Battery cell and battery

Abstract

The utility model relates to the technical field of lithium ion batteries, in particular to a battery cell and a battery. The battery cell comprises a first pole piece, a second pole piece and a diaphragm, the second pole piece and the first pole piece are arranged in an overlapped mode, the diaphragm is arranged between the first pole piece and the second pole piece, and the diaphragm, the first pole piece and the second pole piece are arranged in an overlapped mode, the first pole piece wraps the second pole piece and is wound towards a first direction to form a wound battery cell, the wound battery cell is provided with a tab end and a non-tab end, the tab end is provided with a first groove, the non-tab end is provided with a second groove, and gummed paper is embedded in the first groove and the second groove. The battery comprises the battery cell. The battery cell and the battery provided by the utility model are thinner in thickness, higher in energy density and better in electrolyte infiltration effect.

Description

Technical Field

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

[0002] In the prior art, the battery cell will swell after winding and fail to form a regular plane shape. In the case of uneven shape, adhesive tape needs to be pasted on the battery cell to stick the openings formed at the top and bottom of the battery cell after winding. However, the above process has many adhesive locations, which increases the thickness of the battery cell, and the size of the battery cell will be larger, resulting in a decrease in the energy density of the battery cell. Utility Model Content

[0003] The main purpose of the utility model is to provide a battery cell and a battery, aiming to solve the technical problem that the overall thickness of the battery cell becomes larger and the energy density of the battery cell is reduced after gluing.

[0004] In order to achieve the above object, the utility model proposes a battery cell, comprising:

[0005] First pole piece;

[0006] A second pole piece, the second pole piece and the first pole piece are arranged in a superimposed manner;

[0007] A diaphragm, wherein the diaphragm is disposed between the first pole piece and the second pole piece, and the diaphragm and the first pole piece and the second pole piece are overlapped;

[0008] Among them, the first pole sheet covers the second pole sheet and is wound in a first direction to form a wound battery cell, the wound battery cell has a pole ear end and a non-pole ear end, the pole ear end is provided with a first groove, the non-pole ear end is provided with a second groove, and the first groove and the second groove are embedded with adhesive tape.

[0009] In some embodiments, the first pole piece is provided with a first pole lug, the second pole piece is provided with a second pole lug, the pole lug end includes the first pole lug and the second pole lug, and the first pole lug and the second pole lug are spaced apart;

[0010] Wherein, the first groove is arranged between the first pole lug and the second pole lug.

[0011] In some embodiments, the non-ear end is provided with at least two second grooves, and along the width direction of the wound battery core, the wound battery core has a first side wall and a second side wall which are arranged opposite to each other;

[0012] Among them, the spacing distance D1 between the central axis of the first side wall and the second groove adjacent thereto, the spacing distance D2 between the central axes of the two second grooves, and the spacing distance D3 between the central axis of the second side wall and the second groove adjacent thereto satisfy: D1 = D2 = D3.

[0013] In some embodiments, the groove depth L1 of the first groove satisfies: 10um ≤ L1 ≤ 20um; the groove depth L2 of the second groove satisfies: 10um ≤ L2 ≤ 20um.

[0014] In some embodiments, a third groove is provided on the side wall of the wound battery cell, and hot melt adhesive is provided in the third groove.

[0015] In some embodiments, the groove depth L3 of the third groove satisfies: 5um ≤ L3 ≤ 10um.

[0016] In some embodiments, the hot melt adhesive protrudes in a direction away from the third groove.

[0017] In some embodiments, the thickness L4 by which the hot melt adhesive protrudes in a direction away from the third groove satisfies: 2um ≤ L4 ≤ 4um.

[0018] In some embodiments, the adhesive tape includes a base material layer and an adhesive layer. The adhesive layer is provided on one side of the base material layer, and the adhesive layer faces the first groove and the second groove.

[0019] Among them, the base material layer is a structure made of at least one of thermoplastic polyester, polyethylene, polypropylene, and polyvinyl chloride, and the adhesive layer is a structure made of at least one of acrylic resin, polycarbonate, polyurethane, and rubber.

[0020] Correspondingly, the present utility model also provides a battery, including the battery cell described in any one of the above embodiments.

[0021] Compared with the prior art, the beneficial effects of the present utility model are:

[0022] In the technical solution of the present utility model, in order to avoid the bulging phenomenon of the wound battery cell and ensure that the wound battery cell presents a regular planar morphology, adhesive tape is pasted at the opening of the wound battery cell. At least a part of the adhesive tape is pasted on one side of the opening and winds along the thickness direction of the wound battery cell to the opposite side of the opening and is bonded thereto, forming winding adhesive. Through the bonding effect of the winding adhesive, the opening of the wound battery cell can be constrained to avoid bulging at the opening of the wound battery cell, which may cause the surface of the wound battery cell to be uneven. At the same time, since the adhesive tape has a thickness, in order to avoid the thickness of the adhesive tape affecting the overall thickness of the battery cell and reducing the overall energy density of the battery cell, in the present utility model, grooving treatment is performed at the position where the adhesive tape needs to be pasted, and the adhesive tape is integrally pasted in the first groove and the second groove to achieve the embedded pasting of the adhesive tape on the wound battery cell.

[0023] More preferably, the grooving depth of the first groove and the second groove can be the thickness of the adhesive tape. After the adhesive tape is pasted in the first groove and the second groove, the adhesive tape at the pasting position will be flush with the side wall surface of the wound battery cell. This can not only eliminate the adverse effect of the thickness of the adhesive tape on the overall thickness of the wound battery cell, which is beneficial to improving the energy density of the wound battery cell, but also ensure the overall flatness of the battery cell, which is beneficial to the uniform infiltration of the electrolyte into the wound battery cell.

[0024] The battery applying the above battery cell has a relatively high energy density and a good electrolyte infiltration effect. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0026] Figure 1 It is a schematic diagram of the overall structure of the battery cell provided by an embodiment of the present utility model after winding;

[0027] Figure 2 It is a schematic diagram of the structural parameters of the battery cell provided by an embodiment of the present utility model from the first perspective after winding;

[0028] Figure 3 It is a schematic diagram of the structural parameters of the battery cell provided by an embodiment of the present utility model from the second perspective after winding;

[0029] Figure 4 It is a schematic diagram of the overall structure of the battery cell provided by an embodiment of the present utility model before winding.

[0030] Explanation of the Reference Numerals in the Drawings:

[0031] 100 - Wound battery cell;

[0032] 110 - First electrode tab; 120 - Second electrode tab; 130 - Separator; 140 - Tab end; 150 - Non - tab end; 160 - First side wall; 170 - Second side wall; 180 - Third groove;

[0033] 141 - First groove; 142 - First tab; 143 - Second tab;

[0034] 151 - Second groove;

[0035] 200 - Adhesive tape;

[0036] 300 - Hot melt adhesive;

[0037] X - Width direction of the wound battery cell.

[0038] The realization, functional features and advantages of the purpose of the present utility model will be further described in conjunction with the embodiments and with reference to the accompanying drawings. Detailed implementation manners

[0039] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0040] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0041] In addition, if the descriptions such as "first" and "second" are involved in the embodiments of the present utility model, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be construed as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or", "and / or", or "and / or" appear throughout the text, their meanings include three parallel scenarios. Taking "A and / or B" as an example, it includes scenario A, or scenario B, or the scenario where both A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or inability to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0042] In the prior art, the wound battery cell will bulge and fail to form a regular planar morphology. In the case of uneven morphology, adhesive tape needs to be pasted on the battery cell to stick the openings formed at the top and bottom after winding the battery cell. However, there are many adhesive tape pasting positions in the above process, resulting in an increase in the thickness of the battery cell, a larger size of the battery cell, and a decrease in the energy density of the battery cell.

[0043] To solve the technical problems that the overall thickness of the battery cell becomes larger and the energy density of the battery cell decreases after pasting the adhesive tape, referring to Figures 1 to 4 , an embodiment of the present utility model provides a battery cell, including a first electrode tab 110, a first electrode tab 110 and a separator 130. The second electrode tab 120 and the first electrode tab 110 are stacked. The separator 130 is disposed between the first electrode tab 110 and the second electrode tab 120, and the separator 130 and the first electrode tab 110 and the second electrode tab 120 are stacked. Among them, the first electrode tab 110 wraps the second electrode tab 120 and winds in the first direction to form a wound battery cell 100. The wound battery cell 100 has an ear end 140 and a non-ear end 150. The ear end 140 is provided with a first groove 141, and the non-ear end 150 is provided with a second groove 151. The first groove 141 and the second groove 151 are internally provided with adhesive tape 200.

[0044] Specifically, in order to avoid the bulging phenomenon of the wound battery cell 100 and ensure that the wound battery cell 100 has a regular planar morphology, in this embodiment, a sticker 200 is pasted at the opening of the wound battery cell 100. At least a part of the sticker 200 is pasted on one side of the opening and winds along the thickness direction of the wound battery cell 100 to the opposite side of the opening and is bonded thereto, forming a wound sticker. Through the bonding effect of the wound sticker, the opening of the wound battery cell 100 can be constrained, preventing the opening of the wound battery cell 100 from bulging and causing the surface of the wound battery cell 100 to be uneven. At the same time, since the sticker 200 has a thickness, in order to avoid the thickness of the sticker 200 affecting the overall thickness of the battery cell and reducing the overall energy density of the battery cell, in this embodiment, a grooving process is performed at the position where the sticker 200 needs to be pasted, and the entire sticker 200 is pasted into the first groove 141 and the second groove 151, realizing the embedded pasting of the sticker 200 on the wound battery cell 100.

[0045] More preferably, the grooving depth of the first groove 141 and the second groove 151 can be the thickness of the sticker 200. In this way, when the sticker 200 is pasted into the first groove 141 and the second groove 151, the sticker 200 at the pasted position will be flush with the side wall surface of the wound battery cell 100. This can not only eliminate the adverse effect of the thickness of the sticker 200 on the overall thickness of the wound battery cell 100, which is beneficial to improving the energy density of the wound battery cell 100, but also ensure the overall flatness of the battery cell, which is beneficial to the electrolyte evenly wetting the wound battery cell 100.

[0046] Furthermore, in some embodiments, before the battery cell is wound, the first electrode sheet 110 or the second electrode sheet 120 can be pre-processed so that the active material in the material area corresponding to the sticker area at the tail of the single-sided area of the first electrode sheet 110 or the second electrode sheet 120 is removed to form the first groove 141 and the second groove 151. Exemplarily, for example, the active material in the material area corresponding to the sticker area at the tail of the single-sided area of the first electrode sheet 110 or the second electrode sheet 120 can be removed by means of laser cleaning to form the first groove 141 and the second groove 151. Or, the active material in the material area corresponding to the sticker area at the tail of the single-sided area of the first electrode sheet 110 or the second electrode sheet 120 can also be removed by means of mechanical wiping to form the first groove 141 and the second groove 151. In this embodiment, since the first electrode sheet 110 wraps the second electrode sheet 120 and is wound in the first direction to form the wound battery cell 100, the active material in the material area corresponding to the sticker area at the tail of the single-sided area of the first electrode sheet 110 can be removed to form the first groove 141 and the second groove 151.

[0047] Further, in some embodiments, when removing the active material to form the first groove 141 and the second groove 151, the length and width of the removal area may be greater than a preset actual size of 1 mm - 2 mm (including the end values), and the above tolerance can be determined independently according to the design and the equipment processing capacity. With the above structural dimension design, on the one hand, it can avoid the size of the active material removal area being too large, resulting in too little remaining active material in the battery cell and reducing the energy density of the battery cell. On the other hand, it can avoid the size of the active material removal area being too small, resulting in little thickness gain when the adhesive tape 200 is embedded in the first groove 141 and the second groove 151, which is not conducive to reducing the overall thickness of the battery cell and will also cause a reduction in the energy density of the battery cell.

[0048] Further, in this embodiment, the first electrode sheet 110 may be a positive electrode sheet, then the second electrode sheet 120 is a negative electrode sheet. Similarly, the first electrode sheet 110 may also be a negative electrode sheet, then the second electrode sheet 120 is a positive electrode sheet. A separator 130 is disposed between the first electrode sheet 110 and the second electrode sheet 120. The separator 130 can prevent the first electrode sheet 110 and the second electrode sheet 120 from directly contacting, and thus can prevent a short circuit inside the battery cell. The separator 130 can allow specific ions to pass through. Exemplarily, for example, the separator 130 can allow lithium ions to pass through, so that the lithium ions can migrate between the first electrode sheet 110 and the second electrode sheet 120 to realize the charge and discharge of the battery cell.

[0049] In some embodiments, referring to Figures 1 to 4 , the first electrode sheet 110 is provided with a first tab 142, the second electrode sheet 120 is provided with a second tab 143, the tab end 140 includes the first tab 142 and the second tab 143, and the first tab 142 and the second tab 143 are spaced apart. Among them, the first groove 141 is disposed between the first tab 142 and the second tab 143.

[0050] Specifically, since the positive and negative polarities of the first electrode sheet 110 and the second electrode sheet 120 are opposite, correspondingly, the positive and negative polarities of the first tab 142 and the second tab 143 are also opposite. To avoid direct contact between the first tab 142 and the second tab 143 and cause a short circuit inside the battery cell, in this embodiment, it is necessary to space the first tab 142 and the second tab 143 apart, and the distance between the first tab 142 and the second tab 143 can be adaptively adjusted according to the width of the battery cell. Further, the first groove 141 is disposed between the first tab 142 and the second tab 143. When pasting the adhesive tape 200 later, it is beneficial to paste the adhesive tape 200 in the area centered on the wound battery cell 100, so as to facilitate the firm adhesion of the adhesive tape 200 to the opening, effectively avoiding uneven adhesion caused by the adhesive tape 200 being offset and resulting in the wound battery cell 100 being uneven.

[0051] In some embodiments, referring to Figures 1 to 4 , at least two second grooves 151 are provided at the non-tab end 150. Along the width direction X of the wound battery cell 100, the wound battery cell 100 has a first side wall 160 and a second side wall 170 which are oppositely arranged. Among them, the spacing distance D1 between the center axis of the first side wall 160 and the second groove 151 adjacent thereto, the spacing distance D2 between the center axes of the two second grooves 151, and the spacing distance D3 between the center axis of the second side wall 170 and the second groove 151 adjacent thereto satisfy: D1 = D2 = D3.

[0052] Specifically, in order to ensure the pasting effect of the adhesive tape 200 on the opening of the wound battery cell 100, in this embodiment, at least two second grooves 151 are opened at the non-tab end 150 of the wound battery cell 100. Subsequently, the adhesive tapes 200 can be respectively pasted in the two second grooves 151. Using multiple adhesive tapes 200 can improve the bonding effect on the opening of the wound battery cell 100, so that the opening of the wound battery cell 100 will not crack, and the overall flatness of the wound battery cell 100 is ensured. Further, the multiple adhesive tapes 200 can be located in the equal division area of the non-tab end 150 of the wound battery cell 100. Exemplarily, for example, taking two adhesive tapes 200 as an example, the two adhesive tapes 200 can be respectively pasted at the one-third points of the non-tab end 150, which will make the adhesive force balance of the non-tab end 150 and realize the firm bonding of the adhesive tape 200 to the non-tab end 150.

[0053] In some embodiments, referring to Figure 3 , the groove depth L1 of the first groove 141 satisfies: 10 μm ≤ L1 ≤ 20 μm; the groove depth L2 of the second groove 151 satisfies: 10 μm ≤ L2 ≤ 20 μm. Exemplarily, for example, the value of L1 can be 10 μm, 13 μm, 15 μm, 17 μm, 20 μm, etc., and the value of L2 can be 10 μm, 13 μm, 15 μm, 17 μm, 20 μm, etc. It should be noted that the values of L1 and L2 need to be consistent with the thickness of the adhesive tape 200 used to ensure that the adhesive tape 200 can be snugly embedded in the first groove 141 and the second groove 151, thereby ensuring the overall flatness of the wound battery cell 100.

[0054] In some embodiments, referring to Figures 1 to 4 , a third groove 180 is provided on the side wall of the wound battery cell 100, and a hot melt adhesive 300 is provided in the third groove 180. It should be noted that the above side wall is the attachment surface of the wound battery cell 100.

[0055] Specifically, when the wound battery cell 100 is encapsulated, the wound battery cell 100 needs to be fixed in the cavity of the aluminum-plastic film housing by hot melt adhesive 300. In this embodiment, the hot melt adhesive 300 is disposed in the third groove 180. On the one hand, it is beneficial to eliminate the influence of the thickness of the hot melt adhesive 300 on the overall thickness of the wound battery cell 100, and avoid the increase in the overall thickness of the wound battery cell 100 caused by pasting the hot melt adhesive 300, thereby reducing the overall energy density of the wound battery cell 100. At the same time, pasting the hot melt adhesive 300 in the third groove 180 is beneficial to improve the flatness of the surface of the wound battery cell 100, and effectively avoid the enrichment of the electrolyte in the thickness difference area. On the other hand, since at least a part of the hot melt adhesive 300 is disposed in the third groove 180, after the hot melt adhesive 300 is heated and melted, the third groove 180 is filled with the hot melt adhesive 300, which is beneficial to improve the bonding stability between the wound battery cell 100 and the aluminum-plastic film (compared with merely attaching the hot melt adhesive 300 to the surface of the wound battery cell 100, filling the hot melt adhesive 300 in the third groove 180 is more beneficial to improve the bonding stability between the wound battery cell 100 and the aluminum-plastic film), so that the wound battery cell 100 can be firmly bonded to the aluminum-plastic film, greatly improving the stability of the encapsulation of the wound battery cell 100.

[0056] Further, in some embodiments, two third grooves 180 may be arranged in parallel on the side wall of the wound battery cell 100, and hot melt adhesives 300 are respectively disposed in the two third grooves 180. Adopting such a structure is beneficial to improve the bonding balance between the wound battery cell 100 and the aluminum-plastic film, so that the wound battery cell 100 can evenly bear the adhesive force of the hot melt adhesive 300, and avoid the poor bonding between the wound battery cell 100 and the aluminum-plastic film caused by a single hot melt adhesive 300. Preferably, the size of the substrate of the hot melt adhesive 300 may be 10mm * 50mm.

[0057] In some embodiments, referring to Figure 3 , the groove depth L3 of the third groove 180 satisfies: 5um ≤ L3 ≤ 10um. Exemplarily, for example, the value of L3 may be 5um, 6um, 7um, 8um, 9um, 10um, etc. It should be noted that the grooving size of the third groove 180 may be 1mm to 2mm (including the end values) larger than the preset actual size to facilitate embedding the hot melt adhesive 300 into the third groove 180.

[0058] In some embodiments, the hot melt adhesive 300 protrudes in a direction away from the third groove 180.

[0059] Specifically, in order to improve the bonding effect of the hot melt adhesive 300 and ensure that the hot melt adhesive 300 can provide an effective adhesive force between the wound battery cell 100 and the aluminum-plastic film, in this embodiment, the hot melt adhesive 300 is protrudingly arranged in the third groove 180, so that a part of the hot melt adhesive 300 is arranged outside the third groove 180, rather than the whole of the hot melt adhesive 300 being embedded in the third groove 180. With such a structure, after the hot melt adhesive 300 is heated and melted, it can be ensured that there is always hot melt adhesive 300 between the wound battery cell 100 and the aluminum-plastic film, ensuring that the wound battery cell 100 and the aluminum-plastic film are always bonded by the hot melt adhesive 300, and ensuring the fixed stability of the wound battery cell 100 after encapsulation. Exemplarily, for example, if the whole of the hot melt adhesive 300 is embedded in the third groove 180, after the hot melt adhesive 300 is heated and melted, it may be impossible for the hot melt adhesive 300 to effectively bond with the aluminum-plastic film due to the too deep embedding depth of the hot melt adhesive 300 in the third groove 180, thereby affecting the encapsulation effect of the wound battery cell 100 and reducing the performance of the encapsulated battery cell.

[0060] In some embodiments, the thickness L4 of the hot melt adhesive 300 protruding in the direction away from the third groove 180 satisfies: 2um ≤ L4 ≤ 4um. Exemplarily, for example, the value of L4 can be 2um, 2.5um, 3um, 3.5um, 4um, etc.

[0061] Specifically, in this embodiment, setting the protruding thickness of the hot melt adhesive 300 within the above range, on the one hand, can avoid the protruding thickness of the hot melt adhesive 300 being too small. Exemplarily, for example, the protruding thickness of the hot melt adhesive 300 is set to 0.5um, 1um, 1.5um, etc., resulting in the hot melt adhesive 300 being unable to effectively bond with the aluminum-plastic film, making the bonding effect between the wound battery cell 100 and the aluminum-plastic film poor and affecting the encapsulation effect of the wound battery cell 100. On the other hand, it can also avoid the protruding thickness of the hot melt adhesive 300 being too large. Exemplarily, for example, the protruding thickness of the hot melt adhesive 300 is set to 5um, 5.5um, 6um, etc., which, while ensuring the bonding effect between the wound battery cell 100 and the aluminum-plastic film, results in the overall thickness of the encapsulated battery cell being too large, wasting the material of the hot melt adhesive 300 and reducing the energy density of the wound battery cell 100.

[0062] Therefore, setting the protruding thickness of the hot melt adhesive 300 within the above range can ensure that the protruding thickness of the hot melt adhesive 300 is appropriate, which can not only meet the bonding requirements between the wound battery cell 100 and the aluminum-plastic film, but also reduce the overall thickness of the encapsulated battery cell.

[0063] In some embodiments, the adhesive tape 200 includes a base material layer and an adhesive layer. The adhesive layer is disposed on one side of the base material layer, and the adhesive layer faces the first groove 141 and the second groove 151 to ensure that the adhesive layer can stick the opening of the wound battery cell 100. Among them, the base material layer is a structure made of at least one of thermoplastic polyester, polyethylene, polypropylene, and polyvinyl chloride, and the adhesive layer is a structure made of at least one of acrylic resin, polycarbonate, polyurethane, and rubber. Exemplarily, for example, the base material layer can be a structure made of polyethylene, and the base material layer can also be a composite structure made of polyethylene and polyvinyl chloride. The adhesive layer can be a structure made of acrylic resin, and the adhesive layer can also be a composite structure made of acrylic resin and polycarbonate.

[0064] Correspondingly, another embodiment of the present invention further provides a battery, which includes the battery cell in any of the above embodiments.

[0065] Specifically, in this embodiment, the battery can be a lithium-ion battery. The battery using the above battery cell has a relatively high energy density and a good electrolyte infiltration effect.

[0066] Benefiting from the improvement of the above battery cell, the battery in this embodiment has the same technical effects as the above battery cell, which will not be elaborated here.

[0067] It should be noted that other contents of the battery cell and the battery disclosed in the present invention can be referred to the prior art, which will not be elaborated here.

[0068] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. The battery cell is characterized in that, Comprising: A first pole piece; A second pole piece, the second pole piece and the first pole piece being stacked; A separator, the separator being disposed between the first pole piece and the second pole piece, and the separator and the first pole piece and the second pole piece being stacked; Wherein, the first pole piece wraps the second pole piece and winds in a first direction to form a wound battery cell, the wound battery cell having a tab end and a non-tab end, the tab end being provided with a first groove, the non-tab end being provided with a second groove, and the first groove and the second groove being internally provided with adhesive tape.

2. The battery cell according to claim 1, wherein, The first pole piece is provided with a first tab, the second pole piece is provided with a second tab, the tab end includes the first tab and the second tab, and the first tab and the second tab are spaced apart; Wherein, the first groove is disposed between the first tab and the second tab.

3. The battery cell according to claim 1, characterized in that, The non-tab end is provided with at least two of the second grooves, and along the width direction of the wound battery cell, the wound battery cell has oppositely disposed first sidewalls and second sidewalls; Wherein, the spacing distance D1 between the first sidewall and the central axis of the second groove adjacent thereto, the spacing distance D2 between the central axes of the two second grooves, and the spacing distance D3 between the second sidewall and the central axis of the second groove adjacent thereto satisfy: D1 = D2 = D3.

4. The battery cell according to claim 1, wherein, The groove depth L1 of the first groove satisfies: 10um ≤ L1 ≤ 20um; the groove depth L2 of the second groove satisfies: 10um ≤ L2 ≤ 20um.

5. The battery cell according to claim 1, characterized in that, The sidewall of the wound battery cell is provided with a third groove, and a hot melt adhesive is disposed in the third groove.

6. The battery cell according to claim 5, wherein, The groove depth L3 of the third groove satisfies: 5um ≤ L3 ≤ 10um.

7. The battery cell according to claim 5, wherein The hot melt adhesive protrudes in a direction away from the third groove.

8. The battery cell according to claim 7, characterized in that, The thickness L4 by which the hot melt adhesive protrudes in a direction away from the third groove satisfies: 2um ≤ L4 ≤ 4um.

9. The cell according to claim 1, characterized in that, The adhesive tape includes a base material layer and an adhesive layer, the adhesive layer being disposed on one side of the base material layer, and the adhesive layer facing the first groove and the second groove; Wherein, the base material layer is a structure made of at least one of thermoplastic polyester, polyethylene, polypropylene, and polyvinyl chloride, and the adhesive layer is a structure made of at least one of acrylic resin, polycarbonate, polyurethane, and rubber.

10. A battery, characterized in that, Comprising the battery cell according to any one of claims 1 to 9.

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