Battery

Abstract

The utility model provides a battery which comprises a battery cell body, a first foil tab group, a first switching tab, a welding mark and a bending area, the first foil tab group is connected to the battery cell body, the first switching tab and the first foil tab group are at least partially laminated, the laminated parts of the first foil tab group and the first switching tab are connected through the welding mark, and the first foil tab group is connected with the first switching tab through the bending area. The welding mark is located in the bending area, the first foil tab group located in the bending area is folded, and the first foil tab group located in the bending area and the first transfer tab corresponding to the first foil tab group extend in the first direction. The battery provided by the utility model is relatively high in energy density and safety.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery. Background Art

[0002] The battery mainly includes a battery case, a battery cell and a tab assembly. The battery cell and the electrolyte are encapsulated in the battery case, and the current of the battery cell is conducted out through the tab assembly. The battery cell may include a pole piece and a diaphragm. The tab assembly may include a soft pole tab and a hard pole tab. The soft pole tab is connected to the pole piece, and the hard pole tab is welded to the soft pole tab, and part of the hard pole tab extends outside the battery case to be connected to the device to be powered.

[0003] In the related art, when the thickness of the battery cell is small, the battery cell can basically only adopt a direct welding structure, that is, the soft and hard tabs of the battery cell are directly welded and packaged without bending. However, this method will make it impossible to hide the burrs formed by welding. In order to prevent the burrs from piercing the insulating tape and contacting the battery shell to cause a short circuit, thicker insulating tape needs to be set, which will increase the proportion of insulating tape in the battery thickness, thereby reducing the energy density of the battery. Utility Model Content

[0004] Based on this, the present application provides a battery to solve the deficiencies in the related art.

[0005] The battery provided in the present application includes: a battery cell body, a first foil pole lug group, a first adapter pole lug, a weld mark and a bending area, the first foil pole lug group is connected to the battery cell body, the first adapter pole lug and the first foil pole lug group are at least partially stacked, the stacked parts of the first foil pole lug group and the first adapter pole lug are connected by a weld mark, the weld mark is located in the bending area, the first foil pole lug group located in the bending area is folded in half, and the first foil pole lug group located in the bending area and the first adapter pole lug corresponding thereto both extend along a first direction, and the first direction is the length direction of the battery cell body.

[0006] In a possible implementation, in the first direction, the length L1 of the weld mark and the length L2 of the bending area satisfy: L2 ≥ 1.5*L1.

[0007] In a possible implementation manner, in the first direction, a distance L3 between the bending area and the battery cell body satisfies: L3 ≥ 0.2 mm.

[0008] In a possible embodiment, the first foil tab group includes a first connecting segment and a second connecting segment connected in sequence, the first connecting segment is connected to the battery cell body, the second connecting segment is folded relative to the first connecting segment, the second connecting segment is welded to the first adapter tab, and the first adapter tab is located on the side of the second connecting segment away from the first connecting segment.

[0009] In a possible implementation, the first foil tab group includes a first extension section and a second extension section connected in sequence, and the first transfer tab includes a third extension section and a fourth extension section connected in sequence;

[0010] There is a first bending line between the first extension section and the second extension section, and the second extension section is folded relative to the first extension section along the first bending line. There is a second bending line between the third extension section and the fourth extension section, and the fourth extension section is folded relative to the third extension section along the second bending line;

[0011] The first extension section is connected to the battery cell body, the second extension section is welded to the third extension section, the first extension section, the third extension section, the second extension section, and the fourth extension section are stacked in sequence, and the welding mark is located between the first extension section and the fourth extension section.

[0012] In a possible implementation, the distance L4 between one end of the second extension section close to the second bending line and the second bending line satisfies: L4 ≥ 0.2 mm;

[0013] And / or, the distance L5 between one end of the third extension section close to the first bending line and the first bending line satisfies: L5 ≥ 0.2 mm.

[0014] In a possible implementation, it further includes: a first insulating layer, the first insulating layer is disposed on at least one side of the bending area along the second direction, and the projection of the first insulating layer in the thickness direction of the battery cell body covers the bending area.

[0015] In a possible implementation, it further includes: a second insulating layer, at least two layers of the second insulating layer are located between the first extension section and the third extension section, and / or, at least two layers of the second insulating layer are located between the second extension section and the fourth extension section.

[0016] In a possible implementation, the thickness Hm of the first insulating layer and the thickness Hc of the first transfer tab satisfy: 0.1 * Hc ≤ Hm ≤ 0.7 * Hc.

[0017] In a possible implementation, the first insulating layer is disposed on opposite sides of the bending area along the second direction; the first insulating layer includes a first insulating adhesive tape and a second insulating adhesive tape, the first insulating adhesive tape is disposed on the side of the first foil tab group away from the welding mark, the second insulating adhesive tape is disposed on the side of the first transfer tab away from the welding mark, and the thickness HM1 of the first insulating adhesive tape and the thickness HM2 of the second insulating adhesive tape satisfy: 5 μm ≤ HM2 ≤ HM1 ≤ 30 μm.

[0018] In a possible implementation, it further includes: a third insulating layer, the third insulating layer is connected to the welding mark, and the projection of the third insulating layer in the thickness direction of the battery cell body covers the welding mark.

[0019] In a possible implementation, in the first direction, the length L6 of the third insulating layer satisfies: L1 < L6 < L2.

[0020] In a possible implementation, the length L1 of the welding mark along the first direction and the thickness H of the battery cell body satisfy: L1 ≤ 0.6 * H.

[0021] The battery provided by the embodiment of the present application includes a battery cell body, a first foil tab group, a first transfer tab, a welding mark, and a bending area. By setting the bending area to hide the welding mark, it is possible to avoid short - circuiting of the battery caused by the burr protrusions of the welding mark directly contacting the housing, thereby improving the safety of the battery. By folding the first foil tab group located in the bending area, and making both the first foil tab group and the first transfer tab located in the bending area extend along the first direction, the burr protrusions of the welding mark can be better hidden, and the ineffective thickness of the battery caused by the bending of the first foil tab group and the first transfer tab can also be avoided. Thus, the battery provided by the embodiment of the present application has a relatively high energy density and safety.

[0022] In addition to the technical problems solved by the embodiments of the present application, the technical features constituting the technical solutions, and the beneficial effects brought by these technical features described above, other technical problems that the battery provided by the present application can solve, other technical features included in the technical solutions, and the beneficial effects brought by these technical features will be further described in detail in the specific implementation manners. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 Structural schematic of the battery provided by the embodiment of the present application Figure 1 ;

[0025] Figure 2 Structural schematic of the battery provided by the embodiment of the present application Figure 2 ;

[0026] Figure 3 Structural schematic of the battery provided by the embodiment of the present application Figure 3 ;

[0027] Figure 4 Structural schematic of the battery provided by the embodiment of the present application Figure 4 ;

[0028] Figure 5 isFigure 2 Schematic diagram of the structure of the first foil tab group and the first transfer tab before bending;

[0029] Figure 6 is Figure 3 Schematic diagram of the structure of the bending area in;

[0030] Figure 7 is Figure 3 and Figure 4 Schematic diagram of the structure of the first foil tab group and the first transfer tab before bending in;

[0031] Figure 8 Schematic diagram of the structure of the battery provided by the embodiment of the present application Figure 4 .

[0032] Explanation of reference numerals:

[0033] 100 - battery cell body; 200 - first foil tab group; 210 - first connection section; 220 - second connection section; 230 - first extension section; 240 - second extension section; 250 - first bending line; 300 - first transfer tab; 310 - third extension section; 320 - fourth extension section; 330 - second bending line; 400 - welding mark; 500 - bending area; 600 - first insulating layer; 610 - first insulating adhesive tape; 620 - second insulating adhesive tape; 700 - second insulating layer; 800 - third insulating layer. Detailed implementation manners

[0034] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the accompanying drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals denote the same or similar components or components with the same or similar functions throughout. The described embodiments are some but not all of the embodiments of the present application. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and should not be construed as limiting the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application. The embodiments of the present application will be described in detail below with reference to the drawings.

[0035] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, or an indirect connection through an intermediate medium, or the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0036] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships in the drawings. These are only for the convenience of describing the present application 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. Therefore, it should not be construed as a limitation to the present application.

[0037] In the description and claims of the present application and the above-mentioned drawings, the terms "first", "second", "third" (if any) are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0038] In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or display comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or displays.

[0039] In the related art, when the thickness of the battery cell is small, for example, when the thickness of the battery cell is less than 1 mm, the battery cell can basically only adopt a straight welding structure, that is, the soft tab and the hard tab of the battery cell are directly welded and encapsulated without being bent. However, this method will cause the burr protrusions formed by welding to be unable to be hidden. In order to prevent the burr protrusions from piercing the insulating adhesive tape and contacting the battery case to cause a short circuit, a relatively thick insulating adhesive tape needs to be provided, which will increase the proportion of the insulating adhesive tape in the battery thickness, thereby reducing the energy density of the battery.

[0040] In view of the above problems, the embodiments of the present application provide a battery, wherein the solder mark for connecting the first foil tab group and the first transfer tab is located in the bending area, and the extending directions of the first foil tab group and the first transfer tab located in the bending area are both along the first direction. That is, the first foil tab group located in the bending area can be bent in a folded manner. In this way, even if the thickness of the battery cell body is small, the burr protrusions of the solder mark can be hidden in the bending area, thereby avoiding the burr protrusions from contacting the case to cause a battery short circuit, and the thickness of the insulating layer can also be reduced to reduce the overall thickness of the battery, thus improving the energy density and safety of the battery.

[0041] Refer to Figures 1 to 4As shown in the figure, the battery provided by the embodiment of the present application includes a battery cell body 100, a first foil tab group 200, a first adapter tab 300, a welding mark 400, and a bending area 500. The first foil tab group 200 is connected to the battery cell body 100. The first adapter tab 300 and the first foil tab group 200 are at least partially laminated. The laminated part of the first foil tab group 200 and the first adapter tab 300 is connected by the welding mark 400. The welding mark 400 is located in the bending area 500. The first foil tab group 200 located in the bending area 500 is arranged in a folded manner, and the first foil tab group 200 located in the bending area 500 and the corresponding first adapter tab 300 both extend along the first direction.

[0042] It can be understood that the battery cell body 100 and the electrolyte are encapsulated in a housing. The battery cell body 100 can be formed by winding or laminating electrode sheets and diaphragms. Active materials are coated on the electrode sheets, and then current can be generated by reacting with the electrolyte. The first foil tab group 200 is used to conduct the current of the electrode sheet, and the first adapter tab 300 is used to connect the first foil tab and an external device, and then conduct the current to the external device.

[0043] In order to connect the first foil tab group 200 and the first adapter tab 300, one of the first foil tab group 200 and the first adapter tab 300 needs to be laid on the other, so that the first foil tab group 200 and the first adapter tab 300 are at least partially laminated. Then, the first foil tab group 200 and the first adapter tab 300 are connected by welding, and then a welding mark 400 is formed at the laminated part of the two.

[0044] Since the welding mark 400 has burr protrusions, it is necessary to hide the burr protrusions by bending the welding parts of the first foil tab group 200 and the first adapter tab 300. At the same time, insulating adhesive paper is pasted on the welding mark 400 to isolate the burrs and the housing. However, for the battery cell body 100 with a small thickness, if the bending method in the related technology is adopted, that is, after the first foil tab group 200 and the first adapter tab 300 are bent, they both extend along the second direction. Since the width of the welding mark 400 is large, after the first foil tab group 200 and the first adapter tab 300 are bent, the bent parts of the first foil tab group 200 and the first adapter tab 300 will exceed the thickness of the battery cell body 100, which will increase the ineffective thickness of the battery and thus reduce the energy density of the battery.

[0045] If the first foil tab group 200 and the first adapter tab 300 are not bent after welding and are directly encapsulated with the housing, it is necessary to set a thicker insulating adhesive paper at the welding mark 400 to prevent the insulating adhesive paper from being pierced by the burr protrusions, but this will increase the thickness of the battery.

[0046] Among them, the second direction is along the thickness direction of the battery cell body 100, and the first direction has an included angle with the second direction. For example, the first direction can be perpendicular to the second direction. The first direction is along the length direction of the battery cell body 100, and the first direction can be referred to Figure 2 and Figure 3 the X direction in Figure 2 and Figure 3 the Y direction in.

[0047] Therefore, in the battery according to the embodiment of the present application, the first foil tab group 200 can be folded in half, so that the first foil tab group 200 located in the bending area 500 extends along the first direction. The first transfer tab 300 can be folded in half or not, as long as the first transfer tab 300 located in the bending area 500 also extends along the first direction. In this way, the welding mark 400 can be hidden in the bending area 500. The first foil tab group 200 and the first transfer tab 300 located in the bending area 500 both extend along the first direction. A relatively thin insulating tape can be provided on the side along the first direction of the bending area 500, thereby avoiding increasing the ineffective thickness of the battery. This bending method can improve the safety and energy density of the battery at the same time.

[0048] It should be noted that, in order to improve the welding effect, during welding, welding can be performed from one side of the first transfer tab 300. In the subsequent formed welding mark 400, the burr protrusions are mainly concentrated on the side of the first foil tab group 200 away from the first transfer tab 300. After the bending area 500 is formed by using the bending method provided by the embodiment of the present application, there is at least one layer of the first foil tab group 200 or the first transfer tab 300 between the burr protrusions of the welding mark 400 and the housing, so that the first foil tab group 200 or the first transfer tab 300 can isolate the burr protrusions of the welding mark 400.

[0049] The battery provided by the embodiment of the present application includes a battery cell body 100, a first foil tab group 200, a first transfer tab 300, a welding mark 400, and a bending area 500. By arranging the battery cell body 100 to react with the electrolyte, by arranging the first foil tab group 200 for guiding the current of the battery cell body 100, by arranging the first transfer tab 300 for conducting the first foil tab group 200 and an external device to enable the battery to realize the charge and discharge functions, by arranging the welding mark 400 for connecting the first foil tab group 200 and the first transfer tab 300, and by arranging the bending area 500 for hiding the welding mark 400 to avoid the burr protrusions of the welding mark 400 directly contacting the housing and causing a short circuit of the battery, thereby improving the safety of the battery. By making the first foil tab group 200 and the first transfer tab 300 located in the bending area 500 both extend along the first direction, the burr protrusions of the welding mark 400 can be better hidden, and it is also avoided that the first foil tab group 200 and the first transfer tab 300 bend beyond the thickness of the battery cell body 100 and increase the ineffective thickness of the battery. Thus, the battery provided by the embodiment of the present application has a relatively high energy density and safety.

[0050] Referring to Figure 2 and Figure 3 as shown, it can be understood that if the length L2 of the bending area 500 along the first direction is less than the length L1 of the welding mark 400 along the first direction, the bending line when the first foil tab group 200 or the first transfer tab 300 is bent is located on the welding mark 400, which will cause the welding mark 400 to break, thereby reducing the welding strength between the first foil tab group 200 and the first transfer tab 300, or will cause the first foil tab group 200 to break, and further cause the internal resistance of the battery cell body 100 to increase. Therefore, in a possible implementation manner, in the first direction, the length L1 of the welding mark 400 and the length L2 of the bending area 500 satisfy: L2≥1.5*L1.

[0051] In this way, it can be ensured that the bending line when the first foil tab group 200 or the first transfer tab 300 is bent is located on both sides of the welding mark 400, rather than on the welding mark 400, thereby ensuring the welding strength between the first foil tab group 200 and the first transfer tab 300, and ensuring the strength of the first foil tab group 200. Among them, L1 and L2 can refer to Figure 2 and Figure 3 the marks shown.

[0052] Referring to Figure 2 and Figure 3 as shown, in some implementation manners, in the first direction, the distance L3 between the bending area 500 and the battery cell body 100 satisfies: L3≥0.2mm.

[0053] It should be noted that the bending zone 500 needs to maintain a certain distance from the battery cell body 100 to prevent the first foil transfer tab or the first transfer tab 300 located in the bending zone 500 from causing damage to the battery cell body 100. If the distance L3 between the bending zone 500 and the battery cell body 100 is less than 0.2 mm, the first foil transfer tab or the first transfer tab 300 will hit the battery cell body 100. Therefore, the distance L3 between the bending zone 500 and the battery cell body 100 needs to be greater than or equal to 0.2 mm.

[0054] Among them, L3 can refer to Figure 2 and Figure 3 Marking shown.

[0055] Reference Figure 2 and Figure 5 As shown, in some embodiments, the first foil tab group 200 includes a first connecting segment 210 and a second connecting segment 220 connected in sequence, the first connecting segment 210 is connected to the battery cell body 100, the second connecting segment 220 is folded relative to the first connecting segment 210, the second connecting segment 220 is welded to the first adapter tab 300, and the first adapter tab 300 is located on the side of the second connecting segment 220 away from the first connecting segment 210.

[0056] In this arrangement, the first foil tab group 200 can be bent in a folding manner, that is, the first connecting segment 210 and the second connecting segment 220 are folded in half, while the first transfer tab 300 is not folded in half, and the first transfer tab 300, the second connecting segment 220 and the first connecting segment 210 are stacked in sequence along the second direction. If the end of the second connecting segment 220 close to the battery cell body 100 exceeds the end of the first transfer tab 300 close to the battery cell body 100, the boundaries of the bending area 500 along the first direction are respectively the end of the second connecting segment 220 close to the battery cell body 100, the folding line of the first connecting segment 210 and the second connecting segment 220, The boundary of the bending zone 500 along the second direction is the first connecting segment 210 and the first adapter ear 300, that is, at this time, the bending zone 500 is the end of the second connecting segment 220 close to the battery cell body 100, the first adapter ear 300, the fold line of the first connecting segment 210 and the second connecting segment 220, and the area surrounded by the first connecting segment 210. The weld mark 400 is located in the bending zone 500, and the burr protrusion of the weld mark 400 is located between the first connecting segment 210 and the second connecting segment 220. There is at least one layer of the first connecting segment 210 between the burr protrusion of the weld mark 400 and the shell, which can effectively hide the burr protrusion of the weld mark 400.

[0057] Or, refer to Figure 3 , Figure 4 , Figure 6 and Figure 7As shown, in some other embodiments, the first foil tab group 200 includes a first extension section 230 and a second extension section 240 connected in sequence. The first transfer tab 300 includes a third extension section 310 and a fourth extension section 320 connected in sequence. There is a first bending line 250 between the first extension section 230 and the second extension section 240. The second extension section 240 is folded relative to the first extension section 230 along the first bending line 250. There is a second bending line 330 between the third extension section 310 and the fourth extension section 320. The fourth extension section 320 is folded relative to the third extension section 310 along the second bending line 330.

[0058] The first extension section 230 is connected to the battery cell body 100. The second extension section 240 is welded to the third extension section 310. The first extension section 230, the third extension section 310, the second extension section 240, and the fourth extension section 320 are stacked in sequence. The welding mark 400 is located between the first extension section 230 and the fourth extension section 320.

[0059] In this setting method, both the first foil tab group 200 and the first transfer tab 300 can be bent in a folded manner. That is, the first extension section 230 and the second extension section 240 are folded along the first bending line 250, and the third extension section 310 and the fourth extension section 320 are folded along the second bending line 330. After the second extension section 240 is welded to the third extension section 310 and then bent in the above manner, the first extension section 230, the third extension section 310, the second extension section 240, and the fourth extension section 320 are stacked in sequence along the second direction. The welding mark 400 is located between the first extension section 230 and the fourth extension section 320, and the burr protrusion of the welding mark 400 is located between the second extension section 240 and the fourth extension section 320. The burr protrusion of the welding mark 400 is at least separated from the housing by one layer of the fourth extension section 320, so that the burr protrusion of the welding mark 400 can be effectively hidden.

[0060] Refer to Figure 3 And Figure 6As shown, it should be noted that since the second extension section 240 is located between the third extension section 310 and the fourth extension section 320, if the distance L4 between the end of the second extension section 240 close to the first bending line 250 and the first bending line 250 is less than 0.2 mm, then after folding, the third extension section 310 and the fourth extension section 320 will rebound due to the second extension section 240, resulting in the inability of the third extension section 310 and the fourth extension section 320 to be folded smoothly. Similarly, since the third extension section 310 is located between the first extension section 230 and the second extension section 240, if the distance L5 between the end of the third extension section 310 close to the second bending line 330 and the second bending line 330 is less than 0.2 mm, then after folding, the first extension section 230 and the second extension section 240 will rebound due to the third extension section 310, resulting in the inability of the first extension section 230 and the second extension section 240 to be folded smoothly.

[0061] Therefore, in a possible implementation, the distance L4 between the end of the second extension section 240 close to the first bending line 250 and the first bending line 250 satisfies: L4 ≥ 0.2 mm. And / or, the distance L5 between the end of the third extension section 310 close to the second bending line 330 and the second bending line 330 satisfies: L5 ≥ 0.2 mm.

[0062] With such a setting, it can ensure the smooth folding between the first extension section 230 and the second extension section 240, and ensure the smooth folding between the third extension section 310 and the fourth extension section 320.

[0063] Among them, L4 and L5 can refer to Figure 3 the shown markings.

[0064] Referring to Figure 3 As shown, in a possible implementation, the battery further includes: a first insulating layer 600, the first insulating layer 600 is disposed on at least one side of the bending area 500 along the first direction, and the projection of the first insulating layer 600 in the thickness direction of the battery cell body 100 covers the bending area 500.

[0065] In this way, when the first foil tab group 200 and the first transfer tab 300 are bent to form Figure 2 or Figure 3 the bending area 500 shown, the first insulating layer 600 can be disposed on one side or both sides of the bending area 500 along the first direction, so that the first insulating layer 600 isolates between the bending area 500 and the housing, thereby avoiding the contact between the first foil tab group 200 or the first transfer tab 300 in the bending area 500 and the housing, resulting in battery short - circuit.

[0066] In some embodiments, the first insulating layer 600 is disposed on opposite sides of the bending region 500 along the first direction. In this way, the first insulating layer 600 can prevent the bending region 500 from contacting the housing, thereby improving the safety performance of the battery.

[0067] Referring Figure 4 As shown, in a possible implementation, the battery further includes: a second insulating layer 700, at least two layers of the second insulating layer 700 are located between the first extension segment 230 and the third extension segment 310, and / or, at least two layers of the second insulating layer 700 are located between the second extension segment 240 and the fourth extension segment 320.

[0068] In the above arrangement, after the laminated portions of the first foil tab group 200 and the first adapter tab 300 are welded, the second insulating layer 700 can be first pasted on the side of the first foil tab group 200 facing away from the first adapter tab 300, and on the side of the first adapter tab 300 facing away from the first foil tab group 200. Then, the first extension segment 230 and the second extension segment 240 are folded, and the third extension segment 310 and the fourth extension segment 320 are folded. Finally, the second insulating layer 700 between the first extension segment 230 and the third extension segment 310 can be in a folded state, and the second insulating layer 700 between the second extension segment 240 and the fourth extension segment 320 can be in a folded state. In this way, it is convenient to choose to bend first and then apply glue, or choose to apply glue first and then bend according to different production process flows. Moreover, there are at least two layers of the second insulating layer 700 between the first extension segment 230 and the third extension segment 310, and / or, there are at least two layers of the second insulating layer 700 between the second extension segment 240 and the fourth extension segment 320, which can also effectively prevent the bending region 500 from contacting the housing, thereby improving the safety performance of the battery.

[0069] In a possible implementation, the thickness Hm of the first insulating layer 600 and the thickness Hc of the first adapter tab 300 satisfy: 0.1*Hc ≤ Hm ≤ 0.7*Hc.

[0070] If the thickness Hm of the first insulating layer 600 is less than 0.1*Hc, the protective effect of the first insulating layer 600 on the welding mark 400 of the bending region 500 is poor, and the first insulating layer 600 is easily broken, resulting in the contact between the first foil tab group 200 or the first adapter tab 300 and the housing. If the thickness Hm of the first insulating layer 600 is greater than 0.7*Hc, the thickness of the first insulating layer 600 is too large, which will increase the thickness of the battery. Therefore, setting the thickness Hm of the first insulating layer 600 between 0.1*Hc and 0.7*Hc is a more appropriate range, which can improve the safety and energy density of the battery at the same time.

[0071] Referring Figure 3As shown, in a possible implementation, the first insulating layer 600 includes a first insulating adhesive tape 610 and a second insulating adhesive tape 620. The first insulating adhesive tape 610 is disposed on a side of the first foil tab group 200 away from the welding mark 400, and the second insulating adhesive tape 620 is disposed on a side of the first transfer tab 300 away from the welding mark 400. The thickness HM1 of the first insulating adhesive tape 610 and the thickness HM2 of the second insulating adhesive tape 620 satisfy: 5μm ≤ HM2 ≤ HM1 ≤ 30μm.

[0072] It can be understood that during welding, welding can be performed from one side of the first transfer tab 300. In the subsequent formed welding mark 400, the burr protrusions are mainly concentrated on the side of the first foil tab group 200 away from the first transfer tab 300. Therefore, the first insulating adhesive tape 610 connected to the first foil tab group 200 is thicker to prevent the burr protrusions from piercing the first insulating adhesive tape 610, and the second insulating adhesive tape 620 connected to the first transfer tab 300 is thinner. This can not only take into account the safety performance of the battery but also reduce the thickness of the battery.

[0073] Moreover, by setting the thicknesses of both the first insulating adhesive tape 610 and the second insulating adhesive tape 620 between 5μm and 30μm, the first insulating adhesive tape 610 and the second insulating adhesive tape 620 can effectively protect the bending area 500 and avoid increasing the ineffective volume of the battery due to excessive thicknesses of the first insulating adhesive tape 610 and the second insulating adhesive tape 620.

[0074] Referring to Figure 8 As shown, in a possible implementation, the battery further includes: a third insulating layer 800. The third insulating layer 800 is connected to the welding mark 400, and at least a part of the projection of the third insulating layer 800 in the thickness direction of the battery cell body 100 covers the welding mark 400. In this way, the third insulating layer 800 can effectively protect the burr protrusions of the welding mark 400, thereby preventing burr debris from falling into the battery cell body 100 and causing battery safety problems.

[0075] Continuing to refer to Figure 8 As shown, in a possible implementation, in the first direction, the length L6 of the third insulating layer 800 satisfies: L1 < L6 < L2. That is to say, the length L6 of the third insulating layer 800 needs to be greater than the length L1 of the welding mark 400 to effectively protect the welding mark 400, and the length L6 of the third insulating layer 800 needs to be less than the length L2 of the bending area 500 to prevent the third insulating layer 800 from affecting the folding of the first foil tab group 200 or the first transfer tab 300. Among them, L6 can refer to the Figure 8 marked shown.

[0076] In a possible implementation, the length L1 of the welding mark 400 in the first direction and the thickness H of the battery cell body 100 satisfy: L1 ≤ 0.6 * H.

[0077] With such a setting, on the premise of ensuring reliable welding between the first foil tab group 200 and the first adapter tab 300, the length L1 of the welding mark 400 in the first direction can be minimized as much as possible, thereby reducing the length L2 of the bending area 500 in the first direction, and thus improving the space utilization rate of the battery.

[0078] In a specific implementation, the first foil tab group 200 includes at least two first foil tabs, and the at least two first foil tabs are stacked and connected to form the first foil tab group 200.

[0079] In addition, the battery may further include a second foil tab group and a second adapter tab. The polarities of the second foil tab group and the second adapter tab are the same. The polarities of the first foil tab group 200 and the first adapter tab 300 are the same, and the polarities of the second adapter tab and the first adapter tab 300 are opposite. The second foil tab group is connected to the battery cell body 100. The second foil tab group is formed by stacking and connecting at least two second foil tabs. The second foil tab group is welded to the second adapter tab, and the welding part of the second foil tab group and the second adapter tab can also be bent with reference to the bending method of the bending area 500 to hide the burr protrusions formed by welding the second foil tab group and the second adapter tab, thereby improving the energy density and safety of the battery.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery, characterized in that, include: Battery cell body; A first foil tab group, wherein the first foil tab group is connected to the battery cell body; A first transfer tab, wherein the first transfer tab and the first foil tab group are at least partially stacked; Welding marks, through which the stacked parts of the first foil tab group and the first transfer tab are connected; The welding mark is located in the bending area, the first foil tab group located in the bending area is folded in half, and the first foil tab group located in the bending area and the first transfer tab corresponding thereto both extend along a first direction; the first direction is the length direction of the battery cell body.

2. The battery according to claim 1, characterized in that, In the first direction, the length L1 of the weld mark and the length L2 of the bending area satisfy: L2≥1.5*L1.

3. The battery according to claim 1, characterized in that, In the first direction, a distance L3 between the bending area and the battery cell body satisfies: L3 ≥ 0.2 mm.

4. The battery according to claim 1, characterized in that, The first foil tab group includes a first connecting segment and a second connecting segment connected in sequence, the first connecting segment is connected to the battery cell body, the second connecting segment is folded relative to the first connecting segment, the second connecting segment is welded to the first adapter tab, and the first adapter tab is located on a side of the second connecting segment away from the first connecting segment.

5. The battery according to claim 1, characterized in that, The first foil tab group includes a first extension segment and a second extension segment connected in sequence, and the first transfer tab includes a third extension segment and a fourth extension segment connected in sequence; A first bending line is provided between the first extension segment and the second extension segment, and the second extension segment is folded relative to the first extension segment along the first bending line; a second bending line is provided between the third extension segment and the fourth extension segment, and the fourth extension segment is folded relative to the third extension segment along the second bending line; The first extension segment is connected to the battery cell body, at least part of the second extension segment is welded to at least part of the third extension segment, the first extension segment, the third extension segment, the second extension segment and the fourth extension segment are stacked in sequence, and the weld mark is located between the first extension segment and the fourth extension segment.

6. The battery according to claim 5, characterized in that, A distance L4 between an end of the second extension section close to the second bending line and the second bending line satisfies: L4 ≥ 0.2 mm; And / or, a distance L5 between one end of the third extension segment close to the first bending line and the first bending line satisfies: L5 ≥ 0.2 mm.

7. The battery according to claim 4 or 5, characterized in that, Also includes: A first insulating layer, wherein the first insulating layer is disposed on at least one side of the bending region along a second direction, and a projection of the first insulating layer in the second direction covers the bending region.

8. The battery according to claim 5, characterized in that, Also includes: A second insulating layer, at least two layers of the second insulating layer are located between the first extension segment and the third extension segment, and / or at least two layers of the second insulating layer are located between the second extension segment and the fourth extension segment.

9. The battery according to claim 7, wherein The thickness Hm of the first insulating layer and the thickness Hc of the first switching tab satisfy: 0.1*Hc≤Hm≤0.7*Hc.

10. The battery according to claim 7, characterized in that, The first insulating layer is disposed on two opposite sides of the bending region along the second direction; The first insulating layer includes a first insulating tape and a second insulating tape. The first insulating tape is arranged on the side of the first foil tab group away from the weld mark, and the second insulating tape is arranged on the side of the first transfer tab away from the weld mark. The thickness HM1 of the first insulating tape and the thickness HM2 of the second insulating tape satisfy: 5μm≤HM2≤HM1≤30μm.

11. The battery according to any one of claims 2-6, characterized in that, Also includes: A third insulating layer, wherein the third insulating layer is connected to the weld mark, and at least a portion of the projection of the third insulating layer in the thickness direction of the battery cell body covers the weld mark.

12. The battery according to claim 11, characterized in that, In the first direction, a length L6 of the third insulating layer satisfies: L1<L6<L2.

13. The battery according to any one of claims 2-6, characterized in that, The length L1 of the weld mark along the first direction and the thickness H of the battery cell body satisfy: L1≤0.6*H.

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