CN216085066U

CN216085066U - Cylinder lithium cell

Info

Publication number: CN216085066U
Application number: CN202122642652.3U
Authority: CN
Inventors: 宁亚军; 姬嘉帅; 左帆帆; 夏天军; 于东朋; 王俊
Original assignee: Svolt Energy Technology Wuxi Co Ltd
Current assignee: Svolt Energy Technology Wuxi Co Ltd
Priority date: 2021-10-29
Filing date: 2021-10-29
Publication date: 2022-03-18
Anticipated expiration: 2031-10-29

Abstract

The utility model relates to the technical field of batteries, in particular to a cylindrical lithium battery. The cylinder lithium cell includes: the first end of the shell is provided with a through hole; the positive pole column penetrates through the through hole of the shell and is riveted with the outer edge of the through hole, the positive pole column and the shell are insulated from each other, and the positive pole column is provided with a central hole; the pole group is arranged in the shell, and an aluminum column is arranged at the positive pole end of the pole group and is suitable for being matched and connected with the central hole. According to the cylindrical lithium battery provided by the utility model, the positive pole column is riveted with the shell to realize the fixed connection of the pole group and the shell, and the welding mark formed by welding on the end surface of the first end of the shell is reduced, so that the occupation of the welding mark on the end surface of the first end is avoided, the area of the first end for electrically connecting with an external structure is increased, the contact internal resistance is reduced, the heat generation of the battery is reduced, the overcurrent capacity of the battery is increased, and the cylindrical lithium battery capable of improving the overcurrent capacity is provided.

Description

Cylinder lithium cell

Technical Field

The utility model relates to the technical field of batteries, in particular to a cylindrical lithium battery.

Background

With the increasing maturity of lithium battery technology, the lithium battery is widely applied to the field of electric vehicles as a power battery, the structural part of the lithium battery is an important component of the lithium battery, not only provides guarantee for the lithium battery in the aspect of safety and reliability, meanwhile, the connection between the internal chemical system of the lithium ion battery and the outside is also considered, which affects the performance of the lithium battery, so the design scheme of the structural member of the lithium battery is particularly important, wherein the aluminum column at the positive electrode end is a terminal for connecting the lithium battery with the outside, the aluminum column usually needs to extend out of the shell of the lithium battery and is fixedly connected with the end face of the shell, the connection mode is usually welding, but a solder mark is formed on the end face, and when the end face is used as a negative electrode of a lithium battery and needs to be connected with the outside by welding, because the welding marks formed by welding the aluminum columns cannot be welded in an overlapping mode, the welding area of the negative electrode is reduced, and the overcurrent capacity of the battery is affected.

SUMMERY OF THE UTILITY MODEL

Therefore, the technical problem to be solved by the utility model is to overcome the defect that the overcurrent capacity of the cylindrical lithium battery is limited due to the welding of the positive electrode terminal in the prior art, so that the cylindrical lithium battery capable of improving the overcurrent capacity is provided.

In order to solve the above technical problem, the present invention provides a cylindrical lithium battery, including:

the device comprises a shell, a first end of the shell is provided with a through hole;

the positive pole column penetrates through the through hole of the shell and is riveted with the outer edge of the through hole, the positive pole column and the shell are insulated from each other, and the positive pole column is provided with a central hole;

the pole group is arranged in the shell, an aluminum column is arranged at the positive end of the pole group, and the aluminum column is suitable for being connected with the central hole in a matched mode.

Optionally, the cylindrical lithium battery further includes: the positive current collector is arranged at the positive end of the pole group and is electrically connected with the positive end of the pole group; the aluminum column is electrically connected with the pole group through the positive pole current collector;

and the negative current collector is arranged at the negative end of the pole group, is electrically connected with the negative end of the pole group and is electrically connected with the inner wall of the shell.

Optionally, the cylindrical lithium battery further includes: and the negative electrode cover plate is fixedly connected with the second end of the shell and is suitable for sealing the shell, and one side of the negative electrode cover plate, facing the inside of the shell, is abutted to the negative electrode current collector and is suitable for supporting and fixing the electrode group.

Optionally, the positive electrode pole includes: the aluminum nail penetrates through the through hole of the first end, the cross sections of the two ends of the aluminum nail are larger than the rivet structure of the diameter of the through hole, and the center position of the aluminum nail is provided with the center hole.

Optionally, the positive electrode pole further includes: the first insulating plate is arranged on the outer side of the shell, one end of the first insulating plate is abutted with one surface, facing the outer side of the shell, of the first end, and one end, far away from the first end, of the first insulating plate is abutted with the aluminum nail and is suitable for supporting the aluminum nail;

the insulating pad is of a stepped cylindrical structure and is arranged among the aluminum nail, the first end and the first insulating plate, and the inner wall of the insulating pad is suitable for abutting against the outer wall of the aluminum nail and abutting against the inner wall of the through hole of the first end.

Optionally, the positive electrode pole further includes: the second insulating plate is arranged on the inner side of the shell, one end of the second insulating plate is suitable for abutting against one surface, facing the inner side of the shell, of the first end, and one end, far away from the first end, of the second insulating plate is suitable for abutting against the aluminum nail through the aluminum block.

Optionally, the central hole is a through hole penetrating through the positive pole, and the hole wall of the through hole of the positive pole is suitable for being fixedly connected with the aluminum column.

Optionally, the aluminum column is connected with the through hole of the anode pole in a splicing welding manner.

Optionally, the central hole is a groove on the positive pole, the open end of the groove faces the inside of the casing, the aluminum column is suitable for being embedded into the groove, and the inner wall and the bottom wall of the groove are suitable for being fixedly connected with the aluminum column.

Optionally, the aluminum column and the groove are connected by laser penetration welding or ultrasonic welding.

The technical scheme of the utility model has the following advantages:

1. the cylindrical lithium battery provided by the utility model has the advantages that the positive pole column is arranged in the through hole of the first end of the shell in a penetrating way and is riveted with the outer edge of the through hole, so that the positive pole column is fixedly connected with the shell, the aluminum column of the positive end of the pole group is matched with the central hole of the positive pole column so as to be connected with the positive pole column, so that the pole group is fixedly connected with the shell, when the shell is electrically connected with the negative end of the pole group, namely the first end is used as the negative pole of the lithium battery, the first end is welded with an external structure so as to be electrically connected, compared with the traditional method that the aluminum column is directly or indirectly welded with the shell, the welding mark formed by welding on the end face of the first end of the shell is reduced, the occupation of the space on the end face of the first end by the welding mark is avoided, and the area of the first end for electrically connecting with the external structure is increased, therefore, the overcurrent capacity of the battery is increased, the contact internal resistance of the connecting part is reduced, the heat generation of the battery is reduced, and the performance of the battery is effectively improved.

2. The cylindrical lithium battery provided by the utility model has the advantages that the current at the positive lug of the positive end of the pole group is converged by arranging the positive current collector at the positive end of the pole group and electrically connected with the positive end of the pole group, the current at the negative lug of the negative end of the pole group is converged by arranging the aluminum post and electrically connected with the pole group through the positive current collector, the current at the positive end is electrically connected with the outside through the aluminum post, the current at the negative lug of the negative end of the pole group is converged by arranging the negative current collector at the negative end of the pole group and electrically connected with the negative end of the pole group, the negative current collector is electrically connected with the inner wall of the shell, so that the whole shell is electrically connected with the negative end of the pole group through the negative current collector, the shell is connected with an external circuit as the negative pole of the battery, and the end face provided with the positive pole on the shell can be set as the negative terminal connected with the outside according to requirements, realize that the positive negative terminal of battery lies in same one side, when being favorable to the battery to assemble the module, the design and the welding of module busbar, simple structure and connection convenience.

3. According to the cylindrical lithium battery provided by the utility model, the negative cover plate is fixedly connected with the second end of the shell, so that the second end of the shell is sealed, and the negative end cover is abutted with the negative current collector, so that the pole group is supported and fixed, and the stability and the safety of the battery are ensured.

4. According to the cylindrical lithium battery provided by the utility model, the aluminum nail provided with the anode pole is arranged in the through hole at the first end in a penetrating manner, the aluminum nail is in a rivet structure with the sectional area at two ends larger than the diameter of the through hole, so that the aluminum nail is riveted with the shell, and meanwhile, the first insulating plate, the insulating pad, the second insulating plate and the aluminum block are arranged between the aluminum nail and the shell, so that the aluminum nail is fixed, the aluminum nail is in insulating connection with the shell, the connection between the anode pole and the shell is realized, and the anode pole and the shell are ensured to be insulated from each other.

5. According to the cylindrical lithium battery provided by the utility model, the central hole is a through hole penetrating through the anode pole, the hole wall of the through hole of the anode pole is fixedly connected with the aluminum column in a splicing and welding manner, so that whether the aluminum column is assembled in place or not can be conveniently observed through the through hole of the anode pole, and the aluminum column is only required to be welded with the hole wall of the anode pole, so that the assembling and the welding connection are convenient.

6. According to the cylindrical lithium battery provided by the utility model, the central hole is a groove on the positive pole, and the inner wall and the bottom wall of the groove are fixedly connected with the aluminum column through laser penetration welding or ultrasonic welding, so that the aluminum column is prevented from being exposed outside, the aluminum column is protected from being damaged, and the conductivity and the safety performance of the battery are further ensured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a cross-sectional view of a cylindrical lithium battery of the present invention;

FIG. 2 is a top view of a cylindrical lithium battery of the present invention;

FIG. 3 is an assembly view of the positive terminal post and the housing of the cylindrical lithium battery of the present invention;

FIG. 4 is an assembly view of the present invention with the electrode assembly connected to the current collector and aluminum post;

FIG. 5 is a top view of the assembly of the electrode assembly with current collectors and aluminum posts of the present invention;

FIG. 6 is a schematic structural view of an aluminum nail according to the present invention;

FIG. 7 is a partial schematic view of a positive terminal of a cylindrical lithium battery using the aluminum nail of FIG. 6;

FIG. 8 is a schematic view of another type of aluminum nail structure;

fig. 9 is a partial schematic view of a positive terminal of a cylindrical lithium battery using the aluminum nail of fig. 8.

Description of reference numerals:

1. a positive pole column; 101. an insulating pad; 102. aluminum nails; 103. a first insulating plate; 104. a second insulating plate; 105. an aluminum block; 106. a central bore; 2. an aluminum column; 3. a positive current collector; 4. a housing; 41. a first end; 5. a pole group; 6. a negative current collector; 7. and a negative electrode cover plate.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Referring to fig. 1 to 9, the cylindrical lithium battery provided in this embodiment includes:

a housing 4, a first end 41 of the housing 4 being provided with a through hole;

the positive pole column 1 penetrates through the through hole of the shell 4 and is riveted with the outer edge of the through hole, the positive pole column 1 and the shell 4 are insulated from each other, and the positive pole column 1 is provided with a center hole 106;

the pole group 5 is arranged in the shell 4, an aluminum column 2 is arranged at the positive end of the pole group 5, and the aluminum column 2 is suitable for being matched and connected with the central hole 106.

It should be noted that the outer edge of the through hole refers to the position of the upper and lower surfaces of the first end 41 of the housing 4 near the through hole, and the upper and lower surfaces refer to the "upper" and "lower" arrows in fig. 1.

It should be noted that, when the aluminum column is assembled with the casing in the prior art, the aluminum column is connected with the casing in an insulated manner by arranging the connecting part, the connecting part is welded with the joint of the casing, however, the welding connection forms a welding mark on the end face of the casing, when the negative electrode of the electrode group in the casing is electrically connected with the casing through the connecting part, the whole casing can be used as the negative electrode terminal for connecting the battery with an external circuit, and according to the requirement, one end of the casing provided with the aluminum column can be selected as the negative electrode terminal to be connected with the outside, so that the positive electrode terminal and the negative electrode terminal are positioned on the same side of the battery, which is convenient for designing and connecting components such as a module busbar and the like, and the mode of connecting the negative electrode terminal with the outside is also welding, because the welding mark at the positive electrode terminal occupies the space on the end face, the connecting area for welding the negative electrode terminal is reduced, make the current capacity of battery reduce, be unfavorable for the promotion of battery performance, and this application adopts anodal utmost point post 1 with 4 riveted connected modes of casing can not form the welding seal, therefore make and supply the welded regional grow of negative terminal, the regional grow of welding makes to connect the internal resistance and reduces to the heat production of battery reduces, the current capacity increase of battery.

In the cylindrical lithium battery provided in this embodiment, the positive electrode post 1 is disposed through the through hole of the first end 41 of the casing 4 and riveted to the outer edge of the through hole, so as to fixedly connect the positive electrode post 1 and the casing 4, the aluminum post 2 at the positive electrode end of the electrode group 5 is connected to the positive electrode post 1 by matching with the central hole of the positive electrode post 1, so as to fixedly connect the electrode group 5 and the casing 4, when the casing 4 is electrically connected to the negative electrode end of the electrode group 5, that is, the first end 41 serves as the negative electrode of the lithium battery, the first end 41 is welded to an external structure to achieve electrical connection, and in this embodiment, compared with the conventional welding connection, the manner of riveting the positive electrode post to the casing 4 reduces welding marks formed by welding on the end surface of the first end 41 of the casing 4, therefore, the occupation of the space on the end face of the first end 41 by welding is avoided, the area of the first end 41 for electrically connecting with an external structure is increased, the overcurrent capacity of the battery is increased, the contact internal resistance of a connecting part is reduced, the heat generation of the battery is reduced, and the performance of the battery is effectively improved.

Specifically, the cylinder lithium cell still includes: the positive current collector 3 is arranged at the positive end of the pole group 5 and is electrically connected with the positive end of the pole group 5; the aluminum column 2 is electrically connected with the pole group 5 through the positive electrode current collector 3;

and the negative current collector 6 is arranged at the negative end of the pole group 5, is electrically connected with the negative end of the pole group 5 and is electrically connected with the inner wall of the shell 4.

Optionally, the positive current collector 3 is a disk.

Optionally, the negative current collector 6 is a disk, and the edge of the disk is locally thickened and is suitable for being connected with the inner wall of the shell 4.

Optionally, the connection mode of the positive current collector 3 and the electrode group 5 is laser welding.

Optionally, the connection mode of the negative current collector 6 and the electrode group 5 and the connection mode of the negative current collector and the inner wall of the housing 4 are laser welding.

Optionally, the connection mode of the aluminum column 2 and the positive current collector 3 includes laser welding or ultrasonic welding.

In the cylindrical lithium battery provided in this embodiment, the positive current collector 3 is disposed at the positive end of the electrode group 5 and electrically connected to the positive end of the electrode group 5, so as to achieve current collection at the positive tab of the positive end of the electrode group 5, the aluminum post 2 is disposed to electrically connect to the electrode group 5 via the positive current collector 3, so as to achieve current collection at the positive tab of the negative end of the electrode group 5 via the aluminum post 2, the negative current collector 6 is disposed at the negative end of the electrode group 5 and electrically connected to the negative end of the electrode group 5, so as to achieve current collection at the negative tab of the negative end of the electrode group 5, and the negative current collector 6 is electrically connected to the inner wall of the case 4, so that the entire case 4 is electrically connected to the negative end of the electrode group 5 via the negative current collector 6, so as to achieve connection between the case 4 as the negative electrode of the battery and an external circuit, can will according to the demand be provided with the terminal surface setting of anodal utmost point post 1 on the casing 4 to with external connection's negative terminal, realize that the positive negative terminal of battery lies in same one side, when being favorable to the battery to assemble to the module, the design and the welding of module busbar, simple structure and connection convenience.

Specifically, the cylinder lithium cell still includes: and the negative electrode cover plate 7 is fixedly connected with the second end of the shell 4 and is suitable for sealing the shell 4, and one side, facing the inside of the shell 4, of the negative electrode cover plate 7 is abutted with the negative electrode current collector 6 and is suitable for supporting and fixing the pole group 5.

It should be noted that the second end is an end of the housing 4 opposite to the first end, the second end is an open end, and the pole group is loaded into the housing 4 through the open end; the negative electrode cover plate 7 is hermetically connected with the shell 4, and the negative electrode cover plate 7 is also an explosion-proof valve and plays an explosion-proof role.

Optionally, the negative electrode cover plate 7 and the housing 4 are connected by welding.

The cylinder lithium cell that this embodiment provided, through setting up negative cover plate 7 with the second end fixed connection of casing 4 realizes right the sealed of casing second end, and through negative cover plate 7 with 6 looks butt of negative current collector, it is right to realize the support and the fixed of utmost point group 5 guarantee the stability and the security of battery.

Specifically, the positive electrode post 1 includes: the aluminum nail 102 is inserted into the through hole of the first end 41, the cross-sectional area of both ends of the aluminum nail 102 is larger than the diameter of the through hole, and the center of the aluminum nail 102 is provided with the center hole 106.

Specifically, the positive electrode post 1 further includes: a first insulating plate 103 disposed outside the housing 4, wherein one end of the first insulating plate 103 abuts against one surface of the first end 41 facing the outside of the housing 4, and one end of the first insulating plate 103 away from the first end 41 abuts against the aluminum nail 102 and is adapted to support the aluminum nail 102;

an insulating pad 101 configured as a stepped cylindrical structure is disposed between the aluminum nail 102, the first end 41 and the first insulating plate 103, and an inner wall of the insulating pad 101 is adapted to abut against an outer wall of the aluminum nail 102 and an inner wall of the through hole of the first end 41.

Optionally, the insulating pad 101 is made of fluororubber, and the insulating pad 101 has a sealing effect.

Specifically, the positive electrode post 1 further includes: a second insulating plate 104 and an aluminum block 105, wherein the second insulating plate 104 is disposed on the inner side of the housing 4, one end of the second insulating plate 104 is adapted to abut against a surface of the first end 41 facing the inner side of the housing 4, and one end of the second insulating plate 104 away from the first end 41 is adapted to abut against the aluminum nail 102 through the aluminum block 105.

The cylindrical lithium battery provided by the embodiment is characterized in that the aluminum nail 102 of the positive pole column 1 is arranged in the through hole of the first end 41 in a penetrating manner, the sectional area of the aluminum nail 102 at two ends is larger than the rivet structure of the diameter of the through hole, so that the aluminum nail 102 is riveted with the shell 4, and meanwhile, the first insulating plate 103, the insulating pad 101, the second insulating plate 104 and the aluminum block 105 are arranged between the aluminum nail 102 and the shell 4, so that the aluminum nail 102 is fixed, the aluminum nail 102 is connected with the shell 4 in an insulating manner, and therefore the positive pole column 1 is connected with the shell 4 in an insulating manner, and the positive pole column 1 is ensured to be insulated from the shell 4.

Specifically, the central hole 106 is a through hole penetrating through the positive electrode post 1, and the hole wall of the through hole of the positive electrode post 1 is suitable for being fixedly connected with the aluminum post 2.

Specifically, the aluminum column 2 and the through hole of the anode pole 1 are connected by means of splicing welding.

Optionally, the connection mode of the aluminum column 2 and the through hole of the positive pole column 1 is laser welding.

The cylinder lithium cell that this embodiment provided, through setting up centre bore 106 is for running through the through-hole of anodal utmost point post 1, the pore wall of the through-hole of anodal utmost point post 1 with aluminium post 2 carries out fixed connection in order to splice the welding, is convenient for pass through the through-hole of anodal utmost point post 1 is observed whether the assembly of aluminium post 2 targets in place, and only need with aluminium post 2 with pore wall on the anodal utmost point post 1 welds can, is convenient for assemble and welded connection.

Specifically, the central hole 106 is a groove formed in the positive electrode pole 1, an opening end of the groove faces the inside of the casing 4, the aluminum column 2 is suitable for being embedded into the groove, and the inner wall and the bottom wall of the groove are suitable for being fixedly connected with the aluminum column 2.

Specifically, the aluminum column 2 and the groove are connected by laser penetration welding or ultrasonic welding.

The cylinder lithium cell that this embodiment provided, through setting up centre bore 106 does recess on the anodal utmost point post 1, the inner wall and the diapire of recess with laser pierce through welding or ultrasonic bonding with aluminium post 2 carries out fixed connection, has avoided aluminium post 2 exposes outward, is favorable to the protection aluminium post 2 does not receive the damage, and then guarantees the electric conductive property and the security performance of battery.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the utility model.

Claims

1. A cylindrical lithium battery, comprising:

a housing (4), a first end (41) of the housing (4) being provided with a through hole;

the positive pole column (1) penetrates through the through hole of the shell (4) and is riveted with the outer edge of the through hole, the positive pole column (1) and the shell (4) are insulated from each other, and the positive pole column (1) is provided with a center hole (106);

the pole group (5) is arranged in the shell (4), an aluminum column (2) is arranged at the positive pole end of the pole group (5), and the aluminum column (2) is suitable for being connected with the central hole (106) in a matched mode.

2. The cylindrical lithium battery of claim 1, further comprising: the positive current collector (3) is arranged at the positive end of the pole group (5) and is electrically connected with the positive end of the pole group (5); the aluminum column (2) is electrically connected with the pole group (5) through the positive pole current collector (3);

and the negative current collector (6) is arranged at the negative end of the pole group (5), is electrically connected with the negative end of the pole group (5), and is electrically connected with the inner wall of the shell (4).

3. The cylindrical lithium battery of claim 2, further comprising: and the negative electrode cover plate (7) is fixedly connected with the second end of the shell (4) and is suitable for sealing the shell (4), and one side, facing the inside of the shell (4), of the negative electrode cover plate (7) is abutted to the negative electrode current collector (6) and is suitable for supporting and fixing the electrode group (5).

4. Cylindrical lithium battery according to claim 1, characterized in that the positive electrode post (1) comprises: the aluminum nail (102) penetrates through the through hole of the first end (41), the cross sections of two ends of the aluminum nail (102) are larger than the diameter of the through hole, and the center of the aluminum nail (102) is provided with the center hole (106).

5. Cylindrical lithium battery according to claim 4, characterized in that the positive electrode post (1) further comprises: the first insulating plate (103) is arranged on the outer side of the shell (4), one end of the first insulating plate (103) is abutted with one surface, facing the outer side of the shell (4), of the first end (41), one end, far away from the first end (41), of the first insulating plate (103) is abutted with the aluminum nail (102), and the first insulating plate is suitable for supporting the aluminum nail (102);

the insulating pad (101) is in a stepped cylindrical structure and is arranged among the aluminum nail (102), the first end (41) and the first insulating plate (103), and the inner wall of the insulating pad (101) is suitable for being abutted with the outer wall of the aluminum nail (102) and being suitable for being abutted with the inner wall of the through hole of the first end (41).

6. Cylindrical lithium battery according to claim 5, characterized in that the positive electrode post (1) further comprises: the second insulating plate (104) is arranged on the inner side of the shell (4), one end of the second insulating plate (104) is suitable for being abutted to one surface, facing the inner side of the shell (4), of the first end (41), and one end, far away from the first end (41), of the second insulating plate (104) is suitable for being abutted to the aluminum nail (102) through the aluminum block (105).

7. The cylindrical lithium battery according to any one of claims 1 to 6, wherein the central hole (106) is a through hole penetrating through the positive electrode post (1), and the hole wall of the through hole of the positive electrode post (1) is suitable for being fixedly connected with the aluminum post (2).

8. The cylindrical lithium battery as claimed in claim 7, wherein the aluminum post (2) is connected to the through hole of the positive electrode post (1) by means of a splice welding.

9. The cylindrical lithium battery according to any one of claims 1 to 6, wherein the central hole (106) is a groove on the positive electrode post (1), the open end of the groove faces the inside of the casing (4), the aluminum post (2) is suitable for being embedded into the groove, and the inner wall and the bottom wall of the groove are suitable for being fixedly connected with the aluminum post (2).

10. Cylindrical lithium battery according to claim 9, characterized in that the aluminum pillar (2) is connected to the groove by laser penetration welding or ultrasonic welding.