Battery cell, battery and electronic product

Abstract

A battery cell, a battery and an electronic product. The battery cell comprises a battery cell body (10), a first tab and a second tab, wherein the battery cell body (10) comprises a first electrode sheet and a second electrode sheet; the first tab is connected to the first electrode sheet, and comprises a first metal strip (20) and a first insulating portion (30); the second tab is connected to the second electrode sheet, and comprises a second metal strip (40) and a second insulating portion (50); the second metal strip (40) extends in the direction of height of the battery cell body (10); the second insulating portion (50) is arranged on the second metal strip (40) and protrudes from an edge of the second metal strip (40) in the direction of width of the battery cell body (10); there is a spacing between the first metal strip (20) and the second metal strip (40); and the first insulating portion (30) and the second insulating portion (50) at least partially overlap to form an overlapping region (35). The problem of the lower limit of the width of the battery cell being restricted by means of reducing the lengths of insulating adhesives of positive and negative tabs in the direction of width of the battery cell is solved.

Description

Cells, batteries and electronic products

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on November 22, 2023, with application number 202323161528.0 and application name “Battery Cells, Batteries and Electronic Products”, the entire contents of which are incorporated by reference into this application. Technical Field

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

[0003] Lithium batteries have the advantages of high energy storage density, long service life, high rated voltage, strong adaptability to high and low temperatures, and environmental protection. As more and more technological products (such as VR glasses, wearable watches, sports bracelets, etc.) enter our lives, the emergence of these technological products has put forward higher requirements for lithium battery cells, such as pursuing smaller cell size, reduced space usage, longer battery life, and other goals. For battery cells, small size requires the cell width to be designed to be narrower and narrower. The current method of reducing the cell width is mainly to reduce the length of the positive and negative tabs along the width of the cell, but this method can easily cause the positive and negative tabs to contact and cause a short circuit.

[0004] Application Contents

[0005] The main purpose of the present application is to provide a battery cell, a battery and an electronic product to at least solve the problem of battery cell short circuit caused by contact between positive and negative tabs.

[0006] According to one aspect of the present application, a battery cell is provided, comprising:

[0007] A battery cell body, the battery cell body comprising a first electrode sheet and a second electrode sheet, wherein the first electrode sheet and the second electrode sheet have opposite polarities;

[0008] a first electrode tab, the first electrode tab being connected to the first electrode sheet, the first electrode tab comprising a first metal strip and a first insulating portion, the first metal strip extending in a height direction of the battery cell body, the first insulating portion being disposed on the first metal strip and protruding from an edge of the first metal strip in a width direction of the battery cell body;

[0009] a second electrode tab, the second electrode tab being connected to the second electrode sheet, the second electrode tab comprising a second metal strip and a second insulating portion, the second metal strip extending in a height direction of the battery cell body, the second insulating portion being provided on the second metal strip and protruding from an edge of the second metal strip in a width direction of the battery cell body;

[0010] There is a distance between the first metal strip and the second metal strip, and the first insulating portion and the second insulating portion at least partially overlap to form an overlapping area.

[0011] Furthermore, along the thickness direction of the battery cell body, the battery cell body includes a first side and a second side arranged opposite to each other, and there is a first spacing between the first side and the second side along the thickness direction of the battery cell body, the first metal strip is arranged on one of the first side and the second side, and the second metal strip is arranged on the other of the first side and the second side.

[0012] Furthermore, a gap exists between the projections of the first metal strip and the second metal strip along the thickness direction of the battery cell body.

[0013] Furthermore, the battery cell includes a winding core, in which the first electrode sheet and the second electrode sheet isolated from each other are stacked and wound from the head end to the tail end to form the winding core, wherein the tail end of one of the first electrode sheet and the second electrode sheet is located on the first side, and the tail end of one of the first electrode sheet and the second electrode sheet is located on the second side, the first electrode tab is arranged at the tail end of the first electrode sheet, and the second electrode tab is arranged at the tail end of the second electrode sheet.

[0014] Furthermore, the first metal strip and the second metal strip are arranged on the same side of the cell body along the thickness direction of the cell body, and the first insulating portion and the second insulating portion located between the first metal strip and the second metal strip at least partially overlap and adhere to each other.

[0015] Furthermore, the overlapping area has an overlapping width along the width direction of the battery cell body, and there is a second spacing between the first metal strip and the second metal strip along the width direction of the battery cell body, wherein the ratio between the overlapping width and the second spacing is between 1% and 90%.

[0016] Furthermore, the overlapping width is between 0.1 mm and 5 mm; and / or the second spacing is between 1.5 mm and 7 mm.

[0017] Furthermore, the first insulating part includes a first insulating region and a second insulating region, and the second insulating part includes a third insulating region and a fourth insulating region, wherein the second insulating region and the third insulating region overlap and adhere to the overlapping region, the second insulating region has a first width along the height direction of the battery cell body, and the third insulating region has a second width along the height direction of the battery cell body, and at least one of the first width and the second width gradually increases in a direction close to the overlapping region to form a protrusion protruding from the first insulating region and the fourth insulating region close to or away from the side of the battery cell body.

[0018] Furthermore, the overlapping area has an overlapping thickness along the thickness direction of the battery cell body, and the first insulating region and the fourth insulating region have the same insulation thickness along the thickness direction of the battery cell body; wherein the overlapping thickness is between 0.05 mm and 0.3 mm; and / or the insulation thickness is between 0.04 mm and 0.2 mm.

[0019] Furthermore, the size of the overlapping thickness is a first thickness value, the size of the insulating thickness is a second thickness value, the thermal shrinkage rate between the overlapping area and the first insulating area and the thermal shrinkage rate between the overlapping area and the fourth insulating area are both equal to the ratio of the first thickness value to twice the second thickness value, and the thermal shrinkage rate is greater than or equal to 10% and less than or equal to 90%.

[0020] Furthermore, the raised portion has a raised height along the height direction of the battery cell body, the battery cell body includes a first end, the first end is an end of the battery cell body along the height direction of the battery cell body and where the first electrode tab and the second electrode tab are provided, and the battery cell further includes:

[0021] A plastic shell, wherein the battery cell body is disposed in the plastic shell, the plastic shell comprising a plastic sealing portion, and the plastic sealing portion is located at the first end;

[0022] The plastic sealing portion has a plastic sealing height along the height direction of the battery cell body, and the ratio of the protrusion height to the plastic sealing height is between 0.1 and 0.7.

[0023] Furthermore, the plastic shell has a shell thickness along the thickness direction of the battery body, the sum of the shell thickness and the overlapping thickness is a first overall thickness, the sum of the shell thickness and the insulation thickness is a second overall thickness, and the first overall thickness is greater than the second overall thickness.

[0024] Furthermore, the first overall thickness is between 0.15 mm and 0.6 mm, and the second overall thickness is between 0.14 mm and 0.45 mm.

[0025] Furthermore, the plastic package includes:

[0026] a first aluminum-plastic film coated with a first insulating adhesive, wherein, along the thickness direction of the battery cell body, the first insulating adhesive has a first adhesive thickness at a portion thereof facing the overlapping region, and has a second adhesive thickness at a portion thereof facing the first insulating region or the fourth insulating region;

[0027] a second aluminum-plastic film, wherein the battery cell body is encapsulated in the second aluminum-plastic film, the first aluminum-plastic film is coated on the outer side of the second aluminum-plastic film away from the battery cell body, and the second aluminum-plastic film is coated with a second insulating adhesive, wherein along the thickness direction of the battery cell body, the portion of the second insulating adhesive opposite to the overlapping area has a third adhesive thickness, and the portion of the second insulating adhesive opposite to the first insulating region or the fourth insulating region has a fourth adhesive thickness;

[0028] The sum of the first colloid thickness, the third colloid thickness and the overlapping thickness is a first total insulation thickness, the sum of the second colloid thickness, the fourth colloid thickness and the insulation thickness is a second total insulation thickness, and the first total insulation thickness is greater than the second total insulation thickness.

[0029] Furthermore, the total thickness of the first insulation is between 0.07 mm and 0.5 mm, and the total thickness of the second insulation is between 0.06 mm and 0.4 mm.

[0030] Furthermore, a difference between the first insulation total thickness and the second insulation total thickness is a first thickness difference, and a ratio of the first thickness difference to the second insulation total thickness is between 0.1 and 1.67.

[0031] Furthermore, the raised portion includes:

[0032] a first raised portion, the first raised portion being located on a side of the second insulating region away from the cell body, the first raised portion having a first raised height along a height direction of the cell body, the first raised height being a height between an end of the first raised portion away from the cell body and a side of the first insulating region away from the cell body;

[0033] a second raised portion, the second raised portion being located on a side of the third insulating region away from the cell body, the second raised portion having a second raised height along a height direction of the cell body, the second raised height being the height between an end of the second raised portion away from the cell body and a side of the fourth insulating region away from the cell body;

[0034] Among them, along the width direction of the battery cell body, the distance between the end of the first protrusion away from the battery cell body and the end of the second protrusion away from the battery cell body is D, D is between 0mm and 5.0mm, and the difference between the height of the first protrusion and the height of the second protrusion is H, H is between 0mm and 2mm.

[0035] According to another aspect of the present application, a battery is provided, comprising the battery cell.

[0036] According to another aspect of the present application, an electronic product is provided, comprising the battery.

[0037] Compared with the existing technology, the technical solution of this application has at least the following technical effects:

[0038] The battery cell provided in this application breaks through the lower limit of battery cell width and obtains a smaller ultra-narrow battery cell. The battery cell is configured so that the first and second insulating portions of each tab at least partially overlap to form an overlapping region. The presence of this overlapping region allows the distance between the first and second metal strips of the battery cell to be closer, thereby allowing the battery cell width to be designed to be narrower. Furthermore, due to the overlapping melting and recrystallization in the overlapping region, the first and second metal strips can be more stably and reliably fixed to the battery cell body, avoiding the risk of short circuits caused by the first and second metal strips overlapping, and preventing leakage due to the closer distance between the first and second metal strips. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0040] FIG1 is a schematic structural diagram of a battery cell provided by an embodiment of the present invention;

[0041] FIG2 is a schematic diagram showing a structural comparison between a conventional battery cell and a battery cell provided by an embodiment of the present invention;

[0042] FIG3 is a schematic structural diagram of a stacked core provided by an embodiment of the present invention;

[0043] FIG4 is a schematic diagram of a structure in which tabs are provided on opposite sides of an even-numbered folded core according to an embodiment of the present invention;

[0044] FIG5 is another structural schematic diagram of FIG4;

[0045] FIG6 is a schematic diagram showing a structure in which tabs are provided on different sides of an odd-numbered folded coil core and an even-numbered folded coil core according to an embodiment of the present invention;

[0046] FIG7 is a schematic structural diagram of the first fold of an odd-numbered folded winding core and an even-numbered folded winding core provided by an embodiment of the present invention;

[0047] FIG8 is a schematic structural diagram of the tail-folded tabs of an odd-numbered folded winding core and an even-numbered folded winding core provided by an embodiment of the present invention;

[0048] FIG9 is an enlarged schematic diagram of the overlapping area provided by an embodiment of the present invention.

[0049] Among them, the above-mentioned drawings include the following figure marks: 10, battery cell body; 11, first side; 12, second side; 20, first metal strip; 30, first insulating part; 31, first insulating area; 32, second insulating area; 321, first protrusion; 40, second metal strip; 50, second insulating part; 51, third insulating area; 511, second protrusion; 52, fourth insulating area; 35, overlapping area; 60, plastic sealing part. DETAILED DESCRIPTION

[0050] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0051] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0052] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to actual proportional relationships. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary, not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0053] To address the issue of limiting the lower limit of the cell width by reducing the length of the insulating adhesive of the positive and negative tabs along the cell width, the first embodiment of the present invention provides a cell. As shown in Figure 1, the cell includes a cell body 10, a first tab, and a second tab. The cell body 10 includes a first electrode sheet and a second electrode sheet, the first and second electrode sheets having opposite polarities. The first tab is connected to the first electrode sheet and includes a first metal strip 20 and a first insulating portion 30. The first metal strip 20 extends along the height of the cell body 10 (i.e., in the direction indicated by arrow Y in Figure 2). The first insulating portion 30 is disposed on the first metal strip 20 and protrudes beyond the edge of the first metal strip 20 along the width of the cell body 10 (in the direction indicated by arrow X in Figures 1 and 2). The second tab is connected to the second electrode sheet and includes a second metal strip 40 and a second insulating portion 50. The second metal strip 40 extends along the height of the cell body 10. The second insulating portion 50 is disposed on the second metal strip 40 and protrudes beyond the edge of the second metal strip 40 along the width of the cell body 10. There is a gap between the first metal strip 20 and the second metal strip 40 , and the first insulating portion 30 and the second insulating portion 50 at least partially overlap to form an overlapping region 35 (the overlapping region 35 is shown in FIG. 3 and FIG. 9 ).

[0054] The battery cell provided by the embodiment of the present invention can reduce the length of the first insulating part 30 and the second insulating part 50 of the battery cell along the width direction of the battery cell body 10, and ensure that there is a spacing between the first metal strip 20 and the second metal strip 40, while making the projections of the first insulating part 30 and the second insulating part 50 along the thickness direction of the battery cell body 10 at least partially overlap. This not only avoids the risk of short circuit caused by overlapping of the first metal strip 20 and the second metal strip 40, but also further reduces the width of the battery cell body 10, breaking through the lower limit of the width of the battery cell, thereby obtaining a battery cell product with a smaller battery cell width.

[0055] Therefore, in order to break the lower limit of battery cell width and achieve a smaller, ultra-narrow battery cell, the present invention embodiment configures the battery cell so that the first insulating portion 30 and the second insulating portion 50 of each tab at least partially overlap, forming an overlapping region 35. The presence of this overlapping region 35 allows the distance between the first metal strip 20 and the second metal strip 40 of the battery cell to be closer, thereby enabling the battery cell width to be designed to be narrower. Furthermore, due to the overlapping melting and recrystallization in the overlapping region, the first and second metal strips 20 and 40 can be more stably and reliably fixed to the battery cell body 10, avoiding the risk of short circuits caused by the first and second metal strips 20 and 40 overlapping. Furthermore, the closer distance between the first and second metal strips 20 and 40 prevents leakage.

[0056] Along the thickness direction of the cell body 10 (i.e., the direction indicated by arrow Z in FIG. 1 ), the cell body 10 includes a first side 11 and a second side 12 disposed opposite each other. A first spacing (indicated by j in FIG. 1 ) is defined between the first side 11 and the second side 12 along the thickness direction of the cell body 10. The first metal strip 20 is disposed on one of the first side 11 and the second side 12, and the second metal strip 40 is disposed on the other of the first side 11 and the second side 12. Thus, by disposing the first metal strip 20 and the second metal strip 40 on different sides of the cell body 10, contact and short circuiting between the first metal strip 20 and the second metal strip 40 can be effectively prevented. Furthermore, because the projections of the first insulating portion 30 and the second insulating portion 50 on the corresponding metal strips on different sides along the thickness direction of the cell body 10 at least partially overlap, the width of the cell body 10 can be further reduced, enabling the manufacture of ultra-narrow cells. Secondly, the first insulating portion 30 and the second insulating portion 50, respectively located on the first side 11 and the second side 12, will also contact and overlap with each other to form an overlapping area 35 in actual production. Since the thickness of the overlapping area 35 is relatively large, the first metal strip 20 and the second metal strip 40 can be fixed to the battery cell body 10 more stably and firmly, avoiding contact and short circuit between the first metal strip 20 and the second metal strip 40.

[0057] As shown in Figures 3 to 6, the battery cell in the embodiment of the present invention may include either a stacked core with a laminated structure or a wound core with a wound structure. When the battery cell is a stacked core, a first spacing is provided between the first side 11 and the second side 12 of the stacked core along the thickness direction of the stacked core (i.e., the direction in which the first electrode sheet and the second electrode sheet of the stacked core are stacked). For example, there are multiple layers of laminates between the first electrode sheet on the first side 11 connected to the first metal strip 20 and the second electrode sheet on the second side 12 connected to the second metal strip 40. These laminates include other first electrode sheets, second electrode sheets, a separator, etc. When the battery cell is a wound core with a wound structure, the core can be an even-folded core or an odd-folded core (e.g., the left core in Figure 6 is an odd-folded core, and the right core is an even-folded core). Regardless of whether it is an even-folded or odd-folded core, the first metal strip 20 and the second metal strip 40 can be respectively provided on the first side 11 and the second side 12 of the core along the direction indicated by arrow Z, and the first side 11 and the second side 12 are both the outermost winding ends of the core. If the first electrode sheet is a positive electrode sheet, the second electrode sheet is a negative electrode sheet, and the winding core is an odd-numbered winding core, the first metal strip 20 is connected to the positive electrode sheet on the second side 12, and the second metal strip 40 is connected to the negative electrode sheet on the first side 11. If the winding core is an even-numbered winding core, the first metal strip 20 is connected to the positive electrode sheet on the first side 11, and the second metal strip 40 is connected to the negative electrode sheet on the second side 12. Whether it is a stacked core or a wound core, the embodiment of the present invention effectively separates the first metal strip 20 and the second metal strip 40 by arranging them on the first side 11 and the second side 12 of the battery cell with a first spacing. While effectively preventing the first metal strip 20 and the second metal strip 40 from shorting each other, the projections of the first insulating portion 30 and the second insulating portion 50 on the first side 11 at least partially overlap, which can further reduce the width of the battery cell body 10, enabling the manufacture of ultra-narrow battery cells and meeting customer design requirements for ultra-wide battery cells.

[0058] When the first metal strip 20 and the second metal strip 40 are disposed on the first side 11 and the second side 12 of the battery cell, respectively, a gap exists between the projections of the first metal strip 20 and the second metal strip 40 along the thickness direction of the battery cell body 10. Specifically, when the projections of the first insulating portion 30 and the second insulating portion 50 at least partially overlap, a certain distance exists between the first metal strip 20 and the second metal strip 40 along the width direction of the battery cell body 10. In other words, there is no overlap between the projections of the first metal strip 20 and the second metal strip 40 along the thickness direction of the battery cell body 10. This prevents short circuits between the first metal strip 20 and the second metal strip 40 after packaging, reduces process complexity, and improves product yield.

[0059] When the battery cell in the embodiment of the present invention is a winding core, the mutually isolated first electrode sheet and the second electrode sheet are stacked and wound from the head end to the tail end to form a winding core, and the first electrode sheet and the second electrode sheet are usually separated by a diaphragm. Among them, the tail end of one of the first electrode sheet and the second electrode sheet is located on the first side 11, the tail end of one of the first electrode sheet and the second electrode sheet is located on the second side 12, the first electrode tab is arranged at the tail end of the first electrode sheet, and the second electrode tab is arranged at the tail end of the second electrode sheet. The tail ends of the first electrode sheet and the second electrode sheet are the first folds of the corresponding electrode sheets, and the tail ends of the first electrode sheet and the second electrode sheet are the outermost folds of the corresponding electrode sheets. Therefore, when the first insulating portion and the second insulating portion have an overlapping area, as shown in Figure 6, the embodiment of the present invention can also make the battery cell size smaller by arranging the first electrode tab and the second electrode tab at the outermost folds of the first electrode sheet and the second electrode sheet, respectively, and respectively located on the first side 11 and the second side 12 of the battery cell.

[0060] As shown in Figures 7 and 8, the winding core on the left in Figures 7 and 8 is an odd-fold winding core, and the winding core on the right is an even-fold winding core. For both odd-fold and even-fold winding cores, the first metal strip 20 and the second metal strip 40 of the winding core are arranged on the same side of the battery cell body 10 along the thickness direction of the battery cell body 10, and the first insulating portion 30 and the second insulating portion 50 between the first metal strip 20 and the second metal strip 40 at least partially overlap and fit together. As shown in Figure 7, the winding core is provided with both the first metal strip 20 and the second metal strip 40 along one side of the battery cell body 10 in the thickness direction, and the first insulating portion 30 and the second insulating portion 50 between the first metal strip 20 and the second metal strip 40 at least partially overlap and fit together to form an overlapping region 35. Therefore, the embodiment of the present invention reduces the width of the battery cell by distributing the first pole tab and the second pole tab on the same side of the battery cell, but the first insulating portion 30 and the second insulating portion 50 between the first metal strip 20 and the second metal strip 40 at least partially overlap and fit together. Moreover, since the thickness of the overlapping area 35 where the first insulating portion 30 and the second insulating portion 50 overlap is increased, the first metal strip 20 and the second metal strip 40 can be better fixed and insulated, thereby avoiding contact and short circuit between the first metal strip 20 and the second metal strip 40.

[0061] As shown in Figure 9 , the overlapping region 35 of the first insulating portion 30 and the second insulating portion 50, which overlap and adhere to each other, has an overlap width along the width of the cell body 10 (this overlap width is indicated by the letter K in Figure 9 ). A second spacing (indicated by the letter J in Figures 1 and 9 ) is provided between the first metal strip 20 and the second metal strip 40 along the width of the cell body 10. The ratio of the overlap width to the second spacing is between 1% and 90%, i.e., K / J is greater than or equal to 1% and less than or equal to 90%. Specifically, the value of K / J can include one of 1%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%. Thus, while the first metal strip 20 and the second metal strip 40 have the second spacing to prevent overlapping short circuits, the first insulating portion 30 and the second insulating portion 50 can be ensured to at least partially overlap, thereby enabling the manufacture of ultra-narrow battery cells. Furthermore, because the insulation thickness of the overlapping region 35 between the first insulating portion 30 and the second insulating portion 50 (i.e., the overlapping thickness along the thickness direction of the battery cell body 10 mentioned below) is increased, the first metal strip 20 and the second metal strip 40 can be more stably fixed to the battery cell body 10, avoiding contact and short circuiting between the first metal strip 20 and the second metal strip 40, and obtaining a battery cell with a smaller width. In an embodiment of the present invention, the preferred range value of K / J is greater than or equal to 5% and less than or equal to 60%. For example, the value of K / J may include one of 5%, 10%, 20%, 30%, 40%, 50%, and 60%. Within this preferred range value, not only can a battery cell with a smaller width be obtained, but the difficulty of overlapping the first insulating portion 30 and the second insulating portion 50 is reduced, thereby reducing the difficulty of the battery cell process and achieving a high yield rate.

[0062] In an embodiment of the present invention, the overlap width of the overlap region 35 is between 0.1 mm and 5 mm. Specifically, the overlap width may include any of 0.1 mm, 0.2 mm, 0.4 mm, 0.5 mm, 1 mm, 1.2 mm, 1.5 mm, 2 mm, 2.2 mm, 3 mm, 3.6 mm, 4 mm, 4.3 mm, 4.7 mm, and 5 mm. The second spacing is between 1.5 mm and 7 mm. Specifically, the second spacing may include any of 1.5 mm, 2 mm, 2.1 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, and 7 mm. For example, when the second spacing is 2 mm, the overlap width may be 1 mm. When the second spacing is 3.5 mm, the overlap width may be 2.1 mm. This prevents short circuiting between the first metal strip 20 and the second metal strip 40 while enabling the manufacture of ultra-narrow battery cells.

[0063] In a preferred embodiment of the present invention, the overlap width of the overlap region 35 is between 0.2mm and 3mm, and the second spacing is between 2mm and 5mm. Thus, by further defining upper and lower limits for the second spacing and the overlap region 35, the manufacturing difficulty of ultra-narrow battery cells is reduced. Specifically, the overlap width may include any of 0.2mm, 0.4mm, 0.5mm, 1mm, 1.2mm, 1.5mm, 2mm, 2.2mm, and 3mm. Specifically, the second spacing may include any of 2mm, 2.1mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, and 5mm. By setting the upper limit of the second spacing to no more than 5mm and the lower limit to no less than 2mm, and ensuring that the overlap region 35 is no greater than 3mm and no less than 0.2mm, the manufacturing difficulty of ultra-narrow battery cells is reduced, while also ensuring that the first metal strip 20 and the second metal strip 40 do not short-circuit, resulting in a high battery cell yield.

[0064] As shown in FIG9 , the first insulating portion 30 includes a first insulating region 31 and a second insulating region 32, and the second insulating portion 50 includes a third insulating region 51 and a fourth insulating region 52. The second insulating region 32 and the third insulating region 51 overlap and adhere to form an overlapping region 35. The second insulating region 32 has a first width along the height direction of the battery cell body 10, and the third insulating region 51 has a second width along the height direction of the battery cell body 10. In order to enhance the sealing of the battery cell body 10 after packaging, the embodiment of the present invention gradually increases at least one of the first width and the second width in the direction close to the overlapping area 35 to form a protrusion protruding from the first insulating area 31 and the fourth insulating area 52 close to or away from the battery cell body 10, that is, there is at least one protrusion in the overlapping area 35. The protrusion is mainly caused by the melting and overlapping of the second insulating area 32 and the third insulating area 51. The protrusion is beneficial to enhancing the sealing of the battery cell body 10 after packaging with a plastic shell, and when the battery cell is mechanically abused (such as being affected by collision or external force), it improves the stress relationship between the various structures of the battery cell, improves the structural stability of the battery cell, and increases the heat dissipation area of ​​the battery cell.

[0065] The raised portion in the embodiment of the present invention has a raised height along the height direction of the battery cell body 10. The battery cell body 10 includes a first end, which is the end of the battery cell body 10 along the height direction and at which the first and second tabs are disposed. The battery cell also includes a plastic package, in which the battery cell body 10 is disposed. The plastic package includes a plastic package portion 60, which is located at the first end. The plastic package portion 60 has a plastic package height along the height direction of the battery cell body 10 (as indicated by h3 in FIG. 9 ).

[0066] The raised height in the embodiments of the present invention can be between 0 mm and 2 mm, and specifically can be one of 0 mm, 0.1 mm, 0.3 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1 mm, 1.2 mm, 1.3 mm, 1.6 mm, 1.7 mm, 1.8 mm, 2 mm, etc. Preferably, the raised height is between 0.1 mm and 1 mm, and specifically can be one of 0.1 mm, 0.3 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1 mm, etc. The height of the plastic seal is between 1.0 mm and 3.0 mm, and specifically can be one of 1.0 mm, 1.2 mm, 1.5 mm, 1.7 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 3.0 mm, etc. Preferably, the plastic seal height can also be between 1.5mm and 2.5mm. In this case, the plastic seal height can be specifically one of 1.5mm, 1.7mm, 1.8mm, 2.0mm, 2.2mm, 2.3mm, 2.5mm, etc. In an embodiment of the present invention, the ratio between the protrusion height and the plastic seal height is between 0.1 and 1. The ratio between the protrusion height and the plastic seal height can specifically include one of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, etc. The embodiment of the present invention limits the ratio between the protrusion height and the plastic seal height to the above range to improve the sealing of the battery cell. Preferably, the ratio between the protrusion height and the plastic seal height is between 0.2 and 0.5. In this case, the ratio between the protrusion height and the plastic seal height can specifically include one of 0.2, 0.3, 0.4, 0.5, etc. to prevent the protrusion height from being too small to improve the sealing of the battery cell.

[0067] As shown in FIG9 , in another specific embodiment of the present invention, the raised portion includes a first raised portion 321 and a second raised portion 511. The first raised portion 321 is located on the side of the second insulating region 32 away from the cell body 10. The first raised portion 321 has a first raised height along the height direction of the cell body 10. The first raised height is the height between the end of the first raised portion 321 away from the cell body 10 and the side of the first insulating region 31 away from the cell body 10 (as indicated by h1 in FIG9 ). The second raised portion 511 is located on the side of the third insulating region 51 away from the cell body 10. The second raised portion 511 has a second raised height along the height direction of the cell body 10. The second raised height is the height between the end of the second raised portion 511 away from the cell body 10 and the side of the fourth insulating region 52 away from the cell body 10 (as indicated by h2 in FIG9 ). In the width direction of the cell body 10, the distance between the end of the first protrusion 321 away from the cell body 10 (i.e., the vertex of the first protrusion 321 away from the cell body 10) and the end of the second protrusion 511 away from the cell body 10 (i.e., the vertex of the second protrusion 511 away from the cell body 10) is D (D is the distance shown in FIG9 ), D is between 0 mm and 5.0 mm, and the difference between the first protrusion height and the second protrusion height is H, which is between 0 mm and 2 mm. The size of D can specifically include one of 0 mm, 1.0 mm, 2.0 mm, 3.0 mm, 4.0 mm, 5.0 mm, etc., and the size of H can specifically include one of 0 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, etc.

[0068] The overlapping region 35 has an overlapping thickness along the thickness direction of the battery cell body 10. The first insulating region 31 and the fourth insulating region 52 have the same insulation thickness along the thickness direction of the battery cell body 10. The overlapping thickness is between 0.05 mm and 0.3 mm, and can be specifically one of 0.05 mm, 0.07 mm, 0.08 mm, 0.1 mm, 0.13 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.24 mm, 0.26 mm, 0.27 mm, and 0.3 mm. The overlapping region 35 with this overlapping thickness secures the first metal strip 20 and the second metal strip 40, and improves the sealing performance of the battery cell in the overlapping region 35, preventing leakage of the battery cell. The insulation thickness of the first insulating region 31 and the fourth insulating region 52 are both between 0.04 mm and 0.2 mm. Specifically, the insulation thickness may include one of 0.04 mm, 0.05 mm, 0.07 mm, 0.1 mm, 0.14 mm, 0.15 mm, 0.18 mm, 0.2 mm, etc., thereby performing a sealing effect on the battery cell body 10 after packaging through the first insulating region 31 and the fourth insulating region 52.

[0069] In a preferred embodiment of the present invention, the overlap thickness is between 0.1 mm and 0.2 mm, and specifically can be one of 0.1 mm, 0.13 mm, 0.15 mm, 0.18 mm, and 0.2 mm. This allows the first metal strip 20 and the second metal strip 40 to be secured via the overlap region 35 at this overlap thickness, improving the sealing of the battery cell in the overlap region 35, preventing leakage from the battery cell and avoiding contact and short circuiting between the first metal strip 20 and the second metal strip 40. The insulation thickness is between 0.05 mm and 0.15 mm, and specifically can be one of 0.05 mm, 0.07 mm, 0.1 mm, 0.14 mm, and 0.15 mm.

[0070] In an embodiment of the present invention, the overlap thickness is a first thickness value, the insulation thickness is a second thickness value, and the thermal shrinkage between the overlap region 35 and the first insulation region 31 and the fourth insulation region 52 is equal to the ratio of the first thickness value to twice the second thickness value, and the thermal shrinkage is greater than or equal to 10% and less than or equal to 90%. If the first thickness value is a and the second thickness value is b, then the thermal shrinkage is equal to a / (2b) (the symbol " / " is a division symbol), and the thermal shrinkage satisfies 10%≤a / (2b)≤90%. Specifically, the thermal shrinkage value may include one of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc. Therefore, by limiting the ratio between the overlap thickness and the insulation thickness (i.e., the thermal shrinkage) to within the range of 10% to 90%, the thickness fluctuation from the overlap region 35 to the non-overlap region is avoided, thereby ensuring the consistency of the battery cell appearance and reducing the welding difficulty in the process of manufacturing the battery pack using the battery cell. In addition to the first insulating region 31 and the fourth insulating region 52, the non-overlapping region also includes the area where the second insulating region and the third insulating region do not overlap. The thickness of the area where the second insulating region and the third insulating region do not overlap and the insulation thickness of the first insulating region 31 and the fourth insulating region 52 are both smaller than the overlapping thickness. Usually, the thickness of the area where the second insulating region and the third insulating region do not overlap is the above-mentioned insulation thickness. Therefore, by limiting the ratio between the overlapping thickness and the insulation thickness, it is also limited that the thickness fluctuation from the overlapping area to the area where the second insulating region and the third insulating region do not overlap will not be too large.

[0071] In a preferred embodiment of the present invention, the thermal shrinkage rate satisfies 20%≤a / (2b)≤80%. At this time, the thermal shrinkage rate value may include one of 20%, 30%, 40%, 50%, 60%, 70%, 80%, etc., thereby further reducing the thickness fluctuation from the overlapping area 35 to the first insulating area 31 and the fourth insulating area 52, ensuring the consistency of the battery cell appearance, and greatly reducing the welding difficulty in the process of manufacturing the battery pack using the battery cell.

[0072] The plastic shell has a shell thickness along the thickness direction of the battery body 10, the sum of the shell thickness and the overlapping thickness is the first overall thickness, the sum of the shell thickness and the insulation thickness is the second overall thickness, and the first overall thickness is greater than the second overall thickness. Thus, since the first overall thickness is greater than the second overall thickness, the battery cell has better sealing at the overlapping area 35, thereby preventing leakage of the battery cell. Among them, the first overall thickness is between 0.15mm and 0.6mm. At this time, the first overall thickness can specifically include one of 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, etc. Preferably, the first overall thickness is between 0.2mm and 0.5mm. At this time, the first overall thickness can specifically include 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm. The second overall thickness is between 0.14 mm and 0.45 mm. In this case, the second overall thickness may specifically include one of 0.14 mm, 0.15 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.24 mm, 0.26 mm, 0.29 mm, 0.3 mm, 0.36 mm, 0.4 mm, 0.42 mm, 0.45 mm, etc. Preferably, the second overall thickness is between 0.15 mm and 0.4 mm. In this case, the second overall thickness may specifically include one of 0.15 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.24 mm, 0.26 mm, 0.29 mm, 0.3 mm, 0.36 mm, 0.4 mm, etc.

[0073] The plastic package case in the embodiment of the present invention may include a first aluminum-plastic film and a second aluminum-plastic film. The battery cell body 10 is encapsulated within the second aluminum-plastic film, and the first aluminum-plastic film covers the outer side of the second aluminum-plastic film away from the battery cell body 10. Both the first and second aluminum-plastic films are coated with an insulating adhesive for encapsulation and bonding. The plastic package portion 60 is specifically the portion formed at the first end of the battery cell body 10 after the first and second aluminum-plastic films are encapsulated together. Specifically, the first aluminum-plastic film is coated with a first insulating adhesive. Along the thickness direction of the battery cell body 10, the portion of the first insulating adhesive corresponding to the overlapping region 35 has a first adhesive thickness, and the portion of the first insulating adhesive corresponding to the first insulating region 31 or the fourth insulating region 52 has a second adhesive thickness. The second aluminum-plastic film is coated with a second insulating adhesive. Along the thickness direction of the battery cell body 10, the portion of the second insulating adhesive corresponding to the overlapping region 35 has a third adhesive thickness, and the portion of the second insulating adhesive corresponding to the first insulating region 31 or the fourth insulating region 52 has a fourth adhesive thickness. The sum of the first colloid thickness, the third colloid thickness, and the overlap thickness is the first total insulation thickness, and the sum of the second colloid thickness, the fourth colloid thickness, and the insulation thickness is the second total insulation thickness. By setting the first total insulation thickness to be greater than the second total insulation thickness, this embodiment of the utility model improves the sealing performance of the battery cell in the overlap region 35, preventing leakage of the battery cell.

[0074] The first total insulation thickness is between 0.07 mm and 0.5 mm. In this case, the first total insulation thickness may specifically include one of 0.07 mm, 0.09 mm, 0.1 mm, 0.12 mm, 0.15 mm, 0.17 mm, 0.2 mm, 0.21 mm, 0.24 mm, 0.26 mm, 0.3 mm, 0.33 mm, 0.36 mm, 0.38 mm, 0.4 mm, 0.42 mm, 0.46 mm, 0.5 mm, etc. Preferably, the first total insulation thickness is between 0.1 mm and 0.4 mm. In this case, the first total insulation thickness may specifically include one of 0.1 mm, 0.12 mm, 0.15 mm, 0.17 mm, 0.2 mm, 0.21 mm, 0.24 mm, 0.26 mm, 0.3 mm, 0.33 mm, 0.36 mm, 0.38 mm, 0.4 mm, etc. The second total insulation thickness is between 0.06 mm and 0.4 mm. In this case, the second total insulation thickness may include one of 0.06 mm, 0.08 mm, 0.1 mm, 0.12 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.23 mm, 0.26 mm, 0.29 mm, 0.3 mm, 0.31 mm, 0.34 mm, 0.37 mm, 0.4 mm, etc. Preferably, the second total insulation thickness is between 0.08 mm and 0.3 mm. In this case, the second total insulation thickness may include one of 0.08 mm, 0.1 mm, 0.12 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.23 mm, 0.26 mm, 0.29 mm, 0.3 mm, etc.

[0075] The difference between the first total insulation thickness and the second total insulation thickness is a first thickness difference (i.e., the value by which the first total insulation thickness exceeds the second total insulation thickness). The ratio of the first thickness difference to the second total insulation thickness is between 0.1 and 1.67. At this time, the ratio of the first thickness difference to the second total insulation thickness may specifically include one of 0.1, 0.2, 0.25, 0.4, 0.45, 0.6, 0.65, 0.8, 0.85, 1, 1.1, 1.22, 1.41, 1.5, 1.52, 1.62, 1.65, 1.67, etc. Preferably, the ratio of the first thickness difference to the second total insulation thickness is between 0.25 and 1.5. At this time, the ratio of the first thickness difference to the second total insulation thickness may specifically include one of 0.25, 0.4, 0.45, 0.6, 0.65, 0.8, 0.85, 1, 1.1, 1.22, 1.41, 1.5, etc.

[0076] The second embodiment of the present invention provides a battery, which includes the battery cell provided by the first embodiment of the present invention.

[0077] The third embodiment of the present invention provides an electronic product comprising the battery provided by the second embodiment of the present invention. Such electronic products include VR glasses, wearable watches, and fitness trackers. The battery cells (e.g., lithium batteries) provided by the present invention meet the requirements of these technological electronic products for smaller cell size, reduced space requirements, extended battery life, and other requirements.

[0078] The fourth embodiment of the present invention, based on the three aforementioned embodiments and in conjunction with Figures 1 to 9 , provides an application embodiment of a battery cell. The battery cell in this embodiment includes either a wound core structure or a stacked core structure. When the first tab is a positive tab connected to the positive electrode sheet and the second tab is a negative tab connected to the negative electrode sheet, the battery cell effectively reduces the distance between the positive and negative tabs along the width of the battery cell body 10, achieving an ultra-narrow battery cell design and preventing short circuits between the metal strips of the positive and negative tabs.

[0079] Specifically, this embodiment uses a winding core as an example to illustrate how the present invention manufactures an ultra-narrow battery cell. The winding core has the following characteristics:

[0080] 1) As shown in Figures 7 and 8, regardless of whether the core is an odd-numbered or even-numbered folded core, the first and second tabs can be distributed on the same side of the core, but the tab glue (the tab glue is the insulating portion on the metal strip, and the material can be PP glue) can overlap, that is, the first insulating portion 30 and the second insulating portion 50 at least partially overlap and fit together to form an overlapping area 35, thereby reducing the width of the core and realizing the manufacture of ultra-narrow battery cells. When the first and second tabs are distributed on the same side of the core, they can be simultaneously set at the first fold at the starting end of the core winding (i.e., the inside of the core) (as shown in Figure 4), or they can be simultaneously set on the same side of the outer layer of the core winding (as shown in Figure 8).

[0081] As shown in FIG3 , when the first electrode tab and the second electrode tab are welded to the stacked core, the first insulating portion 30 and the second insulating portion 50 are at least partially overlapped to reduce the width of the stacked core.

[0082] 2) As shown in Figures 1 and 4 to 6, the welding locations of the first and second tabs are separated. For example, the first and second tabs are welded to the outer layer of the winding core, but on opposite sides of the outer layer along the direction indicated by arrow Z. This method can effectively prevent the first and second tabs from short-circuiting. In addition, because the projections of the first insulating portion 30 and the second insulating portion 50 along the direction indicated by arrow Z at least partially overlap to form an overlapping region 35, the manufacture of ultra-narrow battery cells can be achieved, meeting customer design requirements for ultra-narrow battery cells.

[0083] In the setting mode of separating the welding positions of the first pole ear and the second pole ear, as shown in Figures 1 and 4 to 6, one of the first pole ear and the second pole ear can be set at the innermost side of the winding core (such as the first fold of the winding), and the other of the first pole ear and the second pole ear can be set at the outermost side of the winding core (i.e., the outermost layer of the winding), thereby effectively preventing the first pole ear and the second pole ear from contacting and short-circuiting, and realizing the manufacture of ultra-narrow battery cells to meet customer requirements.

[0084] The ultra-narrow battery cell manufactured in this application embodiment can have a width along the direction indicated by arrow X ranging from 8mm to 30mm, specifically including 8mm, 9mm, 10mm, 12mm, 13mm, 15mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 28mm, or 30mm. The thickness along the direction indicated by arrow Z can range from 2.0mm to 10mm, specifically including 2.0mm, 4.0mm, 5.0mm, 7.0mm, 8.0mm, 9.0mm, or 10mm. The height along the direction indicated by arrow Y can range from 30mm to 150mm, specifically including 30mm, 40mm, 50mm, 70mm, 80mm, 90mm, 100mm, 120mm, 130mm, or 150mm. The width of the insulating portion along the direction indicated by arrow Y may be between 1.0 mm and 2.5 mm, and the insulation thickness of the first insulating portion 30 and the second insulating portion 50 may be ≤0.5 mm.

[0085] As can be seen from the structure of a conventional battery cell on the left side of Figure 2, the insulating portions of the first and second tabs of a conventional battery cell do not overlap. The cell width is reduced only by reducing the length of the insulating portion along the width of the cell, which limits the lower limit of the cell width. However, in this application embodiment, since the first insulating portion 30 and the second insulating portion 50 of the two tabs have an overlapping area 35, the cell width can be further reduced on the basis of a conventional cell, resulting in an ultra-narrow cell product that meets the requirements. As shown in Figure 2, the width of the cell obtained after the first insulating portion 30 and the second insulating portion 50 overlap is significantly smaller than the width of a conventional cell that does not overlap.

[0086] When the first pole tab and the second pole tab are arranged on the same side of the winding core, the winding core is placed in the plastic shell for packaging. When the top is sealed, there will be a bulge in the overlapping area 35 of the first insulating part 30 and the second insulating part 50. The bulge is produced by the melting of the insulating material when the first insulating part 30 and the second insulating part 50 overlap (if the first insulating part 30 and the second insulating part 50 are both PP glue, the bulge is produced by the melting of the PP glue). The enlarged view of the overlapping area 35 is shown in Figure 9. The bulge has no effect on the performance of the battery cell and is beneficial to improving the sealing of the battery cell and preventing leakage.

[0087] The present invention has the following characteristics:

[0088] Feature 1: The first insulating portion 30 and the second insulating portion 50 at least partially overlap with an overlapping region 35. This allows for a smaller spacing between the tabs of an ultra-narrow cell (preventing leakage due to the tabs being too close together). Because the overlapping region 35 is thicker (i.e., the thickness is greater than the insulation thickness of the first insulating region 31 and the fourth insulating region 52), it can better secure the first and second tabs, preventing short circuits between the first and second tabs.

[0089] Feature 2: The presence of at least one raised portion. Effect: This helps improve the sealing of the battery cell, improves the stress relationship of the battery cell structure when mechanical abuse occurs, and increases the heat dissipation area of ​​the battery cell.

[0090] The ratio of the overlap width of the overlapping region 35 of the first insulating portion 30 and the second insulating portion 50 to the second spacing between the two tabs is between 1% and 90%, preferably between 5% and 60%. The overlap width is between 0.1 mm and 5 mm, preferably between 0.2 mm and 3 mm. The second spacing between the two tabs is between 1.5 mm and 7 mm, preferably between 2 mm and 5 mm.

[0091] In this embodiment, the height of the raised portion is between 0 mm and 2 mm, preferably between 0.1 mm and 1 mm. The height of the plastic seal portion 60 (commonly known as the top seal) is between 1.0 mm and 3.0 mm, preferably between 1.5 mm and 2.5 mm. The ratio of the raised height to the plastic seal height in this embodiment can be between 0.1 and 0.7, preferably between 0.2 and 0.5.

[0092] When the first insulating portion 30 includes a first raised portion 321 and the second insulating portion 50 includes a second raised portion 511, the distance between the end of the first raised portion 321 away from the cell body 10 and the end of the second raised portion 511 away from the cell body 10 is D, and D is between 0 mm and 5.0 mm, preferably between 0.1 mm and 2.5 mm. The first raised portion 321 has a first raised height along the height direction of the cell body 10, and the second raised portion 511 has a second raised height along the height direction of the cell body 10. The difference between the first raised height and the second raised height is H, and H is between 0 mm and 2 mm, preferably between 0.1 mm and 1.0 mm.

[0093] Feature point three: The first and second tabs are welded to the outermost folds of the first and second electrode sheets of the winding core, respectively, which can make the size of the ultra-narrow battery cell smaller.

[0094] Feature 4: The overlapping thickness of overlapping region 35 is greater than the insulation thickness of the non-overlapping region (specifically, the non-overlapping region includes the non-overlapping area between the second and third insulating regions, as well as the first and fourth insulating regions 31 and 52). Effect: This improves the sealing performance of the battery cell, while maintaining a certain thickness ratio to avoid excessive fluctuations in the thickness of the cell seal edge, thereby ensuring a consistent appearance of the battery cell and reducing the difficulty of welding during the molding process of the battery pack using the cell of this application embodiment.

[0095] 4.1: The overlapping thickness is greater than the insulation thickness, so that the insulation sealing of the overlapping area 35 is better to prevent leakage.

[0096] If the overlap thickness is a and the insulation thickness is b, the thermal shrinkage between the overlap region 35 and the first insulation region 31 and the thermal shrinkage between the overlap region 35 and the fourth insulation region 52 is equal to a / (2b), and the thermal shrinkage satisfies the following conditions:

[0097] 10%≤a / (2b)≤90%.

[0098] Preferably, the heat shrinkage rate satisfies: 20%≤a / (2b)≤80%), thereby avoiding excessive thickness fluctuations from the first insulating region 31 to the overlapping region 35 and from the overlapping region 35 to the fourth insulating region 52 .

[0099] The overlap thickness ranges from 0.05 mm to 0.3 mm, preferably from 0.1 mm to 0.2 mm. The insulation thickness ranges from 0.04 mm to 0.2 mm, preferably from 0.05 mm to 0.15 mm.

[0100] The plastic shell has a shell thickness along the thickness direction of the battery cell body 10. The sum of the shell thickness and the overlapping thickness of the overlapping area 35 is a first overall thickness. The sum of the shell thickness and the insulation thickness of the non-overlapping area (i.e., the overlapping portion of the overlapping area 35 along the width direction of the battery cell body 10, as well as the first insulating area 31, the fourth insulating area 52, etc.) is a second overall thickness. The first overall thickness is greater than the second overall thickness, thereby making the battery cell more sealed at the overlapping area 35, thereby preventing leakage of the battery cell. The first overall thickness is between 0.15mm and 0.6mm. In this case, the first overall thickness can specifically include one of 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, etc. Preferably, the first overall thickness is between 0.2 mm and 0.5 mm, and in this case, the first overall thickness may specifically include 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, and 0.5 mm. The second overall thickness is between 0.14 mm and 0.45 mm, and in this case, the second overall thickness may specifically include one of 0.14 mm, 0.15 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.24 mm, 0.26 mm, 0.29 mm, 0.3 mm, 0.36 mm, 0.4 mm, 0.42 mm, and 0.45 mm. Preferably, the second overall thickness is between 0.15 mm and 0.4 mm. At this time, the second overall thickness may specifically include one of 0.15 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.24 mm, 0.26 mm, 0.29 mm, 0.3 mm, 0.36 mm, 0.4 mm, etc.

[0101] The plastic package case in the embodiment of the present invention may include a first aluminum-plastic film and a second aluminum-plastic film. The battery cell body 10 is encapsulated within the second aluminum-plastic film, and the first aluminum-plastic film covers the outer side of the second aluminum-plastic film away from the battery cell body 10. Both the first and second aluminum-plastic films are coated with an insulating adhesive for encapsulation and bonding. The plastic package portion 60 is specifically the portion formed at the first end of the battery cell body 10 after the first and second aluminum-plastic films are encapsulated together. Specifically, the first aluminum-plastic film is coated with a first insulating adhesive. Along the thickness direction of the battery cell body 10, the portion of the first insulating adhesive corresponding to the overlapping region 35 has a first adhesive thickness, and the portion of the first insulating adhesive corresponding to the first insulating region 31 or the fourth insulating region 52 has a second adhesive thickness. The second aluminum-plastic film is coated with a second insulating adhesive. Along the thickness direction of the battery cell body 10, the portion of the second insulating adhesive corresponding to the overlapping region 35 has a third adhesive thickness, and the portion of the second insulating adhesive corresponding to the first insulating region 31 or the fourth insulating region 52 has a fourth adhesive thickness. The sum of the first colloid thickness, the third colloid thickness, and the overlap thickness is the first total insulation thickness, and the sum of the second colloid thickness, the fourth colloid thickness, and the insulation thickness is the second total insulation thickness. To ensure better sealing of the battery cell in the overlap region 35 and prevent leakage, in this embodiment of the present invention, the first total insulation thickness is greater than the second total insulation thickness. The first and second insulation adhesives at the terminal of this embodiment of the present invention may be PP adhesive, where PP is the abbreviation for polypropylene. The first total insulation thickness is between 0.07mm and 0.5mm. In this case, the first total insulation thickness may specifically include one of 0.07mm, 0.09mm, 0.1mm, 0.12mm, 0.15mm, 0.17mm, 0.2mm, 0.21mm, 0.24mm, 0.26mm, 0.3mm, 0.33mm, 0.36mm, 0.38mm, 0.4mm, 0.42mm, 0.46mm, 0.5mm, etc. Preferably, the first total insulation thickness is between 0.1 mm and 0.4 mm, and in this case, the first total insulation thickness may specifically include one of 0.1 mm, 0.12 mm, 0.15 mm, 0.17 mm, 0.2 mm, 0.21 mm, 0.24 mm, 0.26 mm, 0.3 mm, 0.33 mm, 0.36 mm, 0.38 mm, 0.4 mm, etc. The second total insulation thickness is between 0.06 mm and 0.4 mm, and in this case, the second total insulation thickness may specifically include one of 0.06 mm, 0.08 mm, 0.1 mm, 0.12 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.23 mm, 0.26 mm, 0.29 mm, 0.3 mm, 0.31 mm, 0.34 mm, 0.37 mm, 0.4 mm, etc.Preferably, the second total insulation thickness is between 0.08 mm and 0.3 mm. At this time, the second total insulation thickness may include one of 0.08 mm, 0.1 mm, 0.12 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.23 mm, 0.26 mm, 0.29 mm, 0.3 mm, etc.

[0102] The difference between the first total insulation thickness and the second total insulation thickness is a first thickness difference (i.e., the value by which the first total insulation thickness exceeds the second total insulation thickness). The ratio of the first thickness difference to the second total insulation thickness is between 0.1 and 1.67. At this time, the ratio of the first thickness difference to the second total insulation thickness may specifically include one of 0.1, 0.2, 0.25, 0.4, 0.45, 0.6, 0.65, 0.8, 0.85, 1, 1.1, 1.22, 1.41, 1.5, 1.52, 1.62, 1.65, 1.67, etc. Preferably, the ratio of the first thickness difference to the second total insulation thickness is between 0.25 and 1.5. At this time, the ratio of the first thickness difference to the second total insulation thickness may specifically include one of 0.25, 0.4, 0.45, 0.6, 0.65, 0.8, 0.85, 1, 1.1, 1.22, 1.41, 1.5, etc.

[0103] Therefore, the ultra-narrow battery cell designed using the embodiments of the present invention meets customer requirements for battery cell width. It also prevents the first and second tabs from overlapping and potentially causing a short circuit. It is applicable to both conventional wound cores and stacked cores.

[0104] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0105] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0106] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, characterized in that: include: A battery cell body (10), the battery cell body (10) comprising a first electrode sheet and a second electrode sheet, the first electrode sheet and the second electrode sheet having opposite polarities; a first electrode tab, the first electrode tab being connected to the first electrode sheet, the first electrode tab comprising a first metal strip (20) and a first insulating portion (30), the first metal strip (20) extending in a height direction of the battery cell body (10), the first insulating portion (30) being arranged on the first metal strip (20) and protruding from an edge of the first metal strip (20) in a width direction of the battery cell body (10); a second electrode tab, the second electrode tab being connected to the second electrode sheet, the second electrode tab comprising a second metal strip (40) and a second insulating portion (50), the second metal strip (40) extending in a height direction of the battery cell body (10), the second insulating portion (50) being arranged on the second metal strip (40) and protruding from an edge of the second metal strip (40) in a width direction of the battery cell body (10); There is a distance between the first metal strip (20) and the second metal strip (40), and the first insulating portion (30) and the second insulating portion (50) at least partially overlap to form an overlapping area (35).

2. The battery cell according to claim 1, characterized in that: Along the thickness direction of the battery cell body (10), the battery cell body (10) includes a first side (11) and a second side (12) that are arranged opposite to each other, and a first spacing is provided between the first side (11) and the second side (12) along the thickness direction of the battery cell body (10); the first metal strip (20) is provided on one of the first side (11) and the second side (12); and the second metal strip (40) is provided on the other of the first side (11) and the second side (12).

3. The battery cell according to claim 2, characterized in that: There is a gap between the projections of the first metal strip (20) and the second metal strip (40) along the thickness direction of the battery cell body (10).

4. The battery cell according to any one of claims 2 to 3, characterized in that: The battery cell comprises a winding core, wherein the first electrode sheet and the second electrode sheet isolated from each other are stacked and wound from the head end to the tail end to form the winding core, wherein the tail end of one of the first electrode sheet and the second electrode sheet is located on the first side (11), the tail end of one of the first electrode sheet and the second electrode sheet is located on the second side (12), the first electrode tab is arranged at the tail end of the first electrode sheet, and the second electrode tab is arranged at the tail end of the second electrode sheet.

5. The battery cell according to claim 1, characterized in that: The first metal strip (20) and the second metal strip (40) are arranged on the same side of the battery cell body (10) along the thickness direction of the battery cell body (10), and the first insulating part (30) and the second insulating part (50) located between the first metal strip (20) and the second metal strip (40) at least partially overlap and adhere to each other.

6. The battery cell according to claim 5, characterized in that: The overlapping area (35) has an overlapping width along the width direction of the battery cell body (10), and there is a second spacing between the first metal strip (20) and the second metal strip (40) along the width direction of the battery cell body (10), wherein the ratio between the overlapping width and the second spacing is between 1% and 90%.

7. The battery cell according to claim 6, characterized in that: The overlapping width is between 0.1 mm and 5 mm; and / or the second spacing is between 1.5 mm and 7 mm.

8. The battery cell according to claim 6, characterized in that: The first insulating portion (30) includes a first insulating area (31) and a second insulating area (32), and the second insulating portion (50) includes a third insulating area (51) and a fourth insulating area (52), wherein the second insulating area (32) and the third insulating area (51) overlap and adhere to form the overlapping area (35), the second insulating area (32) has a first width along the height direction of the battery cell body (10), and the third insulating area (51) has a second width along the height direction of the battery cell body (10), and at least one of the first width and the second width gradually increases in a direction close to the overlapping area (35) to form a protrusion protruding from the first insulating area (31) and the fourth insulating area (52) close to or away from the battery cell body (10).

9. The battery cell according to claim 8, characterized in that: The overlapping region (35) has an overlapping thickness along the thickness direction of the battery cell body (10), and the first insulating region (31) and the fourth insulating region (52) have the same insulation thickness along the thickness direction of the battery cell body (10); wherein the overlapping thickness is between 0.05 mm and 0.3 mm; and / or the insulation thickness is between 0.04 mm and 0.2 mm.

10. The battery cell according to claim 9, characterized in that: The size of the overlapping thickness is a first thickness value, the size of the insulating thickness is a second thickness value, the heat shrinkage rate between the overlapping area (35) and the first insulating area (31) and the heat shrinkage rate between the overlapping area (35) and the fourth insulating area (52) are both equal to the ratio of the first thickness value to twice the second thickness value, and the heat shrinkage rate is greater than or equal to 10% and less than or equal to 90%.

11. The battery cell according to claim 9, characterized in that: The raised portion has a raised height along the height direction of the battery cell body (10), the battery cell body (10) comprises a first end, the first end is an end of the battery cell body (10) along the height direction of the battery cell body (10) and provided with the first pole ear and the second pole ear, and the battery cell further comprises: A plastic package shell, the battery cell body (10) is arranged in the plastic package shell, the plastic package shell comprises a plastic package portion (60), and the plastic package portion (60) is located at the first end; The plastic sealing portion (60) has a plastic sealing height along the height direction of the battery cell body (10), and the ratio between the protrusion height and the plastic sealing height is between 0.1 and 0.

7.

12. The battery cell according to claim 11, characterized in that: The plastic package shell has a shell thickness along the thickness direction of the battery cell body (10), the sum of the shell thickness and the overlapping thickness is a first overall thickness, the sum of the shell thickness and the insulating thickness is a second overall thickness, and the first overall thickness is greater than the second overall thickness.

13. The battery cell according to claim 12, characterized in that: The first overall thickness is between 0.15 mm and 0.6 mm, and the second overall thickness is between 0.14 mm and 0.45 mm.

14. The battery cell according to claim 11, characterized in that: The plastic package shell comprises: a first aluminum-plastic film, on which a first insulating glue is coated, and along the thickness direction of the battery body (10), the first insulating glue has a first glue thickness at a portion thereof relative to the overlapping region (35), and has a second glue thickness at a portion thereof relative to the first insulating region (31) or the fourth insulating region (52); a second aluminum-plastic film, the battery body (10) being encapsulated in the second aluminum-plastic film, the first aluminum-plastic film being coated on the outer side of the second aluminum-plastic film away from the battery body (10), the second aluminum-plastic film being coated with a second insulating glue, and along the thickness direction of the battery body (10), the second insulating glue having a third glue thickness at a portion thereof relative to the overlapping region (35), and having a fourth glue thickness at a portion thereof relative to the first insulating region (31) or the fourth insulating region (52); The sum of the first colloid thickness, the third colloid thickness and the overlapping thickness is the first total insulation thickness, the sum of the second colloid thickness, the fourth colloid thickness and the insulation thickness is the second total insulation thickness, and the first total insulation thickness is greater than the second total insulation thickness.

15. The battery cell according to claim 14, characterized in that: The first insulation total thickness is between 0.07 mm and 0.5 mm, and the second insulation total thickness is between 0.06 mm and 0.4 mm.

16. The battery cell according to claim 14 or 15, characterized in that: The difference between the first insulation total thickness and the second insulation total thickness is a first thickness difference, and the ratio of the first thickness difference to the second insulation total thickness is between 0.1 and 1.

67.

17. The battery cell according to claim 8, characterized in that: The raised portion comprises: a first protrusion (321), the first protrusion (321) being located on a side of the second insulating region (32) away from the battery cell body (10), the first protrusion (321) having a first protrusion height along a height direction of the battery cell body (10), the first protrusion height being a height between an end of the first protrusion (321) away from the battery cell body (10) and a side of the first insulating region (31) away from the battery cell body (10); a second protrusion (511), the second protrusion (511) being located on a side of the third insulating region (51) away from the battery cell body (10), the second protrusion (511) having a second protrusion height along a height direction of the battery cell body (10), the second protrusion height being a height between an end of the second protrusion (511) away from the battery cell body (10) and a side of the fourth insulating region (52) away from the battery cell body (10); Among them, along the width direction of the battery cell body (10), the distance between the end of the first protrusion (321) away from the battery cell body (10) and the end of the second protrusion (511) away from the battery cell body (10) is D, D is between 0 mm and 5.0 mm, and the difference between the first protrusion height and the second protrusion height is H, H is between 0 mm and 2 mm.

18. A battery, characterized in that: The battery comprises the battery cell according to any one of claims 1 to 17.

19. An electronic product, characterized in that: The electronic product comprises the battery according to claim 18.

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