A battery cell and a battery
By setting grooves on the active material layer of the lithium-ion battery cell, the glue layer is embedded in the groove, the problem of increasing the cell thickness is solved, and a battery cell with a smaller thickness and a higher flatness is achieved.
Patent Information
- Application Number
- CN202420988192.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-08
- Publication Date
- 2025-04-01
- Estimated Expiration
- 2034-05-08
AI Technical Summary
The battery cells of existing lithium-ion batteries need to be pasted with protective tape at the cutting of the positive electrode head, resulting in an increase in the overall thickness of the battery cells.
A groove is provided on the first active material layer or the second active material layer so that the first glue layer or the second glue layer can be located in the groove, thereby avoiding increasing the cell thickness.
It effectively reduces the overall thickness of the battery cell, improves the flatness of the battery cell, and optimizes the energy density.
Smart Images
Figure CN222705529U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, in particular to a battery core and a battery. Background Art
[0002] A lithium-ion battery is a secondary battery, which consists of an internal bare cell and an outer shell. The internal bare cell is mainly composed of a positive electrode sheet, a negative electrode sheet and an isolation film that are combined in a winding manner. The isolation film is arranged between the positive electrode sheet and the negative electrode sheet. Active substances are coated on the surfaces of the positive and negative electrodes to participate in charging and discharging. In the prior art, a layer of protective tape is pasted on the negative electrode sheet area corresponding to the cutoff point of the positive electrode head to prevent burrs caused by cutting the electrode sheet, but the thickness of the tape will increase the overall thickness of the battery cell. Utility Model Content
[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a battery core having the characteristic of small overall thickness.
[0004] The utility model also provides a battery having the battery core.
[0005] According to the first aspect of the utility model, the battery cell includes: a body, which is formed by stacking a first pole piece, a separator and a second pole piece and then winding them; the first pole piece includes a first section, a second section and a third section, the first section does not have a first active material layer, the second section is provided with a first active material layer, the third section does not have a first active material layer, and an end of the first section away from the second section is a first winding starting point of the first pole piece; the second pole piece includes a fourth section, a fifth section and a sixth section, the two ends of the fifth section are respectively connected to the fourth section and the sixth section, both sides of the sixth section along the thickness direction have a second active material layer, and the fifth section has the second active material layer only on the side away from the fourth section. The fourth segment does not have a second active material layer, wherein one end of the fourth segment away from the fifth segment is the second winding starting point of the second electrode sheet; the fifth segment includes a first straight segment, a second straight segment, a first bending segment and a second bending segment, two ends of the first straight segment are respectively connected to the fourth segment and the first bending segment, two ends of the second straight segment are respectively connected to the first bending segment and the second bending segment, and one end of the second bending segment is connected to the sixth segment; a first glue layer is provided on a side of the second straight segment close to the fourth segment, and a projection of the first winding starting point in the thickness direction of the body falls on the first glue layer; the first active material layer is provided with a groove, and along the thickness direction of the body, the projection of the first glue layer falls within the projection range of the groove.
[0006] The battery cell according to the first embodiment of the utility model has at least the following beneficial effects:
[0007] Since a groove is provided on the first active material layer, and the position of the groove corresponds to the position of the first adhesive layer, the first adhesive layer can be located in the groove, which can effectively avoid the problem of increasing the thickness of the battery cell due to the provision of the first adhesive layer. Specifically, the battery cell has the characteristic of a small overall thickness.
[0008] According to some embodiments of the present invention, along the thickness direction of the body, the thickness of the groove is greater than the thickness of the first adhesive layer.
[0009] According to some embodiments of the present invention, the length of the first adhesive layer in the thickness direction of the body is L1, and the length of the groove in the thickness direction of the body is L2; 2μm≤(L2-L1)≤25μm.
[0010] According to some embodiments of the present invention, the length of the first adhesive layer in the length direction of the body is L3, and the length of the groove in the length direction of the body is L4; 1mm≤(L4-L3)≤6mm.
[0011] According to some embodiments of the present invention, the length of the first adhesive layer in the height direction of the body is L5, and the length of the groove in the height direction of the body is L6; 2mm≤(L6-L5)≤7mm.
[0012] According to some embodiments of the present invention, the length of the first adhesive layer in the thickness direction of the main body is L1, 9μm≤L1≤20μm; and / or, the length of the first adhesive layer in the length direction of the main body is L3, 12mm≤L3≤50mm; and / or, the length of the first adhesive layer in the height direction of the main body is L5, 8mm≤L5≤25mm.
[0013] According to the second aspect of the present invention, the battery cell includes: a body, which is formed by stacking and winding a first pole piece, a separator and a second pole piece; the first pole piece includes a first section, a second section and a third section, the first section does not have a first active material layer, the second section is provided with a first active material layer, the third section does not have a first active material layer, and an end of the first section away from the second section is a first winding starting point of the first pole piece; the second pole piece includes a fourth section, a fifth section and a sixth section, the two ends of the fifth section are respectively connected to the fourth section and the sixth section, both sides of the sixth section along the thickness direction have the second active material layer, and the fifth section has the second active material layer only on the side away from the fourth section. The fourth segment does not have a second active material layer, wherein one end of the fourth segment away from the fifth segment is the second winding starting point of the second electrode sheet; the fifth segment includes a first straight segment, a second straight segment, a first bending segment and a second bending segment, two ends of the first straight segment are respectively connected to the fourth segment and the first bending segment, two ends of the second straight segment are respectively connected to the first bending segment and the second bending segment, and one end of the second bending segment is connected to the sixth segment; a first glue layer is provided on a side of the second straight segment close to the fourth segment, and a projection of the first winding starting point in the thickness direction of the body falls on the first glue layer; the second active material layer is provided with a groove, and along the thickness direction of the body, the projection of the first glue layer falls within the projection range of the groove.
[0014] The battery cell according to the second embodiment of the utility model has at least the following beneficial effects: since a groove is provided on the second active material layer, and the position of the groove corresponds to the position of the first glue layer, the first glue layer can be located in the groove, which can effectively avoid the problem of increasing the thickness of the battery cell by providing the first glue layer. Specifically, the battery cell has the characteristic of a small overall thickness.
[0015] According to some embodiments of the present invention, along the thickness direction of the body, the thickness of the groove is greater than the thickness of the first adhesive layer.
[0016] According to some embodiments of the present invention, the length of the first adhesive layer in the thickness direction of the main body is L1, 9μm≤L1≤20μm; and / or, the length of the first adhesive layer in the length direction of the main body is L3, 12mm≤L3≤50mm; and / or, the length of the first adhesive layer in the height direction of the main body is L5, 8mm≤L5≤25mm.
[0017] A battery according to an embodiment of the third aspect of the utility model comprises the battery cell described in any one of the embodiments of the first aspect or the second aspect.
[0018] The battery according to the third embodiment of the utility model has at least the following beneficial effects: since a groove is provided on the first active material layer or the second active material layer, and the position of the groove corresponds to the position of the first glue layer, the first glue layer can be located in the groove, which can effectively avoid the problem of increasing the thickness of the battery cell by providing the first glue layer. Specifically, the battery cell has the characteristic of a small overall thickness, and the battery formed by the battery cell also has the characteristic of a small overall thickness. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:
[0020] Figure 1 A structural diagram of a battery cell according to an embodiment of the utility model;
[0021] Figure 2 It is a three-dimensional diagram of the first glue layer and the groove in the battery core of the embodiment of the utility model.
[0022] Figure numerals: main body 100, first pole piece 101, first section 102, second section 103, third section 104, first active material layer 105, first winding starting point 106, second pole piece 107, fourth section 108, fifth section 109, sixth section 110, second winding starting point 111, first adhesive layer 112, groove 113, second active material layer 114, isolation film 115, first pole ear 116, second adhesive layer 117, second pole ear 118, third adhesive layer 119, first straight segment 11, first bent segment 12, second straight segment 13, second bent segment 14. DETAILED DESCRIPTION
[0023] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.
[0024] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are 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 cannot be understood as a limitation on the present invention.
[0025] In the description of the present utility model, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used to distinguish the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.
[0026] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.
[0027] In the description of the present invention, reference terms such as "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention.
[0028] It should be noted that in order to make the diagram clearer and more concise, Figure 1 The first active material layer 105 and the second active material layer 114 are not shown in the middle section of the main body 100, but the distribution of the active material layer in each section is clearly described below. Figure 1 The location of each section has been marked.
[0029] refer to Figure 1According to the first embodiment of the utility model, the battery cell includes: a body 100, which is formed by stacking and winding a first pole piece 101, a separator 115, and a second pole piece 107. The first pole piece 101 includes a first section 102, a second section 103, and a third section 104. The first section 102 does not have a first active material layer 105, the second section 103 is provided with a first active material layer 105, and the third section 104 does not have a first active material layer 105. The end of the first section 102 away from the second section 103 is a first winding starting point 106 of the first pole piece 101. The second electrode plate 107 includes a fourth section 108 , a fifth section 109 and a sixth section 110 , the two ends of the fifth section 109 are respectively connected to the fourth section 108 and the sixth section 110 , the sixth section 110 has a second active material layer 114 on both sides along the thickness direction, the fifth section 109 has the second active material layer 114 only on the side facing away from the fourth section 108 , and the fourth section 108 does not have the second active material layer 114 . Among them, the end of the fourth segment 108 away from the fifth segment 109 is the second winding starting point 111 of the second pole piece 107; the fifth segment 109 includes a first straight segment 11, a second straight segment 13, a first bending segment 12 and a second bending segment 14, the two ends of the first straight segment 11 are respectively connected to the fourth segment 108 and the first bending segment 12, the two ends of the second straight segment 13 are respectively connected to the first bending segment 12 and the second bending segment 14, and one end of the second bending segment 14 is connected to the sixth segment 110; a first glue layer 112 is provided on the side of the second straight segment 13 close to the fourth segment 108, and the projection of the first winding starting point 106 in the thickness direction of the main body 100 falls on the first glue layer 112; the first active material layer 105 is provided with a groove 113, and along the thickness direction of the main body 100, the projection of the first glue layer 112 falls within the projection range of the groove 113. The first adhesive layer 112 is provided to prevent the burrs on the first winding starting point 106 from piercing the isolation film 115 and contacting the second pole piece 107 to cause a short circuit; at the same time, the groove 113 is provided at the position of the first active material layer 105 of the body 100 corresponding to the first adhesive layer 112, so that at least a part of the first adhesive layer 112 in the thickness direction of the body 100 can be embedded in the groove 113, reducing the thickness effect caused by the first adhesive layer 112 and improving the overall flatness of the battery cell. At the same time, the first active material layer 105 is a positive electrode active material layer, and the opening of the groove 113 on the first active material layer 105 can optimize the energy density to a certain extent. Since the groove 113 is provided on the first active material layer 105, and the positions of the groove 113 and the first adhesive layer 112 correspond to each other, the first adhesive layer 112 can be located in the groove 113, which can effectively avoid the problem of increasing the thickness of the battery cell caused by the provision of the first adhesive layer 112. Specifically, the battery cell has the characteristic of a small overall thickness.
[0030] It should be noted that, in some embodiments of the present invention, the battery cell further includes a first pole ear 116, the first pole ear 116 is connected to the first section 102, and the battery cell further includes a second adhesive layer 117, the second adhesive layer 117 is bonded to the first pole ear 116 and the first section 102. The first pole ear 116 is the contact point during charging and discharging of the battery cell, responsible for drawing the current from the positive electrode, flowing through the inside of the battery cell, and finally reaching the negative electrode to form a complete circuit. The second adhesive layer 117 can effectively prevent the first pole ear 116 from piercing the isolation film 115 and contacting the second pole piece 107 to cause a short circuit.
[0031] It should be noted that, in some embodiments of the present invention, the battery cell further includes a second pole ear 118, which is connected to the fourth section 108, and the battery cell further includes a third adhesive layer 119, which is bonded to the second pole ear 118 and the fourth section 108. The second pole ear 118 is a contact point during charging and discharging of the battery cell, and is responsible for drawing the current from the positive electrode, flowing through the inside of the battery cell, and finally reaching the negative electrode to form a complete circuit. The third adhesive layer 119 can effectively prevent the second pole ear 118 from piercing the isolation film 115 and contacting the first pole piece 101 to cause a short circuit.
[0032] refer to Figure 1 and Figure 2 In some embodiments of the present invention, along the thickness direction of the body 100, the thickness of the groove 113 is greater than the thickness of the first adhesive layer 112. In this way, the first adhesive layer 112 can be completely embedded in the groove 113 in the thickness direction, further reducing the thickness effect of the first adhesive layer 112 and improving the overall flatness of the battery cell.
[0033] refer to Figure 2 In some embodiments of the present invention, the length of the first adhesive layer 112 in the thickness direction of the body 100 is L1, and the length of the groove 113 in the thickness direction of the body 100 is L2; 2μm≤(L2-L1)≤25μm. For example, (L2-L1) can be 2μm, 5μm, 10μm, 15μm or 25μm. Setting the difference in this way can make the first adhesive layer 112 completely embedded in the groove 113 in the thickness direction of the body 100. When the groove 113 is set at the position closest to the first winding starting point 106, L2-L1=2μm, so that the first adhesive layer 112 can be wrapped while minimizing the thinning of the first active material layer 105. Considering that there are other substances in the battery body 100, if the difference is less than 2μm, the groove 113 may not be able to wrap the first adhesive layer 112; if the difference is set to be greater than 25μm, the first active material layer 105 is thinned too much, which poses a safety hazard. The value of (L2-L1) depends on the distance between the opening position of the groove 113 and the first winding starting point 106. The greater the distance, the greater the difference.
[0034] Specifically, when 2μm≤(L2-L1)<5μm, the difference is small, and the first adhesive layer 112 should be set at a position closer to the first winding starting point 106 to avoid excessive other substances between the groove 113 and the first adhesive layer 112, resulting in the first adhesive layer 112 being unable to be completely embedded in the groove 113 in the thickness direction of the body 100; when 5μm≤(L2-L1)≤15μm, the difference is moderate, and the groove 113 is set at most positions in the thickness direction of the body 100 to take into account the requirements of reducing the thickness of the battery cell and completely embedding the first adhesive layer 112, which is a preferred solution; when 15μm<(L2-L1)≤25μm, the difference is large, and the local flatness is poor. Except for special circumstances where the groove 113 needs to be set far away from the first winding starting point 106, such a large gap thinning is not considered.
[0035] refer to Figure 2 In some embodiments of the present invention, the length of the first adhesive layer 112 in the length direction of the body 100 is L3, and the length of the groove 113 in the length direction of the body 100 is L4; 1mm≤(L4-L3)≤6mm. For example, (L4-L3) can be 1mm, 5mm or 6mm. Such a difference setting can make the first adhesive layer 112 completely embedded in the groove 113 in the length direction of the body 100. When the groove 113 is set at the position closest to the first winding starting point 106, (L4-L3)=1mm, so that the first adhesive layer 112 can be wrapped while minimizing the thinning of the first active material layer 105. Considering that there are other substances in the battery body 100, if the difference is less than 1mm, the groove 113 may not be able to wrap the first adhesive layer 112; if the difference is set to be greater than 6mm, the first active material layer 105 is thinned too much, which poses a safety hazard. The value of (L4-L3) depends on the distance between the opening position of the groove 113 and the first winding starting point 106. The greater the distance, the greater the difference.
[0036] Specifically, when 1mm≤(L4-L3)<3mm, the difference is small, and the first adhesive layer 112 should be set at a position closer to the first winding starting point 106 to avoid excessive other materials between the groove 113 and the first adhesive layer 112, resulting in the first adhesive layer 112 being unable to be completely embedded in the groove 113 in the length direction of the body 100; when 3mm≤(L4-L3)<5mm, the difference is moderate, and the groove 113 is set at most positions in the thickness direction of the body 100 to take into account the requirements of reducing the thickness of the battery cell and completely embedding the first adhesive layer 112, which is a preferred solution; when 5mm≤(L4-L3)≤6mm, the difference is large, and the local flatness is poor. Except for special circumstances where the groove 113 needs to be set far away from the first winding starting point 106, such a large gap thinning is not considered.
[0037] refer to Figure 2 In some embodiments of the present invention, the length of the first adhesive layer 112 in the height direction of the body 100 is L5, and the length of the groove 113 in the height direction of the body 100 is L6; 2mm≤(L6-L5)≤7mm. For example, (L6-L5) can be 2mm, 5mm or 7mm. Such a difference setting can make the first adhesive layer 112 completely embedded in the groove 113 in the height direction of the body 100. When the groove 113 is set at the position closest to the first winding starting point 106, (L6-L5)=7mm. In this way, while ensuring that the first adhesive layer 112 is wrapped, the thinning of the first active material layer 105 can be minimized. Considering that there are other substances in the battery body 100, if the difference is less than 2mm, the groove 113 may not be able to wrap the first adhesive layer 112; if the difference is set to be greater than 7mm, the first active material layer 105 is thinned too much, which poses a safety hazard. The value of (L6-L5) depends on the distance between the opening position of the groove 113 and the first winding starting point 106. The greater the distance, the greater the difference.
[0038] Specifically, when 1mm≤(L6-L5)<2mm, the difference is small, and the first adhesive layer 112 should be set at a position closer to the first winding starting point 106 to avoid excessive other materials between the groove 113 and the first adhesive layer 112, resulting in the first adhesive layer 112 being unable to be completely embedded in the groove 113 in the height direction of the body 100; when 2mm≤(L6-L5)≤4mm, the difference is moderate, and the groove 113 is set at most positions in the thickness direction of the body 100 to take into account the requirements of reducing the thickness of the battery cell and completely embedding the first adhesive layer 112, which is a preferred solution; when 4mm<(L6-L5)≤7mm, the difference is large, and the local flatness is poor. Except for special circumstances where the groove 113 needs to be set far away from the first winding starting point 106, such a large gap thinning is not considered.
[0039] refer to Figure 2 In some embodiments of the present invention, the length of the first adhesive layer 112 in the thickness direction of the body 100 is L1, 9μm≤L1≤20μm. Such a setting can prevent the first winding starting point 106 from piercing the isolation film 115 while minimizing the size of the first adhesive layer 112, thereby reducing the impact of the first adhesive layer 112 on the flatness of the battery body 100. If L1 is set to be less than 9μm, the relative position of the first adhesive layer 112 and the first winding starting point 106 may change during the winding process, resulting in the first adhesive layer 112 not being able to cover the first winding starting point 106 well, which poses a safety hazard; if L1 is set to be greater than 20μm, the size of the first adhesive layer 112 is too large, which will increase the thickness of the body 100, thereby affecting the thickness of the battery.
[0040] refer to Figure 2 In some embodiments of the present invention, the length of the first adhesive layer 112 in the length direction of the body 100 is L3, 12mm≤L3≤50mm. Such a setting can prevent the first winding starting point 106 from piercing the isolation film 115 while minimizing the size of the first adhesive layer 112, thereby reducing the impact of the first adhesive layer 112 on the flatness of the battery body 100. If L3 is set to be less than 12mm, the relative position of the first adhesive layer 112 and the first winding starting point 106 may change during the winding process, resulting in the first adhesive layer 112 not being able to cover the first winding starting point 106 well, posing a safety hazard; if L3 is set to be greater than 50mm, the size of the first adhesive layer 112 is too large, which will increase the thickness of the body 100, thereby affecting the thickness of the battery.
[0041] refer to Figure 2 In some embodiments of the present invention, the length of the first adhesive layer 112 in the height direction of the body 100 is L5, 8mm≤L5≤25mm. Such a setting can prevent the first winding starting point 106 from piercing the isolation film 115 while minimizing the size of the first adhesive layer 112, thereby reducing the influence of the first adhesive layer 112 on the thickness of the battery body 100. If L5 is set to be less than 8mm, the relative position of the first adhesive layer 112 and the first winding starting point 106 may change during the winding process, resulting in the first adhesive layer 112 not being able to cover the first winding starting point 106 well, which poses a safety hazard; if L5 is set to be greater than 25mm, the size of the first adhesive layer 112 is too large, which will increase the thickness of the body 100, thereby affecting the thickness of the battery.
[0042] refer to Figure 1According to the second aspect of the utility model, the battery cell includes: a body 100, which is formed by stacking a first pole piece 101, an isolation film 115, and a second pole piece 107 and then winding them; the first pole piece 101 includes a first section 102, a second section 103, and a third section 104, the first section 102 does not have a first active material layer 105, the second section 103 is provided with a first active material layer 105, and the third section 104 does not have a first active material layer 105, and the end of the first section 102 away from the second section 103 is a first winding starting point 106 of the first pole piece 101; the second pole piece 107 includes a fourth section 108, a fifth section 109, and a sixth section 110, the two ends of the fifth section 109 are respectively connected to the fourth section 108 and the sixth section 110, both sides of the sixth section 110 along the thickness direction have the second active material layer 114, and the fifth section 109 has the second active material layer only on the side away from the fourth section 108. The fourth section 108 does not have a second active material layer 114, wherein one end of the fourth section 108 away from the fifth section 109 is the second winding starting point 111 of the second electrode sheet 107; the fifth section 109 includes a first straight section 11, a second straight section 13, a first bending section 12 and a second bending section 14, the two ends of the first straight section 11 are respectively connected to the fourth section 108 and the first bending section 12, the two ends of the second straight section 13 are respectively connected to the first bending section 12 and the second bending section 14, and one end of the second bending section 14 is connected to the sixth section 110; a first glue layer 112 is provided on one side of the second straight section 13 close to the fourth section 108, and the projection of the first winding starting point 106 in the thickness direction of the body 100 falls on the first glue layer 112; the second active material layer 114 is provided with a groove 113, and along the thickness direction of the body 100, the projection of the first glue layer 112 falls within the projection range of the groove 113. The first adhesive layer 112 is provided to prevent the burrs on the first winding starting point 106 from piercing the isolation film 115 and contacting the second pole piece 107 to cause a short circuit; at the same time, the groove 113 is provided at the position of the second active material layer 114 of the thickness of the body 100 corresponding to the first adhesive layer 112, so that at least a part of the first adhesive layer 112 in the thickness direction of the body 100 can be embedded in the groove 113, reducing the thickness effect caused by the first adhesive layer 112 and improving the overall flatness of the battery cell; at the same time, the second active material layer 114 is a negative electrode active material layer, and the groove 113 is provided on the second active material layer 114 to balance the positive and negative electrode capacities to a certain extent. Since the groove 113 is provided on the second active material layer 114, and the position of the groove 113 corresponds to that of the first adhesive layer 112, the first adhesive layer 112 can be located in the groove 113, which can effectively avoid the problem of increasing the thickness of the battery cell caused by the provision of the first adhesive layer 112. Specifically, the battery cell has the characteristic of a small overall thickness.
[0043] refer to Figure 1 and Figure 2In some embodiments of the present invention, along the thickness direction of the body 100, the thickness of the groove 113 is greater than the thickness of the first adhesive layer 112. In this way, the first adhesive layer 112 can be completely embedded in the groove 113 in the thickness direction, further reducing the thickness effect of the first adhesive layer 112 and improving the overall flatness of the battery cell.
[0044] refer to Figure 2 In some embodiments of the present invention, the length of the first adhesive layer 112 in the thickness direction of the body 100 is L1, 9μm≤L1≤20μm. Such a setting can prevent the first winding starting point 106 from piercing the isolation film 115 while minimizing the size of the first adhesive layer 112, thereby reducing the influence of the first adhesive layer 112 on the thickness of the battery body 100. If L1 is set to be less than 9μm, the relative position of the first adhesive layer 112 and the first winding starting point 106 may change during the winding process, resulting in the first adhesive layer 112 not being able to cover the first winding starting point 106 well, which poses a safety hazard; if L1 is set to be greater than 20μm, the size of the first adhesive layer 112 is too large, which will increase the thickness of the body 100, thereby affecting the thickness of the battery.
[0045] refer to Figure 2 In some embodiments of the utility model, the length of the first adhesive layer 112 in the length direction of the body 100 is L3, 12mm≤L3≤50mm. Such a setting can prevent the first winding starting point 106 from piercing the isolation film 115 while minimizing the size of the first adhesive layer 112, thereby reducing the influence of the first adhesive layer 112 on the thickness of the battery body 100. If L3 is set to be less than 12mm, the relative position of the first adhesive layer 112 and the first winding starting point 106 may change during the winding process, resulting in the first adhesive layer 112 not being able to cover the first winding starting point 106 well, which poses a safety hazard; if L3 is set to be greater than 50mm, the size of the first adhesive layer 112 is too large, which will increase the thickness of the body 100, thereby affecting the thickness of the battery.
[0046] refer to Figure 2In some embodiments of the present invention, the length of the first adhesive layer 112 in the height direction of the body 100 is L5, 8mm≤L5≤25mm. Such a setting can prevent the first winding starting point 106 from piercing the isolation film 115 while minimizing the size of the first adhesive layer 112, thereby reducing the influence of the first adhesive layer 112 on the thickness of the battery body 100. If L5 is set to be less than 8mm, the relative position of the first adhesive layer 112 and the first winding starting point 106 may change during the winding process, resulting in the first adhesive layer 112 not being able to cover the first winding starting point 106 well, which poses a safety hazard; if L5 is set to be greater than 25mm, the size of the first adhesive layer 112 is too large, which will increase the thickness of the body 100, thereby affecting the thickness of the battery.
[0047] The battery according to the third embodiment of the utility model includes the battery cell described in any one of the first embodiment or the second embodiment. The first adhesive layer 112 is provided to prevent the burrs on the first winding starting point 106 from piercing the isolation film 115 and contacting the second pole piece 107 to cause a short circuit; at the same time, the groove 113 is provided at the position of the first active material layer 105 or the second active material layer 114 of the thickness of the body 100 corresponding to the first adhesive layer 112, so that at least a part of the first adhesive layer 112 in the thickness direction of the body 100 can be embedded in the groove 113, reducing the thickness effect brought by the first adhesive layer 112, so that the battery cell as a whole has the characteristic of a smaller thickness, thereby making the battery formed by the battery cell have the characteristic of a smaller thickness.
[0048] The embodiments of the utility model are described in detail above in conjunction with the accompanying drawings, but the utility model is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.
Claims
1. A battery cell, characterized in that: The battery cell comprises: A body, wherein the body is formed by stacking a first pole piece, a separator and a second pole piece and then winding them; The first pole piece includes a first section, a second section and a third section, the first section does not have a first active material layer, the second section is provided with the first active material layer, the third section does not have the first active material layer, and an end of the first section away from the second section is a first winding starting point of the first pole piece; The second pole piece includes a fourth section, a fifth section and a sixth section, the two ends of the fifth section are respectively connected to the fourth section and the sixth section, the second active material layer is provided on both sides of the sixth section in the thickness direction, the second active material layer is provided on only one side of the fifth section away from the fourth section, and the fourth section does not have the second active material layer, wherein the end of the fourth section away from the fifth section is the second winding starting point of the second pole piece; The fifth segment includes a first straight segment, a second straight segment, a first bent segment, and a second bent segment, two ends of the first straight segment are respectively connected to the fourth segment and the first bent segment, two ends of the second straight segment are respectively connected to the first bent segment and the second bent segment, and one end of the second bent segment is connected to the sixth segment; A first adhesive layer is provided on one side of the second straight line segment close to the fourth segment, and a projection of the first winding starting point in the thickness direction of the body falls on the first adhesive layer; The first active material layer is provided with a groove, and along the thickness direction of the body, the projection of the first adhesive layer falls within the projection range of the groove.
2. The battery cell according to claim 1, characterized in that: Along the thickness direction of the body, the thickness of the groove is greater than the thickness of the first adhesive layer.
3. The battery cell according to claim 1, characterized in that: The length of the first adhesive layer in the thickness direction of the body is L1, and the length of the groove in the thickness direction of the body is L2; 2μm≤(L2-L1)≤25μm.
4. The battery cell according to claim 1, characterized in that: The length of the first adhesive layer in the length direction of the main body is L3, and the length of the groove in the length direction of the main body is L4; 1mm≤(L4-L3)≤6mm.
5. The battery cell according to claim 1, characterized in that: The length of the first adhesive layer in the height direction of the main body is L5, and the length of the groove in the height direction of the main body is L6; 2mm≤(L6-L5)≤7mm.
6. The battery cell according to claim 1, characterized in that: The length of the first adhesive layer in the thickness direction of the body is L1, 9mm≤L1≤20μm; and / or, the length of the first adhesive layer in the length direction of the body is L3, 12 mm ≤ L3 ≤ 50 mm; And / or, the length of the first adhesive layer in the height direction of the main body is L5, 8mm≤L5≤25mm.
7. A battery cell, characterized in that: The battery cell comprises: A body, wherein the body is formed by stacking a first pole piece, a separator and a second pole piece and then winding them; The first pole piece includes a first section, a second section and a third section, the first section does not have a first active material layer, the second section is provided with the first active material layer, the third section does not have the first active material layer, and an end of the first section away from the second section is a first winding starting point of the first pole piece; The second pole piece includes a fourth section, a fifth section and a sixth section, the two ends of the fifth section are respectively connected to the fourth section and the sixth section, the second active material layer is provided on both sides of the sixth section in the thickness direction, the second active material layer is provided on only one side of the fifth section away from the fourth section, and the fourth section does not have the second active material layer, wherein the end of the fourth section away from the fifth section is the second winding starting point of the second pole piece; The fifth segment includes a first straight segment, a second straight segment, a first bent segment, and a second bent segment, two ends of the first straight segment are respectively connected to the fourth segment and the first bent segment, two ends of the second straight segment are respectively connected to the first bent segment and the second bent segment, and one end of the second bent segment is connected to the sixth segment; A first adhesive layer is provided on one side of the second straight line segment close to the fourth segment, and a projection of the first winding starting point in the thickness direction of the body falls on the first adhesive layer; The second active material layer is provided with a groove, and along the thickness direction of the body, the projection of the first adhesive layer falls within the projection range of the groove.
8. The battery cell according to claim 7, characterized in that: Along the thickness direction of the body, the thickness of the groove is greater than the thickness of the first adhesive layer.
9. The battery cell according to claim 7, characterized in that: The length of the first adhesive layer in the thickness direction of the body is L1, 9 μm≤L1≤20 μm; and / or the length of the first adhesive layer in the length direction of the body is L3, 12 mm≤L3≤50 mm; And / or, the length of the first adhesive layer in the height direction of the main body is L5, 8mm≤L5≤25mm.
10. A battery, characterized in that The battery comprises the battery cell according to any one of claims 1 to 9.