CN118040250A

CN118040250A - Wide tab lithium ion battery cell and assembly method thereof

Info

Publication number: CN118040250A
Application number: CN202410178358.7A
Authority: CN
Inventors: 胡冬生; 贺恒炟
Original assignee: Hunan Lingpai Energy Storage Technology Co ltd; Hunan Lingpai New Energy Research Institute Co ltd; Hunan Lingpai Technology Group Co ltd; Hunan Lingpai Lithium Energy Co ltd
Current assignee: Hunan Lingpai Energy Storage Technology Co ltd; Hunan Lingpai New Energy Research Institute Co ltd; Hunan Lingpai Technology Group Co ltd; Hunan Lingpai Lithium Energy Co ltd
Priority date: 2024-02-09
Filing date: 2024-02-09
Publication date: 2024-05-14

Abstract

The invention discloses a wide-tab lithium ion battery cell which comprises a top cover, an aluminum shell and a core pack, wherein an opening is formed in one side of the aluminum shell, the core pack is arranged in the aluminum shell, the top cover covers the opening at one side of the aluminum shell, the top cover is connected with a converging component, the core pack comprises a positive electrode tab and a negative electrode tab, the converging component is connected with the positive electrode tab and the negative electrode tab through laser welding and is connected to the top cover, and the effective welding area is more than or equal to 3 times of the sum of cross sectional areas of the connected positive electrode tab or negative electrode tab. The arc R angle positions at the two ends of the positive electrode lug and the negative electrode lug are provided with notches. The positive electrode tab and the negative electrode tab are welded into a flat structure through a pre-welding device. The top cover is provided with a pole, a liquid injection hole and an explosion-proof pressure release valve. The top cover is provided with a top insulating layer penetrating into the aluminum shell end. The core bag is formed by combining a plurality of single-core bag bodies. The core package is provided with a core package insulating layer outside. The problems of complex structure, high processing cost and low utilization of cell margin space of the existing cell are solved.

Description

Wide tab lithium ion battery cell and assembly method thereof

Technical Field

The invention belongs to the technical field of novel batteries, and particularly relates to a wide-range tab lithium ion battery cell and an assembly method thereof.

Background

In the prior art, the increased single battery cell capacity is mainly adopted, and the charging and discharging power is gradually increased so as to meet the requirements of long-time endurance and quick charging and energy supplementing. In the process, new requirements are put forward on the thermal safety performance and the single-body conductivity of the power battery, and particularly the problems of overcurrent and heat dissipation of electric connection of the battery cell lugs and the battery posts are solved. The existing manufacturing process of the coiled core tab is not friendly in connection with the battery cell busbar. The current general structure direction is that one side tab is connected with the top cover component and can be called vertical arrangement, so that the arrangement needs to bend the tab or the bus component, so that the preparation cost is high and the production is not facilitated.

The Chinese patent with the bulletin number of CN219717203U discloses a power battery and an electric device, which adopt a scheme of transverse arrangement and have reasonable structural design. However, when the lug is processed, the two sides of the lug generate a bulge structure, a bus assembly with a special-shaped structure is required to be matched with the lug, the processing technology is complex, the cost of the bus assembly is high, and meanwhile, the utilization of the margin space of the battery core is low.

Disclosure of Invention

The invention aims to provide a wide-tab lithium ion battery cell, which aims to solve the problems of complex structure, high processing cost and low utilization of battery cell margin space of the conventional battery cell.

In order to achieve the purpose of the invention, the invention discloses a wide-tab lithium ion battery cell, which comprises a top cover, an aluminum shell and a core pack, wherein an opening is formed in one side of the aluminum shell, the core pack is arranged in the aluminum shell, the top cover is covered at the opening on one side of the aluminum shell, the top cover is connected with a converging component, the core pack comprises a positive electrode tab and a negative electrode tab, the converging component is connected with the positive electrode tab and the negative electrode tab through laser welding and is connected to the top cover, and the effective welding area is more than or equal to 3 times of the sum of the cross sections of the connected positive electrode tab or negative electrode tab.

As a further improvement of the above technical scheme:

and notches are arranged at the arc R angle positions at the two ends of the positive electrode lug and the negative electrode lug.

The positive electrode tab and the negative electrode tab are welded into a flat structure through a pre-welding device.

And the top cover is provided with a pole, a liquid injection hole and an explosion-proof pressure relief valve.

The top cover stretches into the aluminum shell end and is provided with a top insulating layer.

The core bag is formed by combining a plurality of single-core bag bodies. The pretreated electrode lugs are subjected to core combination treatment by two or more core bags, a core bag stack is formed, the centering degree between the core bags and the alignment degree of the electrode lugs are ensured, and the top cover converging component is partially arranged between the electrode lugs of the core bags, so that the converging component is connected with the electrode lugs of the core bags at the same time to improve the capacity of the battery core. The converging component and the core-spun electrode lug are electrically connected by adopting laser welding, and the actual effective welding area is more than or equal to the sum of the cross-sectional areas of the connected core-spun electrode lugs so as to meet the requirements of high multiplying power and quick charge and discharge of the battery cell; the converging component is arranged in the lug and is hidden in the lug, and the width of the connecting part of the converging component and the lug is preferably not more than the length of the lug; at least one branch exists at the connecting part of the converging component and the core-spun electrode lug so as to meet the requirement of increasing the number of core-spun stacks of the core-spun stacks; the converging component is electrically connected with the core-wrapped electrode lug, and the front and the back of the converging component are adhered with insulating protective layers.

The core bag is externally provided with a core bag insulating layer. The core package and the top cover are covered by the core package protective layer into a whole so as to be placed in the aluminum shell, and form insulation protection of the core package and the aluminum shell, and the core package insulating layer is connected with the top in an insulation manner so as to realize the integrated core package protective layer of the top cover and the core package; the core-covering insulating layer and the periphery of the top insulating protective layer form multi-point connection through hot melting so as to cover the inner wall of the top cover towards the core-covering side, the core-covering lugs, the converging assembly and the core-covering body.

The length of the core containing the electrode lug is narrower than the width of the inner cavity of the aluminum shell, for example, the width is 0-1 mm; optimally, the thickness of the insulating protective layer of the core pack is as thin as possible, such as 0-0.1mm thick; further, after the top cover, the core package and the core package of the core package insulation protection layer are integrally arranged in the shell, the current collecting assembly can be realized, and the electrode lugs and the aluminum shell are contacted as much as possible, so that heat conduction is realized, and the temperature rise amplitude of the battery core is reduced when charging and discharging.

The invention also discloses an assembly method of the wide tab lithium ion battery cell, which comprises the following steps:

s1, installing a confluence assembly on a top cover, and installing an accessory on the top cover at the same time;

S2, forming notches on arc R angles at two ends of a positive electrode tab and a negative electrode tab of the single-core bag body; the flatness of the lug at the arc R angle position consistent with that of the lug at the non-arc R angle position can be ensured during the subsequent pretreatment; the bottom of the notch is in an arc shape so as to prevent the core package non-tab from being damaged in the process notch of the prefabricated tab, in the subsequent processes of tab pretreatment and the like.

S3, pre-welding the tab processed in the step S2 to form a flat structure; the winding core package or the core package stacking lug is attached as much as possible under the action of the pre-welding device, so that a flat whole is formed. The whole length is narrower than the width of the inner cavity of the aluminum shell, such as 0-1 mm.

S4, connecting the tab processed in the step S3 with the confluence component processed in the step S1; after the top cover, the core package and the core package of the core package insulating layer are integrally arranged in the shell, the bus assembly can be realized, and the electrode lugs and the aluminum shell are contacted as much as possible, so that heat conduction is realized, and the temperature rise amplitude of the battery core is reduced when charging and discharging are carried out.

S5, obtaining a structural outer wrapping insulating layer after the treatment in the step S4; the thickness of the insulating layer is as thin as possible, e.g. 0-0.1mm thick.

S6, placing the assembled integral structure into an aluminum shell to finish sealing.

Compared with the prior art, the invention has the beneficial effects that:

The wide tab lithium ion battery cell has low cost, and the bus assembly has simple structure, and particularly has the characteristics of being straight and flat with the electric connection part of the core-in tab, so that the bus assembly is convenient to process and manufacture; because the converging component has the simple structure, the electric connection area meeting the charge and discharge requirements, such as laser welding, thermal diffusion welding and the like, can be obtained at one time by the converging component and the electrode lugs.

The wide tab lithium ion battery cell has high safety, and the tab of the core package is in a straight state and is connected with the converging component, so that the heat energy, mechanical pressure and the like in the welding process are effectively avoided and directly acted on the core package body, and the safety and qualification rate of the manufacturing process are improved; the insulating protective layer of core package wholly coats the top cap, the core package body, utmost point ear and the subassembly that converges to form an organic wholely with the top cap insulating layer, effectively promote the insulating security of electric core.

According to the assembly method of the wide-tab lithium ion battery cell, disclosed by the invention, the battery cell tab is subjected to leveling treatment, so that the assembly cost can be reduced, and the use safety is improved.

Drawings

FIG. 1 is a schematic view of the overall structure of embodiment 1 of the present invention;

Fig. 2 is a schematic diagram of a connection structure between a battery cell and a top cover according to embodiment 1 of the present invention;

FIG. 3 is a schematic diagram of the structure of the battery cell before processing;

FIG. 4 is a schematic view of a tab processing structure according to the present invention;

FIG. 5 is a schematic diagram of the structure of the battery cell after processing;

FIG. 6 is a schematic view of a bus assembly according to embodiment 1 of the present invention;

fig. 7 is a schematic diagram of a connection structure between a battery cell and a top cover according to embodiment 2 of the present invention;

Fig. 8 is a schematic diagram of another layout structure according to embodiment 2 of the present invention.

Reference numerals: 1. a top cover; 101. a pole; 102. a liquid injection hole; 103. an explosion-proof pressure release valve; 104. a top insulating layer; 105. a confluence assembly; 2. an aluminum shell; 3. a core pack; 301. a positive electrode tab; 3011. a notch; 302. a negative electrode tab; 4. a core-clad insulating layer; 5. and a pre-welding device.

Detailed Description

The invention is further described in connection with the following detailed description, in order to make the technical means, the creation characteristics, the achievement of the purpose and the effect of the invention easy to understand.

In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "inner", "outer", "front", "rear", "both ends", "one end", "the other end", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific direction, be configured and operated in the specific direction, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, 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 explicitly specified and limited otherwise, the terms "mounted," "provided," "connected," and the like are to be construed broadly, and may be fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

As shown in fig. 1 to 6, the wide tab lithium ion battery cell of the present embodiment includes a top cover 1, an aluminum case 2 and a core pack 3, wherein an opening is provided on one side of the aluminum case 2, the core pack 3 is disposed in the aluminum case 2, the top cover 1 covers the opening on one side of the aluminum case 2, the top cover 1 is connected with a bus assembly 105, the core pack 3 includes a positive tab 301 and a negative tab 302, and the bus assembly 105 is connected with the positive tab 301 and the negative tab 302 and is connected to the top cover 1. The converging component 105 and the electrode lugs are electrically connected by adopting laser welding, and the actual effective welding area is more than or equal to 3 times of the sum of cross sectional areas of the connected electrode lugs so as to meet the requirements of high multiplying power and quick charge and discharge of the battery cell; the bus assembly 105 is arranged in the tab and is hidden in the tab, and the width of the connecting part of the bus assembly 105 and the tab is preferably not more than the length of the tab; at least one branch exists at the connecting part of the converging component 105 and the tab so as to meet the increase of the core-in-core number of the core-in-core stack. The arc R angle positions at the two ends of the positive electrode tab 301 and the negative electrode tab 302 are provided with notches 3011. The positive electrode tab 301 and the negative electrode tab 302 are welded into a flat structure by the pre-welding device 5. The top cover 1 is provided with a pole 101, a liquid injection hole 102 and an explosion-proof pressure relief valve 103. The top cover 1 is provided with a top insulating layer 104 penetrating into the aluminum shell end. The core bag 3 is formed by combining a plurality of single-core bag bodies. The core pack 3 is provided with a core pack insulating layer 4.

Example 2

As shown in fig. 7, unlike embodiment 1, the aluminum case 2 of this embodiment is provided with two openings, corresponding to two top covers 1, one top cover 1 is provided with one pole 101, and a different-side pole arrangement is adopted, while the core pack 3 is rotated by 90 ° with respect to embodiment 1, and the two side poles 101 are connected to the positive pole tab 301 and the negative pole tab 302, respectively, through the bus bar assembly 105. It is also possible to use only the opposite-side pole in the arrangement direction in embodiment 1 without rotating the core pack 3, as shown in fig. 8.

Example 3

The embodiment introduces an assembly method of a wide tab lithium ion battery cell, which comprises the following steps:

S1, the tab width of a lithium ion core pack 3 with a winding structure is the same as or similar to the core pack width, so that the design target of a wide tab lithium ion battery core is met, and notches 3011 are formed in arc R angles at two ends of a positive electrode tab and a negative electrode tab of a single-core pack body; so as to ensure that the lug at the R-angle position of the arc can keep consistent flatness with the lug at the non-R-angle position during the subsequent pretreatment. The bottom of the tab process gap 3011 is in an arc shape, so as to prevent damage to the core-covered non-tab in the subsequent processes such as pre-processing the tab in the pre-fabricated tab process gap 3011.

S2, pre-welding the tab processed in the step S1, and enabling the winding core package or the core package stacking tab to be attached as much as possible under the action of a pre-welding device 5 to form a flat whole body so as to form a flat structure; the pre-welding device 5 can weld the tab several times in the width direction of the core pack, such as the core pack moves directionally, so as to ensure that the multi-layer tab forms a leveling effect. The total length of the processed product is smaller than the length of the inner cavity of the aluminum shell.

S3, connecting the processed tab with the confluence assembly 105; the bus assembly 105 is integrated with the top cover 1 to improve the reliability of electric connection of the battery cells, simplify the connection flow of the top cover 1, the bus assembly 105 and the core-in tab, and the connection part of the bus assembly 105 and the core-in tab is always parallel to the core-in tab and vertical to the top cover 1; the junction of the manifold assembly 105 and the core wrap tab is characterized as a straight, flat plate.

S4, obtaining a structural outer wrapping insulating layer after the treatment of the step S3; the thickness of the insulating layer is less than 0.1mm.

S5, installing the confluence component 105 on the top cover 1, and installing accessories on the top cover 1, wherein the accessories comprise polar posts, pressure relief valves and the like; to simplify the process, the process is facilitated, and the step S1 and the step S5 may be performed simultaneously, or the step S1 may be performed prior to the step S5.

S6, placing the assembled integral structure into the aluminum shell 2 to finish sealing.

The foregoing is merely exemplary embodiments of the present invention, and specific structures and features that are well known in the art are not described in detail herein. It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. The utility model provides a broad width utmost point ear lithium ion battery core, its characterized in that, including top cap (1), aluminum hull (2) and core package (3), aluminum hull (2) one side is provided with the opening, core package (3) set up in aluminum hull (2), top cap (1) lid in aluminum hull (2) one side opening part, top cap (1) is connected with and converges subassembly (105), core package (3) include anodal utmost point ear (301) and negative pole utmost point ear (302), converge subassembly (105) and anodal utmost point ear (301) and negative pole utmost point ear (302) and link to each other through laser welding to be connected to top cap (1), effective welding area is greater than or equal to the 3 times of the anodal utmost point ear (301) or negative pole utmost point ear (302) cross-sectional area sum that are connected.

2. The wide tab lithium ion battery cell according to claim 1, wherein notches (3011) are arranged at the arc R angle positions at the two ends of the positive electrode tab (301) and the negative electrode tab (302).

3. The broad tab lithium ion cell of claim 2, wherein the positive tab (301) and the negative tab (302) are welded into a flat structure by a pre-welding device.

4. The broad-width tab lithium ion battery cell according to claim 2, wherein the top cover (1) is provided with a pole (101), a liquid injection hole (102) and an explosion-proof pressure release valve (103).

5. A broad tab lithium ion cell as claimed in claim 3, wherein the top cover (1) is provided with a top insulating layer (104) deep into the aluminium can end.

6. The broad tab lithium ion battery cell according to claim 3, wherein the core pack (3) is formed by combining a plurality of single core packs.

7. The broad tab lithium ion battery cell according to any one of claims 1 to 6, wherein a core pack insulation layer (4) is provided outside the core pack (3).

8. The method for assembling the wide-tab lithium ion battery cell is characterized by comprising the following steps of:

s1, installing a confluence assembly (105) on a top cover (1), and installing accessories on the top cover (1);

s2, forming notches (3011) on arc R angles at two ends of a positive electrode tab and a negative electrode tab of the single-core bag body;

s3, pre-welding the tab processed in the step S2 to form a flat structure;

s4, connecting the tab processed in the step S3 with the confluence assembly (105) processed in the step S1;

s5, obtaining a structural outer wrapping insulating layer after the treatment in the step S4;

s6, placing the assembled integral structure into an aluminum shell (2) to finish sealing.

9. The method for assembling a wide tab lithium ion battery cell according to claim 8, wherein: and the total length of the product processed in the step S2 is smaller than the length of the inner cavity of the aluminum shell.

10. The method for assembling a wide tab lithium ion battery cell according to claim 9, wherein: the thickness of the core-coated insulating layer (4) is less than 0.1mm.