CN116345025A - Cylindrical cells that are easy to process - Google Patents

Abstract

The invention provides a cylindrical battery which is convenient to process. The shell comprises a containing cylinder and an end piece, one end of the containing cylinder forms an annular roller groove, the roller groove divides the containing cylinder into a first section and a second section, two side walls of the roller groove are a first side wall and a second side wall respectively, and the outer surface of the joint of the first side wall and the first section forms a round corner structure. The cap assembly comprises a top cover, a PTC element, an explosion-proof piece and a sealing ring which are stacked in sequence. The top cover comprises a main body sheet and a limiting ring, and the other end of the limiting ring is bent to form a curled edge. The sealing ring comprises a first inner sealing section, a second inner sealing section, a first outer sealing section and a second outer sealing section, a slot is formed between the first inner sealing section and the second inner sealing section, the first section is inserted into the slot in an interference mode, the edge of the second outer sealing section is folded to form a clamping edge, and the clamping edge is extruded between the round corner structure and the curled edge. The cylindrical battery convenient to process has the advantages that the curling edge and the round corner structure form the button structure, the curling edge is easy to form, and the processing is convenient.

Description

Cylindrical cells that are easy to process

technical field

The invention relates to the technical field of cylindrical batteries, in particular to a cylindrical battery that is easy to process.

Background technique

Cylindrical batteries are usually sealed by a post-processing process. For cylindrical batteries in the prior art, the edge of the shell port is generally rolled inward by a crimping jig to form a crimp. The lid forms a clasp and clamps the seal ring, thereby encapsulating. Since the curling edge is perpendicular to the side wall of the shell, multiple curling presses are required to complete the sealing process, resulting in low production efficiency and unable to meet the ever-changing market and customer needs.

Therefore, it is necessary to provide a cylindrical battery that is easy to process to solve the above technical problems.

Contents of the invention

The invention provides a cylindrical battery that is easy to process, which reduces the difficulty of packaging, improves the production efficiency, and is more convenient to process.

Technical scheme of the present invention is:

A cylindrical battery that is easy to process, comprising:

The casing includes a housing cylinder, one end of the housing cylinder is recessed along its circumference to form an annular roller groove, and the roller groove divides the housing cylinder into a first section and a second section along its axial direction, and the roller The two side walls of the groove are respectively a first side wall and a second side wall, the first side wall is connected to the first section, the second side wall is connected to the second section, and the second side wall is connected to the second section. The outer surface of the junction between the first side wall and the first section forms a rounded structure;

A cap assembly, which is fixed on the first section, and the cap assembly includes a top cover, a PTC element, a rupture disk and a sealing ring stacked in sequence along the axial direction of the containing cylinder; the top cover is located at the top of the cap assembly On the side away from the second section, the top cover includes a main body piece and a stop ring, the main body piece is connected to one end of the stop ring, and the other end of the stop ring faces toward the central axis of the stop ring. The direction is bent to form an arc-shaped curling in section; both the PTC element and the explosion-proof plate are spaced apart from the limiting ring; a sealing segment, a second inner sealing segment, a first outer sealing segment and a second outer sealing segment, the PTC element and the rupture disk are clamped between the first inner sealing segment and the main body sheet; the The periphery of the PTC element and the explosion-proof disk are all attached to the second inner sealing section, the first outer sealing section is attached to the main body piece, and the second outer sealing section is attached to the limit ring together, the second inner sealing section, the first outer sealing section and the second outer sealing section form a slot opening towards the second section, and the first section is interferingly inserted In the slot, the edge of the second outer sealing section is folded toward the central axis of the sealing ring to form a clamping edge, and the clamping edge is pressed between the fillet structure and the roll between the sides; and,

The electric core is located in the second section.

In the easy-to-process cylindrical battery of the present invention, the first side wall is parallel to the second side wall, and both are perpendicular to the axial direction of the containing cylinder, and the first side wall and the second side wall are The distance between the second side walls is 2-10 times the thickness of the bead; the width of the first side wall is 2-10 times the thickness of the bead.

In the processable cylindrical battery of the present invention, the thickness of the second outer sealing section is smaller than the thickness of the second inner sealing section.

In the easy-to-process cylindrical battery of the present invention, the clamping edge protrudes from the crimping edge.

In the easy-to-process cylindrical battery according to the present invention, the side of the first inner sealing section facing the explosion-proof plate is provided with an annular first ring bone position, and the first ring bone position passes through the explosion-proof plate. Profit extrusion assembly.

In the easy-to-process cylindrical battery of the present invention, the first inner sealing section abuts against the first side wall, and the first inner sealing section protrudes from the first side wall.

In the easy-to-process cylindrical battery according to the present invention, the side of the first inner sealing section facing the first side wall is provided with an annular second ring bone position, and the second ring bone position is connected to the first ring bone position. One side wall interference extrusion assembly.

In the cylindrical battery that is easy to process according to the present invention, the explosion-proof sheet is recessed toward the direction close to the battery core to form a recess, and the side of the recess facing the main body sheet is provided with an annular explosion-proof line; The cylindrical battery further includes a first tab, and the first tab is welded to the recess.

In the cylindrical battery that is easy to process according to the present invention, the cylindrical battery further includes a first insulating sheet, the edge of which is clamped between the second side wall and one end of the battery cell, and the first insulating sheet A through hole is provided, and the first tab passes through the through hole.

In the easy-to-process cylindrical battery of the present invention, the middle part of the top cover protrudes away from the second section to form a boss, and vent holes are provided on the edge of the boss.

Compared with the prior art, the present invention has the beneficial effects as follows: the cylindrical battery of the present invention is easy to process, the first section of which is inserted in the slot with interference, so that the cap assembly cannot move in the direction perpendicular to the axis of the containing cylinder , and make the cap assembly unable to move towards the second section; the clamping edge is squeezed between the rounded corner structure and the curling edge, so that the curling edge and the rounded corner structure form a buckle structure, so that the cap assembly cannot move away from the second segment The direction of the section moves to achieve a stable connection between the cap assembly and the shell; at the same time, the curling is formed by bending the limit ring toward the direction close to the fillet structure, and at the same time, the second outer sealing section is folded along the fillet structure to form a clamping edge In the process of processing, the limit ring can be slightly bent to form curling, which reduces the difficulty of packaging, improves the production efficiency, and is more convenient for processing.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings that need to be used in the embodiments. The drawings in the following description are only corresponding to some embodiments of the present invention. attached drawings.

FIG. 1 is a schematic structural view of a cylindrical battery in the prior art.

Fig. 2 is a schematic longitudinal cross-sectional structure diagram of a cylindrical battery provided by a preferred embodiment of the present invention.

FIG. 3 is a partially enlarged view of FIG. 2 .

FIG. 4 is another partial enlarged view of FIG. 2 .

Fig. 5 is a schematic diagram of an exploded structure of a cylindrical battery provided by a preferred embodiment of the present invention.

Fig. 6 is a schematic perspective view of a three-dimensional cross-sectional structure of a cap assembly of a cylindrical battery provided by a preferred embodiment of the present invention.

Fig. 7 is a schematic diagram of an exploded structure of a cap assembly of a cylindrical battery provided by a preferred embodiment of the present invention.

Among them, the identification in Figure 1 is as follows:

10, shell, 101, curling,

20. Top cover,

30, sealing ring.

Figures 2-7 are marked as follows:

1. Shell,

11. Holder,

111, roller groove, 1111, first side wall, 1112, second side wall,

112. The first paragraph,

113. Second paragraph,

114, rounded corner structure,

12. End pieces,

2. Cap assembly,

21. Top cover,

211, main piece, 2111, boss, 2112, air vent,

212, limit ring, 2121, curling,

22. PTC components,

23. Explosion-proof disc, 231, recessed part, 2311, explosion-proof line,

24, sealing ring,

241, the first inner sealing section, 2411, the first ring bone position, 2412, the second ring bone position,

242, the second inner sealing section,

243. The first outer sealing section,

244, the second outer sealing section, 2441, the clamping edge,

245, slot,

3. Cells,

4, the first insulating sheet, 41, the through hole,

5. The first pole ear.

In the figures, structurally similar units are denoted by the same reference numerals.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts belong to the protection scope of the present invention.

Directional terms mentioned in the present invention, such as "up", "down", "front", "rear", "left", "right", "inside", "outside", "side", "top" Words such as "bottom" and "bottom" only refer to the orientation of the drawings, and the directional terms used are used to illustrate and understand the present invention, but not to limit the present invention.

Words such as "first" and "second" in the terminology of the present invention are only used for descriptive purposes, and should not be understood as indicating or implying relative importance, and not as limiting the sequence.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediary, and it can be the internal communication of two components or the interaction relationship between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

Please refer to FIG. 1. For cylindrical batteries in the prior art, the edge of the port of the shell 10 is generally rolled inward by a crimping jig to form a crimp 101. The crimp 101 needs to overlap with the top cover 20 to a certain size, so that the crimp 101 A buckle structure is formed with the top cover 20, and the sealing ring 30 is clamped, thereby performing packaging. Since the curling edge 101 is perpendicular to the side wall of the casing 10, multiple curling and pressing are required to complete the sealing process, resulting in low production efficiency and unable to meet the ever-changing market and customer needs.

A preferred embodiment of a cylindrical battery that is easy to process and can solve the above technical problems is provided by the present invention as follows.

Referring to FIGS. 2-7 , a preferred embodiment of the present invention provides a cylindrical battery that is easy to process, which includes a case 1 , a cap assembly 2 and a cell 3 . The casing 1 includes a housing cylinder 11 and an end piece 12. One end of the housing cylinder 11 is recessed along its circumference to form an annular roller groove 111. The roller groove 111 divides the housing cylinder 11 into a first section 112 and a second section 113 along its axial direction. . The two side walls of the roller groove 111 are respectively a first side wall 1111 and a second side wall 1112, the first side wall 1111 is connected to the first section 112, the second side wall 1112 is connected to the second section 113, and the first side wall 1112 is connected to the second section 113. A rounded corner structure 114 is formed on the outer surface of the junction between the side wall 1111 and the first section 112 . The end piece 12 is fixed on the other end of the container 11 . The shell 1 can be made of stainless steel or other hardware materials, and the shell 1 is formed by deep drawing and stretching.

The cap assembly 2 is fixed on the first segment 112 , and the cap assembly 2 includes a top cover 21 , a PTC element 22 , a rupture disc 23 and a sealing ring 24 stacked in sequence along the axial direction of the housing cylinder 11 . The top cover 21 is located on the side of the cap assembly 2 away from the second section 113. The top cover 21 includes a main body piece 211 and a limit ring 212. The main body piece 211 is connected to one end of the limit ring 212, and the other end of the limit ring 212 is Bending towards the direction of its central axis forms a curling edge 2121 with an arc-shaped cross section. The curling 2121 is formed by post-processing. The outer diameter of the limiting ring 212 is equal to the outer diameter of the second segment 113 . The top cover 21 can be made of stainless steel or other hardware materials, and the top cover 21 is formed by deep drawing and stretching. Both the PTC element 22 and the explosion-proof disc 23 are spaced apart from the limiting ring 212, and the PTC element 22 is ring-shaped. The PTC element 22 is arranged between the top cover 21 and the explosion-proof plate 23 in a sealed contact state. When the internal temperature of the battery rises, the PTC element 22 greatly increases the battery resistance to interrupt the current. The sealing ring 24 includes a first inner sealing section 241 , a second inner sealing section 242 , a first outer sealing section 243 and a second outer sealing section 244 which are ring-shaped and sequentially connected from the inside to the outside, the PTC element 22 and the explosion-proof disk 23 It is sandwiched between the first inner sealing segment 241 and the main body piece 211 . The peripheral edges of the PTC element 22 and the explosion-proof disc 23 are all bonded to the second inner sealing section 242, the first outer sealing section 243 is bonded to the main body sheet 211, the second outer sealing section 244 is bonded to the limit ring 212, and the second inner sealing section 243 is bonded to the stop ring 212. The sealing section 242, the first outer sealing section 243 and the second outer sealing section 244 form a slot 245 with an opening facing the second section 113, the first section 112 is inserted in the slot 245 with interference, and the second outer sealing section The edge of the sealing section 244 is folded toward the central axis of the sealing ring 24 to form a clamping edge 2441 , and the clamping edge 2441 is squeezed between the fillet structure 114 and the curling edge 2121 . FIG. 6 shows a structure in which the limiting ring 212 is not crimped to form a crimp 2121 , and the second outer sealing section 244 is not folded to form a clamping edge 2441 . The sealing ring 24 plays the role of insulation and sealing, and it can be made of plastic materials such as PP, PI, PS, etc., and its melting point is preferably 100°C-500°C. The explosion-proof sheet 23 is a conductive film structure. The battery core 3 is located in the second section 113, which can be wound or laminated.

In the cylindrical battery that is easy to process in the present invention, the first section 112 is inserted in the slot 245 with interference, so that the cap assembly 2 cannot move in the direction perpendicular to the axis of the containing cylinder 11, and the cap assembly 2 cannot move closer to the first section. The direction of the second section 113 moves; the clamping edge 2441 is squeezed between the rounded structure 114 and the curling edge 2121, so that the curling edge 2121 and the rounded corner structure 114 form a buckle structure, so that the cap assembly 2 cannot move away from the second section 113 direction to move in order to achieve a stable connection between the cap assembly 2 and the housing 1; at the same time, the bead 2121 is formed by bending the limit ring 212 towards the direction of the fillet structure 114, while the second outer sealing section 244 is along the fillet structure 114 The clamping edge 2441 is formed by folding, and the curling edge 2121 can be formed by slightly bending the limiting ring 212 during the processing, which reduces the difficulty of packaging, improves the manufacturing efficiency, and is more convenient for processing.

Please refer to Fig. 3 and Fig. 4, the first side wall 1111 is parallel to the second side wall 1112, and both are perpendicular to the axial direction of the containing cylinder 11, the distance d between the first side wall 1111 and the second side wall 1112 The width w of the first side wall 1111 is 2-10 times the thickness of the curl 2121 . The thickness of the curling edge 2121 is the size of the limit ring 212 in a direction perpendicular to the axis of the containing cylinder 11 . If the distance d between the first side wall 1111 and the second side wall 1112 is too large, the capacity of the battery cell 3 will be small; if the distance d between the first side wall 1111 and the second side wall 1112 is too small, it is not conducive to The limiting ring 212 is crimped by a crimping jig to form the crimp 2121 . The distance d between the first side wall 1111 and the second side wall 1112 is 2-10 times of the thickness of the bead 2121, in the case of crimping the limiting ring 212 to form the bead 2121 by crimping jig , it can ensure that the capacity of the battery cell 3 is as large as possible. The width w of the first side wall 1111 is 2-10 times the thickness of the bead 2121 , which is also convenient for crimping the limiting ring 212 to form the bead 2121 by a crimping jig. The cross-section of the roller groove 111 shown in this embodiment is U-shaped, and it can also be set as V-shaped or other shapes in other embodiments.

Referring to FIG. 3 , the thickness of the second outer sealing section 244 is smaller than the thickness of the second inner sealing section 242 . The thickness of the second outer sealing section 244 is the dimension of the second outer sealing section 244 in a direction perpendicular to the axis of the containing cylinder 11 . The thickness of the second inner sealing section 242 is the dimension of the second inner sealing section 242 in a direction perpendicular to the axis of the containing cylinder 11 . The above-mentioned structure facilitates the formation of the curling edge 2121 and the formation of the clamping edge 2441 at the same time.

Please continue to refer to FIG. 3 , the clamping edge 2441 protrudes from the curling edge 2121 . This structure maintains good insulation between the top cover 21 and the housing 1 .

Please refer to FIG. 3 and FIG. 6 , the side of the first inner sealing section 241 facing the explosion-proof disc 23 is provided with an annular first ring rib 2411 , and the first ring rib 2411 is press-fitted with the explosion-proof disc 23 by interference. This structure enables a good seal between the sealing ring 24 and the explosion-proof disk 23 .

Referring to FIG. 3 , the first inner sealing section 241 abuts against the first side wall 1111 , and the first inner sealing section 241 protrudes from the first side wall 1111 . When an inward force is applied to the cap assembly 2 from the outside along its axial direction, the first inner sealing section 241 abuts against the first side wall 1111, and the first side wall 1111 can share the force of the first section 112 to prevent The first segment 112 is deformed. The first inner sealing section 241 protrudes from the first side wall 1111 , so that there is good insulation between the burst disk 23 and the casing 1 .

Please refer to FIG. 3 and FIG. 6 , the first inner sealing section 241 is provided with an annular second ring rib 2412 on the side facing the first side wall 1111 , and the second ring rib 2412 is squeezed with the first side wall 1111 by interference assembly. This structure enables a good sealing performance between the sealing ring 24 and the housing 1 .

Please refer to Figure 2 and Figure 3, the explosion-proof sheet 23 is recessed toward the direction close to the battery 3 to form a recess 231, and the side of the recess 231 facing the main sheet 211 is provided with an annular explosion-proof wire 2311; the cylindrical battery also includes a first tab 5. The first tab 5 is welded to the recessed part 231 . In the above structure, the first tab 5 is welded to the recessed portion 231 , so that the welding of the first tab 5 and the explosion-proof plate 23 is easy. When the pressure inside the battery exceeds a predetermined level, the pressure presses against the explosion-proof wire 2311, and the explosion-proof wire 2311 is arranged on the recessed part 231, which can speed up the disconnection of the explosion-proof wire 2311, so as to quickly discharge the gas. The explosion-proof wire 2311 illustrated in FIG. 3 is one turn, and in other embodiments, the explosion-proof wire 2311 may also be set to be multiple turns.

Please refer to Figure 2 and Figure 3, the cylindrical battery also includes a first insulating sheet 4, the edge of which is sandwiched between the second side wall 1112 and one end of the cell 3, the first insulating sheet 4 is provided with a through hole 41, the second A through hole 41 is formed in one tab 5 . In the above structure, the first insulating sheet 4 is clamped between the second side wall 1112 and the battery core 3 , so that the first insulating sheet 4 is fixed and stable. The first tab 5 is pierced with a through hole 41 , so that the first tab 5 passes through the first insulating sheet 4 . The through holes 41 illustrated in this embodiment are arc-shaped, and there are three uniformly distributed along the circumferential direction of the first insulating sheet 4 , and other shapes or other numbers may also be provided in other embodiments. The cylindrical battery also includes a second insulating sheet sandwiched between the other end of the cell 3 and the end sheet 12 . The cylindrical battery also includes a second tab, which is welded to the end piece 12 .

Referring to FIG. 3 and FIG. 7 , the middle part of the top cover 21 protrudes away from the second section 113 to form a boss 2111 , and an exhaust hole 2112 is provided on the edge of the boss 2111 . In the above structure, the boss 2111 is convenient to connect with the polarity terminal of the external circuit. When the internal pressure of the battery is too high, the vent hole 2112 can discharge the pressurized gas out of the inner cavity of the casing 1 . This embodiment shows three square exhaust holes 2112, and the number of exhaust holes 2112 can also be set in other numbers, and the shape can also be other shapes such as circle, ellipse, or star.

The processing process of the cylindrical battery that is convenient to process in the preferred embodiment of the present invention:

1. Put the PTC element 22, the explosion-proof disk 23 and the sealing ring 24 into the top cover 21 in sequence, and the second inner sealing section 242 forms a limit for the PTC element 22 and the explosion-proof disk 23, and then weld the PTC element 22 and the explosion-proof disk 23 in sequence , forming a cap assembly 2;

2. Put the cell 3 into the casing 1;

3. Insert the first section 112 into the slot 245, thereby assembling the cap assembly 2 with the housing 1;

4. Drop in the electrolyte;

5. Crimping the limit ring 212 to form a crimp 2121 with a crimping jig, so that the clamping edge 2441 is directly buckled on the fillet structure 114, and the crimp 2121 is indirectly buckled on the fillet structure 114, so that the crimp 2121 and the fillet structure 114 form a buckle structure.

In this way, the processing process of the easy-to-process cylindrical battery of the preferred embodiment is completed.

In the cylindrical battery that is easy to process in the present invention, the first section is interferingly inserted in the slot, so that the cap assembly cannot move in a direction perpendicular to the axis of the containing cylinder, and the cap assembly cannot move in a direction close to the second section ;The clamping edge is squeezed between the rounded corner structure and the curling edge, so that the curling edge and the rounded corner structure form a buckle structure, so that the cap assembly cannot move away from the second section, so as to achieve a stable connection between the cap assembly and the shell ; At the same time, the curling is formed by bending the limit ring toward the direction close to the rounded corner structure, and at the same time, the second outer sealing section is folded along the rounded corner structure to form a clamping edge, and the limit ring is slightly bent during processing Curling can be formed, which reduces the difficulty of packaging, improves the production efficiency, and is more convenient for processing.

In summary, although the present invention has been disclosed as above with preferred embodiments, the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technology of the present invention Any equivalent replacement or change of the idea of the scheme shall fall within the protection scope of the present invention.

Claims (10)

1. A cylindrical battery for facilitating processing, comprising:

the shell comprises a containing cylinder, one end of the containing cylinder is recessed along the circumferential direction of the containing cylinder to form an annular roller groove, the roller groove divides the containing cylinder into a first section and a second section along the axial direction of the containing cylinder, two side walls of the roller groove are a first side wall and a second side wall respectively, the first side wall is connected with the first section, the second side wall is connected with the second section, and the outer surface of the joint of the first side wall and the first section forms a round corner structure;

a cap assembly fixed to the first section, the cap assembly including a top cap, a PTC element, a explosion-proof sheet, and a sealing ring stacked in order along an axial direction of the accommodating cylinder; the top cover is positioned on one side of the cap assembly, which is far away from the second section, and comprises a main body piece and a limiting ring, wherein the main body piece is connected with one end of the limiting ring, and the other end of the limiting ring is bent towards the direction of the center of the limiting ring to form a curled edge with an arc-shaped section; both the PTC element and the explosion-proof piece are arranged at intervals with the limiting ring; the sealing ring comprises a first inner sealing section, a second inner sealing section, a first outer sealing section and a second outer sealing section which are all annular and are sequentially connected from inside to outside, and the PTC element and the explosion-proof sheet are clamped between the first inner sealing section and the main body sheet; the PTC element and the periphery of the explosion-proof piece are attached to the second inner sealing section, the first outer sealing section is attached to the main body piece, the second outer sealing section is attached to the limiting ring, a slot with an opening facing the second section is formed among the second inner sealing section, the first outer sealing section and the second outer sealing section, the first section is inserted into the slot in an interference mode, the edge of the second outer sealing section is folded towards the central axis direction of the sealing ring to form a clamping edge, and the clamping edge is extruded between the round corner structure and the curled edge; the method comprises the steps of,

and a battery cell located in the second section.

2. The ease of manufacture cylindrical battery of claim 1, wherein the first and second side walls are parallel and perpendicular to the axial direction of the containment drum, the distance between the first and second side walls being 2-10 times the thickness of the bead; the width of the first sidewall is 2-10 times the thickness of the bead.

3. The machined facilitating cylindrical battery of claim 1, wherein the thickness of the second outer seal segment is less than the thickness of the second inner seal segment.

4. The easy-to-process cylindrical battery according to claim 1, wherein the clamping edge protrudes from the beading.

5. The cylindrical battery of claim 1, wherein a face of the first inner seal segment facing the rupture disc is provided with a first annular ring of bone, the first annular ring of bone being interference extruded with the rupture disc.

6. The easy-to-process cylindrical battery according to claim 2, wherein the first inner seal segment abuts against the first side wall, and the first inner seal segment protrudes from the first side wall.

7. The cylindrical battery of claim 6, wherein a face of the first inner seal segment facing the first sidewall is provided with an annular second ring of bone sites, the second ring of bone sites being interference extruded with the first sidewall.

8. The cylindrical battery convenient to process according to claim 2, wherein the explosion-proof sheet is recessed in a direction approaching the battery cell to form a recessed portion, and an annular explosion-proof line is arranged on one surface of the recessed portion facing the main body sheet; the cylindrical battery further comprises a first tab, and the first tab is welded with the concave portion.

9. The cylindrical battery of claim 8, further comprising a first insulating sheet having an edge clamped between the second side wall and one end of the cell, the first insulating sheet having a through hole formed therein, the first tab extending through the through hole.

10. The cylindrical battery according to claim 1, wherein the middle part of the top cover protrudes away from the second section to form a boss, and an exhaust hole is formed on the edge of the boss.

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