WO2024031988A1

WO2024031988A1 - Cylindrical battery

Info

Publication number: WO2024031988A1
Application number: PCT/CN2023/081850
Authority: WO
Inventors: 冯树南; 王举; 郭春泰; 何伟; 杨益志
Original assignee: 蓝京新能源(嘉兴)有限公司
Priority date: 2022-08-08
Filing date: 2023-03-16
Publication date: 2024-02-15
Also published as: CN115395145A

Abstract

A cylindrical battery, comprising a casing assembly (2), and a No. 1 current-collecting disc (3), a winding core (1), a No. 2 current-collecting disc (4) and a cover plate (5), which are sequentially arranged inside the casing assembly from bottom to top, wherein the No. 2 current-collecting disc (4) is of a disc structure; an annular No. 2 flange (41) is formed at a circumferential edge of the No. 2 current-collecting disc (4); a bending angle of the No. 2 flange (41) is A, A ≤ 90°; several nicks (43) are uniformly distributed inside the No. 2 current-collecting disc (4) in a circumferential direction; a boss (42) is arranged at the center of the No. 2 current-collecting disc; the protrusion direction of the boss (42) is opposite to the direction of the No. 2 flange (41); the No. 2 current-collecting disc (4) is integrally welded to a casing (21) and the cover plate (5); and two sides of the No. 1 current-collecting disc (3) are respectively welded to the bottom of the winding core (1) and the bottom of the casing assembly (2). By means of simple designs of the current-collecting discs and the cover plate, an improvement in the electrical and thermal conductivity, fast charging capability and manufacturing efficiency of the battery is facilitated, and the cost is also reduced.

Description

A cylindrical battery

Technical field

The invention belongs to the technical field of cylindrical batteries, and in particular relates to a cylindrical battery.

Background technique

The traditional cylindrical battery cover has a complex structure; the cap serves as the positive electrode and the casing serves as the negative electrode. When the battery module is assembled, the positive and negative electrodes are conductively connected from both ends of the cylindrical battery, which is inconvenient for the design and welding of the external module bus; in addition, due to the Lack of ears affects the power performance of the battery. As the size of the cylinder increases, it is difficult for the existing tab form or structure to conduct heat quickly; the roll groove method is used for sealing, and the roll groove position requires at least 2 to 3 mm of space, which reduces the space utilization and energy density of the battery core; The connection between the manifold plate and the casing, the edge flanging of the manifold plate is in contact with the casing and connected through laser welding. After welding, the cover plate is welded to the circumference of the casing. It is a two-pass welding. The equipment investment cost is high, the production process is many, and the efficiency is low; Another form of connection between the manifold plate and the cover plate is to connect the manifold plate to the manifold plate through laser penetration welding of the cover plate. The welding stability is poor and the welding quality cannot be detected.

Contents of the invention

In view of this, the present invention aims to propose a cylindrical battery. The cylindrical lithium ion improves the electrical and thermal conductivity through a simple bus plate design and cover plate design, which is beneficial to improving the fast charging capability of the battery and at the same time improving the Manufacturing efficiency.

In order to achieve the above objects, the technical solution of the present invention is implemented as follows:

A cylindrical battery includes a shell assembly and a No. 1 manifold, a winding core, a No. 2 manifold and a cover plate arranged sequentially from bottom to top inside the case assembly. The No. 2 manifold is a disk structure and the No. 2 manifold is A circle of No. 2 flange is formed on the circumferential edge, and the bending angle of the No. 2 flange is A, A ≤ 90°. There are a number of notches evenly distributed around the circumference of the No. 2 manifold plate, and there is a boss in the center. The raised direction of the platform is the same as that of No. 2 flange. In the opposite direction, the No. 2 manifold is welded to the core and the cover plate, and the two sides of the No. 1 manifold are welded to the bottom of the core and the bottom of the shell assembly respectively.

Further, the housing assembly includes a housing, an insulating sheet, a sealing ring and a pole. The bottom of the housing is provided with a mounting hole. The mounting hole is riveted to the pole through a sealing nail, and the housing and the pole are sealed by a sealing ring. , an insulating sheet is installed at the bottom of the casing, and the insulating sheet is used for insulation between the core and the casing.

Further, the cover plate is an uneven disc, with a circle of steps formed at the circumferential edge of the cover plate, an explosion-proof score is provided on the cover plate, and a cross step is provided in the center.

Furthermore, the center of the pole has a through-hole structure, and a number of steps are formed inside the through-hole structure. From top to bottom, there are step No. 1, step No. 2 and step No. 3 respectively.

Further, the No. 1 manifold has a disk structure, and a No. 1 flange is formed at the circumferential edge of the No. 1 manifold. A conical boss is formed in the center of the No. 1 manifold, and a liquid injection hole is arranged in the middle of the conical boss. hole.

Compared with the existing technology, the cylindrical battery of the present invention has the following advantages:

(1) The cylindrical battery of the present invention improves the electrical and thermal conductivity through a simple manifold and cover plate design, which is beneficial to improving the fast charging capability of the battery, while improving manufacturing efficiency and reducing costs.

(2) In the cylindrical battery of the present invention, the cover plate cooperates with the manifold plate and the casing, and the cover plate, the manifold plate and the casing are welded together through laser peripheral welding to achieve sealing and conductive connection functions while reducing the number of One-time welding reduces costs and improves efficiency.

Description of drawings

The drawings forming a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached picture:

Figure 1 is a schematic diagram of a cylindrical battery according to an embodiment of the present invention;

Figure 2 is a schematic diagram of a housing assembly according to an embodiment of the present invention;

Figure 3 is an enlarged view of the ellipse in Figure 2;

Figure 4 is a schematic diagram of an insulating sheet according to an embodiment of the present invention;

Figure 5 is a schematic diagram of a pole according to an embodiment of the present invention;

Figure 6 is a cross-sectional view of the No. 1 manifold according to the embodiment of the present invention;

Figure 7 is a schematic diagram of the No. 2 manifold according to the embodiment of the present invention;

Figure 8 is a cross-sectional view along line A-A in Figure 7;

Figure 9 is a schematic diagram of a cover plate according to an embodiment of the present invention.

Explanation of reference symbols:

1-winding core; 2-shell assembly; 21-shell; 22-insulation sheet; 23-sealing ring; 24-pole post; 3-No. 1 manifold; 31-No. 1 flange; 32-conical convex Platform; 33-Injection hole; 4-No. 2 manifold; 41-No. 2 flange; 42-Boss; 43-Score; 5-Cover; 51-Step; 52-Explosion-proof score; 53-Cross steps.

Detailed ways

It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", " The orientations or positional relationships indicated by "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and The simplified description is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used to describe purpose and shall not be understood as indicating or implying relative importance or implying an indication of the quantity of technical features indicated. Thus, features defined by "first,""second," etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. Connection, or integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

A cylindrical battery, as shown in Figures 1 to 9, includes a housing assembly 2 and a No. 1 manifold 3, a winding core 1, a No. 2 manifold 4 and a cover plate 5 arranged sequentially inside from bottom to top. The No. 2 manifold 4 is a disk structure. A circle of the No. 2 flange 41 is formed at the circumferential edge of the No. 2 manifold 4, and the bending angle of the No. 2 flange 41 is A, A≤90°, and the No. 2 manifold A number of notches 43 are evenly distributed in the circumference of the plate 4, and a boss 42 is provided at the center. The boss 42 has a raised direction opposite to the direction of the No. 2 flange 41. The No. 2 manifold plate 4 is integrated with the shell and the cover plate 5. Welding, the two sides of the No. 1 manifold 3 are welded to the bottom of the winding core 1 and the bottom of the shell assembly 2 respectively.

The No. 2 manifold plate 4 is welded with the cover plate and the shell at one time by laser welding; the normal situation is that the No. 2 flange of the No. 2 manifold plate is laser welded to the inner wall of the shell first, and after the cover plate is closed, the cover plate and The shell opening is welded. This design saves one welding session.

The winding core 1 is one of a full-lug winding core, a cut-and-stacked tab winding core, or a multi-pole tab winding core.

The housing assembly 2 includes a housing 21, an insulating sheet 22, a sealing ring 23 and a pole 24. The bottom of the housing 21 is provided with a mounting hole. The mounting hole is riveted to the pole 24 through a sealing nail. There is a gap between the housing 21 and the pole 24. It is sealed by a sealing ring 23, and an insulating sheet 22 is installed at the bottom of the housing 21. The insulating sheet 22 is used for insulation between the winding core 1 and the housing 21. The shell is riveted with perforated poles and welded and sealed around the cover, saving space. At the same time, the polarity is directed to the same side, which facilitates module or system design and bus welding.

Shell 1 is a hollow U-shaped metal shell. The sealing ring 23 can be integrally injection molded onto the housing 21 , or can be divided into two sealing rings 22 and assembled after separate injection molding.

The center of the pole 24 has a through-hole structure, and several steps are formed inside the through-hole structure. From top to bottom, they are the first step 241, the second step 242 and the third step 243. The first step 241 is used for the first manifold. 3 is welded to the pole 24. The second step 242 is used to isolate the contamination of the electrolyte during liquid injection or precharging so that it will not affect the welding position of the sealing nail. The third step 243 is the flat surface after the pole 24 is riveted and is used for sealing. Sealing welding of nails and poles. The pole 24 has a central structure with multiple steps. In addition to being used for manifold welding, cap welding and as a liquid injection hole, it also prevents the electrolyte from contaminating the cap welding position during liquid injection or precharging, reducing the production process. Bad, no need to add cleaning process.

The No. 1 manifold 3 has a disk structure. The No. 1 flange 31 is formed at the circumferential edge of the No. 1 manifold 3 and a conical boss 32 is formed in the middle. A liquid injection hole 33 is provided in the middle of the conical boss 32 . The conical boss hole structure in the center of No. 1 bus plate 3 is convenient for installation in alignment with the pole hole. At the same time, the tapered shape prevents welding dust from entering the inside of the roll core. There are flanges around it to increase the strength and also play a role in supporting the battery core;

The two sides of the No. 1 manifold 3 are welded to the winding core 1 and the pole 24 respectively. The No. 1 flange 3 mainly strengthens the No. 1 manifold 3 and plays a supporting role in the shell core 1 to prevent the roll core 1 from tilting. The tapered boss 32 facilitates the positioning and installation of the through-hole structure of the No. 1 busbar 3 and the pole 24, and at the same time prevents dust from falling into the inside of the core 1 when the No. 1 busbar 3 and the pole 24 are welded; it also has an integrated liquid injection hole 33 Function: The injection hole 33 serves as the injection hole for the electrolyte.

The No. 2 manifold 4 is a disk structure. A circle of the No. 2 flange 41 is formed at the circumferential edge of the No. 2 manifold 4, and the bending angle of the No. 2 flange 41 is A, A≤90°, and the No. 2 manifold Disk 4 circumferential internal average There are some notches 43 on the cloth, and a boss 42 is provided in the center. The boss 42 has a protruding direction opposite to the direction of the No. 2 flange 41. The design method of the No. 2 busbar 4 is to be welded together with the cover plate, the No. 2 busbar 4 and the shell, saving one welding and reducing manufacturing costs; the design of the punched petals and flanges of the busbar can absorb electricity Core height deviation. The boss 42 is inserted into the center hole of the core 1 to facilitate the positioning of the No. 2 manifold 4. There is a No. 2 flange 41 around it in the opposite direction to the convex direction of the central boss. The bending angle of the No. 2 flange 41 is ≤90°. , so that after entering the shell, the No. 2 flange 41 is in close contact with the inner wall of the shell to facilitate subsequent welding; the notch 43 is a die-cut notch petal, and the notch groove of the notch 43 can, on the one hand, circulate the electrolyte and quickly absorb it. On the other hand, the petals of the notch 43 facilitate the folding of the second flange 41 to be higher than the petal welding plane of the second manifold 4, which can be used to absorb the height deviation of the winding core 1. The second bus plate 4 has die-cut petal scores and an elastic bending structure, which can be used to absorb electrolyte and assembly tolerances.

The cover plate 5 is an uneven disk, and a circle of steps 51 is formed at the circumferential edge of the cover plate 5. The cover plate 5 is provided with explosion-proof notches 52, and a cross step 53 is provided in the center. The cover plate 5 has a structure and a reinforced structure for positioning with the housing 21 and the No. 1 manifold 3, and also integrates an explosion-proof function.

The step 51 is formed by stamping and is used for assembly and welding with the housing 21 and the second manifold 4. An incomplete circle of explosion-proof notches 52 is formed on the cover plate 5 by stamping for explosion-proof and exhaust at the bottom; In addition, there is an inwardly concave cross step 53 in the center of the cover plate 5, which is mainly used to enhance the strength of the cover plate. At the same time, the cross step 53 can compress the core 1 to prevent movement during use, resulting in poor connection or other problems.

The assembly process of a cylindrical battery is:

Place the housing assembly 2 in advance, that is, after riveting the pole 24 and the housing 21, place the insulating member 22 inside the housing 21, and then perform the following steps:

S1. The pole tab under the winding core 1 is laser welded to the No. 1 manifold 3. After welding, an integrated structure is formed and inserted into the housing 21. Then the center boss of the No. 1 manifold 3 is welded to the No. 1 step 241;

S2. Press the boss 42 of the No. 2 manifold plate 4 onto the top of the roll core 1. The tabs above the roll core 1 are in contact with the second The No. 2 manifold 4 is laser welded; then the cover plate is put on, and the cover step 51 cooperates with the No. 2 flange 41 and the housing 21, and then the No. 2 manifold 4 is integrated with the casing 21 and the cover 5 by laser welding.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims

A cylindrical battery, which is characterized by: including a shell assembly and a No. 1 manifold, a winding core, a No. 2 manifold and a cover plate arranged sequentially from bottom to top. The No. 2 manifold is a disk structure, and the No. 2 manifold is a disc structure. A No. 2 flange is formed on the circumferential edge of the No. 2 manifold, and the bending angle of the No. 2 flange is A, A≤90°. There are several notches evenly distributed in the circumferential interior of the No. 2 manifold, and there is a Boss, the convex direction of the boss is opposite to the direction of the No. 2 flange. The No. 2 manifold is integrally welded with the shell and cover. The two sides of the No. 1 manifold are respectively connected with the bottom of the winding core and the bottom of the shell assembly. welding.
A cylindrical battery according to claim 1, characterized in that: the casing assembly includes a casing, an insulating sheet, a sealing ring and a pole, the bottom of the casing is provided with a mounting hole, and the mounting hole is riveted to the pole through a sealing nail. , the shell and the pole are sealed by a sealing ring, and an insulating sheet is installed at the bottom of the shell. The insulating sheet is used for insulation between the winding core and the shell.
A cylindrical battery according to claim 2, characterized in that: the cover plate is an uneven disk, a circle of steps is formed at the circumferential edge of the cover plate, an explosion-proof score is provided on the cover plate, and an explosion-proof score is provided at the center. There are cross steps.
A cylindrical battery according to claim 2, characterized in that: the center of the pole has a through-hole structure, and several steps are formed inside the through-hole structure. From top to bottom, they are step one, step two and step three. No. steps.
A cylindrical battery according to claim 1, characterized in that: the No. 1 busbar has a disk structure, the No. 1 flange is formed at the circumferential edge of the No. 1 busbar, and the center of the No. 1 busbar forms a conical shape. The boss has a liquid injection hole in the middle of the tapered boss.