding groove satisfies: T<F<T+10mm;

[0033] and / or, the distance between the side wall of the second protective tape and the groove wall of the first embedding groove is a, wherein 0.5 mm ≤ a ≤ 10 mm;

[0034] And / or, the distance between the bottom wall of the second protective tape and the bottom wall of the first embedding groove is b, wherein 0.5 mm≤b≤10 mm.

[0035] The purpose of doing this is to reduce the manufacturing difficulty and avoid the second protective tape from covering the misalignment, causing the second protective tape to overlap with the edge of the first embedded groove and unable to reduce the thickness at this position. At the same time, the gap cannot be too large to avoid too much active material being removed, resulting in capacity loss and ultimately energy density loss.

[0036] In some optional embodiments, the embedding groove further includes a second embedding groove, and along the thickness direction of the first pole piece, the second embedding groove and the first embedding groove are respectively located on opposite sides of the first pole piece, and a second protective tape is provided in the second embedding groove.

[0037] It should be noted that when the tab slot is a double-sided tab slot, protective tape is required on both sides, so a second embedding groove needs to be set on the back side of the first active material layer. Accordingly, two second protective tapes are also provided, which are respectively set in the first embedding groove and the second embedding groove.

[0038] In some optional embodiments, the embedding groove further includes a third embedding groove, the third embedding groove is connected to the groove, and the first protective adhesive tape is accommodated in the third embedding groove;

[0039] The difference between the depth of the third embedding groove and the thickness of the first protective tape is greater than or equal to -5um and less than or equal to 5um.

[0040] It should be noted that the first protective tape has thickness. When it is pasted on the paste, it will increase the thickness of the first pole piece, resulting in the thickness of the winding core at this position, thereby increasing the thickness of the lithium battery and causing energy density loss; at the same time, the first active material layer covered by the first protective tape is ineffective, that is, it does not provide capacity, so the first active material layer covered by the first protective tape can be removed and the first protective tape can be embedded in the first pole piece.

[0041] In some optional embodiments, the embedding groove further includes a fourth embedding groove. Along the thickness direction of the first pole piece, the fourth embedding groove and the third embedding groove are respectively located on opposite sides of the first pole piece, and a first protective tape is provided in the fourth embedding groove.

[0042] It should be noted that when the tab slot is a double-sided tab slot, double-sided protective tape is required, so a fourth embedding slot needs to be set on the back side of the first active material layer. Correspondingly, two first protective tapes are also set in the third embedding slot and the fourth embedding slot respectively.

[0043] The present application also provides a battery, comprising the battery cell as described above.

[0044] The utility model provides an electric cell and a battery, wherein the battery comprises an electric cell; the electric cell comprises a first pole piece, a diaphragm and a second pole piece which are wound, wherein the diaphragm is located between adjacent first pole pieces and second pole pieces; the first pole piece comprises a first current collector and a first active material layer coated on both sides of the first current collector, wherein a pole lug groove and a groove are provided on the first active material layer, wherein a first pole lug electrically connected to the first current collector is provided in the pole lug groove, and protective adhesive paper is provided in the pole lug groove; along the width direction of the first pole piece, the pole lug groove and the groove are arranged oppositely at the edge of the first pole piece, and the protective adhesive paper covers the groove.

[0045] By setting the pole ear groove, the thickness of the first pole ear and the protective tape can be hidden in the first active material layer of the first pole piece to reduce the ineffective thickness of the first pole piece, thereby reducing the ineffective thickness of the core, improving the energy density of the lithium-ion battery, improving space utilization, and improving the endurance of electronic products; in addition, the setting of the protective tape is used to avoid burrs generated at the edge of the pole ear groove, and burrs generated at the welding point when the first pole ear is welded piercing the diaphragm, causing the positive and negative pole pieces to contact and cause fire and explosion and other safety problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0047] Figure 1 A schematic diagram of a first cutting method of a battery cell provided in an embodiment of the present application;

[0048] Figure 2 A schematic diagram of the structure of a first pole piece provided in an embodiment of the present application under a first cutting method;

[0049] Figure 3a for Figure 2 A cross-sectional view of A-A';

[0050] Figure 3b for Figure 2 A cross-sectional view of B-B';

[0051] Figure 3c for Figure 2 Another cross-sectional view of B-B' in FIG.

[0052] Figure 4a for Figure 2 Another cross-sectional view taken along line A-A';

[0053] Figure 4b for Figure 2Another cross-sectional view taken along the line BB' in FIG.

[0054] Figure 4c for Figure 2 Another cross-sectional view taken along the line B-B' in FIG.

[0055] Figure 5 A schematic structural diagram of another first pole piece provided in an embodiment of the present application under a first cutting method;

[0056] Figure 6a for Figure 5 A cross-sectional view of A-A';

[0057] Figure 6b for Figure 5 A cross-sectional view of B-B';

[0058] Figure 6c for Figure 5 Another cross-sectional view of B-B' in FIG.

[0059] Figure 7a for Figure 5 Another cross-sectional view taken along line A-A';

[0060] Figure 7b for Figure 5 Another cross-sectional view taken along the line BB' in FIG.

[0061] Figure 7c for Figure 5 Another cross-sectional view taken along the line B-B' in FIG.

[0062] Figure 8 A schematic diagram of a second cutting method for a battery cell provided in an embodiment of the present application;

[0063] Fig. 9 A schematic diagram of the structure of a first pole piece provided in an embodiment of the present application under a second cutting method;

[0064] Fig.10a for Fig. 9 A cross-sectional view of A-A';

[0065] Fig.10b for Fig. 9 A cross-sectional view of B-B';

[0066] Fig.11a for Fig. 9 Another cross-sectional view taken along line A-A';

[0067] Fig.11b for Fig. 9 Another cross-sectional view taken along the line BB' in FIG.

[0068] Fig.12A schematic diagram of the structure of another first pole piece provided in an embodiment of the present application under a second cutting method;

[0069] Fig.13a for Fig.12 A cross-sectional view of A-A';

[0070] Fig.13b for Fig.12 A cross-sectional view of B-B';

[0071] Fig.13c for Fig.12 Another cross-sectional view of B-B' in FIG.

[0072] Fig.14a for Fig.12 Another cross-sectional view taken along line A-A';

[0073] Fig.14b for Fig.12 Another cross-sectional view taken along the line BB' in FIG.

[0074] Fig.15 A schematic diagram of the structure of another first pole piece provided in an embodiment of the present application under a second cutting method;

[0075] Fig.16 for Fig.15 A cross-sectional view of A-A';

[0076] Fig.17 A schematic diagram of the structure of another first pole piece provided in an embodiment of the present application under a second cutting method;

[0077] Fig.18a for Fig.17 A cross-sectional view of A-A';

[0078] Fig.18b for Fig.17 Another cross-sectional view taken along line A-A';

[0079] Fig.19 A schematic diagram of a third cutting method for a battery cell provided in an embodiment of the present application;

[0080] Fig. 20 A schematic diagram of the structure of a first pole piece provided in an embodiment of the present application under a third cutting method;

[0081] Fig.21 for Fig. 20 A cross-sectional view of A-A';

[0082] Fig. 22 A schematic diagram of the structure of another first pole piece provided in an embodiment of the present application under a third cutting method;

[0083] Fig.23a for Fig. 22 A cross-sectional view of A-A';

[0084] Figure 23b for Fig. 22 Another cross-sectional view of A-A'.

[0085] Description of reference numerals:

[0086] 100-battery cells;

[0087] 110- first pole piece;

[0088] 111- a first current collector;

[0089] 112- first active material layer;

[0090] 113-first pole lug;

[0091] 120-first protective tape;

[0092] 130- second protective tape;

[0093] 140-ear slot;

[0094] 142-groove;

[0095] 150-first embedding groove;

[0096] 160 - second embedding slot;

[0097] 170 - third embedding slot;

[0098] 180- fourth embedded slot;

[0099] 190 - fifth embedding slot. DETAILED DESCRIPTION

[0100] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a one-cavity embodiment of the utility model, not an embodiment of the whole cavity. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model. All other embodiments obtained are within the scope of protection of the utility model. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0101] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0102] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, it can be the communication of the inner cavities of two components or the interaction relationship between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0103] It should be noted that in the description of the present utility model, the terms "first", "second", and "third" are only used to facilitate the description of different chambers, and cannot be understood as indicating or implying a sequential relationship, relative importance, or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", and "third" may explicitly or implicitly include at least one of the features.

[0104] At present, in order to improve the fast charging performance of the battery, the central structure of the positive and negative pole tabs in lithium-ion batteries has been widely used. The positive pole tab is welded in the middle of the positive pole piece, and the negative pole tab is welded in the middle of the negative pole piece, which can effectively reduce the internal resistance of the battery and achieve the effect of fast charging. However, the current solution requires the use of protective glue at the position of the pole tab welding to prevent the pole tab welding point from piercing the diaphragm and causing safety problems. This results in the protrusion of the pole tab and protective glue at the position of the pole tab, which increases the ineffective thickness of the battery.

[0105] In order to overcome the defects in the prior art, the battery cell and battery provided by the utility model, through the setting of the pole ear groove, the thickness of the first pole ear and the protective tape can be hidden in the first active material layer of the first pole sheet to reduce the ineffective thickness of the first pole sheet, thereby reducing the ineffective thickness of the winding core, improving the energy density of the lithium-ion battery, improving the space utilization rate, and improving the endurance of electronic products; in addition, the setting of the protective tape is used to avoid burrs generated at the edge of the pole ear groove, and burrs generated at the welding point generated when the first pole ear is welded pierce the diaphragm, causing the positive and negative pole sheets to contact and cause safety problems such as fire and explosion.

[0106] The content of the utility model will be described in detail below with reference to the accompanying drawings so that those skilled in the art can understand the content of the utility model more clearly and in detail.

[0107] Figure 1 A schematic diagram of a first cutting method of a battery cell provided in an embodiment of the present application, Figure 2 A schematic diagram of the structure of a first pole piece provided in an embodiment of the present application under a first cutting method, Figure 3a for Figure 2 A cross-sectional view of A-A' in FIG. Figure 3b for Figure 2 A cross-sectional view of B-B' in FIG. Figure 3c for Figure 2 Another cross-sectional view of B-B' in FIG. Figure 4a for Figure 2 Another cross-sectional view of A-A' in FIG. Figure 4b for Figure 2 Another cross-sectional view of BB' in FIG. Figure 4c for Figure 2 Another cross-sectional view of B-B' in FIG. Figure 5 A schematic diagram of the structure of another first pole piece provided in an embodiment of the present application under a first cutting method, Figure 6a for Figure 5 A cross-sectional view of A-A' in FIG. Figure 6b for Figure 5 A cross-sectional view of B-B' in FIG. Figure 6c for Figure 5 Another cross-sectional view of B-B' in FIG. Figure 7a for Figure 5 Another cross-sectional view of A-A' in FIG. Figure 7b for Figure 5 Another cross-sectional view of BB' in FIG. Figure 7c for Figure 5 Another cross-sectional view of BB' in FIG.

[0108] like Figures 1 to 7c As shown, an embodiment of the present application provides a battery cell 100, comprising a wound first pole piece 110, a diaphragm and a second pole piece, wherein the diaphragm is located between the adjacent first pole piece 110 and the second pole piece;

[0109] The first pole sheet 110 includes a first current collector 111 and a first active material layer 112 coated on both sides of the first current collector 111, a pole lug groove 140 and a groove 142 are provided on the first active material layer 112, a first pole lug 113 electrically connected to the first current collector 111 is provided in the pole lug groove 140, and a protective tape is provided in the pole lug groove 140; along the width direction of the first pole sheet 110, the pole lug groove 140 and the groove 142 are arranged opposite to each other at the edge of the first pole sheet 110, and the protective tape covers the groove 142.

[0110] It should be noted that if Figure 2 and Figure 5 As shown, the width direction of the first pole piece 110 is Y, wherein in the Y direction, the pole ear groove 140 and the groove 142 are arranged opposite to each other at the edge of the first pole piece 110 .

[0111] It is understandable that the first pole tab 113 can be located in the pole tab groove 140 in the thickness direction of the battery cell 100, which can offset a portion of the thickness of the first pole tab 113 and reduce the stacking thickness at the first pole tab 113. As a result, the flatness of the winding core is further improved, the thickness of the winding core can be reduced to a certain extent, and the space utilization and energy density of the battery are improved.

[0112] It should be noted that the protective tape is provided on the tab groove 140 to prevent burrs from being generated on the edge of the tab groove 140. The burrs generated at the welding points during the welding of the tabs may pierce the diaphragm, causing the positive and negative electrodes to contact and cause fire and explosion, and other safety issues.

[0113] It should be noted that the protective tape has thickness. When it is pasted on the paste, it will increase the thickness of the first pole piece 110, resulting in the thickness of the winding core at this position, thereby increasing the thickness of the lithium battery and causing energy density loss; at the same time, the first active material layer 112 covered by the protective tape is ineffective, that is, it does not provide capacity, so the first active material layer 112 covered by the protective tape can be removed and the protective tape can be embedded in the first pole piece 110.

[0114] In some optional embodiments, the first active material layer 112 is further provided with an embedding groove, which is connected to the pole tab groove 140 along the thickness direction of the first pole piece 110 and is located on a side away from the first current collector 111;

[0115] The protective tape is located in the embedding groove and covers the tab groove 140 .

[0116] Specifically, the protective tape is accommodated in the embedding groove to reduce the thickness.

[0117] It should be noted that the embedding groove is provided on the surface layer of the first active material layer 112.

[0118] Specifically, the surface of the first active material layer 112 is formed by extending and concave toward the first current collector 111.

[0119] It is mainly used to accommodate the protective tape to reduce the installation thickness of the protective tape.

[0120] In some optional embodiments, the protective tape is located in the embedding groove and covers the tab groove 140 .

[0121] Through the above-mentioned setting, that is, through the setting of the pole ear groove 140, the thickness of the first pole ear 113 and the protective tape can be hidden in the first active material layer 112 of the first pole piece 110 to reduce the ineffective thickness of the first pole piece 110, thereby reducing the ineffective thickness of the winding core, improving the energy density of the lithium-ion battery, improving the space utilization rate, and improving the endurance of electronic products; in addition, the setting of the protective tape is used to avoid burrs generated at the edge of the pole ear groove 140, and burrs generated at the welding point generated when the first pole ear 113 is welded piercing the diaphragm, causing the positive and negative pole pieces to contact and cause fire and explosion and other safety problems.

[0122] It should be noted that the first electrode sheet 110 may be a positive electrode sheet, wherein the first current collector 111 is a positive electrode current collector, the first active material layer 112 is a positive electrode active material layer, and the first electrode tab 113 is a positive electrode tab.

[0123] It should be noted that the second electrode sheet may be a negative electrode sheet, wherein the second current collector is a negative electrode current collector, the second active material layer is a negative electrode active material layer, and the second electrode tab is a negative electrode tab.

[0124] It should be noted that the second current collector is a high-strength copper foil current collector with a tensile strength of 300MPa-700MPa, an elongation of 2.0%-11%, and a surface density of 30g / m2-65g / m2. The purpose is to effectively improve the problem of the second current collector breaking due to the stress difference generated during the welding process; at the same time, it can also effectively reduce the burrs on the solder joints and reduce the risk of puncture. At the same time, it can also increase the tensile force value at the welding point, reduce the contact impedance, and reduce the internal resistance of the core.

[0125] In some embodiments, the cross-sectional shape of the groove 142 is rectangular, conical, circular, etc., and can be adjusted according to actual conditions without further restrictions.

[0126] like Figures 1 to 7c As shown, in some optional embodiments, the tab groove 140 is located on at least one side of the first active material layer 112 , that is, the tab groove 140 is one of a double-sided tab groove 140 and a single-sided tab groove 140 .

[0127] It should be noted that if the tab slot 140 is a double-sided tab slot 140 , it means that there are two tab slots 140 . At this time, there are two protective tapes, and the two protective tapes are respectively located in the two tab slots 140 . The effect is as above and will not be elaborated here.

[0128] like Figures 1 to 7cAs shown, in some optional embodiments, when the first pole piece 110 is cut by the first cutting method, the pole lug groove 140 is cut into two parts, one part is the pole lug groove 140, and the other part is the groove 142. The groove 142 is opened at the bottom of the first pole piece 110, and the first protective adhesive tape 120 is arranged in the groove 142; the pole lug groove 140 includes the pole lug groove 140. In order to avoid burrs generated at the edge of the pole lug groove 140, and burrs generated at the welding point generated during the welding of the pole lug piercing the diaphragm, causing the positive and negative pole pieces to contact and cause fire and explosion and other safety problems, a second protective adhesive tape 130 is arranged in the pole lug groove 140.

[0129] It should be noted that, taking into account the production tolerances in the actual production process, in order to improve the production yield, the pole lug groove 140 is generally decomposed along 1mm-5mm away from the upper edge of the pole lug groove 140 to decompose the pole lug groove 140 into the pole lug groove 140 and the groove 142, wherein the groove 142 is located at the bottom of the first pole piece 110, and the pole lug groove 140 is located at the top of the first pole piece 110.

[0130] It should be noted that the second protective tape 130 is provided on the tab groove 140 to prevent burrs from being generated on the edge of the tab groove 140. The burrs generated at the welding points during the tab welding may pierce the diaphragm and cause the positive and negative electrodes to contact, resulting in fire and explosion and other safety issues.

[0131] like Figures 1 to 7c As shown, in some optional embodiments, the width of the tab slot 140 is M, wherein M satisfies: 5 mm ≤ M ≤ 20 mm;

[0132] The length of the tab slot 140 is N, where N satisfies: 5 mm ≤ N ≤ 50 mm;

[0133] The width M' of the groove 142, wherein M' satisfies: 5 mm ≤ M' ≤ 20 mm;

[0134] The length of the groove 142 is R, where R satisfies: 1 mm ≤ R ≤ 10 mm.

[0135] It should be noted that the width of the tab slot 140 and the width of the groove 142 can be 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm or 15 mm or any value therebetween.

[0136] The length of the tab groove 140 may be 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, or 35 mm, or any value therebetween.

[0137] The length of the groove 142 may be 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm, or any value therebetween.

[0138] like Figures 1 to 7c As shown, in some optional embodiments, the distance between the side wall of the first pole lug 113 and the side wall of the pole lug groove 140 is greater than 1 mm and less than 10 mm;

[0139] The distance between the bottom wall of the first pole tab 113 and the bottom wall of the pole tab groove 140 is greater than 1 mm and less than 10 mm;

[0140] The distance between the top of the welding section of the first pole tab 113 and the bottom of the insulating pad of the first pole tab 113 is greater than or equal to 0.5 mm and less than or equal to 5 mm.

[0141] The first pole ear 113 is welded on the pole ear groove 140, and there is no restriction on the width S of the first pole ear 113. However, in the width direction, the distance between the first pole ear 113 and the pole ear groove 140 is greater than 1 mm and less than 10 mm. There is no restriction on the length of the pole ear welding end, but the distance between the lower edge of the first pole ear 113 and the lower edge of the pole ear groove 140 is greater than 1 mm and less than 10 mm. The advantages of this are: when it is greater than 1 mm, it can reduce the manufacturing difficulty, and at the same time avoid the overlap of the first pole ear 113 with the first active material layer 112 during welding, resulting in cold welding, causing the problem of increased internal resistance of the battery; less than 10 mm is to avoid excessive loss of the first active material layer 112, resulting in capacity loss, and ultimately leading to energy density loss; the distance between the top of the welding section of the first pole ear 113 and the bottom of the insulating pad of the first pole ear 113 is between 0.5 mm and 5 mm, so as to avoid the insulating pad of the first pole ear 113 piercing the first current collector 111, resulting in the first pole sheet 110 breaking.

[0142] like Figures 1 to 7c As shown, in some optional embodiments, the relationship between the width K of the second protective adhesive tape 130 and the width M of the tab groove 140 satisfies: M<K<M+15mm;

[0143] The relationship between the length T of the second protective tape 130 and the length N of the tab groove 140 satisfies: N<T<N+20mm;

[0144] The distance between the top of the second protective tape 130 and the bottom of the insulating pad of the first electrode tab 113 is greater than or equal to 1 mm and less than or equal to 10 mm.

[0145] The relationship between the width K of the second protective tape 130 and the width M of the tab groove 140 is set, and when covering, it must cover the edge of the tab groove 140 by at least 1 mm. The purpose of doing so is to reduce the manufacturing difficulty and avoid the risk of the second protective tape 130 covering misalignment, resulting in the burrs on the edge of the tab groove 140 being exposed and piercing the diaphragm. At the same time, the coverage area cannot be too large to avoid too much active material being covered and failing, resulting in capacity loss and ultimately energy density loss.

[0146] At the same time, the relationship between the length T of the second protective tape 130 and the length N of the tab groove 140 is set, and when covering, the lower edge of the second protective tape 130 must cover the lower edge of the tab groove 140 by at least 1 mm. The purpose of this is to reduce the manufacturing difficulty and avoid the risk of the second protective tape covering misalignment, resulting in the burrs on the edge of the tab groove 140 being exposed and piercing the diaphragm. At the same time, the coverage area cannot be too large to avoid too much active material being covered and failing, resulting in capacity loss and ultimately energy density loss.

[0147] The distance between the top of the second protective tape 130 and the bottom of the insulating pad of the first pole piece 113 is set mainly to protect the pole piece welding section beyond the upper edge of the first pole piece 110 from short-circuiting with the second pole piece.

[0148] like Figures 1 to 7c As shown, in some optional embodiments, the relationship between the width M' of the groove 142 and the width K' of the first protective adhesive tape 120 satisfies: M'<K'<M'+10mm;

[0149] The relationship between the length T' of the first protective glue and the length R of the groove 142 satisfies: R<T'<R+15mm;

[0150] The distance between the top of the first protective glue and the top of the groove 142 is greater than 1 mm, and the distance between the bottom of the first protective glue and the bottom of the first pole piece 110 is greater than or equal to 0.5 mm and less than or equal to 10 mm.

[0151] It should be noted that the relationship between the width M' of the groove 142 and the width K' of the first protective tape 120 is set, and when covering, it must cover the edge of the groove 142 by at least 1 mm. The purpose of doing so is to reduce the manufacturing difficulty and avoid the risk of the first protective tape 120 covering misalignment, resulting in the burr on the edge of the groove 142 being exposed and piercing the diaphragm. At the same time, the coverage area cannot be too large to avoid too much active material being covered and failing, resulting in capacity loss and ultimately energy density loss.

[0152] The relationship between the length T' of the first protective glue and the length R of the groove 142 is set, and when covering, the lower edge of the first protective glue paper 120 must cover the lower edge of the groove 142 by at least 1 mm. The purpose of this is to reduce the manufacturing difficulty and avoid the risk of the first protective glue covering misalignment, resulting in the risk of burrs on the edge of the groove 142 being exposed and piercing the diaphragm. At the same time, the coverage area cannot be too large to avoid too much active material being covered and failing, resulting in capacity loss, and ultimately leading to energy density loss.

[0153] The arrangement between the top of the first protective glue and the top of the groove 142 is mainly to protect the electrode ear welding section beyond the lower edge of the first electrode sheet 110 from being short-circuited with the second electrode sheet.

[0154] In some embodiments, regarding the punching of the exposed first current collector 111 , it may be punched or not, preferably not punched. If punched, the size of the groove 142 will be 1 mm larger than the size of the punching.

[0155] like Figures 1 to 7c As shown, in some optional embodiments, the embedding groove includes a first embedding groove 150;

[0156] The relationship between the width K of the second protective tape 130 and the width E of the first embedding groove 150 satisfies: K<E<K+10mm;

[0157] And / or, the relationship between the length T of the second protective tape 130 and the length F of the first embedding groove 150 satisfies: T<F<T+10mm;

[0158] and / or, the distance between the side wall of the second protective tape 130 and the groove wall of the first embedding groove 150 is a, wherein 0.5 mm ≤ a ≤ 10 mm;

[0159] And / or, the distance between the bottom wall of the second protective tape 130 and the bottom wall of the first embedding groove 150 is b, wherein 0.5 mm≤b≤10 mm.

[0160] like Figures 1 to 7c As shown, the size of the first embedding groove 150 is larger than that of the second protective tape 130. When covering, the second protective tape 130 must be embedded in the first embedding groove 150, and a gap of at least a=0.5mm-3mm is retained with the edge of the first embedding groove 150. The purpose of doing so is to reduce the manufacturing difficulty and avoid the second protective tape 130 from covering misalignment, resulting in the second protective tape 130 overlapping the edge of the first embedding groove 150 and failing to reduce the thickness at this position. At the same time, the gap cannot be too large to avoid too much active material being removed, resulting in capacity loss and ultimately energy density loss.

[0161] When covering, the second protective tape 130 must be embedded in the first embedding groove 150, and a gap of at least b=0.5mm-3mm is retained with the lower edge of the first embedding groove 150. The purpose of this is to reduce the manufacturing difficulty and avoid the second protective tape 130 from covering misalignment, resulting in the second protective tape 130 overlapping with the edge of the first embedding groove 150 and failing to reduce the thickness at this position. At the same time, the gap cannot be too large to avoid too much active material being removed, resulting in capacity loss and ultimately energy density loss.

[0162] In some embodiments, the upper edge of the first embedded groove 150 is flush with the edge of the first pole piece 110 .

[0163] In some optional embodiments, the embedding groove also includes a second embedding groove 160. Along the thickness direction of the first pole piece 110, the second embedding groove 160 is arranged opposite to the first embedding groove 150 and is respectively located on opposite sides of the first pole piece 110. A second protective tape 130 is provided in the second embedding groove 160.

[0164] It should be noted that if Figure 6a As shown, the thickness direction of the first pole piece 110 is X, wherein in the X direction, the second embedding groove 160 and the first embedding groove 150 are respectively located at two side edges of the first pole piece 110 .

[0165] It should be noted that when the tab groove 140 is a double-sided tab groove 140, it is necessary to apply protective tape on both sides, so a second embedding groove 160 needs to be set on the back side of the first active material layer 112. Correspondingly, there are also two second protective tapes 130, which are respectively set in the first embedding groove 150 and the second embedding groove 160.

[0166] In some embodiments, the first embedding groove 150 may also be disposed on one side, and its depth needs to be twice the thickness of the protective tape.

[0167] It should be noted that the groove depth design and structure of the second embedded groove 160 can refer to the above-mentioned first embedded groove 150, and the details are not repeated here. Alternatively, the second embedded groove 160 and the first embedded groove 150 have the same structure and play the same role.

[0168] like Figures 6b to 7c As shown, in some optional embodiments, the embedding groove further includes a third embedding groove 170, the third embedding groove 170 is connected to the groove 142, and the first protective adhesive tape 120 is accommodated in the third embedding groove 170;

[0169] The difference between the depth of the third embedding groove 170 and the thickness of the first protective tape 120 is greater than or equal to -5um and less than or equal to 5um.

[0170] It should be noted that the first protective tape 120 has a thickness. When it is pasted on the paste, it will increase the thickness of the first pole piece 110, resulting in the thickness of the winding core at this position, thereby increasing the thickness of the lithium battery and causing energy density loss; at the same time, the first active material layer 112 covered by the first protective tape 120 is ineffective, that is, it does not provide capacity, so the first active material layer 112 covered by the first protective tape 120 can be removed, and the first protective tape 120 can be embedded in the first pole piece 110.

[0171] Specifically, the first protective tape 120 is received in the third embedding groove 170 to reduce the thickness.

[0172] In some embodiments, the size of the third embedding groove 170 can refer to the first embedding groove 150 described above, and the details are not repeated here.

[0173] It should be noted that such a configuration can ensure that at least a portion of the first protective tape 120 is embedded in the third embedding groove 170 .

[0174] Of course, the relationship between the first embedding groove 150 and the second protective tape 130 and between the second embedding groove 160 and the second protective tape 130 can refer to the above.

[0175] like Figures 6b to 7c As shown, in some optional embodiments, the embedding groove also includes a fourth embedding groove 180. Along the thickness direction of the first pole piece 110, the fourth embedding groove 180 is arranged opposite to the third embedding groove 170, and are respectively located on the opposite sides of the first pole piece 110. The first protective tape 120 is provided in the fourth embedding groove 180.

[0176] It should be noted that if Figure 6b and Figure 6c As shown, the thickness direction of the first pole piece 110 is X, wherein in the X direction, the fourth embedding groove 180 and the third embedding groove 170 are respectively located at two side edges of the first pole piece 110 .

[0177] It should be noted that when the tab groove 140 is a double-sided tab groove 140, it is necessary to apply protective tape on both sides, so a fourth embedding groove 180 needs to be set on the back side of the first active material layer 112. Correspondingly, there are also two first protective tapes 120, which are respectively set in the third embedding groove 170 and the fourth embedding groove 180.

[0178] In some embodiments, the third embedding groove 170 may also be disposed on one side, and its depth needs to be twice the thickness of the protective tape.

[0179] like Figure 6c The first current collector 111 may be punched or not, preferably not punched. If punched, the size of its groove 142 will be 1 mm larger than the size of punching. It needs to be provided with protective glue on both sides, so it is necessary to provide a fourth embedding groove 180 on the back side. For details, refer to the first embedding groove 150.

[0180] like Figure 7a , Figure 7b as well as Figure 7c Respectively Figure 6a , Figure 6b as well as Figure 6c Correspondingly, it is a cross-sectional view of the design of the embedded groove when the tab groove 140 is single-sided, which will not be described here.

[0181] Figure 8 A schematic diagram of a second cutting method of a battery cell provided in an embodiment of the present application, Fig. 9 A schematic diagram of the structure of a first pole piece provided in an embodiment of the present application under a second cutting method, Fig.10a for Fig. 9 A cross-sectional view of A-A' in FIG. Fig.10b for Fig. 9 A cross-sectional view of B-B' in FIG. Fig.11a for Fig. 9 Another cross-sectional view of A-A' in FIG. Fig.11b for Fig. 9 Another cross-sectional view of BB' in FIG.

[0182] like Figures 8 to 11b As shown, in some optional embodiments, when the first pole piece 110 is cut by the second cutting method, there is a gap between the top of the pole lug groove 140 and the top of the first pole piece 110 .

[0183] It should be noted that when the first pole piece 110 is cut, a portion of the paste is left on the top of the pole ear groove 140, which is also to avoid the influence of tolerance factors in the production process.

[0184] A portion of the paste is left at the top of the tab groove 140, and after the first tab 113 is welded, the first tab 113 is overlapped with the paste at the top of the tab groove 140, as shown in FIG. Fig.10a As shown, it seriously affects the thickness of the battery and affects the energy density of the battery.

[0185] Fig.12 A schematic diagram of the structure of another first pole piece provided in an embodiment of the present application under a second cutting method, Fig.13a for Fig.12 A cross-sectional view of A-A' in FIG. Fig.13b for Fig.12 A cross-sectional view of B-B' in FIG. Fig.13c for Fig.12 Another cross-sectional view of B-B' in FIG.

[0186] like Figure 12 to Figure 13c As shown, in some optional embodiments, at least one side of the first active material layer 112 is provided with a fifth embedding groove 190, and the notch of the fifth embedding groove 190 extends to the top edge of the first active material layer 112;

[0187] The width of the fifth embedding groove 190 is greater than the width of the first pole tab 113 and smaller than the width of the pole tab groove 140 ;

[0188] A portion of the first electrode tab 113 is located in the fifth embedding groove 190 , and a distance between the first electrode tab 113 and the fifth embedding groove 190 is greater than or equal to 0.5 mm.

[0189] like Figure 12 to Figure 13c As shown, the paste on the top of the pole ear groove 140 is removed together, and a fifth embedding groove 190 is set, the depth of which directly cleans the surface of the first current collector 111; at the same time, it is necessary to ensure that when the first pole ear 113 is embedded in the fifth embedding groove 190, there is a gap of at least 0.5mm-1mm between its edge and the edge of the fifth embedding groove 190 to avoid overlapping. It can clean or remove the paste on the top of one side of the pole ear groove 140, or it can remove the top paste on both sides to set two fifth embedding grooves 190.

[0190] In some optional embodiments, the angle between the groove wall of the fifth embedding groove 190 and the groove bottom of the fifth embedding groove 190 ranges from 25° to 80°.

[0191] It should be noted that the groove wall of the fifth embedding groove 190 is inclined relative to the groove bottom of the fifth embedding groove 190 to prevent the vertical side wall from breaking the first current collector 111 .

[0192] Fig.14a for Fig.12 Another cross-sectional view of A-A' in FIG. Fig.14b for Fig.12 Another cross-sectional view of BB' in FIG. Fig.15 A schematic diagram of the structure of another first pole piece provided in an embodiment of the present application under a second cutting method, Fig.16 for Fig.15 A cross-sectional view of A-A' in FIG. Fig.17 A schematic diagram of the structure of another first pole piece provided in an embodiment of the present application under a second cutting method, Fig.18a for Fig.17 A cross-sectional view of A-A' in FIG. Fig.18b for Fig.17 Another cross-sectional view of A-A'.

[0193] like Figures 14a to 18b As shown, in some optional embodiments, there is a gap between the pole tab groove 140 and the top of the first pole piece 110 , and the gap accommodates part of the first pole tab 113 .

[0194] It should be noted that the paste at the notch is punched out to avoid the first electrode tab 113 from overlapping with the paste.

[0195] In some embodiments, the punched shape can be a semicircle, a square, or a rectangle, the width of which is greater than the width of the first electrode tab 113 and less than the width of the electrode tab groove 140 , and the first electrode tab 113 overlaps with the notch.

[0196] The specific effects can be referred to above, and I will not go into details here.

[0197] Fig.19A schematic diagram of a third cutting method of a battery cell provided in an embodiment of the present application, Fig. 20 A schematic diagram of the structure of a first pole piece provided in an embodiment of the present application under a third cutting method, Fig.21 for Fig. 20 A cross-sectional view of A-A' in FIG. Fig. 22 A schematic diagram of the structure of another first pole piece provided in an embodiment of the present application under a third cutting method, Fig.23a for Fig. 22 A cross-sectional view of A-A' in FIG. Figure 23b for Fig. 22 Another cross-sectional view of A-A'.

[0198] like Figure 19 to Figure 23b As shown, in some optional embodiments, when the first pole piece 110 is cut by the third cutting method, the notch of the pole ear groove 140 is flush with the top of the first pole piece 110 .

[0199] It should be noted that the specific effects can be referred to above and will not be elaborated in detail here.

[0200] The battery cell provided in the embodiment of the present application includes a wound first pole sheet, a diaphragm and a second pole sheet, the diaphragm is located between the adjacent first pole sheet and the second pole sheet; the first pole sheet includes a first current collector and a first active material layer coated on both sides of the first current collector, the first active material layer is provided with a pole lug groove and a groove, the pole lug groove is provided with a first pole lug electrically connected to the first current collector, and the pole lug groove is provided with protective tape; along the width direction of the first pole sheet, the pole lug groove and the groove are arranged opposite to each other at the edge of the first pole sheet, and the protective tape covers the groove.

[0201] By setting the pole ear groove, the thickness of the first pole ear and the protective tape can be hidden in the first active material layer of the first pole piece to reduce the ineffective thickness of the first pole piece, thereby reducing the ineffective thickness of the core, improving the energy density of the lithium-ion battery, improving space utilization, and improving the endurance of electronic products; in addition, the setting of the protective tape is used to avoid burrs generated at the edge of the pole ear groove, and burrs generated at the welding point when the first pole ear is welded piercing the diaphragm, causing the positive and negative pole pieces to contact and cause fire and explosion and other safety problems.

[0202] In addition, an embodiment of the present application further provides a battery, including a battery cell 100 .

[0203] The specific structure, working principle and function of the battery cell 100 have been described in detail in the aforementioned embodiments and will not be repeated here.

[0204] The battery provided in the embodiment of the present application, through the setting of the pole lug groove, the thickness of the first pole lug and the protective tape can be hidden in the first active material layer of the first pole piece to reduce the ineffective thickness of the first pole piece, thereby reducing the ineffective thickness of the core, improving the energy density of the lithium-ion battery, improving the space utilization rate, and improving the endurance of electronic products; in addition, the setting of the protective tape is used to avoid burrs generated at the edge of the pole lug groove, and burrs generated at the welding point when the first pole lug is welded piercing the diaphragm, causing the positive and negative pole pieces to contact and cause safety problems such as fire and explosion.

[0205] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A battery cell, characterized in that: It includes a first pole piece, a diaphragm and a second pole piece, wherein the diaphragm is located between the first pole piece and the second pole piece that are adjacent to each other; The first pole piece comprises a first current collector and a first active material layer coated on both sides of the first current collector, the first active material layer is provided with a pole tab groove and a groove, the pole tab groove is provided with a first pole tab electrically connected to the first current collector, and the pole tab groove is provided with a protective adhesive tape; Along the width direction of the first pole piece, the pole ear groove is arranged opposite to the groove at the edge of the first pole piece, and the protective tape covers the groove.

2. The battery cell according to claim 1, characterized in that: The first active material layer is also provided with an embedding groove, which is connected to the pole tab groove along the thickness direction of the first pole piece and is located on a side away from the first current collector; The protective tape is located in the embedding groove and covers the tab groove.

3. The battery cell according to claim 2, characterized in that: A first protective adhesive tape is provided in the groove; A second protective adhesive tape is arranged in the tab groove.

4. The battery cell according to any one of claims 1 to 3, characterized in that: The width of the tab slot is M, where M satisfies: 5mm≤M≤20mm; The length of the tab slot is N, wherein N satisfies: 5mm≤N≤50mm; The width of the groove is M', wherein M' satisfies: 5mm≤M'≤20mm; The length of the groove is R, where R satisfies: 1mm≤R≤10mm.

5. The battery cell according to claim 4, characterized in that: The distance between the side wall of the first pole lug and the side wall of the pole lug groove is greater than 1 mm and less than 10 mm; The distance between the bottom wall of the first pole lug and the bottom wall of the pole lug groove is greater than 1 mm and less than 10 mm; The distance between the top of the welding section of the first pole tab and the bottom of the insulating pad of the first pole tab is greater than or equal to 0.5 mm and less than or equal to 5 mm.

6. The battery cell according to claim 3, characterized in that: The relationship between the width K of the second protective tape and the width M of the tab groove satisfies: M<K<M+15mm; The relationship between the length T of the second protective tape and the length N of the tab groove satisfies: N<T<N+20mm; The distance between the top of the second protective tape and the bottom of the insulating pad of the first electrode tab is greater than or equal to 1 mm and less than or equal to 10 mm.

7. The battery cell according to claim 6, characterized in that: The relationship between the width M' of the groove and the width K' of the first protective tape satisfies: M'<K'<M'+10mm; The relationship between the length T' of the first protective glue and the length R of the groove satisfies: R<T'<R+15mm; The distance between the top of the first protective glue and the top of the groove is greater than 1 mm, and the distance between the bottom of the first protective glue and the bottom of the first pole piece is greater than or equal to 0.5 mm and less than or equal to 10 mm.

8. The battery cell according to claim 3, characterized in that: The embedding groove comprises a first embedding groove; The relationship between the width K of the second protective tape and the width E of the first embedding groove satisfies: K<E<K+10mm; And / or, the relationship between the length T of the second protective tape and the length F of the first embedding groove satisfies: T<F<T+10mm; and / or, the distance between the side wall of the second protective tape and the groove wall of the first embedding groove is a, wherein 0.5 mm ≤ a ≤ 10 mm; And / or, the distance between the bottom wall of the second protective tape and the bottom wall of the first embedding groove is b, wherein 0.5 mm≤b≤10 mm.

9. The battery cell according to claim 8, characterized in that: The embedding groove further includes a second embedding groove. Along the thickness direction of the first pole piece, the second embedding groove and the first embedding groove are respectively located on opposite sides of the first pole piece. The second protective tape is arranged in the second embedding groove.

10. The battery cell according to claim 8, characterized in that: The embedding groove further includes a third embedding groove, the third embedding groove is communicated with the groove, and the first protective adhesive tape is accommodated in the third embedding groove; The difference between the depth of the third embedding groove and the thickness of the first protective tape is greater than or equal to -5um and less than or equal to 5um.

11. The battery cell according to claim 10, characterized in that: The embedding groove further includes a fourth embedding groove. Along the thickness direction of the first pole piece, the fourth embedding groove and the third embedding groove are respectively located on opposite sides of the first pole piece. The first protective tape is arranged in the fourth embedding groove.

12. A battery, characterized in that: Comprising the battery cell as described in any one of claims 1 to 11.

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