Battery cell and battery

Abstract

A battery cell body comprises a first pole piece, a diaphragm and a second pole piece, and the first pole piece, the diaphragm and the second pole piece are arranged in a laminated manner along a first direction; the first pole piece is provided with a first gap, the second pole piece is provided with a second gap, the first gap and the second gap are mutually staggered along a third direction, and the first direction, the second direction and the third direction are vertical in pairs; the first pole piece comprises a first sub-tab exposed in the second gap, and the second pole piece comprises a second sub-tab exposed in the first gap; the electrode adapter comprises a body section and a bent section formed by bending, the bent section of the electrode adapter is at least partially located in the second notch and is in welded connection with the first sub tab, and the body section is located on the side, away from the battery cell body, of the bent section. The battery cell provided by the utility model can improve the energy density of the battery.

Description

Technical Field

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

[0002] Due to the high energy density characteristics, lithium-ion batteries have been gradually widely used in the field of consumer electronics. With the increasing demand of consumer electronics for the energy density of lithium-ion batteries, improving the energy per unit space of lithium-ion batteries has become one of the development directions of lithium-ion batteries.

[0003] In the production process of a stacked structure lithium-ion battery, soft tabs on multiple lithium-ion battery electrodes are welded to an external electrode adapter, and a stacked core formed by laminating multiple electrodes is encapsulated in a packaging film. There will be a gap between the stacked core and the packaging film to provide an installation space for the soft tabs and the electrode adapter. However, this will reduce the proportion of the stacked core that can provide battery capacity in the lithium-ion battery, which is not conducive to improving the energy density of the lithium-ion battery. Summary of the Utility Model

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. For this reason, an object of the utility model is to provide a battery cell and a battery, in which the structure formed after the electrode adapter is welded to the first sub-tab is arranged in the second notch, reducing the installation space occupied by the connection structure between the first sub-tab and the electrode adapter in the battery, increasing the proportion of the stacked core that can provide battery capacity, and thus improving the energy density of the battery.

[0005] A battery cell according to an embodiment of the utility model includes: a battery cell body, including a first electrode, a separator, and a second electrode, the first electrode and the second electrode having opposite polarities, and the first electrode, the separator, and the second electrode being sequentially laminated in a first direction; a first notch is provided at one end of the first electrode along a second direction, a second notch is provided at one end of the second electrode along the second direction, the first notch and the second notch are offset from each other in a third direction, and the first direction, the second direction, and the third direction are perpendicular to each other in pairs; the first electrode includes a first sub-tab exposed in the second notch, and the second electrode includes a second sub-tab exposed in the first notch; an electrode adapter, the electrode adapter includes a body section and a bent section formed by bending, at least a part of the bent section of the electrode adapter is located in the second notch and is welded to the first sub-tab, and the body section is located on the side of the bent section away from the battery cell body.

[0006] For the battery cell of the present utility model, a second notch is provided at one end of the second electrode sheet of the battery cell body. The first electrode sheet has a first sub-tab exposed in the second notch. The bent section of the electrode adapter is located in the second notch after being welded to the first sub-tab of the first electrode sheet, reducing the installation space occupied by the connection structure between the first sub-tab and the electrode adapter in the battery, increasing the proportion of the stacked cores that can provide battery capacity, and thus increasing the energy density of the battery.

[0007] In some embodiments, there are multiple first electrode sheets and multiple second electrode sheets. The multiple first sub-tabs and the multiple second sub-tabs are arranged in a stacked manner and are respectively connected to the electrode adapter.

[0008] In some embodiments, the height h of the bent section in the first direction and the thickness H of the battery cell body in the first direction satisfy: h ≤ H.

[0009] In some embodiments, the included angle θ between the body section and the bent section satisfies: 60° ≤ θ ≤ 120°.

[0010] In some embodiments, the included angle between the bent section and the reference plane is less than or equal to 90°, and the reference plane is jointly determined by the second direction and the third direction.

[0011] In some embodiments, a third notch and a fourth notch are further provided at one end of the separator along the second direction. The third notch and the first notch are opposite to each other along the first direction, the fourth notch and the second notch are opposite to each other along the first direction. The first sub-tab is also exposed in the fourth notch, and the second sub-tab is also exposed in the third notch.

[0012] In some embodiments, the outer contours of the first electrode sheet and the second electrode sheet are both inside the outer contour of the separator. The separator includes an extension portion extending beyond the first electrode sheet along the second direction. Part of the structure of the extension portion surrounds the third notch and the fourth notch. The value range of the width d of the extension portion along the second direction is: 0 < d < 3 mm.

[0013] According to some embodiments of the present utility model, the extension portion bends and extends along the direction parallel to the bent section.

[0014] According to some embodiments of the present utility model, the sum of the thickness of the welded part of the first sub-tab and the electrode adapter and the thickness of the extension portion is less than the depth of the second notch along the second direction; and / or, the sum of the thickness of the welded part of the second sub-tab and the electrode adapter and the thickness of the extension portion is less than the depth of the first notch along the second direction.

[0015] According to some embodiments of the present invention, the first sub-tab and the second sub-tab are respectively welded to the corresponding electrode adapter to form welding marks, and the welding marks do not extend beyond the edge of the separator located outside the third notch along the second direction.

[0016] Furthermore, the welding marks do not extend beyond the edge of the second pole piece located outside the second notch along the second direction.

[0017] According to some embodiments of the present invention, it further includes: a protective glue, the protective glue covers the welding marks, and the protective glue is within the first notch.

[0018] According to some embodiments of the present invention, the projection of the extension portion in the first direction and the projection of the protective glue in the first direction at least partially overlap.

[0019] The second aspect of the present invention further provides a battery, including: the above-mentioned battery cell; an outer film shell, the outer film shell covers the battery cell.

[0020] For the battery of the present invention, due to the use of the battery cell of the above first aspect, the laminated core ratio of the battery's capacitance can be increased, the energy density of the battery is improved, and the battery's endurance time is extended.

[0021] Some of the additional aspects and advantages of the present invention will be given in the following description, some will become obvious from the following description, or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0023] Figure 1 is a schematic structural diagram of the battery cell of the embodiment of the present invention assembled in the battery;

[0024] Figure 2 is Figure 1 the cross-sectional structural diagram at A-A in

[0025] Figure 3 is Figure 1 the cross-sectional structural diagram at B-B in

[0026] Figure 4 is Figure 1 the cross-sectional structural diagram at C-C in

[0027] Figure 5 is a schematic diagram of the connection process between the electrode adapter and the tab of the battery cell of the embodiment of the present invention;

[0028] Figure 6 Schematic diagram of the first electrode of the battery cell according to an embodiment of the present invention;

[0029] Figure 7 Schematic diagram of the second electrode of the battery cell according to an embodiment of the present invention.

[0030] Reference numerals:

[0031] 100 - battery cell;

[0032] 10 - battery cell body; 101 - first electrode; 1011 - first notch; 1012 - first sub-tab; 102 - separator; 1021 - third notch; 1022 - fourth notch; 1023 - extension part; 103 - second electrode; 1031 - second notch; 1032 - second sub-tab;

[0033] 20 - electrode adapter; 21 - body section; 22 - bent section; 23 - welding mark;

[0034] 30 - protective glue;

[0035] 200 - battery;

[0036] 201 - outer film case. Detailed implementation manners

[0037] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0038] Lithium - ion batteries have been gradually widely used in the field of consumer electronics due to their high energy density characteristics. With the increasing demand of consumer electronics for the continuous improvement of the energy density of lithium - ion batteries, improving the energy per unit space of lithium - ion batteries has become one of the development directions of lithium - ion batteries.

[0039] In the production process of laminated - structure lithium - ion batteries, the soft tabs on multiple lithium - ion battery electrodes are welded to an external electrode adapter, and the laminated core formed by laminating multiple electrodes is encapsulated in a packaging film. There will be a gap between the laminated core and the packaging film to provide an installation space for the soft tabs and the electrode adapter. However, this will reduce the proportion of the laminated core that can provide battery capacity in the lithium - ion battery, thus being unfavorable for the improvement of the energy density of lithium - ion batteries.

[0040] In view of this, an embodiment of the first aspect of the present utility model provides a battery cell. By providing a receiving groove at one end of the battery cell body, the tab and the bent section of the electrode adapter are received in the receiving groove, reducing the space occupied by the tab and the electrode adapter between the battery cell body and the outer film case, increasing the proportion of the stackable battery capacity that can be provided, and thus increasing the energy density of the battery.

[0041] Reference is made below Figures 1 to 7 to describe a battery cell 100 according to an embodiment of the first aspect of the present utility model.

[0042] Reference is made to Figures 1 to 7 such that the battery cell 100 may include a battery cell body 10 and an electrode adapter 20.

[0043] Reference is made to Figure 6 and Figure 7 such that the battery cell body 10 may include a first electrode tab 101, a separator 102, and a second electrode tab 103, wherein the first electrode tab 101 and the second electrode tab 103 have opposite polarities.

[0044] For convenience of description, the thickness direction of the battery cell body 10 may be the first direction, such as Figure 1 the Z direction shown, the length direction of the battery cell body 10 may be the second direction, such as Figure 1 the X direction shown, and the width direction of the battery cell body 10 may be the third direction, such as Figure 1 the Y direction shown, and the first direction, the second direction, and the third direction are perpendicular to each other pairwise.

[0045] Among them, the first electrode tab 101 may be a negative electrode tab. The negative electrode tab may be one of the electrodes in a lithium-ion battery and is usually made of graphite or other carbon materials, which can effectively adsorb and release lithium ions. During battery discharge, lithium ions move from the positive electrode to the negative electrode, and vice versa during charging. Along the second direction, a first notch 1011 is provided at one end of the first electrode tab 101. The first electrode tab 101 may include a first sub-tab 1012. The first sub-tab 1012 and the first notch 1011 are provided at the same end of the first electrode tab 101 and are offset along the third direction. When the battery cell body 10 is a stacked battery cell, the first electrode tabs 101 are arranged in a stacked manner. Correspondingly, the first notches 1011 of the plurality of first electrode tabs 101 are opposite to each other, and the first sub-tabs 1012 of the plurality of first electrode tabs 101 are arranged in a stacked manner to jointly form the first tab, i.e., the negative tab.

[0046] Understandably, the first electrode tab 101 may include a first current collector and a first active layer. The first current collector includes a first coating setting area and a first blank foil area. The first active layer is coated and disposed on the first coating setting area. The first blank foil area is the area on the first current collector where the first active layer is not provided. Among them, the first blank foil area can be used as the first sub-tab 1012. The two sides of the first blank foil area along the third direction may be spaced apart from the first coating setting area, so as to facilitate the connection of the first sub-tab 1012 with other structures such as the electrode adapter 20.

[0047] The second electrode tab 103 may be a positive electrode tab. The positive electrode tab can be used as the other pole of the lithium-ion battery. Commonly used materials include lithium cobalt oxide (LiCoO2), lithium nickel manganese cobalt oxide (NMC), lithium iron phosphate (LFP), etc. The selection of the positive electrode tab material determines the energy density, power characteristics and stability of the battery. When the battery is working, the positive electrode tab releases lithium ions, and these lithium ions migrate to the negative electrode through the electrolyte. Along the second direction, a second notch 1031 is provided at one end of the second electrode tab 103. The second electrode tab 103 may include a second sub-tab 1032. The second sub-tab 1032 and the second notch 1031 are provided at the same end of the second electrode tab 103 and are staggered along the third direction. Moreover, the first sub-tab 1012 and the second sub-tab 1032 are located at the same end of the first electrode tab 101 and the second electrode tab 103. When the cell body 10 is a stacked cell, the second electrode tabs 103 are multiple and arranged in layers. Correspondingly, the second notches 1031 of the multiple second electrode tabs 103 are opposite to each other, and the second sub-tabs 1032 of the multiple second electrode tabs 103 are arranged in layers with each other, jointly forming the second tab, that is, the positive tab.

[0048] Understandably, the second electrode tab 103 may include a second current collector and a second active layer. The second current collector includes a second coating setting area and a second blank foil area. The second active layer is coated and disposed on the second coating setting area. The second blank foil area is the area on the second current collector where the second active layer is not provided. Among them, the second blank foil area can be used as the second sub-tab 1032. The two sides of the second blank foil area along the third direction may be spaced apart from the second coating setting area, so as to facilitate the connection of the second sub-tab 1032 with other structures such as the electrode adapter 20.

[0049] The separator 102 is located between the first electrode tab 101 and the second electrode tab 103, mainly for separating the first electrode tab 101 and the second electrode tab 103 to prevent short circuit caused by physical contact between the first electrode tab 101 and the second electrode tab 103.

[0050] As Figures 2 to 4As shown, the first electrode tab 101 and the second electrode tab 103 are arranged in an interleaved and stacked manner along the first direction, and the adjacent first electrode tab 101 and second electrode tab 103 are separated by a separator 102, so that the battery cell 100 of this embodiment is formed as a stacked battery cell. At the same time, the first notch 1011 and the second notch 1031 are offset from each other along the third direction, and the first notch 1011 is opposite to the second sub-tab 1032, the second notch 1031 is opposite to the first sub-tab 1012, the first sub-tab 1012 is exposed in the second notch 1031, and the second sub-tab 1032 is exposed in the first notch 1011.

[0051] The electrode adapter 20 can realize the connection between the battery cell body 10 and the electrodes of the battery 200. The electrodes include a positive electrode and a negative electrode. Therefore, two electrode adapters 20 can be provided and connected to the positive electrode and the negative electrode respectively. The electrode adapter 20 can include a body section 21 and a bent section 22 formed by bending. At least part of the structure of the bent section 22 of one electrode adapter 20 (the electrode adapter 20 connected to the positive electrode of the outer shell) is located in the first notch 1011 and is welded to the second sub-tab 1032. At least part of the structure of the other electrode adapter 20 (the electrode adapter 20 connected to the negative electrode of the outer shell) is located in the second notch 1031 and is welded to the first sub-tab 1012; wherein, at least part of the structure of the bent sections 22 of the two electrode adapters 20 is located in the first notch 1011 or the second notch 1031, which can be that a part of the bent section 22 is located in the first notch 1011 or the second notch 1031, or the entire bent section 22 is received in the first notch 1011 or the second notch 1031. The body section 21 is located on the side of the corresponding bent section 22 away from the battery cell body 10 and is connected to the corresponding electrode to transmit electric energy.

[0052] For the battery cell 100 of the present invention, by means of the structure in which the second notch 1031 accommodates the welding of the electrode adapter 20 and the first sub-tab 1012, and the first notch 1011 accommodates the welding of the electrode adapter 20 and the second sub-tab 1032, the space occupied by the electrode adapter 20 is reduced, the gap between the battery cell body 10 and the outer membrane case 201 of the battery 200 is reduced, thereby increasing the proportion of the stacked cores providing the battery 200 capacity, and further improving the energy density of the battery 200.

[0053] Reference Figure 2 and Figure 4, the first electrode tab 101 and the second electrode tab 103 can both be provided in multiple numbers. The multiple first sub-electrode tabs 1012 of the multiple first electrode tabs 101 can be stacked and arranged in the first direction and connected to one of the electrode connectors 20 (the electrode connector 20 connected to the negative electrode). The multiple second sub-electrode tabs 1032 of the multiple second electrode tabs 103 can be stacked and arranged in the first direction and connected to the other electrode connector 20 (the electrode connector 20 connected to the positive electrode). By setting both the first sub-electrode tab 1012 and the second sub-electrode tab 1032 in a stacked arrangement structure, the reliability of the connection between the first sub-electrode tab 1012 and the second sub-electrode tab 1032 and the corresponding electrode connector 20 can be improved, which is beneficial to ensuring continuous current conduction between the battery cell body 10 and the electrode connector 20.

[0054] Reference Figure 2 、 Figure 4 and Figure 5 , further, one end of the separator 102 in the first direction can be provided with a third notch 1021 and a fourth notch 1022. Along the first direction, the third notch 1021 is opposite to the first notch 1011, and the fourth notch 1022 is opposite to the second notch 1031. The first sub-electrode tab 1012 is simultaneously exposed to the second notch 1031 and the third notch 1021, and the second sub-electrode tab 1032 is simultaneously exposed to the first notch 1011 and the fourth notch 1022. In this way, the third notch 1021 and the fourth notch 1022 can be used as structures on the separator 102 for avoiding the first sub-electrode tab 1012 and the second sub-electrode tab 1032, so that the bent sections 22 of the two electrode connectors 20 can be respectively received in the first notch 1011 and the second notch 1031.

[0055] As Figure 5 shown, taking the connection process between the electrode connector 20 and the first sub-electrode tab 1012 as an example, the connection process between the electrode connector 20 and the battery cell body 10 is described as follows: The electrode connector 20 is arranged parallel to the second direction at one end of the battery cell body 10. The multiple stacked first sub-electrode tabs 1012 are attached to one side of the electrode connector 20 and welded. The connection part between the first sub-electrode tab 1012 and the electrode connector 20 is bent towards the first direction. At this time, the electrode connector 20 forms a bent section 22 and a body section 21 until the bent section 22 enters the inside of the second notch 1031 from outside the second notch 1031. On the one hand, it is convenient for the bending operation, and on the other hand, the bending radius can be effectively limited to avoid the bent section 22 exceeding the side wall of the battery cell body 10 due to too large a bending radius. When the bent section 22 is substantially parallel to the first direction, the electrode connector 20 is moved in the second direction so that the bent section 22 is received in the accommodating structure formed by the stacking of the multiple second notches 1031 and the multiple third notches 1021, so as to reduce the head space of the battery cell body 10 occupied by the electrode connector 20, increase the proportion of the stacked cores providing the battery 200 capacity, and thus improve the energy density of the battery 200.

[0056] Reference Figure 2 、 Figure 3 and Figure 4 In some embodiments, the angle between the bent section 22 and the body section 21 may be θ, and the angle θ may satisfy: 60° ≤ θ ≤ 120°. For example, the angle θ may be 60°, 65°, 70°, 75°, 80°, 85°, 90°, 95°, 100°, 105°, 110°, 115° or 120°. On the one hand, it is to avoid the angle between the body section 21 and the bent section 22 being too small. For example, when it is less than 60°, the bent section 22 is inclined away from the side of the battery cell body 10 relative to the first direction, resulting in a large pulling force of the bent section 22 on the corresponding first sub-tab 1012 or the second sub-tab 1032, which is not conducive to reliable connection. On the other hand, it also avoids the angle between the body section 21 and the bent section 22 being too large. For example, when it is greater than 120°, the distance between the body section 21 and the battery cell body 10 in the second direction is further increased, which is not conducive to reducing the gap between the battery cell body 10 and the outer film shell 201 of the battery 200. Of course, the angle θ between the bent section 22 and the body section 21 can also be selected according to specific design requirements, and the present application does not limit this.

[0057] Preferably, when the angle θ is 90°, the bent section 22 extends along the first direction in the receiving groove 11, and the body section 21 extends along the second direction. At this time, when the battery cell 100 is encapsulated in the battery 200, the operation is the most convenient, and the battery cell body 10 is respectively connected to the corresponding electrode adapter 20 through the first sub-tab 1012 and the second sub-tab 1032, with high reliability.

[0058] Continuing to refer to Figure 2 and Figure 4 Furthermore, the angle between the bent section 22 and the reference plane is less than or equal to 90°. For example, the angle between the bent section 22 and the reference plane may be 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80° or 90°. The reference plane is jointly determined by the second direction and the third direction. In other words, the reference plane may be the X-Y plane, and the angle between the bent section 22 and the X-Y plane is less than or equal to 90°. This further limits the angle between the bent section 22 and the second direction, so that the extending direction of the body section 21 is substantially parallel to the second direction, thus facilitating the encapsulation of the battery cell 100.

[0059] Continuing to refer to Figure 2, Further, in the thickness direction (i.e., the first direction) of the battery cell body 10, the height h of the bent section 22 and the thickness H of the battery cell body 10 satisfy: h ≤ H, such that the height h of the bent section 22 does not exceed the thickness H of the battery cell body 10, avoiding the height of the bent section 22 exceeding the thickness of the battery cell body 10, which is conducive to the thin and light design of the battery 200. In addition, it is also beneficial to improve the utilization rate of the head space of the battery 200, thereby increasing the energy density of the battery 200. It is also convenient for packaging the battery cell 100.

[0060] Reference Figures 2 to 5 , In some embodiments, the outer contours of the first electrode tab 101 and the second electrode tab 103 are both inside the outer contour of the separator 102. In other words, the projection of any one of the first electrode tab 101 and the second electrode tab 103 in the reference plane is inside the projection of the separator 102 in the reference plane. In this way, it can be ensured that the separator 102 can completely separate the first electrode tab 101 and the second electrode tab 103, which is beneficial to improving the safety of the battery cell 100 and avoiding short circuits.

[0061] Reference Figures 5 to 7 , In some embodiments, the separator 102 may include an extension portion 1023 that extends in the second direction and extends beyond the first electrode tab 101. The partial contours of the extension portion 1023 located at the third notch 1021 and the fourth notch 1022 surround the third notch 1021 and the fourth notch 1022 respectively. In the second direction, the value range of the width d of the extension portion 1023 may be: 0 < d < 3 mm. For example, the width d of the extension portion 1023 may be 0.1 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm or 2.9 mm. Of course, the present application does not limit this, and the width d of the extension portion 1023 can be reasonably set according to actual needs. In this way, on the one hand, when the width of the extension portion 1023 is too large, it occupies too much space of the first notch 1011 and the second notch 1031, making it inconvenient to set the electrode adapter 20; on the other hand, when the width of the extension portion 1023 is too small, the isolation performance of the first electrode tab 101 and the second electrode tab 103 is poor.

[0062] To ensure the rationality and safety of the battery 200 design, during the design, both the length dimension and the width dimension of the negative electrode sheet are larger than the length dimension and the width dimension of the positive electrode sheet, that is, both the length dimension and the width dimension of the first electrode sheet 101 are larger than the length dimension and the width dimension of the second electrode sheet 103. The extension part 1023 extends beyond the first electrode sheet 101, which can ensure that the extension part 1023 extends beyond the second electrode sheet 103, thereby ensuring the physical separation of the separator 102 from the first electrode sheet 101 and the second electrode sheet 103. At the same time, both the first sub-tab 1012 and the second sub-tab 1032 extend beyond the extension part 1023, and the extension part 1023 has a certain supporting and fixing effect on the first sub-tab 1012 and the second sub-tab 1032, preventing any one of the first sub-tab 1012 and the second sub-tab 1032 from contacting the electrode sheet with the opposite polarity. Limiting the width d of the extension part 1023 can also prevent the active material layer of the first electrode sheet 101 and the second electrode sheet 103 from being cut during the processing of the first notch 1011 and the second notch 1031, resulting in energy density loss.

[0063] In some embodiments, when two electrode connectors 20 are respectively connected to the battery cell body 10 and are received in the first notch 1011 and the second notch 1031, a plurality of stacked first sub-tabs 1012 and second sub-tabs 1032 will bend along with the corresponding bending segments 22. In this way, both the first sub-tab 1012 and the second sub-tab 1032 will squeeze the extension part 1023 of the separator 102, causing the extension part 1023 to bend along with the first sub-tab 1012 and the second sub-tab 1032, that is, the extension part 1023 will bend and extend in a direction parallel to the bending segment 22. At this time, the extension part 1023 and the bending segment 22 of the electrode connector 20 are substantially stacked in the second direction, blocking the bending segment 22 from directly contacting the battery cell 100, avoiding a short circuit in the battery 200 and resulting in a safety accident, thereby improving the safety of the battery 200.

[0064] In some embodiments, in the second direction, the sum of the thickness of the welding portion of the first sub-tab 1012 and the electrode adapter 20 and the thickness of the epitaxial portion 1023 is less than the depth of the second notch 1031. At the same time, the sum of the thickness of the welding portion of the second sub-tab 1032 and the electrode adapter 20 and the thickness of the epitaxial portion 1023 is less than the depth of the first notch 1011. In this way, after the first sub-tab 1012 and the second sub-tab 1032 are respectively welded to the electrode adapter 20, the welding portion of the first sub-tab 1012 and the bent section 22 of the electrode adapter 20 can be received in the second notch 1031, and the welding portion of the second sub-tab 1032 and the bent section 22 of the electrode adapter 20 can be received in the first notch 1011. The storage effect is good, and it can reduce the occupation of the head space of the battery 200 by the overall structure formed by the first sub-tab 1012 and the second sub-tab 1032 and the corresponding electrode adapter 20, which is convenient for encapsulating the battery cell 100 during the process of assembling the battery 200.

[0065] In some embodiments, the first sub-tab 1012 and the second sub-tab 1032 arranged in a stacked manner have a certain thickness in the second direction. Therefore, when the first sub-tab 1012 and the second sub-tab 1032 are respectively welded to the corresponding electrode adapter 20, a weld mark 23 can be formed on the electrode adapter 20. The weld mark 23 can be a protrusion parallel to the bent section 22. The bent section 22 is received in the first notch 1011 and the second notch 1031. Along the second direction, the weld mark 23 does not exceed the edge of the separator 102 outside the third notch 1021. Of course, the weld mark 23 also does not exceed the edge of the separator 102 outside the fourth notch 1022. By restricting the position of the weld mark 23 within the third notch 1021 or the fourth notch 1022, it is avoided that the weld mark 23 exceeds the edge of the separator 102 during encapsulation. In this way, the weld mark 23 will not interfere with the outer film case 201 of the battery 200, resulting in a short circuit, thereby improving the safety of the battery 200.

[0066] Reference Figure 2 、 Figure 4 and Figure 5 Furthermore, in the second direction, the weld mark 23 does not exceed the edge of the second electrode plate 103 outside the second notch 1031. The second electrode plate 103 is used as the positive electrode plate, and among the first electrode plate 101, the separator 102, and the second electrode plate 103, the length dimension and the width dimension are both the smallest. Restricting the weld mark 23 not to exceed the edge of the second electrode plate 103 outside the second notch 1031 can enable the bent section 22 of the first sub-tab 1012 and the electrode adapter 20 to be completely received in the second notch 1031, which is convenient for encapsulation and improves the safety of the battery 200 at the same time. The structure is simple and the practicability is strong.

[0067] According to some embodiments of the present utility model, the battery cell 100 may further include a protective adhesive 30. The protective adhesive 30 may include adhesive tape. After the first sub-tab 1012 and the second sub-tab 1032 arranged in a stacked manner are respectively welded to the corresponding electrode adapter 20, the welding mark 23 is coated with the adhesive tape to ensure the stable connection between the first sub-tab 1012 and the second sub-tab 1032 and the corresponding electrode adapter 20. The adhesive tape completely coats the welding mark 23, preventing the first sub-tab 1012 and the second sub-tab 1032 from contacting the electrode plates with different polarities and causing a short circuit, thereby improving the safety of the battery 200. The adhesive tape and the welding mark 23 are received in the corresponding notch together, that is, the adhesive tape wrapping the first sub-tab 1012 and the welding mark 23 is received in the second notch 1031, and the adhesive tape including the second sub-tab 1032 and the welding mark 23 is received in the first notch 1011, which is convenient for encapsulation.

[0068] Furthermore, the protective adhesive 30 may further include tab glue. The tab glue may be disposed on the body section 21 of the electrode adapter 20. After the battery cell body 10 is encapsulated in the outer film case 201 of the battery 200, it is fixed by the tab glue.

[0069] Since the extension portion 1023 of the separator 102 bends along with the first sub-tab 1012 and the second sub-tab 1032, after bending, the projection of the extension portion 1023 in the first direction at least partially overlaps with the projection of the protective adhesive 30 in the first direction. For example, inside the outer film case 201 of the battery 200, the tab glue may protrude towards the battery cell body 10. In the first direction, the projection of the extension portion 1023 overlaps with the projection of the protruding portion of the tab glue. In this way, the gap between the battery cell body 10 and the outer film case 201 can be restricted to be small enough, thereby increasing the energy of the battery 200.

[0070] The second aspect of the present utility model further provides a battery 200. The battery 200 may be a lithium-ion battery, a sodium-ion battery, or other types of batteries.

[0071] The battery 200 may include the above-mentioned battery cell 100 and an outer film case 201, and the outer film case 201 wraps the battery cell 100. Due to the use of the above-mentioned battery cell 100, the stacked core ratio of the battery capacity provided by the battery 200 increases, the energy density of the battery 200 is improved, and the battery life of the battery 200 is extended.

[0072] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. 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 a suitable manner in any one or more embodiments or examples.

[0073] In the description of the present utility model, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.

[0074] In the description of the present utility model, the "first feature" and "second feature" may include one or more of such features.

[0075] In the description of the present utility model, the meaning of "a plurality of" is two or more.

[0076] In the description of the present utility model, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through additional features therebetween.

[0077] In the description of the present utility model, the first feature being "above", "over", and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the horizontal height of the first feature is higher than that of the second feature.

[0078] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present utility model, and the scope of the present utility model is defined by the claims and their equivalents.

Claims

1. A battery cell, characterized in that: include: The battery cell body comprises a first pole piece, a diaphragm and a second pole piece, wherein the first pole piece and the second pole piece have opposite polarities, and the first pole piece, the diaphragm and the second pole piece are sequentially stacked along a first direction; A first notch is provided at one end of the first pole piece along the second direction, a second notch is provided at one end of the second pole piece along the second direction, the first notch and the second notch are staggered with each other along the third direction, and the first direction, the second direction and the third direction are perpendicular to each other; The first pole piece includes a first sub-pole lug exposed in the second notch, and the second pole piece includes a second sub-pole lug exposed in the first notch; An electrode adapter, the electrode adapter includes a main body section and a bent section formed by bending, the bent section of the electrode adapter is at least partially located in the second notch and is welded to the first sub-pole ear, and the main body section is located on a side of the bent section away from the battery body.

2. The battery cell according to claim 1, characterized in that: There are multiple first pole pieces and multiple second pole pieces, and multiple first sub-pole tabs and multiple second sub-pole tabs are stacked and respectively connected to the electrode adapter.

3. The battery cell according to claim 1, characterized in that: A height h of the bent section in the first direction and a thickness H of the battery cell body in the first direction satisfy: h≤H.

4. The battery cell according to claim 1, characterized in that: The included angle θ between the main body section and the bending section satisfies: 60°≤θ≤120°.

5. The battery cell according to claim 1, characterized in that: The angle between the bending section and a reference plane is less than or equal to 90°, and the reference plane is determined by the second direction and the third direction.

6. The battery cell according to claim 1, characterized in that: The diaphragm is further provided with a third notch and a fourth notch at one end along the second direction, the third notch is opposite to the first notch along the first direction, and the fourth notch is opposite to the second notch along the first direction. The first sub-electrode tab is further exposed to the fourth notch, and the second sub-electrode tab is further exposed to the third notch.

7. The battery cell according to claim 6, characterized in that: The diaphragm includes an extension portion extending beyond the first pole piece along the second direction, and a partial structure of the extension portion surrounds the third notch and the fourth notch, The value range of the width d of the extension portion along the second direction is: 0<d<3mm.

8. The battery cell according to claim 7, characterized in that: The extension portion is bent and extended along a direction parallel to the bending section.

9. The battery cell according to claim 7, characterized in that: The sum of the thickness of the welding portion between the first sub-pole tab and the electrode adapter and the thickness of the extension portion is less than the depth of the second notch along the second direction; and / or the sum of the thickness of the welding portion between the second sub-pole tab and the electrode adapter and the thickness of the extension portion is less than the depth of the first notch along the second direction.

10. The battery cell according to claim 7, characterized in that: The first sub-electrode tab and the second sub-electrode tab are respectively welded to the corresponding electrode adapter to form a weld mark, and the weld mark does not exceed the edge of the diaphragm along the second direction outside the third notch.

11. The battery cell according to claim 10, characterized in that: The weld mark does not exceed the edge of the second pole piece outside the second notch along the second direction.

12. The battery cell according to claim 10, characterized in that: Also includes: Protective glue, the protective glue covers the weld mark, and the protective glue is in the first notch.

13. The battery cell according to claim 12, characterized in that: A projection of the extension portion in the first direction at least partially overlaps with a projection of the protective glue in the first direction.

14. A battery, characterized in that: include: The battery cell according to any one of claims 1 to 13; An outer film shell covers the battery core.

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