A single cell and a battery pack

Abstract

The application discloses a single battery and a battery pack. The single battery comprises a shell, a top cover assembly, an electric core, a first insulating paper and a second insulating paper. A first extension part of the first electric core and a second extension part of the second electric core extend in a direction of approaching each other along a first direction. The first insulating paper on the first extension part and the first insulating paper on the second extension part are connected with each other. The second insulating paper is arranged on the side of the first bending part away from the first main part and the side of the second bending part away from the second main part. The two first insulating papers are connected with each other, so that the first electric core and the second electric core can be pulled tight, and the possibility of the electric core being deflected due to stress release when the bending part cracks is reduced. Meanwhile, the second insulating paper can not only form insulation protection for the bending part of the tab, but also form a certain convergence effect on the cracked part of the bending part, so that the possibility of the cracked part of the bending part being short-circuited with the shell is reduced, and the safety and reliability of the single battery are improved.

Description

Technical Field

[0001] This application belongs to the field of battery technology, specifically relating to a single cell battery and a battery pack. Background Technology

[0002] A single battery cell typically includes a casing and a cell housed within the casing. To improve the space utilization within the single battery cell and increase its energy density, the tabs of the cell are usually welded to the top cover assembly, and then the tabs are bent before the cell is installed into the casing.

[0003] In related technologies, bending the tab will cause stress concentration, making the bent section of the tab prone to cracking. When the bent section of the tab cracks, the stress will be released, which will cause the cell to tilt, making it easy for the cracked tab to short-circuit with the shell. Utility Model Content

[0004] This application aims to provide a single cell and a battery pack that can solve the problem in related technologies where stress concentration occurs when the tab is bent, making the bent section of the tab prone to cracking. When the bent section of the tab cracks, stress is released, which in turn causes the cell to tilt, making it easy for the cracked tab to short-circuit with the casing.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application propose a single-cell battery having a first orientation, the single-cell battery comprising: a casing; Top cover assembly, the top cover assembly being connected to the housing; The battery cell is disposed within the housing. The battery cell includes a first battery cell and a second battery cell arranged along the first direction. The first battery cell includes a first body portion and a first electrode tab. The first electrode tab includes a first bending portion and a first extension portion. The first extension portion is electrically connected to the top cover assembly. The first bending portion is electrically connected between the first body portion and the first extension portion. The second cell includes a second body portion and a second electrode tab. The second electrode tab includes a second bent portion and a second extension portion. The second extension portion is electrically connected to the top cover assembly. The second bent portion is electrically connected between the second body portion and the second extension portion. The first extension portion and the second extension portion both extend in a direction that is closer to each other along the first direction. The first extension portion facing the first main body portion and the second extension portion facing the second main body portion are both provided with first insulating paper, and the first insulating paper on the first extension portion and the first insulating paper on the second extension portion are connected; Both the side of the first bend away from the first insulating paper and the side of the second bend away from the first insulating paper are provided with second insulating paper.

[0006] Optionally, the single cell further has a second direction perpendicular to the first direction, the first extension and the first main body are spaced apart in the second direction, and the second extension and the second main body are spaced apart in the second direction; At least a portion of the first insulating paper on the first extension and at least a portion of the first insulating paper on the second extension are stacked and bonded in the second direction; Alternatively, the single cell may further include a first connecting layer with insulating properties, the first connecting layer connecting the first insulating paper on the first extension and the first insulating paper on the second extension, and the first connecting layer and the first main body and the second main body are all spaced apart in the second direction; Alternatively, the first insulating paper on the first extension portion and the first insulating paper on the second extension portion are integrally formed.

[0007] Optionally, the top cover assembly includes a top cover plate and an electrode post, the top cover plate is connected to the housing, the electrode post passes through the top cover plate, and the first extension and the second extension are both electrically connected to the electrode post; The first electrode has a first surface and a second surface disposed opposite to each other. The first surface is covered with the first insulating paper, and the second surface is covered with the second insulating paper. The first electrode includes a plurality of first electrode layers stacked together. Each first electrode layer of the first electrode is electrically connected to the first main body. The plurality of first electrode layers are welded to form a first solder mark. The first solder mark is disposed on the first surface, and the first insulating paper attached to the first surface covers the first solder mark. The second electrode has a third surface and a fourth surface disposed opposite to each other. The third surface is covered with the first insulating paper, and the fourth surface is covered with the second insulating paper. The second electrode includes a plurality of stacked second electrode layers. Each second electrode layer of the second electrode is electrically connected to the second main body. The plurality of second electrode layers are welded to form a second solder mark. The second solder mark is disposed on the third surface, and the first insulating paper attached to the third surface covers the second solder mark.

[0008] Optionally, the first extension is welded to the pole to form a third weld mark, the third weld mark covering the first weld mark, and the first insulating paper attached to the first surface covering the first weld mark and the third weld mark; the second extension is welded to the pole to form a fourth weld mark, the fourth weld mark covering the second weld mark, and the first insulating paper attached to the third surface covering the second weld mark and the fourth weld mark. And / or, when the second insulating paper affixed to the second surface also covers the first extension portion, the projected outline of the second insulating paper affixed to the second surface and the projected outline of the first solder mark are spaced apart when projected on a plane perpendicular to the second direction; when the second insulating paper affixed to the fourth surface also covers the second extension portion, the projected outline of the second insulating paper affixed to the fourth surface and the projected outline of the second solder mark are spaced apart when projected on a plane perpendicular to the second direction.

[0009] Optionally, the top cover assembly further includes a connecting piece, the connecting piece including a first welding portion and a second welding portion connected to each other, the first welding portion being welded to the pole post, the second welding portion being welded to the plurality of first pole tab layers of the first pole tab to form a fifth weld mark, the second welding portion also being welded to the plurality of second pole tab layers of the second pole tab to form a sixth weld mark, the first insulating paper attached to the first surface covering the fifth weld mark, and the first insulating paper attached to the third surface covering the sixth weld mark.

[0010] Optionally, the plurality of first tab layers of the first tab and the plurality of second tab layers of the second tab are all located on the side of the second weld portion away from the pole post in the second direction; the second insulating paper attached to the second surface and the fourth surface also covers at least a portion of the second weld portion; and the second insulating paper attached to the second surface is connected to the second insulating paper attached to the fourth surface.

[0011] Optionally, the second insulating paper attached to the second surface and the second insulating paper attached to the fourth surface are stacked and bonded in the second direction; Alternatively, the single cell may further include a second connecting layer with insulating properties, the second connecting layer connecting the second insulating paper attached to the second surface and the second insulating paper attached to the fourth surface, and the second connecting layer being attached to the side of the second welding portion facing the electrode post; Alternatively, the second insulating paper affixed to the second surface and the second insulating paper affixed to the fourth surface may be integrally formed.

[0012] Optionally, the first electrode tab further includes a first folding portion, the first folding portion connecting the first main body portion and the first bending portion, the first main body portion having a first side surface and a second side surface opposite to each other in the first direction; the first insulating paper attached to the first surface is also attached to the first bending portion and the first folding portion, and the second insulating paper attached to the second surface is also attached to the first folding portion and the first side surface. The second electrode also includes a second folding portion, which connects the second main body portion and the second bending portion. The second main body portion has a third side surface and a fourth side surface opposite to each other in the first direction. The first insulating paper attached to the third surface is also attached to the second bending portion and the second folding portion, and the second insulating paper attached to the fourth surface is also attached to the second folding portion and the third side surface.

[0013] Optionally, the first main body has a first end face in the second direction, and the first end face is spaced apart from the first extension in the second direction; the first insulating paper attached to the first surface is also attached to the first end face and the second side face. The second main body has a second end face in the second direction, and the second end face is spaced apart from the second extension in the second direction; the first insulating paper attached to the third surface is also attached to the second end face and the fourth side face.

[0014] Secondly, embodiments of this application provide a battery pack comprising: a single battery cell as described in any of the preceding claims.

[0015] In an embodiment of this application, a single battery cell includes: a casing, a top cover assembly, a battery cell, a first insulating paper, and a second insulating paper. The top cover assembly is connected to the casing, and the battery cell is disposed inside the casing. The battery cell includes a first battery cell and a second battery cell arranged along a first direction. The first battery cell includes a first body portion and a first electrode tab. The first electrode tab includes a first bent portion and a first extension portion. The first extension portion is electrically connected to the top cover assembly, and the first bent portion is electrically connected between the first body portion and the first extension portion. The second battery cell includes a second body portion and a second electrode tab. The second electrode tab includes a second bent portion and a second extension portion. The second extension portion is electrically connected to the top cover assembly, and the second bent portion is electrically connected between the second body portion and the second extension portion. The first extension portion and the second extension portion extend along the first direction toward each other. The first extension portion is provided with a first insulating paper on the side facing the first body portion, and the second extension portion is provided with a first insulating paper on the side facing the first body portion. A first insulating paper is provided on one side of the body, and the first insulating paper on the first extension is connected to the first insulating paper on the second extension; a second insulating paper is provided on the side of the first bend away from the first body, and a second insulating paper is provided on the side of the second bend away from the second body; in this way, the first insulating paper on the first extension and the first insulating paper on the second extension are connected to each other, thereby tightening the first and second cells, reducing the possibility of the first and second cells becoming misaligned due to stress release caused by cracking of the first and second bends when the battery is assembled; at the same time, the second insulating paper not only forms insulation protection between the bend of the tab and the shell, but also forms a certain binding effect on the cracked part of the bend when the bend cracks, reducing the possibility of short circuit between the cracked part of the bend and the shell, thus improving the safety and reliability of the single battery.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of a single battery cell according to an embodiment of this application; Figure 2 According to the embodiments of this application, along Figure 1 Sectional view of line AA in the middle; Figure 3 According to the embodiments of this application Figure 2 An enlarged view of section B, shown in the center circle; Figure 4 This is a schematic diagram of a first type of installation of the first insulating paper according to an embodiment of this application; Figure 5This is a schematic diagram of the first installation of the second insulating paper according to an embodiment of this application; Figure 6 This is a partial schematic diagram of a single battery cell according to an embodiment of this application; Figure 7 This is a cross-sectional view of a second type of single-cell battery according to an embodiment of this application; Figure 8 According to the embodiments of this application Figure 7 Enlarged view of section C, shown in the center circle; Figure 9 This is a second installation diagram of the first insulating paper according to the embodiments of this application; Figure 10 This is a second installation diagram of the second insulating paper according to an embodiment of this application; Figure 11 This is a cross-sectional view of a third type of single-cell battery according to an embodiment of this application; Figure 12 According to the embodiments of this application Figure 11 Enlarged view of section D shown in the center circle; Figure 13 This is a third installation diagram of the first insulating paper according to the embodiments of this application; Figure 14 This is a third installation diagram of the second insulating paper according to the embodiments of this application.

[0018] Figure label: 1: Housing; 10: Receiving cavity; 2: Top cover assembly; 21: Top cover plate; 22: Terminal post; 22a: First terminal post; 22b: Second terminal post; 3: Battery cell; 3a: First battery cell; 31a: First main body; 311a: First side; 312a: Second side; 313a: First end face; 32a: First tab; 321a: First bend; 322a: First extension; 323a: First fold; 3b: Second battery cell; 31b: Second main body; 311b: Third side; 312b: Second... Four sides; 313b: Second end face; 32b: Second pole lug; 321b: Second bend; 322b: Second extension; 323b: Second fold; 324b: Third surface; 325b: Fourth surface; 4: First insulating paper; 5: Second insulating paper; 6: First connecting layer; 7: Connecting piece; 71: First welding part; 72: Second welding part; 8: Second connecting layer; 9: Explosion-proof valve; M: First weld mark; N: Second weld mark; P: Third weld mark; Q: Fourth weld mark; X: First direction; Z: Second direction. Detailed Implementation

[0019] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein 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 accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0020] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0021] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0023] The following description, in conjunction with the accompanying drawings, details a single battery cell and a battery pack provided in this application through specific embodiments and application scenarios.

[0024] like Figures 1 to 14As shown, a single-cell battery according to some embodiments of this application includes: a housing 1, a top cover assembly 2, a cell 3, a first insulating paper 4, and a second insulating paper 5. The top cover assembly 2 is connected to the housing 1. The cell 3 is disposed inside the housing 1 and includes a first cell 3a and a second cell 3b arranged along a first direction X. The first cell 3a includes a first body portion 31a and a first electrode tab 32a. The first electrode tab 32a includes a first bending portion 321a and a first extension portion 322a. The first extension 322a is electrically connected to the top cover assembly 2, and the first bending portion 321a is electrically connected between the first main body 31a and the first extension 322a; the second battery cell 3b includes a second main body 31b and a second electrode 32b, the second electrode 32b includes a second bending portion 321b and a second extension 322b, the second extension 322b is electrically connected to the top cover assembly 2, and the second bending portion 321b is electrically connected between the second main body 31b and the second extension 322b; the first extension 322a and the second extension 322a... b both extend in a direction closer to each other along the first direction X; the first extension 322a is provided with a first insulating paper 4 on the side facing the first main body 31a, and the second extension 322b is provided with a first insulating paper 4 on the side facing the second main body 31b, and the first insulating paper 4 on the first extension 322a and the first insulating paper 4 on the second extension 322b are connected to each other; the first bending portion 321a is provided with a second insulating paper 5 on the side away from the first insulating paper 4, and the second bending portion 321b is provided with a second insulating paper 5 on the side away from the first insulating paper 4.

[0025] In this embodiment, the first insulating paper 4 on the first extension 322a and the first insulating paper 4 on the second extension 322b of the single cell are interconnected, thereby tightening the first cell 3a and the second cell 3b in the first direction X, reducing the possibility of the first cell 3a and the second cell 3b becoming skewed due to stress release when the bending portion 321 cracks; at the same time, the second insulating paper 5 provided on the side of the first bending portion 321a away from the first insulating paper 4 and the side of the second bending portion 321b away from the first insulating paper 4 can not only form insulation protection between the first bending portion 321a and the second bending portion 321b and the shell 1, but also, when the first bending portion 321a and the second bending portion 321b crack, the second insulating paper 5 can form a certain binding effect on the cracked parts of the first bending portion 321a and the second bending portion 321b, reducing the possibility of short circuit between the cracked parts of the first bending portion 321a and the second bending portion 321b and the shell 1, thus improving the safety and reliability of the single cell.

[0026] It needs to be explained that a single cell has a first direction X and a second direction Z that are perpendicular to each other. The first direction X specifically refers to the length direction of the single cell, and the second direction Z specifically refers to the height direction of the single cell. It can be understood that the first direction X and the second direction Z are perpendicular to each other. Specifically, they can be "perpendicular" in the strict sense, that is, the angle between the first direction X and the second direction Z is 90°; or they can be "approximately perpendicular", that is, the angle between the first direction X and the second direction Z includes a certain error. Considering the measurement and the error associated with the measurement of a specific quantity (that is, the limitation of the measurement system), the error is within the acceptable deviation range for a specific value as determined by a person skilled in the art. For example, the angle between the first direction X and the second direction Z is 90°±5°.

[0027] In specific applications, such as Figure 2 and Figure 3 As shown, the housing 1 has a receiving cavity 10, the battery cell 3 is disposed in the receiving cavity 10, and the top cover assembly 2 covers the receiving cavity 10 to protect the battery cell 3 and other components inside the receiving cavity 10. The receiving cavity 10 is generally also filled with electrolyte. The first main body 31a and the second main body 31b are specifically formed by stacking multiple positive and negative electrode plates and a separator. The separator is disposed between adjacent positive and negative electrode plates, which insulates and isolates adjacent positive and negative electrode plates while allowing ions (lithium ions, sodium ions, etc.) to pass through and migrate between the positive and negative electrode plates, thereby forming a complete current circuit to carry out electrochemical reactions and generate current.

[0028] Specifically, the first tab 32a and the second tab 32b can be the uncoated and protruding parts of the metal foil of the positive and negative electrode plates, or they can be metal sheets welded to the positive or negative electrode plates for electrical connection. In specific applications, the first battery cell 3a and the second battery cell 3b will be "joined" when installed into the receiving cavity 10 of the housing 1. During the "joining", the first tab 32a and the second tab 32b will be bent to adapt to the installation space. When the first tab 32a and the second tab 32b are bent, the bent parts are the first bent part 321a and the second bent part 321b, and the parts electrically connected to the side of the top cover assembly 2 facing the battery cell 3 are the first extension part 322a and the second extension part 322b. Since the first extension part 322a and the second extension part 322b are welded to the top cover assembly 2, the first extension part 322a and the second extension part 322b will extend along the first direction X and extend towards each other.

[0029] It should be noted that there are two battery cells 3, namely a first battery cell 3a and a second battery cell 3b. The first extension 322a of the first battery cell 3a and the second extension 322b of the second battery cell 3b extend in a direction close to each other along the first direction X, so as to be electrically connected to the component (positive post or negative post) of the same polarity of the top cover assembly 2. Of course, multiple battery cells 3 can also be provided, and they can be arranged between two adjacent battery cells 3. Those skilled in the art can make arrangements according to actual needs, and this application does not limit this.

[0030] In practical applications, when the first bending portion 321a and the second bending portion 321b crack, the stress from bending is released, causing the cell 3 to deviate towards the casing 1. This can easily lead to a short circuit between the cracked first bending portion 321a or the second bending portion 321b and the casing 1. In this application, the first extension portion 322a facing the first main body portion 31a and the second extension portion 322b facing the second main body portion 31b are both provided with first insulating paper 4, which are connected to each other. Thus, the two first insulating papers 4 can form a pulling force on the first cell 3a and the second cell 3b, bringing them closer together. This reduces the possibility of the first cell 3a and the second cell 3b deviating, lowers the probability of a short circuit between the first bending portion 321a or the second bending portion 321b and the casing 1, and improves the safety and reliability of the single battery cell.

[0031] Understandably, the side of the first bend 321a away from the first insulating paper 4 and the side of the second bend 321b away from the first insulating paper 4 are both provided with second insulating paper 5. Thus, the second insulating paper 5 can form insulation protection between the first bend 321a, the second bend 321b and the shell 1. At the same time, when the first bend 321a and the second bend 321b crack, it can bind the cracked parts of the first bend 321a and the second bend 321b, reducing the probability of short circuit between the cracked part of the bend 321a and the shell 1.

[0032] It should be noted that the first insulating paper 4 and the second insulating paper 5 can be any one of polyimide film tape, polyester film tape, polytetrafluoroethylene film tape, and composite material tape, etc. Those skilled in the art can choose according to actual needs, and this application does not limit them.

[0033] Understandably, the first insulating paper 4 on the first extension 322a and the first insulating paper 4 on the second extension 322b are interconnected. Specifically, the two first insulating papers 4 can overlap each other in the first direction X to connect, or the two first insulating papers 4 are a single piece, such as... Figure 12 As shown; it can also be connected using additional insulating paper, such as Figure 3 and Figure 8As shown, those skilled in the art can make settings according to actual needs, and this application does not impose any restrictions on this.

[0034] like Figures 1 to 14 As shown, in some embodiments of this application, the single cell battery also has a second direction Z perpendicular to the first direction X, the first extension 322a and the first main body 31a are spaced apart in the second direction Z, and the second extension 322b and the second main body 31b are spaced apart in the second direction Z; at least a portion of the first insulating paper 4 on the first extension 322a and at least a portion of the first insulating paper 4 on the second extension 322b are stacked and bonded in the second direction Z.

[0035] In this embodiment of the application, by stacking and bonding the first insulating paper 4 on the first extension 322a and the first insulating paper 4 on the second extension 322b in the second direction Z, the connection reliability of the two first insulating papers 4 can be guaranteed, while facilitating the operation and improving convenience.

[0036] In specific applications, the first insulating paper 4 on the first extension 322a and the first insulating paper 4 on the second extension 322b are stacked and bonded in the second direction Z, which enables the two first insulating papers 4 to form a relatively reliable connection. Specifically, the first insulating paper 4 is an insulating tape. By overlapping and bonding them together, it can ensure that the first battery cell 3a and the second battery cell 3b are pulled "inward", that is, closer to each other, thereby reducing the probability of the first battery cell 3a and the second battery cell 3b being misaligned.

[0037] Understandably, the specific dimensions of the overlapping portion of the first insulating paper 4 on the first extension 322a and the first insulating paper 4 on the second extension 322b in the second direction Z, along the first direction X, are determined by the adhesive force between the two. As long as it can be ensured that the two will not easily separate, those skilled in the art can set it according to actual needs, and this application does not limit it in this regard.

[0038] It should be noted that, as Figure 3 As shown, the first extension portion 322a and the first main body portion 31a are spaced apart in the second direction Z, and the second extension portion 322b and the first main body portion 31b are spaced apart in the second direction Z.

[0039] like Figures 1 to 10 As shown, in some embodiments of this application, the single cell battery further includes a first connecting layer 6 with insulating properties. The first connecting layer 6 connects the first insulating paper 4 on the first extension 322a and the first insulating paper 4 on the second extension 322b. The first connecting layer 6 is spaced apart from the first main body 31a and the second main body 31b in the second direction Z.

[0040] In this embodiment, the first insulating paper 4 on the first extension 322a and the first insulating paper 4 on the second extension 322b are connected by the first connecting layer 6. This creates an "inward" pulling force on the first battery cell 3a and the second battery cell 3b, while the first connecting layer 6 provides insulation protection between the main body 31 and the top cover assembly 2, further improving the insulation performance.

[0041] In specific applications, the first connecting layer 6 has insulating properties, and can be insulating tape or insulating sheet, etc. Those skilled in the art can choose according to actual needs, and this application does not limit it.

[0042] Understandably, the first connecting layer 6 is located in the second direction Z between the first main body portion 31a and the second main body portion 31b and the top cover assembly 2, thereby forming an insulating barrier between the first main body portion 31a and the second main body portion 31b and the top cover assembly 2.

[0043] like Figures 11 to 14 As shown, in some embodiments of this application, the first insulating paper 4 on the first extension 322a and the first insulating paper 4 on the second extension 322b are integrally disposed.

[0044] In this embodiment, by integrally setting the first insulating paper 4 on the first extension 322a and the first insulating paper 4 on the second extension 322b, the operation steps can be reduced and the convenience can be improved; at the same time, the structural strength of the first insulating paper 4 can be guaranteed, and it is not easy to detach when the first battery cell 3a and the second battery cell 3b are tightened.

[0045] In specific applications, such as Figure 13 As shown, before the first battery cell 3a and the second battery cell 3b are "joined", the two ends of the integrally formed first insulating paper 4 are respectively attached to the first extension 322a and the second extension 322b, so that the first battery cell 3a and the second battery cell 3b can be tightened after "joining".

[0046] like Figure 1 , Figure 3 , Figure 6 , Figure 8 and Figure 12As shown, in some embodiments of this application, the top cover assembly 2 includes a top cover sheet 21 and a pole post 22. The top cover sheet 21 is connected to the housing 1, and the pole post 22 passes through the top cover sheet 21. The first extension 322a and the second extension 322b are both electrically connected to the pole post 22. The first tab 32a has a first surface 324a and a second surface 325a disposed opposite to each other. The first surface 324a is covered with a first insulating paper 4, and the second surface 325a is covered with a second insulating paper 5. The first tab 32a includes a plurality of stacked first tab layers. Each first tab layer of the first tab 32a is electrically connected to the first main body 31a, and the plurality of first tab layers are welded to form a first solder mark. M, a first solder mark M is disposed on a first surface 324a, and a first insulating paper 4 is attached to the first surface 324a and covers the first solder mark M; a second electrode tab 32b has a third surface 324b and a fourth surface 325b disposed opposite to each other, the third surface 324b is attached with the first insulating paper 4, and the fourth surface 325b is attached with the second insulating paper 5; the second electrode tab 32b includes a plurality of stacked second electrode tab layers, each of the second electrode tab layers being electrically connected to the second main body 31b; the plurality of second electrode tab layers are welded to form a second solder mark N, the second solder mark N is disposed on the third surface 324b, and the first insulating paper 4 is attached to the third surface 324b and covers the second solder mark N.

[0047] In this embodiment, multiple first tab layers of the first tab 32a are welded to form a first solder mark M, which is located on the first extension 323a. The first insulating paper 4 covers the first solder mark M, thereby ensuring the connection area between the first insulating paper 4 and the first extension 323a. Multiple second tab layers of the second tab 32b are welded to form a second solder mark N, which is located on the second extension 323b. The first insulating paper 4 covers the second solder mark N, thereby ensuring the connection area between the first insulating paper 4 and the second extension 323b. Thus, when the first insulating paper 4 applies a pulling force to the first battery cell 3a and the second battery cell 3b, the first insulating paper 4 is not easily detached from the first battery cell 3a and the second battery cell 3b, ensuring the reliability of the connection.

[0048] In a specific application, the top cover assembly 2 includes a top cover plate 21 and a terminal post 22. The top cover plate 21 is connected to the housing 1 and seals the receiving cavity 10. The terminal post 22 passes through the top cover plate 21 and is at least partially exposed to form an electrical connection point on the side of the top cover plate 21 opposite to the battery cell 3; for example Figure 1As shown, the electrode 22 includes a first electrode 22a and a second electrode 22b, which are positive and negative electrodes, respectively. In practical applications, the first electrode 22a is electrically connected to the first tab 32a of the first battery cell 3a and the second tab 32b of the second battery cell 3b, both of which are positive tabs. Similarly, the second electrode 22b is electrically connected to the third tab of the first battery cell 3a and the fourth tab of the second battery cell 3b, both of which are negative tabs, thus forming a current flow path. Specifically, the electrode is electrically connected to the extension of the corresponding tab, which can be a direct weld connection or an indirect weld connection, thereby ensuring the reliability of the connection.

[0049] Specifically, the first tab 32a has a first surface 324a and a second surface 325a disposed opposite to each other, and the second tab 32b has a third surface 324b and a fourth surface 325b disposed opposite to each other. The first surface 324a is the side surface of the first tab 32a facing away from the top cover assembly 2, the third surface 324b is the side surface of the second tab 32b facing away from the top cover assembly 2, that is, the "inner surface", the second surface 325a is the side surface of the first tab 32a facing the top cover assembly 2, and the fourth surface 325b is the side surface of the second tab 32b facing the top cover assembly 2, that is, the "outer surface".

[0050] It should be noted that, as Figure 6 As shown, the first tab 32a includes multiple stacked first tab layers (not shown in the figure), and the second tab 32b includes multiple stacked second tab layers (not shown in the figure). The multiple first tab layers of the first tab 32a are welded to form a first weld mark M, and the multiple second tab layers of the second tab 32b are welded to form a second weld mark N. Specifically, the multiple first tab layers of the first tab 32a are formed by ultrasonic welding or laser welding to form the first weld mark M, and the multiple second tab layers of the second tab 32b are formed by ultrasonic welding or laser welding to form the second weld mark N. The first weld mark M and the second weld mark N refer to the welding "marks" formed on the first surface 324a and the third surface 324b during welding, respectively. By covering the first weld mark M and the second weld mark N with the first insulating paper 4, the connection area between the first insulating paper 4 and the first extension 322a and the second extension 322b can be guaranteed, thereby improving the connection reliability. At the same time, it also avoids the welding slag or burrs generated by the weld mark from falling off or piercing the corresponding main body.

[0051] In specific applications, multiple first tab layers of the first tab 32a are first welded together by ultrasonic welding or laser welding to form a first weld mark M. Multiple second tab layers of the second tab 32b are then welded together by ultrasonic welding or laser welding to form a second weld mark N. After welding, the first extension 322a of the first tab 32a and the second extension 322b of the second tab 32b are welded together with the pole post 22 by laser welding. Then, the first insulating paper 4 is pasted on the first extension 322a. Then, the "core assembly" is performed and the first battery cell 3a and the second battery cell 3b are installed into the receiving cavity 10 of the housing 1.

[0052] like Figure 1 , Figure 3 , Figure 6 and Figure 8 As shown, in some embodiments of this application, the first extension 322a is welded to the pole post 22 to form a third solder mark P, the third solder mark P covers / is disposed on the first solder mark M, the first insulating paper 4 is attached to the first surface 324a to cover the first solder mark M and the third solder mark P, the second extension 322b is welded to the pole post 22 to form a fourth solder mark Q, the fourth solder mark Q covers / is disposed on the second solder mark N, and the first insulating paper 4 is attached to the third surface 324b to cover the second solder mark N and the fourth solder mark Q.

[0053] In this embodiment, by setting a first insulating paper 4 affixed to the first surface 324a to cover the first solder mark M and the third solder mark P, and setting a first insulating paper 4 affixed to the third surface 324b to cover the second solder mark N and the fourth solder mark Q, the first insulating paper 4 can be adhered to the welding positions of the first extension 322a and the second extension 322b, thereby ensuring the connection reliability of the first insulating paper 4. When the first insulating paper 4 applies a pulling force to the first battery cell 3a and the second battery cell 3b, the extension 323 will not be deformed; at the same time, it also prevents the welding slag or burrs generated by welding the tab and the post from damaging the corresponding main body.

[0054] In specific applications, the third solder mark P is located within the first solder mark M, and the fourth solder mark Q is located within the second solder mark N. The third solder mark P can fall entirely within the range of the first solder mark M, or it can fall partially within the range of the first solder mark M. The setting relationship between the fourth solder mark Q and the second solder mark N is similar. Those skilled in the art can set it according to actual needs, and this application does not impose any restrictions on it.

[0055] like Figure 3 , Figure 5 and Figure 6As shown, in some embodiments of this application, when the second insulating paper 5 affixed to the second surface 325a also covers the first extension 322a, the projection outline of the second insulating paper 5 affixed to the second surface 325a and the projection outline of the first solder mark M are spaced apart when projected on a plane perpendicular to the second direction Z. When the second extension 322b of the second insulating paper 5 affixed to the fourth surface 325b also covers the second extension 322b, the projection outline of the second insulating paper 5 affixed to the fourth surface 325b and the projection outline of the second solder mark N are spaced apart when projected on a plane perpendicular to the second direction Z.

[0056] In this embodiment, the second insulating paper 5, which is attached to the second surface 325a, also covers the first extension 322a, and the second insulating paper 5, which is attached to the fourth surface 325b, also covers the second extension 322b. This covers both the first extension 322a and the second extension 322b, thereby increasing the connection area between the second insulating paper 5 and the first tab 32a and the second tab 32b. This reduces the probability of the second insulating paper 5 detaching from the first tab 32a and the second tab 32b when the first bend 321a and the second bend 321b crack, thus improving insulation performance and convergence capability. Simultaneously, the second insulating paper 5 is spaced apart from the first solder mark M in the first direction X, and from the second solder mark N in the first direction X, ensuring that the second insulating paper 5 does not affect the welding between the first tab 32a and the second tab 32b and the pole post 22.

[0057] In specific applications, such as Figure 3 As shown, one second insulating paper 5 can cover the first bent portion 321a and part of the first extension portion 322a, and another second insulating paper 5 can cover the second bent portion 321b and part of the second extension portion 322b, thereby making the second insulating paper 5 form an insulating protection between the first tab 32a and the second tab 32b and the housing 1.

[0058] like Figures 6 to 14 As shown, in some embodiments of this application, the top cover assembly 2 further includes a connecting piece 7. The connecting piece 7 includes a first welding part 71 and a second welding part 72 that are connected to each other. The first welding part 71 is welded to the pole post 22. The second welding part 72 is welded to a plurality of first pole tab layers of the first pole tab 32a to form a fifth weld mark. The second welding part 72 is also welded to a plurality of second pole tab layers of the second pole tab 32b to form a sixth weld mark. The first insulating paper 4 attached to the first surface 324a covers the fifth weld mark. The first insulating paper 4 attached to the third surface 324b covers the sixth weld mark.

[0059] In this embodiment of the application, the first insulating paper 4 applied to the first surface 324a covers the fifth solder mark, and the first insulating paper 4 applied to the third surface 324b covers the sixth solder mark, thereby ensuring the bonding area when the first insulating paper 4 is pasted with the first tab 32a and the second tab 32b, and thus ensuring the reliability of the connection between the first insulating paper 4 and the first tab 32a and the second tab 32b.

[0060] In specific applications, the connecting piece 7 is a metal piece that can be welded to the pole post 22, the first electrode tab 32a, and the second electrode tab 32b respectively, thereby reducing the difficulty of welding the first electrode tab 32a and the second electrode tab 32b directly to the pole post 22 and improving the ease of installation.

[0061] Optionally, such as Figure 9 and Figure 10 As shown, the connecting piece 7 includes a first welding part 71 and a second welding part 72 that are connected to each other. There are two second welding parts 72, both of which are located on the same side of the first welding part 71 and are spaced apart along the first direction X. The first welding part 71 is welded to the pole post 22, and the two second welding parts 72 are welded to the first extension 322a and the second extension 322b, respectively.

[0062] It should be noted that in practical applications, multiple tab layers are first welded together by ultrasonic welding or laser welding, and then welded to the second welding part 72 to form a fifth weld mark. The first insulating paper 4 is then pasted onto the first extension 322a and at least part of the second welding part 72 to cover the fifth weld mark. Then, the first welding part 71 is welded to the pole post 22. Alternatively, the first welding part 71 can be welded to the pole post 22 first, and then the first insulating paper 4 can be pasted. The welding method at the second extension 322b and the pasting method of the first insulating paper 4 are similar and will not be described again here.

[0063] like Figures 7 to 14 As shown, in some embodiments of this application, the plurality of first tab layers of the first tab 32a and the plurality of second tab layers of the second tab 32b are all located on the side of the second weld portion 72 away from the pole post 22 in the second direction Z; the second insulating paper 5 attached to the second surface 325a and the fourth surface 325b also covers at least part of the second weld portion 72; and the second insulating paper 5 attached to the second surface 325a is connected to the second insulating paper 5 attached to the fourth surface 325b.

[0064] In the embodiments of this application, the second insulating paper 5 affixed to the second surface 325a and the fourth surface 325b also covers at least a portion of the second welding portion 72, thereby increasing the bonding area of ​​the second insulating paper 5 and ensuring the insulation effect of the second insulating paper 5; at the same time, the connection between the second insulating paper 5 affixed to the second surface 325a and the second insulating paper 5 affixed to the fourth surface 325b can further improve the insulation coverage of the second insulating paper 5 between the first electrode tab 32a and the second electrode tab 32b and the housing 1, and can apply a pulling force that brings the first battery cell 3a and the second battery cell 3b closer to each other, so as to reduce the possibility of the first battery cell 3a and the second battery cell 3b being misaligned.

[0065] In specific applications, the multiple first tab layers of the first tab 32a and the multiple second tab layers of the second tab 32b are all located on the side of the second welding part 72 away from the pole post 22 in the second direction Z. That is, the first extension 322a and the second extension 322b are welded to the side of the second welding part 72 away from the pole post 22. After the first extension 322a and the second extension 322b are welded to the second welding part 72, the second insulating paper 5 is pasted on the second welding part 72 to ensure the reliability of the connection.

[0066] It should be noted that the second insulating paper 5 attached to the second surface 325a is connected to the second insulating paper 5 attached to the fourth surface 325b, thereby forming a "semi-encircling" type of insulation protection on the "outer side" of the tab 32, which can improve the protection effect.

[0067] like Figures 7 to 14 As shown, in some embodiments of this application, the second insulating paper 5 attached to the second surface 325a and the second insulating paper 5 attached to the fourth surface 325b are stacked and bonded in the second direction Z.

[0068] In this embodiment of the application, by stacking and bonding the second insulating paper 5 attached to the second surface 325a and the second insulating paper 5 attached to the fourth surface 325b in the second direction Z, the connection reliability of the two second insulating papers 5 can be guaranteed, while facilitating the operation and improving convenience.

[0069] In specific applications, the second insulating paper 5 attached to the second surface 325a and the second insulating paper 5 attached to the fourth surface 325b are stacked and bonded in the second direction Z, which enables the two second insulating papers 5 to form a relatively reliable connection. Specifically, the second insulating paper 5 is an insulating tape. By overlapping and bonding them together, it can ensure that the first battery cell 3a and the second battery cell 3b are pulled "inward", that is, brought closer to each other, thereby reducing the probability of the first battery cell 3a and the second battery cell 3b being misaligned.

[0070] Understandably, the specific dimensions of the overlapping portion of the second insulating paper 5 on the second surface 325a and the second insulating paper 5 on the fourth surface 325b in the second direction Z, along the first direction X, are determined by the adhesive force between the two. As long as it can be ensured that the two will not easily separate, those skilled in the art can set it according to actual needs, and this application does not impose any restrictions on it.

[0071] like Figures 7 to 14 As shown, in some embodiments of this application, the single cell further includes a second connecting layer 8 with insulating properties. The second connecting layer 8 connects the second insulating paper 5 attached to the second surface 325a and the second insulating paper 5 attached to the fourth surface 325b, and the second connecting layer 8 is attached to the side of the second welding part 72 facing the electrode post 22.

[0072] In this embodiment, the second insulating paper 5 attached to the second surface 325a and the second insulating paper 5 attached to the fourth surface 325b are connected together by the second connecting layer 8. This creates an "inward" pulling force on the first battery cell 3a and the second battery cell 3b, which brings them closer together. At the same time, the second connecting layer 8 can form insulation protection between the first electrode 32a, the second electrode 32b and the top cover assembly 2, further improving the insulation performance.

[0073] In specific applications, the second connecting layer 8 has insulating properties, and can be insulating tape or insulating sheet, etc. Those skilled in the art can choose according to actual needs, and this application does not limit it.

[0074] Understandably, the second connecting layer 8 is located in the second direction Z between the first tab 32a and the second tab 32b and the top cover assembly 2, thereby providing insulation between the tab 32 and the top cover assembly 2.

[0075] like Figures 11 to 14 As shown, in some embodiments of this application, the second insulating paper 5 on the first battery cell 3a and the second insulating paper 5 on the second battery cell 3b are integrally disposed.

[0076] In this embodiment, by integrally setting the second insulating paper 5 attached to the second surface 325a and the second insulating paper 5 attached to the fourth surface 325b, the operation steps can be reduced and the convenience can be improved; at the same time, the structural strength of the second insulating paper 5 can be guaranteed, and it is not easy to detach when the first battery cell 3a and the second battery cell 3b are tightened.

[0077] In specific applications, such as Figure 14As shown, before the first battery cell 3a and the second battery cell 3b are "joined", one end of the integrally formed second insulating paper 5 is attached to the second surface 325a and the other end is attached to the fourth surface 325b, so that the first battery cell 3a and the second battery cell 3b can be tightened after "joining".

[0078] like Figures 1 to 14 As shown, in some embodiments of this application, the first tab 32a further includes a first gathering portion 323a, which connects the first main body portion 31a and the first bending portion 321a. The first main body portion 31a has a first side surface 311a and a second side surface 312a opposite to each other in the first direction X. The first insulating paper 4, which is attached to the first surface 324a, is also attached to the first bending portion 321a and the first gathering portion 323a. The second insulating paper 5, which is attached to the second surface 325a, is also attached to the first gathering portion 323a and the first bending portion 321a. One side 311a; the second electrode 32b also includes a second folding portion 323b, the second folding portion 323b is connected to the second main body portion 31b and the second bending portion 321b, the second main body portion 31b has a third side 311b and a fourth side 312b opposite to each other in the first direction X; the first insulating paper 4 attached to the third surface 324b is also attached to the second bending portion 321b and the second folding portion 323b, and the second insulating paper 5 attached to the fourth surface 325b is also attached to the second folding portion 323b and the third side 311b.

[0079] In this embodiment, by providing the first insulating paper 4 attached to the first surface 324a and also attached to the first bending portion 321a and the first gathering portion 323a, and the first insulating paper 4 attached to the third surface 324b and also attached to the second bending portion 321b and the second gathering portion 323b, the bonding area between the two first insulating papers 4 and the first electrode tab 32a and the second electrode tab 32b can be increased. This ensures the connection reliability of the first insulating paper 4 and improves its insulation protection range. At the same time, the second insulating paper 5 attached to the second surface 325a and also attached to the first gathering portion 323a and the first side surface 311a, and the second insulating paper 5 attached to the fourth surface 325b and also attached to the second gathering portion 323b and the third side surface 311b, increases the bonding area between the second insulating paper 5 and the first battery cell 3a and the second battery cell 3b. This improves the connection reliability of the second insulating paper 5 and enhances its insulation protection range.

[0080] In specific applications, such as Figure 3 , Figure 8 and Figure 12As shown, the first main body 31a has a first side surface 311a and a second side surface 312a opposite to each other in the first direction X, and the second main body 31b has a third side surface 311b and a fourth side surface 312b opposite to each other in the first direction X; the first side surface 311a and the third side surface 311b specifically refer to the "outer large surface" of the first main body 31a and the second main body 31b, and the second side surface 312a and the fourth side surface 312b specifically refer to the "inner large surface" of the first main body 31a and the second main body 31b, where inner and outer refer to the direction towards the adjacent battery cell 3 as inner side and the direction away from the adjacent battery cell 3 as outer side, and "large surface" refers to one side surface of the largest surface of the first main body 31a and the second main body 31b.

[0081] In practical applications, the first insulating paper 4 can be sequentially bonded to the first extension 322a, the first bending portion 321a, and the first gathering portion 322a of the first electrode tab 32a (the bonding method of the first insulating paper 4 and the second electrode tab 32b is the same, and will not be described again here). The second insulating paper 5 can be sequentially bonded to the first extension 322a, the first bending portion 321a / first gathering portion 322a of the first electrode tab 32a, and the first side surface 311a of the first main body portion 31 (the bonding method of the second insulating paper 5 and the second electrode tab 32b is the same, and will not be described again here).

[0082] like Figures 1 to 14 As shown, in some embodiments of this application, the first main body 31a has a first end face 313a in the second direction Z, and the first end face 313a and the first extension 322a are spaced apart in the second direction Z; the first insulating paper 4 attached to the first surface 324a is also attached to the first end face 313a and the second side surface 312a; the second main body 31b has a second end face 313b in the second direction Z, and the second end face 313b and the second extension 322b are spaced apart in the second direction Z; the first insulating paper 4 attached to the third surface 324b is also attached to the second end face 313b and the fourth side surface 312b.

[0083] In this embodiment, by providing the first insulating paper 4 attached to the first surface 324a and also attached to the first end face 313a and the second side face 312a, and the first insulating paper 4 attached to the third surface 324b and also attached to the second end face 313b and the fourth side face 312b, the bonding area between the first insulating paper 4 and the first tab 32a and the first main body 31a, as well as between the first insulating paper 4 and the second tab 32b and the second main body 32b, can be increased. This improves the connection reliability of the first insulating paper 4 and increases the insulation protection range of the first insulating paper 4.

[0084] In specific applications, the first end face 311a specifically refers to the end face of the first main body 31a facing the top cover assembly 2, and the first electrode 32a extends from the first end face 311a and is exposed on the first end face 311a; the second end face 311b specifically refers to the end face of the second main body 31b facing the top cover assembly 2, and the second electrode 32b extends from the second end face 311b and is exposed on the second end face 311b.

[0085] In practical applications, the first insulating paper 4 can be sequentially bonded to the first extension 322a, the first bending portion 321a, the first gathering portion 323a of the first electrode tab 32a, and the first end face 311a and the second side face 312a of the first main body portion 31a (the bonding method between the first insulating paper 4 and the second battery cell 3b is the same, and will not be described in detail here), thereby having a large bonding area.

[0086] like Figure 1 As shown, in some embodiments of this application, the single battery also includes an explosion-proof valve 9, which is disposed on the top cover assembly 2 and can connect to the receiving cavity 10 of the housing 1. In the event of thermal runaway or other situations in the single battery, the high-temperature and high-pressure gas in the receiving cavity 10 can be released to reduce the possibility of the single battery exploding, thereby improving the safety of the single battery.

[0087] In some embodiments of this application, a battery pack is also proposed, comprising individual batteries as described in any of the above embodiments.

[0088] In the embodiments of this application, the battery pack includes the single battery cells described in any of the above embodiments, and thus has the beneficial effects of the single battery cells described in any of the above embodiments, which will not be repeated here.

[0089] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0090] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A single-cell battery having a first orientation (X), characterized in that, include: Shell (1); Top cover assembly (2), which is connected to the housing (1); The battery cell (3) is disposed inside the housing (1). The battery cell (3) includes a first battery cell (3a) and a second battery cell (3b) arranged along the first direction (X). The first battery cell (3a) includes a first main body (31a) and a first electrode (32a). The first electrode (32a) includes a first bent portion (321a) and a first extension portion (322a). The first extension portion (322a) is electrically connected to the top cover assembly (2). The first bent portion (321a) is electrically connected between the first main body (31a) and the first extension portion (322a). The second battery cell (3b) includes a second main body (31b) and a second tab (32b). The second tab (32b) includes a second bent portion (321b) and a second extension portion (322b). The second extension portion (322b) is electrically connected to the top cover assembly (2). The second bent portion (321b) is electrically connected between the second main body (31b) and the second extension portion (322b). The first extension portion (322a) and the second extension portion (322b) both extend in a direction closer to each other along the first direction (X). The first extension (322a) facing the first main body (31a) and the second extension (322b) facing the second main body (31b) are both provided with first insulating paper (4), and the first insulating paper (4) on the first extension (322a) and the first insulating paper (4) on the second extension (322b) are connected. The first bend (321a) and the second bend (321b) are both provided with a second insulating paper (5) on the side opposite to the first insulating paper (4).

2. The single-cell battery according to claim 1, characterized in that, The single cell also has a second direction (Z) perpendicular to the first direction (X), the first extension (322a) and the first main body (31a) are spaced apart in the second direction (Z), and the second extension (322b) and the second main body (31b) are spaced apart in the second direction (Z); At least a portion of the first insulating paper (4) on the first extension (322a) and at least a portion of the first insulating paper (4) on the second extension (322b) are stacked and bonded in the second direction (Z); Alternatively, the single cell may further include a first connecting layer (6) with insulating properties, the first connecting layer (6) connecting the first insulating paper (4) on the first extension (322a) and the first insulating paper (4) on the second extension (322b), and the first connecting layer (6) and the first main body (31a) and the second main body (31b) are all spaced apart in the second direction (Z); Alternatively, the first insulating paper (4) on the first extension (322a) and the first insulating paper (4) on the second extension (322b) are integrally disposed.

3. The single-cell battery according to claim 2, characterized in that, The top cover assembly (2) includes a top cover plate (21) and a pole post (22). The top cover plate (21) is connected to the housing (1). The pole post (22) passes through the top cover plate (21). The first extension (322a) and the second extension (322b) are both electrically connected to the pole post (22). The first electrode tab (32a) has a first surface (324a) and a second surface (325a) disposed opposite to each other. The first surface (324a) is covered with the first insulating paper (4), and the second surface (325a) is covered with the second insulating paper (5). The first electrode tab (32a) includes a plurality of first electrode tab layers stacked together. Each first electrode tab layer of the first electrode tab (32a) is electrically connected to the first main body (31a). The plurality of first electrode tab layers are welded to form a first solder mark (M). The first solder mark (M) is disposed on the first surface (324a), and the first insulating paper (4) attached to the first surface (324a) covers the first solder mark (M). The second electrode tab (32b) has a third surface (324b) and a fourth surface (325b) disposed opposite to each other. The third surface (324b) is covered with the first insulating paper (4), and the fourth surface (325b) is covered with the second insulating paper (5). The second electrode tab (32b) includes a plurality of stacked second electrode tab layers. Each second electrode tab layer of the second electrode tab (32b) is electrically connected to the second main body (31b). The plurality of second electrode tab layers are welded to form a second solder mark (N). The second solder mark (N) is disposed on the third surface (324b), and the first insulating paper (4) disposed on the third surface (324b) covers the second solder mark (N).

4. The single-cell battery according to claim 3, characterized in that, The first extension (322a) is welded to the pole (22) to form a third solder mark (P), the third solder mark (P) covering the first solder mark (M), and the first insulating paper (4) attached to the first surface (324a) covers the first solder mark (M) and the third solder mark (P); the second extension (322b) is welded to the pole (22) to form a fourth solder mark (Q), the fourth solder mark (Q) covering the second solder mark (N), and the first insulating paper (4) attached to the third surface (324b) covers the second solder mark (N) and the fourth solder mark (Q); And / or, when the second insulating paper (5) affixed to the second surface (325a) also covers the first extension (322a), the projected outline of the second insulating paper (5) affixed to the second surface (325a) is spaced apart from the projected outline of the first solder mark (M) when projected on a plane perpendicular to the second direction (Z), and when the second insulating paper (5) affixed to the fourth surface (325b) also covers the second extension (322b), the projected outline of the second insulating paper (5) affixed to the fourth surface (325b) is spaced apart from the projected outline of the second solder mark (N) when projected on a plane perpendicular to the second direction (Z).

5. The single-cell battery according to claim 3, characterized in that, The top cover assembly (2) further includes a connecting piece (7), which includes a first welding part (71) and a second welding part (72) connected to each other. The first welding part (71) is welded to the pole post (22), and the second welding part (72) is welded to the plurality of first pole tab layers of the first pole tab (32a) to form a fifth weld mark. The second welding part (72) is also welded to the plurality of second pole tab layers of the second pole tab (32b) to form a sixth weld mark. The first insulating paper (4) attached to the first surface (324a) covers the fifth weld mark, and the first insulating paper (4) attached to the third surface (324b) covers the sixth weld mark.

6. The single-cell battery according to claim 5, characterized in that, The plurality of first tab layers of the first tab (32a) and the plurality of second tab layers of the second tab (32b) are all located on the side of the second weld portion (72) away from the pole post (22) in the second direction (Z); the second insulating paper (5) attached to the second surface (325a) and the fourth surface (325b) also covers at least part of the second weld portion (72); and the second insulating paper (5) attached to the second surface (325a) is connected to the second insulating paper (5) attached to the fourth surface (325b).

7. The single-cell battery according to claim 6, characterized in that, The second insulating paper (5) attached to the second surface (325a) and the second insulating paper (5) attached to the fourth surface (325b) are stacked and bonded in the second direction (Z); Alternatively, the single cell may further include a second connecting layer (8) with insulating properties, the second connecting layer (8) connecting the second insulating paper (5) attached to the second surface (325a) and the second insulating paper (5) attached to the fourth surface (325b), and the second connecting layer (8) being attached to the side of the second welding part (72) facing the pole post (22); Alternatively, the second insulating paper (5) attached to the second surface (325a) and the second insulating paper (5) attached to the fourth surface (325b) may be integrally formed.

8. The single-cell battery according to any one of claims 3-7, characterized in that, The first electrode tab (32a) further includes a first folding portion (323a), which connects the first main body portion (31a) and the first bending portion (321a). The first main body portion (31a) has a first side surface (311a) and a second side surface (312a) opposite to each other in the first direction (X). The first insulating paper (4) attached to the first surface (324a) is also attached to the first bending portion (321a) and the first folding portion (323a), and the second insulating paper (5) attached to the second surface (325a) is also attached to the first folding portion (323a) and the first side surface (311a). The second electrode tab (32b) further includes a second folding portion (323b), which connects the second main body portion (31b) and the second bending portion (321b). The second main body portion (31b) has a third side surface (311b) and a fourth side surface (312b) opposite to each other in the first direction (X). The first insulating paper (4) attached to the third surface (324b) is also attached to the second bending portion (321b) and the second folding portion (323b), and the second insulating paper (5) attached to the fourth surface (325b) is also attached to the second folding portion (323b) and the third side surface (311b).

9. The single-cell battery according to claim 8, characterized in that, The first main body (31a) has a first end face (313a) in the second direction (Z), and the first end face (313a) and the first extension (322a) are spaced apart in the second direction (Z); the first insulating paper (4) attached to the first surface (324a) is also attached to the first end face (313a) and the second side face (312a). The second main body (31b) has a second end face (313b) in the second direction (Z), and the second end face (313b) and the second extension (322b) are spaced apart in the second direction (Z); the first insulating paper (4) attached to the third surface (324b) is also attached to the second end face (313b) and the fourth side surface (312b).

10. A battery pack, characterized in that, include: The single-cell battery as described in any one of claims 1-9.

Images