Single battery and battery pack

Abstract

The present application relates to the related technical field of batteries. Disclosed are a single battery and a battery pack, which are used to solve the problems of short circuits and low yield rates of single batteries due to the fact that welding slag and metal burrs in existing single batteries escape into battery cells. The single battery provided in the present application comprises: a cap, wherein the cap is provided with a terminal post hole penetrating the cap in a first direction Z; a terminal post, which passes through the terminal post hole; at least two battery cells, each of which comprises a body and a tab bundle connected to the body, wherein each tab bundle consists of a plurality of stacked tabs and has a welding portion, there is a gap between welding portions of tab bundles of two adjacent battery cells in a second direction X, and in a non-welding area of each welding portion, there is a slit between two adjacent tabs on the same tab bundle in the first direction Z; and a protective adhesive structure, which comprises a filling portion and a covering portion, wherein the filling portion fills gaps and slits, and the covering portion is connected to the surface of each welding portion that faces away from the terminal post and at least covers a welding mark formed in a welding area of each welding portion.

Description

Single cells and battery packs

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on March 18, 2024, with application number 202420527771.5 and application name “Single Cell and Battery Pack”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to, but is not limited to, the technical field of batteries, and specifically to a single cell and a battery pack. Background Art

[0003] In the battery electrical connection assembly scheme, the tabs of the battery cell are usually first gathered together along one of the large surfaces and then welded together. The tabs that are too long are then cut off. Finally, the tabs are welded to the pole posts of the cover to complete the electrical connection. Currently, these processes mostly use ultrasonic welding, laser welding, or resistance welding. Welding slag, burrs, etc. generated during the welding process, as well as metal burrs generated during the tab cutting process, can fall into the battery or metal debris can be hidden in the gaps between the tabs. After liquid injection, it flows into the battery with the electrolyte, which can easily cause a short circuit and safety accident, posing a hidden danger to battery safety. SUMMARY OF THE INVENTION

[0004] The present application provides a single cell battery and a battery pack, which can solve the problem that welding slag and metal burrs in the single cell battery escape into the battery core, causing short circuits and low yield of the single cell battery.

[0005] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0006] The single cell provided in this application includes:

[0007] The cover has a first direction Z and a second direction X that are perpendicular to each other, and the cover is provided with a pole hole that passes through the cover along the first direction Z;

[0008] A pole, passing through the pole hole;

[0009] At least two battery cells are arranged along the second direction X and are both provided on the same side of the cover, the battery cell comprising a body and a tab bundle connected to the body, the tab bundle being composed of a plurality of tabs stacked in a layer and having a welding portion, wherein a gap is provided between the welding portions of the tab bundles of two adjacent battery cells in the second direction X, the welding region of the welding portion is welded to the pole post and forms a weld mark in the welding region, and a gap is provided between two adjacent tabs on the same tab bundle in the first direction Z in the non-welding region of the welding portion;

[0010] The protective glue structure comprises a filling portion and a covering portion, wherein the filling portion is filled in the gap and the slit, and the covering portion is connected to the surface of the welding portion facing away from the pole and at least covers the welding mark.

[0011] In some embodiments of the present application, the filling portion contacts the pole, and the area enclosed by the orthographic projection of the weld print on the cover is located within the area enclosed by the orthographic projection of the covering portion on the cover.

[0012] In some embodiments of the present application, the area enclosed by the orthographic projection of the covering portion on the cover body is located within the area enclosed by the orthographic projection of the welding portion on the cover body.

[0013] In some embodiments of the present application, the single battery further includes:

[0014] an insulating layer connected to a surface of the cover body facing the tab bundle and arranged around the outer periphery of the pole;

[0015] The protective glue structure further includes an extension portion, which covers a surface of the insulating layer facing away from the cover and is connected to the insulating layer.

[0016] In some embodiments of the present application, the tab bundle further has a connecting portion, the connecting portion is connected between the welding portion and the body, and the covering portion does not cover the connecting portion.

[0017] In some embodiments of the present application, the protective glue structure has a first edge and a second edge, the first edge and the second edge are arranged opposite to each other along the second direction X, the cover body has a first side and a second side arranged opposite to each other, the first side is close to the first edge and has a first interval W1mm with the first edge in the second direction X, the second side is close to the second edge and has a second interval W2mm with the second edge in the second direction X, and satisfies: 0.1≤W1≤80, 0.1≤W2≤80.

[0018] In some embodiments of the present application, the size of the gap in the first direction Z is H1 mm, the size of the portion of the filling part filled in the gap 100 in the first direction Z is H2 mm, and the following condition is satisfied: H2 ≥ H1.

[0019] In some embodiments of the present application, a portion of the filling part that fills the gap has a size of H2 mm in the first direction Z and satisfies: 0.05≤H2≤5.

[0020] In some embodiments of the present application, a dimension of the covering portion in the first direction Z is H3 mm, and satisfies: 0.05≤H3≤2.5.

[0021] In some embodiments of the present application, the above-mentioned single battery further includes the third direction Y, the first direction Z, the second direction X and the third direction Y intersect each other, and in the third direction Y, the size of the extension portion is F mm and satisfies: 1≤F≤300.

[0022] The protective glue structure of the present application includes a filling portion and a covering portion. The filling portion of the protective glue structure is filled in the gap between the welding portions of the tab bundles of two adjacent battery cells, as well as in the non-welding area of ​​the welding portion and the gap between two adjacent tabs on the same tab bundle in the first direction Z. The protective glue structure covers the surface of the welding portion facing away from the pole and at least covers the weld mark to absorb foreign matter such as welding slag and burrs generated during the welding process. In specific production, the above-mentioned protective glue structure can be formed by curing a protective glue with castability. It is precisely based on the castability of the protective glue that it can flow and fill in the above-mentioned gaps and crevices, and it can absorb metal burrs generated when the tab bundle is cut. Therefore, the above-mentioned technical solution adopted in the present application can prevent the problem of battery short circuit caused by metal burrs or welding slag escaping into the battery cell, thereby affecting the performance of the single cell, and thus helping to improve the yield rate of the single cell.

[0023] On the other hand, the present application also provides a battery pack, comprising:

[0024] Box;

[0025] The single cell battery as described in the above technical solution is accommodated in the box.

[0026] Since the battery pack provided in the present application includes the single battery as described in the above technical solution, the two can solve the same problem and achieve the same effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0028] FIG1 is a schematic structural diagram of a single cell in an embodiment of the present application;

[0029] FIG2 is a schematic structural diagram of a single battery in an expanded state according to an embodiment of the present application;

[0030] FIG3 is an AA cross-sectional view of FIG2 in an embodiment of the present application;

[0031] FIG4 is an enlarged view of portion B in FIG3 of the embodiment of the present application;

[0032] FIG5 is an enlarged view of portion C in FIG2 of an embodiment of the present application;

[0033] FIG6 is another structural schematic diagram of a single cell according to an embodiment of the present application;

[0034] FIG7 is an enlarged view of portion D in FIG6 of the embodiment of the present application;

[0035] Figure 8 is a cross-sectional view of EE in Figure 7 of the embodiment of the present application;

[0036] FIG9 is an enlarged view of portion G in FIG1 of an embodiment of the present application.

[0037] The main reference numerals in the drawings of this application specification are described as follows:

[0038] 1-cover; 11-first side; 12-second side;

[0039] 2-pole;

[0040] 3-battery cell; 31-body; 32-tab bundle; 321-welding portion; 3211-welding area; 3212-welding mark; 3213-non-welding area; 322-connecting portion;

[0041] 4-protective adhesive structure; 41-filling portion; 42-covering portion; 43-extension portion; 44-first edge; 45-second edge;

[0042] 5-Insulation layer;

[0043] 6- housing;

[0044] 100-gap;

[0045] 200-Gap. Modes for Carrying Out the Invention

[0046] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0047] In the field of secondary batteries, in order to reduce the hidden dangers of welding slag and metal burrs, insulating tape is usually pasted in high-risk areas after dust removal. Insulating tape is used to absorb metal foreign matter, but this tape can only be applied to a single horizontal surface. The electrical connection structure of the tabs has multiple height differences and there are gaps between the tabs, which may cause missed metal debris and other foreign matter. In addition, the viscosity of the tape decreases after being soaked in electrolyte, and the adsorption effect will be reduced, which will still cause metal debris and other foreign matter to escape into the battery cell, causing a short circuit.

[0048] The present application provides a single cell and a battery pack, which are described in detail below. In the following embodiments, the description of each embodiment has its own focus. For parts not described in detail in one embodiment, please refer to the relevant description of other embodiments.

[0049] 1 to 4 , the single cell battery provided in the present application includes a cover 1, a pole 2, at least two battery cells 3, and a protective adhesive structure 4. The cover 1 has a first direction Z and a second direction X that are perpendicular to each other. The cover 1 is provided with a pole hole (not shown in the figure) that passes through the cover 1 along the first direction Z, wherein angles between 85° and 95° can be considered perpendicular to each other. The pole 2 is passed through the pole hole. At least two battery cells 3 are arranged along the second direction X and are all arranged on the same side of the cover 1. Each battery cell 3 includes a body 31 and a tab bundle 32 connected to the body 31. The tab bundle 32 is composed of a plurality of tabs stacked together and has a welding portion 321. In the second direction X, a gap 100 is defined between the welding portions 321 of the tab bundles 32 of two adjacent battery cells 3. The welding region 3211 of the welding portion 321 is welded to the electrode 2, forming a weld mark 3212 on the welding region 3211. In the non-welding region 3213 of the welding portion 321, a gap 200 is defined between two adjacent tabs on the same tab bundle 32 in the first direction Z. The protective adhesive structure 4 includes a filling portion 41 and a covering portion 42. The filling portion 41 fills the gap 100 and the gap 200. The covering portion 42 is connected to the surface of the welding portion 321 facing away from the electrode 2 and at least covers the weld mark 3212.

[0050] The protective glue structure 4 of the present application includes a filling portion 41 and a covering portion 42. The filling portion 41 of the protective glue structure 4 is filled in the gap 100 between the welding portion 321 of the tab bundle 32 of two adjacent battery cells 3, and is filled in the gap 200 in the first direction Z between two adjacent tabs corresponding to the non-welding area 3213 of the welding portion 321 in the same tab bundle 32. The protective glue structure 4 covers the surface of the welding portion 321 facing away from the pole 2 and at least covers the weld mark 3212 to absorb foreign matter such as welding slag and burrs generated during the welding process. In the specific production process, the above-mentioned protective glue structure 4 can be formed by curing a protective glue with castability. It is precisely based on the castability of the protective glue that it can flow and fill in the above-mentioned gap 100 and gap 200, which can absorb metal burrs generated when the tab bundle 32 is cut. Therefore, the above technical solution adopted in the present application can prevent metal burrs or welding slag from escaping into the battery cell 3 and causing battery short circuit, thereby affecting the performance of the single cell, and is conducive to improving the yield rate of the single cell.

[0051] It should be noted that, referring to Figures 1 and 2, during the specific production process, it is necessary to weld the multiple tabs stacked in the tab bundle 32, and then weld the tab bundle 32 to the pole 2 mounted on the cover 1 to achieve the connection between them. The housing 6 has an accommodating cavity and an opening communicating with the accommodating cavity.

[0052] Furthermore, in the non-welding area 3213 of the welding portion 321, a gap 200 is formed between two adjacent tabs on the same tab bundle 32 in the first direction Z. It can also be understood that in the portion of the welding portion 321 of the tab bundle 32 that is not welded, or in the remaining portion of the welding portion 321 except the welding area 3211, a gap 200 is formed between two adjacent tabs in the same tab bundle 32 in the stacking direction.

[0053] As shown in Figure 3, the upper battery cell 3 of the two battery cells 3 needs to be flipped counterclockwise, and the lower battery cell 3 of the two battery cells 3 needs to be flipped clockwise, so that the two battery cells 3 are close to each other, completing the core closing operation, and are installed in the accommodating cavity of the shell 6 (see Figure 1 for the label), and finally the above-mentioned cover 1 is welded and fixed to the opening to seal the above-mentioned accommodating cavity to form a closed space, thereby sealing the two battery cells 3 in the accommodating cavity of the shell 6.

[0054] As can be seen from Figures 2 to 4 , the filling portion 41 contacts the electrode 2, and the area enclosed by the orthographic projection of the weld mark 3212 on the cover 1 is located within the area enclosed by the orthographic projection of the covering portion 42 on the cover 1. That is, the filling portion 41 completely fills the gap 100 and is in contact with the electrode 2, thereby preventing the presence of an exposed area between the filling portion 41 and the surface of the electrode 2 facing the weld portion 321, from which metal burrs and welding slag can escape into the battery cell 3. Furthermore, the covering portion 42 completely covers the weld mark 3212, thereby improving the adsorption effect of the protective adhesive structure 4 and further preventing metal burrs or welding slag from escaping into the battery cell 3.

[0055] In some embodiments of the present application, referring to FIG5 , the area enclosed by the orthographic projection of the covering portion 42 on the cover body 1 is located within the area enclosed by the orthographic projection of the welding portion 321 on the cover body 1. In this embodiment, it is only necessary to ensure that the covering portion 42 can completely cover the welding mark 3212, thereby controlling the amount of material used to make the covering portion 42, thereby effectively controlling the manufacturing cost of the single battery.

[0056] In other embodiments of the present application, the area enclosed by the orthographic projection of the covering portion 42 on the cover body 1 overlaps the area enclosed by the orthographic projection of the welding portion 321 on the cover body 1. For example, the filling portion 41 and the gap 100 both extend along the third direction Y, and the gap 100 is in contact with and connected to the filling portion 41 at any position along the third direction Y.

[0057] In conjunction with Figures 6 to 8, in some embodiments of the present application, the single cell further includes an insulating layer 5, which is connected to the surface of the cover 1 facing the tab bundle 32 and is arranged around the outer periphery of the terminal 2. The protective adhesive structure 4 also includes an extension portion 43 connected to the covering portion 42. The extension portion 43 covers the surface of the insulating layer 5 facing away from the cover 1 and is connected to the insulating layer 5 to increase the structural stability of the single cell.

[0058] It should be noted that the above-mentioned single battery also includes a third direction Y. The first direction Z, the second direction X, and the third direction Y intersect with each other. The portions of the above-mentioned filling portion 41 and covering portion 42 extending from the electrode 2 along the third direction Y or extending from the welded portion 43 connected to the tab bundle 32 on the electrode 2 along the third direction Y are used to form the above-mentioned extension portion 43. In addition, the above-mentioned filling portion 41, covering portion 42, and extension portion 43 have an integrated structure, that is, they can be formed in a single process during processing and manufacturing.

[0059] For example, in the third direction Y, the size of the extension portion 43 is F mm and satisfies: 1≤F≤300, so as to ensure that the structural stability of the single cell with the extension portion 43 is good, which is conducive to ensuring the yield rate of the single cell; if F is greater than 300, it is easy to interfere with the cell joining process, resulting in slow cell joining or even failure to join.

[0060] 1 and 9 , when the above-mentioned battery cells 3 are combined, the battery cells 3 need to be flipped over so that two adjacent battery cells are close to each other. Here, the connection portion 322 in the tab bundle 32 of the same battery cell 3 will be bent. After the above-mentioned battery cells 3 are combined, the welding portion 321 extends along the second direction X, the battery cell 3 extends along the first direction Z, and the extension direction of the connection portion 322 intersects both the first direction Z and the second direction X.

[0061] As shown in FIG3 , before the battery cells 3 are joined together, the body 31 , the connecting portion 322 , and the welding portion 321 of the same battery cell 3 extend in sequence along the X direction.

[0062] Therefore, if the covering portion 42 extends to the portion where the tab bundle 32 is connected to the main body 31, on the one hand, it will interfere with the folding and closing of the battery cell 3 when the battery cell 3 is closed, and on the other hand, it will cause material waste. Referring to Figures 1 and 9, the tab bundle 32 of the present application also has a connecting portion 322, which is connected between the welding portion 321 and the main body 31. The covering portion 42 does not cover the connecting portion 322, that is, the size of the covering portion 42 in the second direction X does not need to be designed to be very large. Such a design can, on the one hand, save the manufacturing materials required for the protective glue structure 4, and on the other hand, maintain the flexibility of the tab bundle 32, making it convenient for the battery cell 3 to be folded and closed.

[0063] 7 , the protective adhesive structure 4 has a first edge 44 and a second edge 45 , which are arranged opposite to each other along the second direction X. The cover body 1 has a first side 11 and a second side 12 arranged opposite to each other along the second direction X. The first side 11 is close to the first edge 44 and has a first spacing W1 mm ​​with the first edge 44 in the second direction X. The second side 12 is close to the second edge 45 and has a second spacing W2 mm with the second edge 45 in the second direction X, and satisfies the following conditions: 0.1≤W1≤80, 0.1≤W2≤80. This prevents the protective adhesive structure 4 from overflowing from the welding portion 321 of the tab bundle 32 after dispensing glue on the surface of the welding portion 321 of the tab bundle 32 facing away from the pole 2 and after being extruded by the pressing block. In addition, the manufacturing material of the protective adhesive structure 4 can be saved. If either W1 or W2 is greater than 80, it will interfere with the core closing process, which is not conducive to the folding of the tab bundle 32 and affects the core closing.

[0064] In order to better prevent metal debris or welding slag from entering the body 31 of the battery cell 3 through the above-mentioned gap 100 or gap 200, thereby causing the problem of low yield of the single battery, the size of the above-mentioned gap 100 in the first direction Z is H1mm, and the size of the part of the filling part 41 filled in the gap 100 in the first direction Z is H2mm, and satisfies: H2≥H1, thereby ensuring that the gap 100 is completely filled by the filling part 41, and relying on the material flowability of the protective glue structure 4, in the non-welding area 3213 in the welding part 321, the tiny gap 200 in the first direction Z between the two adjacent tabs in the same tab bundle 32 close to the gap 100 will also be filled by the filling part 41.

[0065] Among them, the above-mentioned protective glue structure 4 can be obtained by coating glue, or by pasting tape and then hot-pressing and softening the tape; or, it can also be obtained by a dispensing process and then extrusion molding using a pressing block, which is not specifically limited in this application.

[0066] 4 , the portion of the filling portion 41 filling the gap 100 has a size of H2 mm in the first direction Z and satisfies: 0.05≤H2≤5, ensuring that the filling portion 41 can fill the gap 100 without causing material waste.

[0067] In other embodiments, the dimension of the covering portion 42 in the first direction Z is H3 mm and satisfies: 0.05≤H3≤2.5. Since the weld mark 3212 on the surface of the welding portion 321 of the tab bundle 32 facing away from the pole 2 is an uneven surface, the dimension H3 of the covering portion 42 in the first direction Z is controlled to be between 0.05 and 2.5, which can ensure that the covering portion 42 completely covers the weld mark 3212.

[0068] It should be noted that, as shown in FIG4 , the surfaces of the filling portion 41 and the covering portion 42 facing away from the tab bundle 32 are substantially in the same plane. In this embodiment, H2 - H3 = H1. Of course, the surfaces of the filling portion 41 and the covering portion 42 facing away from the tab bundle 32 may not be in the same plane, and this application does not impose any specific limitations on this.

[0069] It should be noted that the performance of the protective adhesive structure in the embodiment of the present application is represented by the yield rate η of the single cell. During the specific test, a stable production line was selected and different adhesive coating schemes were used for verification. Each scheme produced 10,000 pieces of products. The proportion of defective products in the batch was collected and the yield rate was calculated. The testing method includes: screening out defective products through hi-pot testing and K value (voltage drop of the battery per unit time) testing, and determining the number of defects caused by welding and cutting foreign matter through disassembly analysis and sampling testing.

[0070] The performance of the technical solution provided in the embodiments of this application is evaluated in conjunction with specific embodiments below.

[0071] Examples 1 to 24 are provided. Examples 1 to 4 satisfy 0.1≤W1≤80, with the remaining parameters being constants, for example, the second interval W2mm, H2, H3, and F. Examples 5 to 8 satisfy 0.1≤W2≤80, with the remaining parameters being constants, for example, the first interval W1mm, H2, H3, and F. Examples 9 to 12 satisfy 0.05≤H2≤5, with H2=H1, with the remaining parameters being constants, for example, the first interval W1mm, the second interval W2mm, H3, and F. Examples 13 to 16 satisfy 0.05≤H2≤5, with H2>H1, with the remaining parameters being constants, for example, the first interval W1mm, the second interval W2mm, H3, and F. Examples 17 to 20 satisfy 0.05≤H3≤2.5, with the remaining parameters being constants, for example, the first interval W1mm, the second interval W2mm, H2, and F. Examples 21 and 24 satisfy 1≤F≤300, and the remaining parameters are fixed values, for example, the first interval W1mm, the second interval W2mm, H2, and H3. Specific parameters and test results are detailed in Table 1.

[0072] Table 1

[0073]

[0074] In combination with Examples 1 to 24 and the comparative example, it can be seen that the above-mentioned protective glue structure 4 can ensure that the single cell has a higher yield η, while for the protective glue structure 4 without the covering portion 42 or the extension portion 43, the yield of the single cell is relatively low; at the same time, for the embodiments where W1 and W2 are lower than the range value, there will be interference between the tabs during the cell assembly process, affecting the assembly and ultimately leading to a decrease in the yield; for the embodiments where F is lower than the range value, there will be a risk of metal foreign matter and burrs escaping, and the yield will also be reduced accordingly; using a conventional glue sticking solution to stick it to the surface of the weld mark 3212, the yield is also relatively low.

[0075] In some embodiments of the present application, the present application further provides a battery pack, which includes a box body and the single battery described in the above technical solution, and the single battery is accommodated in the box body.

[0076] Since the battery pack provided in the present application includes the single battery as described in the above technical solution, the two can solve the same problem and achieve the same effect.

[0077] The above is only a specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the scope of protection of the present application.

Claims

1. A single cell battery, wherein: include: The cover body (1) has a first direction (Z) and a second direction (X) perpendicular to each other, and the cover body (1) is provided with a pole hole penetrating the cover body (1) along the first direction (Z); A pole (2) is passed through the pole hole; At least two battery cells (3) are arranged along the second direction (X) and are both provided on the same side of the cover (1); the battery cell (3) comprises a body (31) and a tab bundle (32) connected to the body (31); the tab bundle (32) is composed of a plurality of tabs stacked and provided with a welding portion (321); in the second direction (X), a gap (100) is provided between the welding portions (321) of the tab bundles (32) of two adjacent battery cells (3); a welding area (3211) of the welding portion (321) is welded to the pole (2) and forms a weld mark (3212) at the welding area; and in the non-welding area (3213) of the welding portion (321), a gap (200) is provided between two adjacent tabs on the same tab bundle (32) in the first direction (Z); The protective adhesive structure (4) comprises a filling portion (41) and a covering portion (42), wherein the filling portion (41) fills the gap (100) and the slit (200), and the covering portion (42) is connected to the surface of the welding portion (321) facing away from the pole (2) and at least covers the welding mark (3212).

2. The single cell according to claim 1, wherein: The filling portion (41) contacts the pole (2), and the area enclosed by the orthographic projection of the weld mark (3212) on the cover body (1) is located within the area enclosed by the orthographic projection of the covering portion (42) on the cover body (1).

3. The single cell according to claim 2, wherein: The area enclosed by the orthographic projection of the covering portion (42) on the cover body (1) is located within the area enclosed by the orthographic projection of the welding portion (321) on the cover body (1).

4. The single cell according to claim 1, wherein: Also includes: An insulating layer (5) is connected to the surface of the cover (1) facing the pole lug bundle (32) and is arranged around the outer periphery of the pole (2).

5. The single cell according to claim 4, wherein: The protective glue structure (4) further includes an extension portion (43), wherein the extension portion (43) covers a surface of the insulating layer (5) facing away from the cover body (1) and is connected to the insulating layer (5).

6. The single cell according to claim 5, wherein: The filling portion (41), the covering portion (42) and the extending portion (43) are an integrated structure.

7. The single cell according to claim 1, wherein: The tab bundle (32) further comprises a connecting portion (322), wherein the connecting portion (322) is connected between the welding portion (321) and the body (31), and the covering portion (42) does not cover the connecting portion (322).

8. The single cell according to claim 5, wherein: The protective glue structure (4) has a first edge (44) and a second edge (45), and the first edge (44) and the second edge (45) are arranged opposite to each other along the second direction (X). The cover body (1) has a first side (11) and a second side (12) arranged opposite to each other, the first side (11) is close to the first edge (44) and has a first interval W1mm with the first edge (44) in the second direction (X), the second side (12) is close to the second edge (45) and has a second interval W2mm with the second edge (45) in the second direction (X), and satisfies: 0.1≤W1≤80, 0.1≤W2≤80.

9. The single cell according to claim 2, wherein: The size of the gap (100) in the first direction (Z) is H1 mm, the size of the portion of the filling portion (41) filled in the gap (100) in the first direction (Z) is H2 mm, and the following condition is satisfied: H2 ≥ H1.

10. The single cell according to claim 9, wherein: The size of the portion of the filling portion (41) filled in the gap (100) in the first direction (Z) is H2 mm, and satisfies: 0.05≤H2≤5.

11. The single cell according to claim 9, wherein: The dimension of the covering portion (42) in the first direction (Z) is H3 mm, and satisfies: 0.05≤H3≤2.

5.

12. The single cell according to claim 11, wherein: The surfaces of the filling portion (41) and the covering portion (42) facing away from the tab bundle (32) are located in the same plane and satisfy the following: H2-H3=H1.

13. The single cell according to claim 11, wherein: Surfaces of the filling portion (41) and the covering portion (42) facing away from the tab bundle (32) are located in different planes.

14. The single cell according to claim 5, wherein: The single cell further includes a third direction (Y), the first direction (Z), the second direction (X) and the third direction (Y) intersect each other, and in the third direction (Y), the size of the extension portion (43) is F mm, and satisfies: 1≤F≤300.

15. A battery pack, wherein: include: Box; The single battery according to any one of claims 1 to 14, wherein the single battery is accommodated in the box.

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