Battery cell and battery

Abstract

Provided in the present application are a battery cell (100) and a battery. The battery cell (100) comprises: a first electrode sheet (1), a separator (3) and a second electrode sheet (2), which are stacked and wound, wherein the first electrode sheet (1) and the second electrode sheet (2) each comprise a plurality of electrode sheet layers formed by means of winding; the first electrode sheet (1) and the second electrode sheet (2) have opposite polarities; the first electrode sheet (1) is provided with at least two first tabs (4); the second electrode sheet (2) is provided with at least one second tab (5); the first electrode sheet (1) comprises a first current collector (11) and a first active material layer (12) which coats either side of the first current collector (11); the first active material layer (12) is provided with at least two first empty foil regions (13), and the first tabs (4) are correspondingly arranged in the first empty foil regions (13) and are connected to the first current collector (11); and the first active material layer (12) is provided on the surface of the side of the first current collector (11) facing away from at least one first tab (4). The battery cell in the present application can increase the over-current capacity, thereby facilitating a reduction in temperature rise of the battery and an increase in energy density.

Description

Cells and Batteries

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 25, 2023, with application number 202321637421.6 and application name “Battery Cells and Batteries”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of new energy technology, and in particular to a battery cell and a battery. Background Art

[0003] With the rapid development and application of 5G, batteries have more and more application scenarios, and consumers have higher and higher performance requirements for batteries in electronic products.

[0004] At present, the mainstream batteries on the market all have a bipolar lug structure, that is, one positive lug and one negative lug. However, the structure and number of the lugs themselves cause the battery to have a large temperature rise during operation. In addition, when connecting the lugs to the current collectors, it is necessary to set up empty foil areas on the active material layers on both sides of the current collector to connect the lugs. This will result in a reduction in coating, which is not conducive to improving the battery energy density.

[0005] Summary of the Invention

[0006] The present application provides a battery cell and a battery, which can overcome the above technical problems by providing the battery cell with at least two first pole tabs and at least one second pole tab, and providing a first active material layer on the surface of the first current collector facing away from the at least one first pole tab.

[0007] The present application provides a battery cell, comprising: a first pole piece, a diaphragm, and a second pole piece arranged and wound in a stacked manner, wherein the first pole piece and the second pole piece each include a plurality of pole piece layers formed by winding, wherein the polarities of the first pole piece and the second pole piece are opposite, and the first pole piece is provided with at least two first pole tabs; the second pole piece is provided with at least one second pole tab; the first pole piece 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 at least two first empty foil areas, and the first pole tabs are correspondingly arranged in the first empty foil areas and connected to the first current collector; the first active material layer is provided on the surface of the first current collector on the side facing away from at least one first pole tab.

[0008] The battery cell of the present application is provided with at least two first tabs and at least one second tab, which significantly increases the battery's overall current capacity, reduces the resistance difference between adjacent tabs, and helps reduce the battery's temperature rise. Furthermore, by configuring the first tab and the first current collector to be connected on one side, lithium ions can be properly intercalated and deintercalated on the side of the first current collector not welded to the first tab, effectively unleashing its full capacity. Furthermore, the two layers of insulating adhesive used to cover the first tab on that side can be eliminated, thereby reducing the number of adhesive tape layers, reducing the overall battery thickness, and increasing energy density.

[0009] Optionally, the two first electrode tabs are located on both sides of the second electrode tab in the thickness direction and / or width direction of the battery cell.

[0010] Optionally, an insulating rubber layer is provided between at least one pole piece layer where the first pole tab is located and at least one adjacent pole piece layer where the second pole tab is located, and the insulating rubber layer covers the first pole tab and the second pole tab on both sides.

[0011] Optionally, a center distance H between at least one of the first electrode tab and the second electrode tab in the width direction of the battery core is in the range of 16 mm ≤ H < 20 mm.

[0012] According to some embodiments of the present application, one of the pole piece layer where the first pole tab is located and the pole piece layer where the second pole tab is located is provided with a first insulating rubber layer, and the first insulating rubber layer covers the first pole tab and the second pole tab; the other of the pole piece layer where the first pole tab is located and the pole piece layer where the second pole tab is located is provided with a first rubber layer and a second rubber layer, and the first rubber layer covers the first pole tab and the second rubber layer covers the second pole tab.

[0013] Optionally, the first adhesive layer and the second adhesive layer are a second insulating adhesive layer integrally connected.

[0014] Optionally, the second pole piece includes a second current collector and a second active material layer coated on both sides of the second current collector, the second active material layer on one side of the second current collector has a second empty foil area, and the second pole tab is connected to the second empty foil area.

[0015] Optionally, the first active material layer is provided on the surface of the first current collector facing away from the first electrode tab.

[0016] Optionally, the first empty foil areas corresponding to the two first electrode tabs are respectively located on both sides of the first current collector.

[0017] Optionally, the two first pole tabs and the second pole tab are both located on the same side of a center line of the battery cell in the thickness direction.

[0018] In some embodiments, the first pole tab close to the center line of the battery cell along the thickness direction is located on the side of the first current collector facing away from the center line of the battery cell along the thickness direction; and / or, the first pole tab away from the center line of the battery cell along the thickness direction is located on the side of the first current collector facing the center of the battery cell.

[0019] A second aspect of the present application provides a battery, comprising: a housing defining a cell accommodating cavity; and a cell according to the first aspect of the present application, the cell being disposed in the cell accommodating cavity.

[0020] According to the battery of the present application, by providing the battery cell of the first aspect described above, the overall current capacity of the battery can be significantly increased, which helps to reduce the temperature rise of the battery and can improve the energy density of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without inventive work. Among them:

[0022] FIG1 is a schematic structural diagram of a battery cell according to a first embodiment of the present application;

[0023] FIG2 is a schematic structural diagram of a battery cell according to a second embodiment of the present application;

[0024] FIG3 is a schematic structural diagram of a battery cell according to a third embodiment of the present application;

[0025] FIG4 is a schematic structural diagram of a first pole piece according to an embodiment of the present application;

[0026] FIG5 is a schematic structural diagram of a battery cell according to an embodiment of the present application.

[0027] Explanation of the accompanying reference numerals: 100-battery cell; 1-first pole piece; 11-first current collector; 12-first active material layer; 13-first empty foil area; 2-second pole piece; 21-second current collector; 22-second active material layer; 23-second empty foil area; 3-diaphragm; 4-first electrode tab; 41-first insulating adhesive layer; 42-first adhesive layer; 43-third adhesive layer; 5-second electrode tab; 51-second insulating adhesive layer; 52-second adhesive layer; 53-fourth adhesive layer; L-center line. DETAILED DESCRIPTION

[0028] The following describes in detail embodiments of the present application. 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 application and are not to be construed as limiting the present application.

[0029] With the rapid development and application of 5G, battery applications are expanding, and consumers are demanding higher performance from batteries in electronic products. Currently, mainstream batteries on the market all have a bipolar tab structure, with one positive tab and one negative tab. However, the tab's inherent structure and limited number of tabs result in significant temperature rise during operation. Furthermore, connecting the tabs to the current collector requires a hollow foil area on both sides of the active material layer to connect the tabs. This reduces the amount of coating available and hinders improving battery energy density.

[0030] In view of this, the present application provides a battery cell and a battery, wherein the battery cell is provided with at least two first pole tabs and at least one second pole tab, which can improve the battery's current carrying capacity and reduce temperature rise; the first pole tab and the first current collector are connected on one side, which helps to improve the battery's energy density.

[0031] The battery cell 100 according to the embodiment of the first aspect of the present application is described in detail below with reference to Figures 1 to 5.

[0032] As shown in FIG5 , the battery cell 100 of the embodiment of the present application may be a wound core. The battery cell 100 includes a first electrode sheet 1 , a separator 3 , and a second electrode sheet 2 .

[0033] Referring to Figures 1-3, specifically, the first electrode sheet 1, the separator 3, and the second electrode sheet 2 can be stacked in the thickness direction and then wound to form the battery cell 100. After winding, the first electrode sheet 1 and the second electrode sheet 2 each include multiple electrode sheet layers, that is, the first electrode sheet 1 forms a stack of multiple first electrode sheet layers, and the second electrode sheet 2 forms a stack of multiple second electrode sheet layers. Of course, the multiple electrode sheet layers of the first electrode sheet 1 are connected sequentially, and the multiple electrode sheet layers of the second electrode sheet 2 are also connected sequentially.

[0034] The first electrode piece 1 and the second electrode piece 2 have opposite polarities. The first electrode piece 1 is provided with at least two first electrode tabs 4, and the second electrode piece 2 is provided with at least one second electrode tab 5. For example, the first electrode piece 1 may be a positive electrode piece and the second electrode piece 2 may be a negative electrode piece; alternatively, the first electrode piece 1 may be a negative electrode piece and the second electrode piece 2 may be a positive electrode piece. The positive electrode piece may have two positive electrode tabs and the negative electrode piece may have one negative electrode tab; alternatively, the positive electrode piece may have one positive electrode tab and the negative electrode piece may have two negative electrode tabs.

[0035] The following description will be made by taking the first electrode 1 as the positive electrode, the second electrode 2 as the negative electrode, the first electrode 1 having two first electrode tabs 4 as positive electrode tabs, and the second electrode 2 having one second electrode tab 5 as negative electrode tab as an example.

[0036] 1 to 3 , the first electrode 1 includes a first current collector 11 and a first active material layer 12 . The first active material layer 12 is coated on both sides of the first current collector 11 in the thickness direction. The first active material layer 12 on one side of the first current collector 11 has a first empty foil area 13 . The first empty foil area 13 can be formed by cleaning the first active material layer 12 on that side. The first electrode tab 4 is arranged in the corresponding first empty foil area 13 and is connected to the first current collector 11 by welding methods such as laser welding. The first active material layer 12 is provided on the surface of the first current collector 11 on the side facing away from at least one first electrode tab 4 .

[0037] That is to say, the first electrode tab 4 and the first current collector 11 are laser welded on one side. In this way, the side of the first current collector 11 that is not welded to the first electrode tab 4 can normally deintercalate lithium ions and exert its capacity, and the two layers of insulating adhesive used to cover the first electrode tab 4 on this side can be eliminated, thereby reducing the number of adhesive paper layers, reducing the overall thickness of the battery, and improving the energy density.

[0038] It can be understood that, of the two first electrode tabs 4 , only one of them can be welded to the first current collector 11 using a single-side welding method, or both of them can be welded to the first current collector 11 using a single-side welding method.

[0039] According to the battery cell 100 of the embodiment of the present application, by providing the battery cell 100 with at least two first pole tabs 4 and at least one second pole tab 5, the overall current capacity of the battery can be significantly increased, the resistance difference between adjacent pole tabs can be reduced, and the temperature rise of the battery can be reduced. Furthermore, by configuring the first pole tab 4 and the first current collector 11 to be connected on one side, lithium ions can be normally intercalated and deintercalated on the side of the first current collector 11 not welded to the first pole tab 4, thereby realizing its full capacity. Furthermore, the two layers of insulating adhesive used to cover the first pole tab 4 on this side can be eliminated, thereby reducing the number of adhesive tape layers, reducing the overall thickness of the battery, and improving the energy density.

[0040] Optionally, in the thickness direction of the battery cell 100, the two first pole tabs 4 are respectively located on both sides of the second pole tab 5, that is, the two first pole tabs 4 are respectively located on the upper and lower sides of the second pole tab 5; in the width direction of the battery cell 100, the two first pole tabs 4 are respectively located on both sides of the second pole tab 5, that is, the two first pole tabs 4 are respectively located on the left and right sides of the second pole tab 5. It is understandable that the horizontal spacing between the two first pole tabs 4 and the second pole tab 5 can be the same or different, and the horizontal spacing between the two first pole tabs 4 and the second pole tab 5 can be adjusted according to actual needs to avoid short circuiting of the positive and negative pole tabs of the battery cell 100.

[0041] Optionally, an insulating rubber layer is provided between the pole piece layer where at least one first pole tab 4 is located and the pole piece layer where at least one adjacent second pole tab 5 is located, and the insulating rubber layer covers the first pole tab 4 and the second pole tab 5 located on both sides thereof.

[0042] It is understandable that an insulating rubber layer may be provided only between the upper first and second pole tabs 4, 5, or only between the lower first and second pole tabs 4, 5. Alternatively, an insulating rubber layer may be provided between both the upper first and second pole tabs 4, 5 and the lower first and second pole tabs 4, 5. When an insulating rubber layer is provided between only one first and second pole tabs 4, 5, to ensure insulation between the other first and second pole tabs 4, 5, separate insulating rubber layers may be provided for the other first and second pole tabs 4, 5, respectively, to cover their respective respective layers.

[0043] For example, as shown in Figure 1, there is a first arrangement gap and a second arrangement gap between the pole piece layer where each first pole tab 4 is located and the pole piece layer where the second pole tab 5 is located. The first arrangement gap and the second arrangement gap are respectively located on both sides of the diaphragm 3. At least one of the first arrangement gap and the second arrangement gap is provided with an insulating rubber layer, and the insulating rubber layer can simultaneously cover the adjacent first pole tabs 4 and second pole tabs 5.

[0044] By providing an insulating rubber layer that can simultaneously cover the adjacent first and second tabs 4, 5, the problem of overlapping insulation layers of adjacent tabs due to an increased number of tabs can be avoided. This can avoid the risk of excessive battery thickness, improve production yield, and reduce costs. Furthermore, the flatness of the battery cell 100 can be improved, the consistency of the formation interface can be enhanced, and safety risks such as lithium plating can be avoided. Furthermore, during the battery cycle, failures caused by uneven thickness expansion can be avoided, thereby improving the battery's service life and overall performance.

[0045] Optionally, in some embodiments, the horizontal center distance H between at least one first pole tab 4 and the second pole tab 5 (i.e., the distance between the centerline of the first pole tab 4 in the width direction and the centerline of the second pole tab 5 in the width direction) is in the range of 16 mm ≤ H < 20 mm. For example, the horizontal center distance H between the first upper pole tab (i.e., the first pole tab 4 located on the upper side) and the second pole tab 5 is 16 mm ≤ H < 20 mm, or the horizontal center distance H between the first lower pole tab (i.e., the first pole tab 4 located on the lower side) and the second pole tab 5 is 16 mm ≤ H < 20 mm, or the horizontal center distance H between both first pole tabs 4 and the second pole tab 5 is 16 mm ≤ H < 20 mm. That is, when the center distance between the first pole tab 4 and the second pole tab 5 is within the above range, an insulating adhesive layer can be provided between the corresponding first pole tab 4 and the second pole tab 5 to avoid the problem of multiple insulating adhesive layers easily overlapping when separate insulating adhesive layers are provided for the first pole tab 4 and the second pole tab 5. When the center distance between the first electrode tab 4 and the second electrode tab 5 is greater than the above range, since the first electrode tab 4 and the second electrode tab 5 are already relatively far apart, an insulating rubber layer may be provided between the corresponding first electrode tab 4 and the second electrode tab 5, or an insulating rubber layer may be provided separately to cover the first electrode tab 4 and the second electrode tab 5. Preferably, when the center distance between the first electrode tab 4 and the second electrode tab 5 is greater than the above range, an insulating rubber layer is provided separately to cover the first electrode tab 4 and the second electrode tab 5, so as to avoid using more materials and causing unnecessary waste when providing the insulating rubber layer.

[0046] According to some embodiments of the present application, in conjunction with Figures 1-3 , one of the electrode layer where the first electrode tab 4 resides and the electrode layer where the second electrode tab 5 resides is provided with a first insulating adhesive layer 41, while the other is provided with a first adhesive layer 42 and a second adhesive layer 52. The first insulating adhesive layer 41 covers both the first electrode tab 4 and the second electrode tab 5, the first adhesive layer 42 covers the first electrode tab 4, and the second adhesive layer 52 covers the second electrode tab 5. For example, the electrode layer where the first electrode tab 4 resides may be provided with the first insulating adhesive layer 41, while the electrode layer where the second electrode tab 5 resides may be provided with the first adhesive layer 42 and the second adhesive layer 52; alternatively, the electrode layer where the first electrode tab 4 resides may be provided with the first adhesive layer 42 and the second adhesive layer 52, while the electrode layer where the second electrode tab 5 resides may be provided with the first insulating adhesive layer 41. In this way, the sides of the first and second electrode tabs 4 and 5 facing each other form a double-layer insulation structure, which can reduce the risk of tab exposure, thereby improving battery safety, and can also avoid the problem of multiple adhesive layers overlapping, reducing thickness.

[0047] For example, as shown in FIG1 , a first insulating adhesive layer 41 may be provided on the side of the electrode layer where the upper first electrode tab 4 is located facing the second electrode tab 5 , and the first insulating adhesive layer 41 may cover both the first electrode tab 4 and the second electrode tab 5 . A first adhesive layer 42 and a second adhesive layer 52 are attached to the electrode layer where the second electrode tab 5 is located, and the first adhesive layer 42 is arranged opposite to the first electrode tab 4, and the second adhesive layer 52 is arranged opposite to the second electrode tab 5. At this time, the first adhesive layer 42 and the second adhesive layer 52 are both overlapped with the first insulating adhesive layer 41. In this way, even if the first insulating adhesive layer 41 covers the first electrode tab 4 or the second electrode tab 5 and there is a problem of leakage resulting in the first electrode tab 4 and the second electrode tab 5 being exposed, the first adhesive layer 42 can also form a supplementary cover for the defective area where the first insulating adhesive layer 41 covers the first electrode tab 4, and the second adhesive layer 52 can form a supplementary cover for the defective area where the first insulating adhesive layer 41 covers the second electrode tab 5. Through the cooperation between the first adhesive layer 42 and the first insulating adhesive layer 41 or the cooperation between the second adhesive layer 52 and the first insulating adhesive layer 41, it can be further ensured that the first electrode tab 4 and the second electrode tab 5 are isolated to prevent the problem of short circuit.

[0048] Optionally, referring to FIG. 1 and FIG. 2 , the first adhesive layer 42 and the second adhesive layer 52 are arranged at intervals. In this way, the arrangement of the first adhesive layer 42 and the second adhesive layer 52 is relatively simple.

[0049] Optionally, referring to Figure 3, considering that when the distance between the first electrode tab 4 and the second electrode tab 5 is close, the first adhesive layer 42 and the second adhesive layer 52 may also have the problem of overlapping, therefore, the first adhesive layer 42 and the second adhesive layer 52 can be connected as a whole to form a second insulating adhesive layer 51, and the second insulating adhesive layer 51 is arranged in a stacked manner with the first insulating adhesive layer 41. In this way, the stacking of the first adhesive layer 42 and the second adhesive layer 52 can be further avoided, and the adhesive lamination process is simplified, which helps to improve production efficiency.

[0050] It should be noted that in the prior art, the first insulating adhesive layer 41 is divided into a third adhesive layer and a fourth adhesive layer attached to the electrode layer where the first tab is located. In other words, the first insulating adhesive layer 41 of this embodiment is formed by merging the third and fourth adhesive layers in the prior art into one. In the prior art, the third and first adhesive layers both face the first tab, so that the first tab forms a double layer of insulation with the second tab. The fourth and second adhesive layers both face the second tab, so that the second tab forms a double layer of insulation with the first tab. Since only the third and fourth adhesive layers are provided, even if a missing adhesive layer problem occurs, the first and second tabs are usually not completely exposed, but only partially. Therefore, the area of ​​the first adhesive layer is usually smaller than that of the third adhesive layer, and the area of ​​the second adhesive layer is usually smaller than that of the fourth adhesive layer. For example, the width of the third and fourth adhesive layers is 20 mm and the length is 25 mm, while the width of the first and second adhesive layers is 12 mm and the length is 22 mm. The thickness of the first, second, third, and fourth adhesive layers is 0.016 mm. Moreover, the spacing between the first and second adhesive layers is greater than the spacing between the third and fourth adhesive layers. In addition, the adhesive layers on both sides of the first and second tabs are symmetrically arranged.

[0051] Therefore, in the prior art, when the center distance between the first upper tab and the second tab is in the range of 16mm-20mm, the third adhesive layer on both sides of the first upper tab and the fourth adhesive layer on both sides of the second tab may form a four-layer overlapping structure with a total thickness of 4*0.016=0.064mm; when the center distance between the first upper tab and the second tab is in the range of 12mm-16mm, due to the further reduction in the spacing between the first upper tab and the second tab, the above-mentioned four-layer structure may overlap with the second adhesive layer on both sides of the second tab to form a six-layer overlapping structure with a total thickness of 6*0.016=0.096mm; and when the center distance between the first upper tab and the second tab is reduced to less than 12mm, the above-mentioned six-layer structure may overlap with the first adhesive layer on both sides of the first upper tab to form an eight-layer overlapping structure with a total thickness of 8*0.016=0.128mm. The overlap of the adhesive tape between the first lower tab (the first tab 4 located on the lower side) and the second tab is the same as described above and will not be repeated here.

[0052] Therefore, in this embodiment, the third adhesive layer 43 and the fourth adhesive layer 53 can be combined to form the first insulating adhesive layer 41, or the first adhesive layer 42 and the second adhesive layer 52 can be combined to form the second insulating adhesive layer 51, depending on the center-to-center distance H between the first and second tabs 4 and 5. For example, when the center-to-center distance H between the first and second tabs 4 and 5 is within the range of 16 mm to 20 mm, the third adhesive layer 43 and the fourth adhesive layer 53 are combined to form the first insulating adhesive layer 41 of this embodiment, while the first and second adhesive layers 42 and 52 can be combined or not. When the center-to-center distance H between the first and second tabs 4 and 5 is further reduced, for example, to less than 16 mm, the third adhesive layer 43 and the fourth adhesive layer 53 are combined to form the first insulating adhesive layer 41, and the first and second adhesive layers 42 and 52 are combined to form the second insulating adhesive layer 51. In this way, the combination of adhesive layers can be flexibly selected according to different situations to minimize the thickness of the overlapping structure.

[0053] Optionally, in combination with Figures 1 to 3, the second electrode 2 includes a second current collector 21 and a second active material layer 22, and the second active material layer 22 is respectively coated on both sides of the second current collector 21 along the thickness direction to ensure that when the battery cell 100 is a wound core, electrochemical reactions can be carried out on both sides of each electrode layer of the first electrode 1 and the second electrode 2.

[0054] Accordingly, the second active material layer 22 on one side of the second current collector 21 has a second hollow foil area 23. The second hollow foil area 23 can be formed by cleaning the second active material layer 22 on that side. The second electrode tab 5 is welded to the second hollow foil area 23, that is, the second electrode tab 5 and the second current collector 21 are welded on one side. In this way, the side of the second current collector 21 that is not welded to the first electrode tab 4 can normally deintercalate and extract lithium ions. Preferably, the second hollow foil area 23 is formed on both sides of the second current collector 21, and the second electrode tab 5 and the second current collector 21 are welded on both sides.

[0055] Optionally, a first active material layer 12 is provided on the surface of the first current collector 11 on the side facing away from the first pole tab 4. In this way, the first pole tab 4 and the first current collector 11 are laser welded on one side. In this way, the side of the first current collector 11 that is not welded to the first pole tab 4 can normally deintercalate lithium ions and exert its capacity, and the two layers of insulating adhesive layers on this side used to cover the first pole tab 4 can be eliminated, thereby reducing the number of adhesive paper layers, reducing the overall thickness of the battery, and improving the energy density.

[0056] Optionally, in combination with Figures 1 to 3, the two first empty foil areas 13 are located on the side of the pole piece layer in which they are located facing the second pole ear 5. In this way, the insulating rubber layer between the first pole ear 4 and the second pole ear 5 can be conveniently set as an integrated structure, such as the first insulating rubber layer 41 and the second insulating rubber layer 51 mentioned above, thereby realizing the combined optimization of the number of insulating rubber layers, avoiding the problem of overlapping insulating rubber layers between adjacent pole ears due to the small center distance, improving the consistency of battery thickness, and thus improving the battery energy density.

[0057] Optionally, referring to Figure 4, the two first empty foil areas 13 are respectively located on both sides of the first current collector 11. In this way, it can be ensured that after the first pole piece 1 is wound, the two first pole tabs 4 are respectively located on the side of their respective pole piece layers facing the second pole tab 5, so as to facilitate the merging and optimization of the insulating adhesive layer between the first pole tab 4 and the second pole tab 5, thereby reducing the number of adhesive layers of the battery.

[0058] Optionally, referring to Figure 5, the two first pole tabs 4 and the second pole tab 5 are both located on the same side of the center line L of the battery cell 100 in the thickness direction, and, of the two first pole tabs 4, the first pole tab 4 close to the center line L is located on the side of the pole sheet layer facing away from the center line L, and the first pole tab 4 away from the center line L is located on the side of the pole sheet layer facing the center line L. In this way, it can be ensured that after the first pole sheet 1 is wound, the two first pole tabs 4 are respectively located on the side of the pole sheet layer facing the second pole tab 5, so as to achieve the merging and optimization of the insulating glue layer between the first pole tab 4 and the second pole tab 5, and reduce the number of glue layers of the battery.

[0059] It can be understood that by merging and eliminating the number of insulating adhesive layers, the number of overlapping insulating adhesive layers between each first electrode tab 4 and the second electrode tab 5 is reduced from 4 layers in the conventional structure to 2 layers, with a total thickness of 2*0.016=0.032mm, a thickness reduction of 50%. In addition, by single-sided laser welding of the first electrode tab 4 to the first current collector 11, the coating area of ​​the first current collector 11 facing away from the first electrode tab 4 is increased by approximately (2*25*20)=1000mm. 2 , accounting for about 0.73% of the total area of ​​the positive electrode coating, which can increase the battery energy density by about 0.73%.

[0060] Some specific embodiments of the battery cell 100 according to the present application are described below.

[0061] Example 1

[0062] Referring to Figures 1, 4, and 5, the battery cell 100 of this embodiment is a wound core. The battery cell 100 includes: a first electrode sheet 1, a separator 3, and a second electrode sheet 2, which are stacked and wound together. The first electrode sheet 1 is a positive electrode sheet, and the second electrode sheet 2 is a negative electrode sheet. After winding, the first electrode sheet 1 and the second electrode sheet 2 each include multiple electrode sheet layers. The multiple electrode sheet layers of the first electrode sheet 1 are connected sequentially, and the multiple electrode sheet layers of the second electrode sheet 2 are also connected sequentially. The first electrode sheet 1 is provided with two first electrode tabs 4, which serve as positive electrode tabs, namely a first upper electrode tab and a first lower electrode tab. The second electrode sheet 2 is provided with a second electrode tab 5, which serves as a negative electrode tab. The two first electrode tabs 4 are located on either side of the second electrode tab 5 in the thickness and width directions of the battery cell 100, and the electrode sheet layers containing the two first electrode tabs 4 are adjacent to the electrode sheet layers containing the second electrode tab 5. The center distance H between the first upper electrode tab and the second electrode tab 5 is in the range of 16mm≤H<20mm.

[0063] The first electrode 1 includes a first current collector 11 and a first active material layer 12. The first active material layer 12 is respectively coated on both sides of the first current collector 11 along the thickness direction. A first empty foil area 13 is provided on the side of the electrode layer where each first electrode tab 4 is located facing the second electrode tab 5. Each first electrode tab 4 is connected to the corresponding first empty foil area 13 on one side by laser welding.

[0064] The second electrode piece 2 includes a second current collector 21 and a second active material layer 22. The second active material layer 22 is respectively coated on both sides of the second current collector 21 along the thickness direction. There are second hollow foil areas 23 on both sides of the electrode layer where the second electrode tab 5 is located. The second electrode tab 5 is connected to the second hollow foil area 23 by laser welding.

[0065] Among them, the lower side of the pole piece layer where the first upper pole ear is located is affixed with a first insulating rubber layer 41, and the first insulating rubber layer 41 simultaneously covers the adjacent first pole ear 4 and second pole ear 5, and the upper side of the pole piece layer where the second pole ear 5 is located is affixed with a first rubber layer 42 and a second rubber layer 52, and the first rubber layer 42 is arranged opposite to the first upper pole ear, and the second rubber layer 52 is arranged opposite to the second pole ear 5, and both are overlapped with the first insulating rubber layer 41.

[0066] Two insulating rubber layers are attached to the upper side of the pole piece layer where the first lower pole tab is located, one of which is opposite to the first pole tab 4 to cover the upper surface of the first lower pole tab, and the other is opposite to the second pole tab 5 to cover the lower surface of the second pole tab 5. Two insulating rubber layers are attached to the lower side of the pole piece layer where the second pole tab 5 is located, one of which is opposite to the second pole tab 5 to cover the lower surface of the second pole tab 5, and the other is opposite to the first lower pole tab to cover the upper surface of the first lower pole tab.

[0067] In this embodiment, by merging and eliminating the number of insulating adhesive layers, the number of overlapping insulating adhesive layers between each first electrode tab 4 and second electrode tab 5 is reduced from 4 layers in the conventional structure to 2 layers, with a total thickness of 2*0.016=0.032mm, a thickness reduction of 50%. In addition, by single-sided laser welding of the first electrode tab 4 to the first current collector 11, the coating area of ​​the first current collector 11 facing away from the first electrode tab 4 is increased by approximately (2*25*20)=1000mm. 2 , accounting for about 0.73% of the total area of ​​the positive electrode coating, which can increase the battery energy density by about 0.73%.

[0068] Example 2

[0069] Referring to Figures 2, 4, and 5, the battery cell 100 of this embodiment is a wound core. The battery cell 100 includes: a first electrode sheet 1, a separator 3, and a second electrode sheet 2, which are stacked and wound together. The first electrode sheet 1 is a positive electrode sheet, and the second electrode sheet 2 is a negative electrode sheet. After winding, the first electrode sheet 1 and the second electrode sheet 2 each include multiple electrode sheet layers. The multiple electrode sheet layers of the first electrode sheet 1 are connected sequentially, and the multiple electrode sheet layers of the second electrode sheet 2 are also connected sequentially. The first electrode sheet 1 has two first electrode tabs 4, which serve as positive electrode tabs, namely a first upper electrode tab and a first lower electrode tab. The second electrode sheet 2 has a second electrode tab 5, which serves as a negative electrode tab. The two first electrode tabs 4 are located on either side of the second electrode tab 5 in the thickness and width directions of the battery cell 100, and the electrode sheet layers containing the two first electrode tabs 4 are adjacent to the electrode sheet layer containing the second electrode tab 5. The center-to-center distance H between the first upper electrode tab, the first lower electrode tab, and the second electrode tab 5 is in the range of 16 mm ≤ H < 20 mm.

[0070] The first electrode 1 includes a first current collector 11 and a first active material layer 12. The first active material layer 12 is respectively coated on both sides of the first current collector 11 along the thickness direction. A first empty foil area 13 is provided on the side of the electrode layer where each first electrode tab 4 is located facing the second electrode tab 5. Each first electrode tab 4 is connected to the corresponding first empty foil area 13 on one side by laser welding.

[0071] The second electrode piece 2 includes a second current collector 21 and a second active material layer 22. The second active material layer 22 is respectively coated on both sides of the second current collector 21 along the thickness direction. There are second hollow foil areas 23 on both sides of the electrode layer where the second electrode tab 5 is located. The second electrode tab 5 is connected to the second hollow foil area 23 by laser welding.

[0072] Among them, the lower side of the pole piece layer where the first upper pole ear is located is affixed with a first upper insulating rubber layer, and the first upper insulating rubber layer simultaneously covers the lower surface of the upper first pole ear 4 and the upper surface of the second pole ear 5. The upper side of the pole piece layer where the second pole ear 5 is located is affixed with a first upper rubber layer and a second upper rubber layer, and the first upper rubber layer is arranged opposite to the upper first pole ear 4, and the second upper rubber layer is arranged opposite to the second pole ear 5, and both are overlapped with the first upper insulating rubber layer.

[0073] The lower side of the pole piece layer where the first lower pole ear is located is also provided with a first lower insulating rubber layer, which covers the upper surface of the first lower pole ear and the lower surface of the second pole ear 5 at the same time. The lower side of the pole piece layer where the second pole ear 5 is located is provided with a first lower rubber layer and a second lower rubber layer, and the first lower rubber layer is arranged opposite to the first lower pole ear, and the second lower rubber layer is arranged opposite to the second pole ear 5, and both are overlapped with the first lower insulating rubber layer.

[0074] In this embodiment, by merging and eliminating the number of insulating adhesive layers, the number of overlapping insulating adhesive layers between each first electrode tab 4 and second electrode tab 5 is reduced from 4 layers in the conventional structure to 2 layers, with a total thickness of 2*0.016=0.032mm, a thickness reduction of 50%. In addition, by single-sided laser welding of the first electrode tab 4 to the first current collector 11, the coating area of ​​the first current collector 11 facing away from the first electrode tab 4 is increased by approximately (2*25*20)=1000mm. 2 , accounting for about 0.73% of the total area of ​​the positive electrode coating, which can increase the battery energy density by about 0.73%.

[0075] Example 3

[0076] Referring to Figures 3, 4, and 5, the battery cell 100 of this embodiment is a wound core. The battery cell 100 comprises: a first electrode sheet 1, a separator 3, and a second electrode sheet 2, which are stacked and wound together. The first electrode sheet 1 is a positive electrode sheet, and the second electrode sheet 2 is a negative electrode sheet. After winding, each of the first electrode sheet 1 and the second electrode sheet 2 comprises multiple electrode layers. The multiple electrode layers of the first electrode sheet 1 are sequentially connected, and the multiple electrode layers of the second electrode sheet 2 are also sequentially connected. The first electrode sheet 1 has two first electrode tabs 4, which serve as positive electrode tabs: a first upper electrode tab and a first lower electrode tab. The second electrode sheet 2 has a second electrode tab 5, which serves as a negative electrode tab. The two first electrode tabs 4 are located on either side of the second electrode tab 5 in the thickness and width directions of the battery cell 100, and the electrode layer containing the two first electrode tabs 4 is adjacent to the electrode layer containing the second electrode tab 5. The center-to-center distance H between the first upper electrode tab, the first lower electrode tab, and the second electrode tab 5 is in the range of 12 mm ≤ H < 16 mm.

[0077] The first electrode 1 includes a first current collector 11 and a first active material layer 12. The first active material layer 12 is respectively coated on both sides of the first current collector 11 along the thickness direction. A first empty foil area 13 is provided on the side of the electrode layer where each first electrode tab 4 is located facing the second electrode tab 5. Each first electrode tab 4 is connected to the corresponding first empty foil area 13 on one side by laser welding.

[0078] The second electrode piece 2 includes a second current collector 21 and a second active material layer 22. The second active material layer 22 is respectively coated on both sides of the second current collector 21 along the thickness direction. There are second hollow foil areas 23 on both sides of the electrode layer where the second electrode tab 5 is located. The second electrode tab 5 is connected to the second hollow foil area 23 by laser welding.

[0079] Among them, a first upper insulating rubber layer is attached to the lower side of the pole piece layer where the first upper pole ear is located, and the first upper insulating rubber layer simultaneously covers the lower surface of the first upper pole ear and the upper surface of the second pole ear 5; a second upper insulating rubber layer is attached to the upper side of the pole piece layer where the second pole ear 5 is located, and the second upper insulating rubber layer simultaneously covers the lower surface of the first pole ear 4 and the upper surface of the second pole ear 5, and overlaps with the first upper insulating rubber layer.

[0080] A first lower insulating rubber layer is also provided on the lower side surface of the pole piece layer where the first lower pole ear is located, and the first lower insulating rubber layer simultaneously covers the upper surface of the first lower pole ear and the lower surface of the second pole ear 5. A second lower insulating rubber layer is provided on the lower side surface of the pole piece layer where the second pole ear 5 is located, and the second lower insulating rubber layer simultaneously covers the upper surface of the first lower pole ear and the lower surface of the second pole ear 5, and overlaps with the first lower insulating rubber layer.

[0081] In this embodiment, by merging and eliminating the number of insulating adhesive layers, the number of overlapping insulating adhesive layers between each first electrode tab 4 and second electrode tab 5 is reduced from 4 layers in the conventional structure to 2 layers, with a total thickness of 2*0.016=0.032mm, a thickness reduction of 50%. In addition, by single-sided laser welding of the first electrode tab 4 to the first current collector 11, the coating area of ​​the first current collector 11 facing away from the first electrode tab 4 is increased by approximately (2*25*20)=1000mm. 2 , accounting for about 0.73% of the total area of ​​the positive electrode coating, which can increase the battery energy density by about 0.73%.

[0082] The following describes a battery according to an embodiment of the second aspect of the present application.

[0083] The battery of the embodiment of the present application may include: a housing and the battery cell 100 in the above embodiment.

[0084] Specifically, the housing defines a cell accommodating cavity, and the cell 100 may be disposed in the cell accommodating cavity.

[0085] According to the battery of the embodiment of the present application, by providing the battery cell 100 of the above embodiment, the overall current capacity of the battery can be significantly increased, which helps to reduce the temperature rise of the battery and improve the energy density of the battery.

[0086] The following describes an electronic device according to an embodiment of the third aspect of the present application.

[0087] The electronic device of this embodiment includes: a device body and the battery in the above embodiment.

[0088] Specifically, the device body has a battery compartment and a power supply interface. The battery is arranged in the battery compartment and connected to the power supply interface to supply power to the device body.

[0089] According to the electronic device of the embodiment of the present application, by setting the battery of the above embodiment, the battery temperature rise is reduced and the battery energy density is increased, so the heat generation of the electronic device can be reduced and the battery life can be improved.

[0090] In this application, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0091] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do 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. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, characterized in that: include: A first pole piece, a diaphragm and a second pole piece are stacked and wound, wherein the first pole piece and the second pole piece each include a plurality of pole piece layers formed by winding, wherein the first pole piece and the second pole piece have opposite polarities, The first pole piece is provided with at least two first pole lugs; The second pole piece is provided with at least one second pole lug; The first pole piece 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 at least two first empty foil areas, and the first electrode tabs are correspondingly arranged in the first empty foil areas and connected to the first current collector; The first active material layer is disposed on a surface of the first current collector that is away from at least one of the first electrode tabs.

2. The battery cell according to claim 1, characterized in that: The two first electrode tabs are located on both sides of the second electrode tab in the thickness direction and / or the width direction of the battery cell.

3. The battery cell according to claim 2, characterized in that: An insulating rubber layer is provided between at least one pole piece layer where the first pole lug is located and at least one adjacent pole piece layer where the second pole lug is located, and the insulating rubber layer covers the first pole lug and the second pole lug.

4. The battery cell according to any one of claims 1 to 3, characterized in that: The range of the center distance H between at least one of the first pole tab and the second pole tab in the width direction of the battery core is: 16 mm ≤ H < 20 mm.

5. The battery cell according to claim 3, characterized in that: A first insulating rubber layer is attached to one of the pole piece layer where the first pole lug is located and the pole piece layer where the second pole lug is located, and the first insulating rubber layer covers the first pole lug and the second pole lug; The other of the pole piece layer where the first pole tab is located and the pole piece layer where the second pole tab is located is attached with a first adhesive layer and a second adhesive layer, wherein the first adhesive layer covers the first pole tab and the second adhesive layer covers the second pole tab.

6. The battery cell according to claim 5, characterized in that: The first adhesive layer and the second adhesive layer are a second insulating adhesive layer connected integrally.

7. The battery cell according to any one of claims 1 to 6, characterized in that: The second pole piece includes a second current collector and a second active material layer coated on both sides of the second current collector. The second active material layer on one side of the second current collector has a second empty foil area, and the second pole tab is connected to the second empty foil area.

8. The battery cell according to any one of claims 1 to 7, characterized in that: The first active material layer is disposed on the surface of the first current collector which is away from the first electrode tab.

9. The battery cell according to claim 8, characterized in that: The first empty foil areas corresponding to the two first electrode tabs are respectively located on both sides of the first current collector.

10. The battery cell according to any one of claims 1 to 5, characterized in that: The two first pole tabs and the second pole tab are both located on the same side of a center line of the battery core in a thickness direction.

11. The battery cell according to any one of claims 1 to 5, characterized in that: The first electrode tab close to the center line of the battery cell in the thickness direction is located on a side of the first current collector facing away from the center of the battery cell; and / or The first electrode tab, which is away from the center line of the battery cell along the thickness direction, is located on a side of the first current collector facing the center of the battery cell.

12. A battery, characterized in that: include: A housing defining a cell receiving cavity; The battery cell according to any one of claims 1-11, wherein the battery cell is arranged in the battery cell accommodating cavity.

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